Ane Eriksen

• Rozier-Delgado, Pablo; Vonderscher, Mylène; Blervaque, Léo; Brivio, Francesca; Buuveibaatar, Bayarbaatar & Chamaillé-Jammes, Simon [Show all 28 contributors for this article] (2026). Evaluation of mammalian endurance using accelerometry in natura: bridging exercise physiology and ecology. Journal of Experimental Biology. ISSN 0022-0949. 229(7). doi: 10.1242/jeb.251129. Full text in Research Archive
• Kirchner, Theresa Margret; Devineau, Olivier; Thompson, Daniel P.; Thiel, Alexandra; Chimienti, Marianna & Evans, Alina [Show all 8 contributors for this article] (2026). Predicting energy expenditure from dynamic body acceleration in a large boreal ungulate species. Animal Biotelemetry. 14. doi: 10.1186/s40317-025-00440-2. Full text in Research Archive Show summary

  Abstract Background Energy expenditure is a central topic in ecology because of the importance of overall energy balance on individual fitness, which can affect populations and ecosystems. However, energy expenditure is difficult to measure in wild animals due to logistic constraints and invasiveness of most methods. Here, we developed a method to calculate energy expenditure of moose ( Alces alces ) from accelerometer data. We implanted heart rate loggers and deployed accelerometer collars on eight captive female moose and simultaneously recorded heart rate (every 30 s) and accelerometer data (continuously at 32 Hz) during three-day-long sampling periods in spring, early and late summer, and autumn (n = 25 sampling periods). We used a previously published random forest model to predict seven common behaviors from the accelerometer data. We fitted a dynamic generalized additive model to predict heart rate from dynamic body acceleration. Because we could not measure energy expenditure directly, we used a previously published calibration equation of moose metabolic rate against heart rate to calculate energy expenditure from heart rate. Finally, we compared behavior-specific energy expenditures to published values. Results Our model accurately predicted the trends observed in our heart rate measurements: increasing heart rate with increasing dynamic body acceleration and seasonal variation in heart rate, with a median heart rate of 32 bpm in the autumn and 58 bpm in late summer. Calculated energy expenditure was comparable between our measured and predicted heart rates, increased with increasing activity level of the behavior from lying to running and varied by season. Our estimates of behavior-specific energy expenditures were lower than previously reported values in early summer and autumn and higher in spring. Conclusions The method presented here facilitates the estimation of movement-based energy expenditure in moose from collar-mounted accelerometers, giving vital parameters for bioenergetic models and future studies of energetic consequences of disturbances and changing environmental conditions. Furthermore, the use of collar-mounted accelerometers to estimate energy expenditure circumvents the need for surgical logger implantation. We discuss the use of dynamic generalized additive models to account for varying slopes in the relationship of dynamic body acceleration with heart rate over a range of behaviors.

• Ausilio, Giorgia; Wikenros, Camilla; Sand, Håkan; Devineau, Olivier; Wabakken, Petter & Eriksen, Ane [Show all 10 contributors for this article] (2025). Contrasting risk patterns from human hunters and a large carnivore influence the habitat selection of shared prey. Oecologia. ISSN 0029-8549. 2017. doi: 10.1007/s00442-025-05742-z. Full text in Research Archive Show summary

  Spatial patterns of human hunting and predation risk are mediated by the physical landscape, with hunting risk often associated with different habitat features than those linked to large carnivores. Risk from hunters and carnivores also varies over time, and prey may adjust anti-predator strategies accordingly. We used GPS data from 17 female moose (Alces alces) tracked over two fall–winter seasons (2018–2020) in south-central Scandinavia to study moose habitat selection in response to diel and seasonal variation in risk from wolves (Canis lupus) and human hunters. Predation risk was quantified using spatial models based on known wolf and hunter kill-sites. We applied resource selection functions and Generalized Additive Mixed Models to model moose habitat selection in response to wolf and hunting risk. Moose avoided high-risk hunting areas during the day throughout the hunting season but relaxed this avoidance at night and after the season ended. In contrast, we found no evidence that moose adjusted habitat use in response to diel or seasonal variation in wolf predation risk. These results suggest that human hunting was the primary driver of moose habitat selection during the hunting season, becoming less relevant when hunting ceased. Our findings highlight the dominant role of human risk in shaping prey behaviour and the importance of accounting for hunting when evaluating predator–prey dynamics in human-dominated systems. An increased understanding of the risk effects arising from humans and large carnivores on prey can deepen our understanding of the ecological roles of predators and humans.

• Sand, Håkan; Zimmermann, Barbara; Wabakken, Petter; Eriksen, Ane & Wikenros, Camilla (2025). Quantifying large carnivore predation relative to human harvest on moose in an intensively managed boreal ecosystem. Ecological Applications. ISSN 1051-0761. 35(1). doi: 10.1002/eap.70000. Full text in Research Archive Show summary

  The return of large carnivores to areas with strong anthropogenic impact often results in conflicts among different interest groups. One cause of conflict is that large carnivores compete with humans for wild game species. In Scandinavia, the recolonization of wolves (Canis lupus) and brown bears (Ursus arctos) has important ramifications for the harvest of an ungulate species with high economic and recreational value, the moose. We estimated wolf and brown bear predation rates on moose (Alces alces) relative to harvest, natural causes of death, and vehicle collisions within 20 wolf territories. We used data on multi-season kill rates of wolves and brown bears on moose combined with wolf territory sizes and estimates of the population density of brown bears and moose. Wolf predation rate on moose was not related to the density of moose, wolf pack size, nor kill rate but was positively related to wolf density and strongly negatively related to the abundance of moose within wolf territories. Estimated annual wolf and brown bear predation rates averaged 8.6% (range 2.8%–16.9%) and 2.3% (range 0%–12.7%) respectively, among wolf territories, whereas estimated annual harvest rates averaged 17.5% (range 8.1%–33.1%). In wolf territories with relatively high bear densities, the combined predation rates from wolves and brown bears exceeded harvest rates. Across wolf territories, harvest rates were not related to wolf predation rates or to the combined predation rates from wolves and brown bears, indicating that large carnivore predation and harvest were not compensatory to each other at this spatial level. The recolonization of these large carnivores in the Scandinavian boreal forest ecosystem may have small to significant consequences for the sustainable management of moose populations depending on the local conditions of both wolves, brown bears, and moose. Comparison of annual mortality rates for moose in our study in Scandinavia with corresponding data from areas with lower anthropogenic impact (Alaska) shows lower total mortality rates in Scandinavia. This likely results from a different age and sex composition of moose killed by wolves and brown bears versus harvest, in combination with a significant difference in the relative importance of these mortality factors between areas.

• Wikenros, Camilla; Zimmermann, Barbara; Månsson, Johan; Eriksen, Ane; Wabakken, Petter & Sand, Håkan (2025). Retrospective analyses to understand how wolf territory density impacts moose quotas, harvest and observation rate. European Journal of Wildlife Research. ISSN 1612-4642. 71. doi: 10.1007/s10344-025-01920-9. Full text in Research Archive Show summary

  The ever-growing human population along with the expansion of settlements and land use, and effective hunting methods increasingly influence wildlife populations. Knowledge of management responses to re-establishing large carnivores is important to understand the overall impact of humans on large carnivores and their prey populations. We examined the response of moose (Alces alces) harvest, but also population size and composition in relation to wolf (Canis lupus) territory density along a latitudinal gradient in two bordering countries in northern Europe. Moose harvest density was negatively related to wolf territory density with model estimates showing that harvest was 35% (Norway) to 39% (Sweden) lower in moose management units (MMUs) with average wolf territory density, compared to MMUs without wolves during the previous five years. The corresponding model estimates for moose observation rate was 21% lower in Sweden and 1% lower in Norway. In both countries, management actions were taken to reduce the total moose mortality (reduced harvest) as well as to maximize productivity in the population (reduced harvest of adult females) in response to increased wolf territory density. Annual changes in quotas were related to fulfilment of last year´s quota and wolf territory density in the previous two years. The annual change in harvest were affected by actual harvest the previous year and by set quotas, showing that harvest followed management plans. Abilities to adjust to new conditions is a key in wildlife management where conflicting societal objectives such as forestry, sustainable ungulate harvest yield, and carnivore conservation should be balanced.

• Lorand, Charlotte Muguette Renée; Bouet, Lea Charlotte Marie; Devineau, Olivier; Chimienti, Marianna; Evans, Alina & Callahan, Peggy [Show all 9 contributors for this article] (2025). A supervised model to identify wolf behavior from tri-axial acceleration. Animal Biotelemetry. 13. doi: 10.1186/s40317-025-00400-w. Full text in Research Archive Show summary

  Background In wildlife studies, animal behavior serves as a key indicator of the impact of environmental changes and anthropogenic disturbances. However, wild animals are elusive and traditional GPS studies only provide limited insight into their daily activities. To address this issue, behavior classification models have increasingly been used to detect specific behaviors in wildlife equipped with tri-axial accelerometers. Such models typically need to be trained on data from the target species. The present study focuses on developing a behavioral classification model tailored to the grey wolf (Canis lupus) and encompassing a variety of ecologically relevant behaviors. Methods We collected data from nine captive wolves equipped with collar-mounted tri-axial accelerometers recording continuous acceleration at 32 Hz (“fine-scale”) and averaged acceleration over 5-min intervals (“activity”). Using simultaneous video observations, we trained Random Forest models to classify wolf acceleration data into specific behaviors. We investigated the potential limits to the generalizability of these models to unlabeled data through individual-based cross-validation. Results We present: (1) a model classifying fine-scale acceleration data (32 Hz) into 12 distinct behaviors (lying, trotting, stationary, galloping, walking, chewing, sniffing, climbing, howling, shaking, digging and jumping) with a class recall of 0.77–0.99 (0.01–0.91 in cross-validation), (2) a model classifying activity data (5-min averages) into 3 behavior categories (static, locomotion and miscellaneous) with a class recall of 0.43–0.91 (0.39–0.92 in cross-validation). Although classification performance decreased following cross-validation, recall scores for lying, trotting, stationary, galloping, walking and chewing individual behaviors (as well as static and locomotion categories) remained above 0.6. Classification performance was consistently poorer for rare behaviors, which constituted less than 1.1% of the training dataset. Conclusions We demonstrate the use of collar-mounted accelerometer to distinguish between 12 behaviors and 3 behavior categories in captive wolves, at fine-scale (32 Hz) and averaged 5-min resolutions, respectively. We also discuss the generalizability of the two models to free-ranging settings. These models can be employed to support future behavioral studies examining questions such as conflict mitigation, wolf responses to human disturbances, or specific activity budgets.

• Forti, Alessandro; Lissillour, Pierre; Eriksen, Ane; Cerjak, Benoit; Campon, Carla & Motlova, Sona [Show all 8 contributors for this article] (2024). Carnivore exclosures to protect sheep affect the distribution of a wild cervid. Wildlife Biology. ISSN 0909-6396. doi: 10.1002/wlb3.01301. Full text in Research Archive Show summary

  With the recent recovery of large carnivores in Europe, preventive measures to protect livestock are on the rise. Fences that exclude carnivores from grazing areas have been proven as effective, but they can be costly as well as posing a barrier for wildlife. We studied the effect of exclosures of > 10 km2 to protect sheep Ovis aries on the distribution and density of moose Alces alces using fecal pellet group counts in two study areas in southeastern Norway. During the summer grazing season, the fences were powered. Outside of the grazing season, one exclosure remained fenced while the other fence was demounted. This quasi-experimental setting allowed us to investigate whether fences had a barrier effect for moose, and/or whether moose density was affected by interactions with sheep (competition or facilitation) or large carnivores (refuge hypothesis). During winter, moose pellet group density was about equal inside and outside of the exclosure with demounted wire strands, but less than half inside the permanently fenced exclosure compared to outside, indicating a potential fragmentation effect of the fence. During the grazing season, when wire strands were powered, moose pellet group density was equal or doubled inside as compared to outside both exclosures. Moose may have sought refuge from large carnivores inside the fences. Fecal pellet group densities of moose and sheep inside the fence were neither positively (facilitation) nor negatively (competition) correlated. However, moose used young forest, the most used habitat type by sheep, to a lesser extent inside than outside of the exclosures, maybe due to interference competition. Our study demonstrates that livestock protection fences can have an impact on more than the targeted wildlife species. To understand the mechanisms behind direct and indirect effects of fences, monitoring the movement and survival of individuals by means of GPS and camera traps would be needed.

• Bataillard, Léa; Eriksen, Ane; Melo, Fabiano R. de; Milagres, Adriana P; Devineau, Olivier & Vital, Orlando V (2024). Using ecological niche modelling to prioritise areas for conservation of the critically endangered Buffy-Headed marmoset (Callithrix flaviceps). Ecology and Evolution. 14(4). doi: 10.1002/ece3.11203. Full text in Research Archive Show summary

  Endemic to the Atlantic Forest in Southeastern Brazil, the critically endangered Buffy-Headed marmoset (Callithrix flaviceps) is lacking the required attention for effective conservation. We modelled its ecological niche with the main objectives of (1) defining suitable habitat and (2) prioritising areas for conservation and/or restoration. The current geographical range of Callithrix flaviceps in the Atlantic Forest of Southeast Brazil. We used Ensemble Species Distribution Modelling to define current habitat suitability considering four climate and two landscape variables. To identify areas to prioritise for conservation and/or restoration, we predicted future habitat suitability considering the intermediate (RCP4.5) and extreme (RCP8.5) climate change scenarios for the years 2050 and 2070. Among the variables included to predict current species distribution, tree canopy cover, precipitation seasonality and temperature seasonality were the most important whereas digital elevation model and precipitation during the wettest month were the least important. Callithrix flaviceps was most likely to occur in areas with tree canopy cover >80%, high precipitation seasonality and temperature seasonality between 21 and 23°C. From the future suitability prediction maps, the Caparaó National Park stands out as a likely key area for the preservation of the species. Furthermore, high climatic suitability but low landscape suitability suggests that habitat restoration in ‘Serra das Torres’ (South of the current distribution area) might be a useful strategy. However, creating ecological corridors on the west side of Caparaó would be necessary to improve connectivity. More surveys within and beyond the current geographical range are required to define more precisely the distribution of the species. Our results support the notion that seasonality is important for Callithrix flaviceps and that as a montane species, it prefers colder environments and higher altitudes. Within both climate change scenarios, Caparaó National Park was predicted to be highly suitable, with a high probability of presence.

• Nordli, Kristoffer; Walton, Zea Ann; Eriksen, Ane; Rogstad, Marius; Zimmermann, Barbara & Wikenros, Camilla [Show all 8 contributors for this article] (2024). Carcass provisioning and intra-guild risk avoidance between two sympatric large carnivores. Behavioral Ecology and Sociobiology. ISSN 0340-5443. 78. doi: 10.1007/s00265-023-03423-6. Full text in Research Archive Show summary

  Apex carnivores that rely primarily on predation play a central but complex role within scavenging ecology by potentially suppressing intra-guild competitors, but also facilitating them by providing a reliable supply of carrion. We investigated the competitive relationship between sympatric wolves (Canis lupus) and wolverines (Gulo gulo) in Norway across three seasons. We deployed remote cameras at fresh wolf kills (n = 29) and built Bayesian generalized linear mixed models (GLMMs) to explore the use of fresh wolf-killed prey by sympatric wolves and wolverines. Our results showed that wolves facilitated wolverines by providing scavenging opportunities. Biomass available from wolf kills was influenced by seasonal wolf prey preference and group size. Wolverines visited 100% of wolf kills in fall and winter, whereas only 18% in summer. We found that in winter, wolverines visited wolf kills 3.6 and 6.7 times more often than single wolves and wolf groups revisited their kills, and spent 10 and 25 times as much time at carcasses compared to single wolves and groups of wolves. Thus, wolverines played an important role in the depletion of wolf-killed prey, with potential effects on the scavenging behavior of other guild members. Understanding how globally threatened top predators may function as key species in scavenging processes is important to conservation as this may have community-wide cascading effects and support important ecosystem functions and services.

• Mayer, Martin; Furuhovde, Erlend; Nordli, Kristoffer; Ausilio, Giorgia; Wabakken, Petter & Eriksen, Ane [Show all 9 contributors for this article] (2024). Monitoring GPS-collared moose by ground versus drone approaches: efficiency and disturbance effects. Wildlife Biology. ISSN 0909-6396. doi: 10.1002/wlb3.01213. Full text in Research Archive Show summary

  Efficient wildlife management requires precise monitoring methods, for example to estimate population density, reproductive success, and survival. Here, we compared the efficiency of drone (equipped with a RGB camera) and ground approaches to detect and observe GPS-collared female moose Alces alces and their calves. We also quantified how drone (n = 42) and ground (n = 41) approaches affected moose behavior and space use (n = 24 individuals). The average time used for drone approaches was 17 min compared to 97 min for ground approaches, with drone detection probability being higher (95% of adult female moose and 88% of moose calves) compared to ground approaches (78% of adult females and 82% of calves). Drone detection success increased at lower drone altitudes (50–70 m). Adult female moose left the site in 35% of drone approaches (with > 40% of those moose becoming disturbed once the drone hovered < 50 m above ground) compared to 56% of ground approaches. We failed to find short-term effects (3 h after approaches) of drone approaches on moose space use, but moose moved > fourfold greater distances and used larger areas after ground approaches (compared to before the approaches had started). Similarly, longer-term (24 h before and after approaches) space use did not differ between drone approaches compared to days without known disturbance, but moose moved comparatively greater distances during days of ground approaches. In conclusion, we could show that drone approaches were highly efficient to detect adult moose and their calves in the boreal forest, being faster and less disturbing than ground approaches, making them a useful tool to monitor and study wildlife.

• Wikenros, Camilla; Nordli, Kristoffer; Amato, Giulia; Persson, Jens; Ausilio, Giorgia & Versluijs, Erik [Show all 9 contributors for this article] (2024). Carnivore guild utilization of hunter-provided food sources in boreal forest. Wildlife Biology. ISSN 0909-6396. 2024(6). doi: 10.1002/wlb3.01249. Full text in Research Archive Show summary

  Scavenging is an alternative foraging strategy to predation for many carnivore species, as they shift between predation and scavenging in response to changes in resource availability. The use of carrion may lead to interspecific competition and is thus influenced by a risk–reward trade-off to balance coexistence with guild-members, where smaller species are expected to be more vigilant due to their vulnerability to larger competitors. We used cameras to investigate the utilization of viscera from the annual moose Alces alces hunt by four sympatric carnivore species: wolf Canis lupus, wolverine Gulo gulo, red fox Vulpes vulpes and pine marten Martes martes in south–central Scandinavia, in relation to body size and habitat. Red foxes had highest probability of visiting viscera sites in both open and forested habitats. Visits by both red foxes and pine martens were longer in open habitats, while number of visits or activity did not differ between habitats. For pine martens, the probability of visiting viscera sites was twice as high in forest compared to open habitat; consequently, red foxes showed the highest overall use of viscera. Red foxes were most vigilant, especially in open habitat, whereas wolverines and pine martens spent a higher proportion of time feeding. Increased vigilance of red foxes facilitates extended resources use in open habitat, while for pine martens, the risk–reward decision occurs before leaving forest cover and entering open habitats. Viscera were not used to a large extent by wolves or wolverines. Wolves are generally less prone to scavenging and wolverines probably use other food resources, more suitable for caching. Overall, competition did not prevent use of viscera, probably due to small-scale temporal segregation and limited use by the larger carnivores. Consequently, this pulse of human-subsidized food resources before winter may have important implications for the smaller facultative scavengers.

• Miltz, Cecilia; Eriksen, Ane; Wikenros, Camilla; Wabakken, Petter; Sand, Håkan & Zimmermann, Barbara (2024). Will future wind power development in Scandinavia have an impact on wolves? Wildlife Biology. ISSN 0909-6396. 2024(6). doi: 10.1002/wlb3.01250. Full text in Research Archive Show summary

  The global energy demand is growing, and the world is shifting towards using more renewable energy, like increased onshore wind power development. We used Global Positioning System (GPS) and Very High Frequency (VHF) location data from adult, territorial wolves Canis lupus in Scandinavia (Sweden and Norway; 1999–2021), to examine the potential for wind power development to affect wolf behavioural ecology. We examined the spatial overlap of areas proposed for wind power development with wolf territory activity centres prior to construction, to test to what extent overlap varies with season, time of day and social status (breeding versus non-breeding wolves). Measures of overlap were the distance between wolf activity centre points and nearest proposed wind turbine, the probability of proposed wind turbines being within the activity centre, and the density of proposed wind turbines within the activity centre. The wolf activity centre points were closer to sites of proposed turbines in early summer than in late winter and the density of proposed turbines in the activity centre was higher in early summer than in late winter. These findings probably result from an altitudinal shift in wolf area use between summer and winter. We also found that the probability for proposed turbines to be within the activity centre was higher for non-breeding than for breeding wolves during early summer, whereas it was higher for breeding compared to non-breeding wolves during late winter. This difference might be an effect of that breeding wolves have a restricted area use during the early summer season (denning period), resulting in a lower probability of turbines being inside their activity centre as compared to late winter. There was no clear pattern for other seasonal and social status differences. The results should be viewed as a starting point for further research and supplemented with before-after studies.

• Ausilio, Giorgia; Sand, Håkan; Wikenros, Camilla; Aronsson, Malin; Milleret, Cyril Pierre & Nordli, Kristoffer [Show all 12 contributors for this article] (2023). Effects of large carnivores, hunter harvest, and weather on the mortality of moose calves in a partially migratory population. Wildlife Biology. ISSN 0909-6396. doi: 10.1002/wlb3.01179. Full text in Research Archive Show summary

  Survival of juvenile ungulates represents an important demographic parameter that influences population dynamics within ecosystems. In many ecological systems, the mortality of juvenile ungulates is influenced by various factors, including predation by large carnivores, human hunting activities and weather. While wolves Canis lupus are known to prey on moose Alces alces throughout all seasons, brown bears Ursus arctos primarily engage in predation during early summer, while human harvest primarily occurs in autumn and early winter. Hence, understanding the impacts of predation, harvest, and weather on the survival of juvenile moose is crucial for adaptive population management and the determination of sustainable harvest rates. To investigate the summer and autumn–winter survival of moose calves in relation to carnivore occurrence (wolf presence and bear density), summer habitat productivity, winter severity, human harvest, and migratory behaviour (migratory versus resident), we analysed data collected from 39 GPS-collared female moose in south-central Scandinavia. Our findings revealed significant interannual variation in summer survival rates, with areas with relatively higher bear densities exhibiting calf mortality rates twice as high as those in regions with low bear density. During the autumn–winter period, calf survival was lowest in the presence of wolves and deep snow, and it exhibited a negative correlation with the proportion of clearcuts and young forests within the mother's home range. Additionally, calf survival was negatively correlated with the risk of human hunting, and calves of stationary females displayed ten times higher survival rates compared to migratory individuals. Our study provides valuable insights into the survival of moose calves coexisting with two large carnivores and humans. Improving our understanding of the mechanisms causing calf survival to fluctuate has become increasingly important as many local moose populations in Scandinavia are declining and exposed to expanding predator populations, intense hunting pressure, and other threats associated with climate change.

• Nordli, Kristoffer; Wabakken, Petter; Eriksen, Ane; Sand, Håkan; Wikenros, Camilla & Maartmann, Erling [Show all 7 contributors for this article] (2023). Spatial and temporal cohesion of parents and offspring in a social large carnivore. Animal Behaviour. ISSN 0003-3472. 197, p. 155–167. doi: 10.1016/j.anbehav.2022.12.006. Full text in Research Archive Show summary

  Social organization in animals is a fundamental factor driving population dynamics and individual spatial distribution. Affiliation among kin is common in social groups, but kinship is no safeguard against intraspecific competition. Within social groups, the closest competitors are often related. In this study, we present 14 years of GPS-position movement data from 65 pairs (i.e. breeding pair, pup–adult breeder and pup–pup) of Scandinavian wolves, Canis lupus. We investigated social behaviour by examining spatial and temporal patterns of cohesion through winter to early summer (January to July) including two key reproductive periods, mating and birth, using mixed regressive nonlinear time series analysis (GAMM). During the mating period, breeding wolf pairs remained cohesive, while offspring increasingly dissociated. Offspring became even more solitary until the next birth period, when most permanently left their natal pack and territory. We suggest that the social organization of wolves may be modulated by intraspecific competition related to social aggression during the mating period and food competition around the birthing period. Early independence followed by immediate natal dispersal may be advantageous to both offspring and parents if the chances of finding food and a breeding partner and settling in a vacant area are high.

• Kirchner, Theresa Margret; Devineau, Olivier; Chimienti, Marianna; Thompson, Daniel P.; Crouse, John & Evans, Alina [Show all 8 contributors for this article] (2023). Predicting moose behaviors from tri-axial accelerometer data using a supervised classification algorithm. Animal Biotelemetry. 11(1). doi: 10.1186/s40317-023-00343-0. Full text in Research Archive Show summary

  Background Monitoring the behavior of wild animals in situ can improve our understanding of how their behavior is related to their habitat and affected by disturbances and changes in their environment. Moose (Alces alces) are keystone species in their boreal habitats, where they are facing environmental changes and disturbances from human activities. How these potential stressors can impact individuals and populations is unclear, in part due to our limited knowledge of the physiology and behavior of moose and how individuals can compensate for stress and disturbances they experience. We collected data from collar-mounted fine-scale tri-axial accelerometers deployed on captive moose in combination with detailed behavioral observations to train a random forest supervised classification algorithm to classify moose accelerometer data into discrete behaviors. To investigate the generalizability of our model to collared new individuals, we quantified the variation in classification performance among individuals. Results Our machine learning model successfully classified 3-s accelerometer data intervals from 12 Alaskan moose (A. a. gigas) and two European moose (A. a. alces) into seven behaviors comprising 97.6% of the 395 h of behavioral observations conducted in summer, fall and spring. Classification performance varied among behaviors and individuals and was generally dependent on sample size. Classification performance was highest for the most common behaviors lying with the head elevated, ruminating and foraging (precision and recall across all individuals between 0.74 and 0.90) comprising 79% of our data, and lower and more variable among individuals for the four less common behaviors lying with head down or tucked, standing, walking and running (precision and recall across all individuals between 0.28 and 0.79) comprising 21% of our data. Conclusions We demonstrate the use of animal-borne accelerometer data to distinguish among seven main behaviors of captive moose and discuss generalizability of the results to individuals in the wild. Our results can support future efforts to investigate the detailed behavior of collared wild moose, for example in the context of disturbance responses, time budgets and behavior-specific habitat selection.

• Versluijs, Erik; Eriksen, Ane; Fuchs, Boris; Wikenros, Camilla; Sand, Håkan & Wabakken, Petter [Show all 7 contributors for this article] (2022). Wolf Responses to Experimental Human Approaches Using High-Resolution Positioning Data. Frontiers in Ecology and Evolution. 10. doi: 10.3389/fevo.2022.792916. Full text in Research Archive Show summary

  Humans pose a major mortality risk to wolves. Hence, similar to how prey respond to predators, wolves can be expected to show anti-predator responses to humans. When exposed to a threat, animals may show a fight, flight, freeze or hide response. The type of response and the circumstances (e.g., distance and speed) at which the animal flees are useful parameters to describe the responses of wild animals to approaching humans. Increasing knowledge about behavioral responses of wolves toward humans might improve appropriate management and decrease conflicts related to fear of wolves. We did a pilot study by conducting 21 approach trials on seven GPS-collared wolves in four territories to investigate their responses to experimental human approaches. We found that wolves predominantly showed a flight response (N = 18), in a few cases the wolf did not flee (N = 3), but no wolves were seen or heard during trials. When wolves were downwind of the observer the flight initiation distance was significantly larger than when upwind, consistent with the hypothesis that conditions facilitating early detection would result in an earlier flight. Our hypothesis that early detection would result in less intense flights was not supported, as we found no correlation between flight initiation distances and speed, distance or straightness of the flight. Wolves in more concealed habitat had a shorter flight initiation distance or did not flee at all, suggesting that perceived risk might have been affected by horizontal visibility. Contrary to our expectation, resettling positions were less concealed (larger horizontal visibility) than the wolves’ initial site. Although our small number of study animals and trials does not allow for generalizations, this pilot study illustrates how standardized human approach trials with high-resolution GPS-data can be used to describe wolf responses at a local scale. In continuation, this method can be applied at larger spatial scales to compare wolf flight responses within and between populations and across anthropogenic gradients, thus increasing the knowledge of wolf behavior toward humans, and potentially improving coexistence with wolves across their range.

• Eriksen, Ane; Versluijs, Erik; Fuchs, Boris; Zimmermann, Barbara; Wabakken, Petter & Ordiz, Andres [Show all 15 contributors for this article] (2022). A Standardized Method for Experimental Human Approach Trials on Wild Wolves. Frontiers in Ecology and Evolution. 10. doi: 10.3389/fevo.2022.793307. Full text in Research Archive Show summary

  As wolves recolonize areas of Europe ranging from moderate to high anthropogenic impact, fear of wolves is a recurring source of conflict. Shared tools for evaluating wolf responses to humans, and comparing such responses across their range, can be valuable. Experiments in which humans approach wild wolves can increase our understanding of how wolves respond to humans, facilitating human-wolf coexistence. We have developed the first standardized protocol for evaluating wolf responses to approaching humans using high-resolution GPS data, and tested it on wild wolves. We present a field protocol for experimentally approaching GPS-collared wolves, a descriptive comparison of two statistical methods for detecting a measurable flight response, a tutorial for identifying wolf flight initiation and resettling positions, and an evaluation of the method when reducing GPS positioning frequency. The field protocol, a data collection form, and the tutorial with R code for extracting flight parameters are provided. This protocol will facilitate studies of wolf responses to approaching humans, applicable at a local, national, and international level. Data compiled in a standardized way from multiple study areas can be used to quantify the variation in wolf responses to humans within and between populations, and in relation to predictors such as social status, landscape factors, or human population density, and to establish a baseline distribution of wolf response patterns given a number of known predictors. The variation in wolf responses can be used to assess the degree to which results can be generalized to areas where GPS studies are not feasible, e.g., for predicting the range of likely wolf behaviors, assessing the likelihood of wolf-human encounters, and complementing existing tools for evaluating reports of bold wolves. Showing how wolves respond to human encounters should help demystify the behavior of wild wolves toward humans in their shared habitat.

• Ausilio, Giorgia; Wikenros, Camilla; Sand, Håkan; Wabakken, Petter; Eriksen, Ane & Zimmermann, Barbara (2022). Environmental and anthropogenic features mediate risk from human hunters and wolves for moose. Ecosphere. 13(12). doi: 10.1002/ecs2.4323. Full text in Research Archive Show summary

  Landscape characteristics, seasonal changes in the environment, and daylight conditions influence space use and detection of prey and predators, resulting in spatiotemporal patterns of predation risk for the prey. When predators have different hunting modes, the combined effects of multiple predators are mediated by the physical landscape and can result in overlapping or contrasting patterns of predation risk. Humans have become super-predators in many anthropogenic landscapes by harvesting game species and competing with large carnivores for prey. Here, we used the locations of wolf (Canis lupus)-killed and hunter-killed moose (Alces alces) in south-central Scandinavia to investigate whether environmental and anthropogenic features influenced where wolves and hunters killed moose. We predicted that the combined effects of wolves and hunters would result in contrasting spatial risk patterns due to differences in hunting modes. We expected these contrasting spatial risk patterns also to differ temporally. During the hunting season, the probability of a wolf kill increased with distance to bogs, whereas it decreased with increasing building density and distance to clearcuts and young forests. After the hunting season, the probability of a wolf kill increased with increasing terrain ruggedness and decreased with increasing building density, distance to main roads, and distance to clearcuts and young forests. The probability of a hunter kill was highest closer to bogs, main and secondary roads, in less rugged terrain and in areas with lower building density. Hunters killed all moose during the day, whereas wolves killed most moose at night during and after the hunting season. Our findings suggest that environmental and anthropogenic features mediate hunting and wolf predation risk. Additionally, we found that hunter- and wolf-killed moose exhibited contrasting spatial associations to landscape features, most likely due to the different hunting modes displayed by hunters and wolves. However, wolf predation and hunting risks also contrasted over time since wolves killed mostly at night and hunters were restricted to hunting during daytime and during the hunting season. This temporal segregation in risk might therefore suggest that moose could minimize risk exposure by taking advantage of spatiotemporally vacant hunting domains.

• Wikenros, Camilla; Sand, Håkan; Månsson, Johan; Maartmann, Erling; Eriksen, Ane & Wabakken, Petter [Show all 7 contributors for this article] (2020). Impact of a recolonizing, cross‑border carnivore population on ungulate harvest in Scandinavia. Scientific Reports. 10(1), p. 1–11. doi: 10.1038/s41598-020-78585-8. Full text in Research Archive Show summary

  Predation from large carnivores and human harvest are the two main mortality factors afecting the dynamics of many ungulate populations. We examined long-term moose (Alces alces) harvest data from two countries that share cross-border populations of wolves (Canis lupus) and their main prey moose. We tested how a spatial gradient of increasing wolf territory density afected moose harvest density and age and sex composition of the harvested animals (n= 549,310), along a latitudinal gradient during 1995–2017. In areas containing average-sized wolf territories, harvest density was on average 37% (Norway) and 51% (Sweden) lower than in areas without wolves. In Sweden, calves made up a higher proportion of the moose harvest than in Norway, and this proportion was reduced with increased wolf territory density, while it increased in Norway. The proportion of females in the adult harvest was more strongly reduced in Sweden than in Norway as a response to increased wolf territory density. Moose management in both countries performed actions aimed to increase productivity in the moose population, in order to compensate for the increased mortality caused by wolves. These management actions are empirical examples of an adaptive management in response to the return of large carnivores.

• Sanchez, David Carricondo; Zimmermann, Barbara; Wabakken, Petter; Eriksen, Ane; Milleret, Cyril Pierre & Ordiz, Andres [Show all 8 contributors for this article] (2020). Wolves at the door? Factors influencing the individual behavior of wolves in relation to anthropogenic features. Biological Conservation. ISSN 0006-3207. 244. doi: 10.1016/j.biocon.2020.108514. Full text in Research Archive Show summary

  The recovery of large carnivores in human-dominated landscapes comes with challenges. In general, large carnivores avoid humans and their activities, and human avoidance favors coexistence, but individual variation in large carnivore behavior may occur. The detection of individuals close to human settlements or roads can trigger fear in local communities and in turn demand management actions. Understanding the sources of individual variation in carnivore behavior towards human features is relevant and timely for ecology and conservation. We studied the movement behavior of 52 adult established wolves ((Canis lupus), 44 wolf pairs) with GPS-collars over two decades in Scandinavia in relation to settlements, buildings, and roads. We fit fine-scale movement data to individual step selection functions to depict the movement decisions of wolves while travelling, and then used weighted linear mixed models to identify factors associated with potential individual pair deviations from the general behavioral patterns. Wolves consistently avoided human settlements and main roads, with little individual variation. Indeed, after correcting for season, time of the day, and latitude, there was little variability in habitat selection among wolf pairs, demonstrating that all wolf pairs had similar movement pattern and generally avoided human features of the landscape. Wolf avoidance of human features was lower at higher latitudes particularly in winter, likely due to seasonal prey migration. Although occasional sightings of carnivores or their tracks near human features do occur, they do not necessarily require management intervention. Communication of scientific findings on carnivore behavior to the public should suffice in most cases.

• Milleret, Cyril; Ordiz, Andres; Perez, Ana Sanz; Uzal, Antonio; Sanchez, David Carricondo & Eriksen, Ane [Show all 11 contributors for this article] (2019). Testing the influence of habitat experienced during the natal phase on habitat selection later in life in Scandinavian wolves. Scientific Reports. 9. doi: 10.1038/s41598-019-42835-1. Full text in Research Archive Show summary

  Natal habitat preference induction (NHPI) occurs when characteristics of the natal habitat influence the future habitat selection of an animal. However, the influence of NHPI after the dispersal phase has received remarkably little attention. We tested whether exposure to humans in the natal habitat helps understand why some adult wolves Canis lupus may approach human settlements more than other conspecifics, a question of both ecological and management interest. We quantified habitat selection patterns within home ranges using resource selection functions and GPS data from 21 wolf pairs in Scandinavia. We identified the natal territory of each wolf with genetic parental assignment, and we used human-related characteristics within the natal territory to estimate the degree of anthropogenic influence in the early life of each wolf. When the female of the adult wolf pair was born in an area with a high degree of anthropogenic influence, the wolf pair tended to select areas further away from humans, compared to wolf pairs from natal territories with a low degree of anthropogenic influence. Yet the pattern was statistically weak, we suggest that our methodological approach can be useful in other systems to better understand NHPI and to inform management about human-wildlife interactions.

• Eriksen, Ane & Wabakken, Petter (2018). Activity patterns at the Arctic Circle: nocturnal eagle owls and interspecific interactions during continuous midsummer daylight. Journal of Avian Biology. ISSN 0908-8857. 49(7). doi: 10.1111/jav.01781. Full text in Research Archive
• Eriksen, Ane; Wabakken, Petter; Maartmann, Erling & Zimmermann, Barbara (2018). Den site selection by male brown bears at the population’s expansion front. PLOS ONE. 13(8), p. 1–18. doi: 10.1371/journal.pone.0202653. Full text in Research Archive
• Zimmermann, Barbara; Sand, Håkan; Wabakken, Petter; Wikenros, Camilla; Eriksen, Ane & Strømseth, Thomas Holm [Show all 13 contributors for this article] (2014). Ulven som rovdyr på klauvvilt i Skandinavia. In Storaas, Torstein & Langdal, Kjell (Ed.), Ikkje berre ulv og bly - glimt frå forskninga på Evenstad. Oplandske Bokforlag. ISSN 9788275182232. p. 221–245. Full text in Research Archive Show summary

  Med ulvens tilbakekomst og bestandsøkning i Skandinavia spurte mange om ulven ville påvirke klauvviltbestanden og redusere elgjaktens avkastning. Det Skandinaviske Ulveforskningsprosjektet SKANDULV (http://skandulv.nina.no/) har derfor fokusert mye av forskningen på ulvens rolle som rovdyr. Ved å merke ulv med GPS og lete etter byttedyrrester på GPS-posisjonene kunne vi konstatere at elg var det viktigste byttedyret til ulv, og at rådyr bare hadde betydning i områder med svært høye rådyrtettheter. Blant elgene selekterte ulv for kalver og de eldste dyrene i bestanden. Ofte var de gamle byttedyrene i dårlig hold. Drapsraten lå på gjennomsnittlig 0,25 (vinter) og 0,58 (sommer) elg per flokk per døgn og varierte med tilgang på elg og flokkstørrelse. Ulvepar uten valper og små ulveflokker la ned mer bytte enn nødvendig for å dekke sine daglige energibehov, mens i store flokker klarte ikke ulveparet å legge ned nok bytte til alle flokkmedlemmene. Totalt vil ulveflokker ta 100 – 144 elger i løpet av et år. Hvor stor del av elgene i et jaktområde som blir drept av ulv, avhenger av ulverevirets størrelse og elgens tetthet i området. SKANDULV har utviklet et web-basert verktøy for rettighetshavere for å forutsi jaktens avkastning i områder med ulv og/eller bjørn ved forskjellige høstingsregimer (http://www.algforvaltning.se/moosemodel/). Denne nye kunnskapen om ulvenes atferd og påvirkning på elgbestanden i Skandinavia er viktig for forvaltningen. I denne artikkelen belyser vi flere aspekter ved ulvens rolle som rovdyr i det kompliserte samspillet med landskapet, flere rovdyrarter, åtselsetere, klauvvilt og mennesker.

• Slagsvold, Tore; Kleiven, Kari; Eriksen, Ane & Johannessen, Lars Erik (2013). Vertical and horizontal transmission of nest site preferences in titmice. Animal Behaviour. ISSN 0003-3472. 85(2), p. 323–328. doi: 10.1016/j.anbehav.2012.10.024. Full text in Research Archive
• Slagsvold, Tore; Eriksen, Ane; Ayala, Rosa Mary de; Husek, Jan & Wiebe, Karen (2013). POSTFLEDGING MOVEMENTS IN BIRDS: DO TIT FAMILIES TRACK ENVIRONMENTAL PHENOLOGY? The AUK: A Quarterly Journal of Ornithology. ISSN 0004-8038. 130(1), p. 36–45. doi: 10.1525/auk.2012.12122. Full text in Research Archive
• Eriksen, Ane; Slagsvold, Tore & Lampe, Helene M. (2011). Vocal Plasticity - are Pied Flycatchers, Ficedula Hypoleuca, Open-Ended Learners? Ethology. ISSN 0179-1613. 117(3), p. 188–198. doi: 10.1111/j.1439-0310.2010.01864.x. Full text in Research Archive
• Eriksen, Ane; Wabakken, Petter; Zimmermann, Barbara; Andreassen, Harry Peter; Arnemo, Jon Martin & Gundersen, Hege [Show all 13 contributors for this article] (2011). Activity patterns of predator and prey: a simultaneous study of GPS-collared wolves and moose. Animal Behaviour. ISSN 0003-3472. 81(2), p. 423–431. doi: 10.1016/j.anbehav.2010.11.011. Full text in Research Archive Show summary

  We studied the simultaneous activity patterns of a breeding wolf, Canis lupus, pair and five adult moose, Alces alces, cows from April to November 2004 in a wolf territory in southeastern Norway. All study animals were GPS collared, and we used a total of 8297 fixes to analyse their temporal activity patterns. We examined the daily activity rhythm of the two species and how this varied seasonally through the study period, and investigated the association in activity patterns between the two species. Wolf activity peaked at dawn. The distance moved per time unit and the linearity of the movement were higher in wolves than in moose, but both species showed a decrease in these variables in June, coinciding with the denning and calving seasons. With the exception of the summer months when the activity of wolves and moose was limited by the raising of offspring, we found no correlation between the temporal activities of the two species. Hence, we did not find support for the hypothesis that the wolves and moose in Scandinavia have adjusted to each other’s activity patterns. We discuss the results in light of the relative density of the two species and the intensive human harvest of moose, and hypothesize that synchronicity of predator–prey activity patterns may be ratio dependent.

• Eriksen, Ane; Wabakken, Petter; Zimmermann, Barbara; Andreassen, Harry Peter; Arnemo, Jon Martin & Gundersen, Hege [Show all 13 contributors for this article] (2009). Encounter frequencies between GPS-collared wolves (Canis lupus) and moose (Alces alces) in a Scandinavian wolf territory. Ecological Research. ISSN 0912-3814. 24(3), p. 547–557. doi: 10.1007/s11284-008-0525-x. Full text in Research Archive
• Eriksen, Ane; Lampe, Helene M. & Slagsvold, Tore (2009). Interspecific cross-fostering affects song acquisition but not mate choice in pied flycatchers, Ficedula hypoleuca. Animal Behaviour. ISSN 0003-3472. 78(4), p. 857–863. doi: 10.1016/j.anbehav.2009.07.005. Full text in Research Archive Show summary

  Laboratory studies suggest that young birds prefer to learn conspecific songs over songs from heterospecifics. However, field studies have shown that many species copy heterospecific song. We crossfostered pied flycatchers, Ficedula hypoleuca, to nests of blue tits, Cyanistes caeruleus, and great tits, Parus major, in the field. Recent studies have shown that species recognition is genetically determined in pied flycatchers. However, we found that most cross-fostered males included song types from the foster species in their repertoire, with an even stronger effect if reared with heterospecific nestmates. Furthermore, in cross-fostered males frequency range and syllable number per strophe were intermediate between control flycatchers and the foster species. The results contrast with those obtained when blue tits and great tits are cross-fostered in the field; the tits not only adopt songs from the foster species but, in contrast to the flycatchers, they also become sexually imprinted on it. Vocal mimicry may include a cost of reduced species recognition, but this cost may be minimized by also keeping a large proportion of conspecific song in the repertoire. Our finding highlights the importance of early experience for song acquisition, showing that altered social-rearing conditions may cause a mixed choice of song tutors. Depending on different proximate mechanisms, song used in mate choice may more readily respond to environmental change than mate choice itself. Changes in song by learning may thus serve as an essential first step in hybridization and speciation processes.

View all works in NVA

• Zimmermann, Barbara; Hellbaum, Paige; Ausilio, Giorgia; Sand, Håkan; Wikenros, Camilla & Eriksen, Ane [Show all 11 contributors for this article] (2025). Counteracting management of a transboundary moose population in Scandinavia. Full text in Research Archive
• Zimmermann, Barbara; Forti, Alessandro; Lissillour, Pierre; Eriksen, Ane; Wabakken, Petter & Cerjak, Benoit [Show all 8 contributors for this article] (2025). Carnivore exclosures to protect sheep in the boreal forest affect the area use of moose. Full text in Research Archive
• Zimmermann, Barbara; Forti, Alessandro; Lissillour, Pierre; Eriksen, Ane; Cerjak, Benoit & Campon, Carla [Show all 8 contributors for this article] (2025). Effekter av rovdyravvisende gjerder på storvilt. Full text in Research Archive
• Eriksen, Ane; Rozier-Delgado, Pablo; Lorand, Charlotte Muguette Renée; Devineau, Olivier; Nordli, Kristoffer & Loison, Anne [Show all 7 contributors for this article] (2025). Uncovering the triggers of wolf fatigue: From sports science to wolf energetics. Full text in Research Archive
• Lorand, Charlotte Muguette Renée; Eriksen, Ane; Devineau, Olivier; Chimienti, Marianna; Wikenros, Camilla & Sand, Håkan [Show all 8 contributors for this article] (2025). Close encounters with wolves: who's tiptoeing around whom? Full text in Research Archive
• Zimmermann, Barbara; Sand, Håkan; Ausilio, Giorgia; Wikenros, Camilla; Eriksen, Ane & Wabakken, Petter (2024). Ikke lett å være elg! Full text in Research Archive
• Eriksen, Ane; Lorand, Charlotte Muguette Renée; Versluijs, Erik; Chimienti, Marianna; Devineau, Olivier & Bouet, Lea [Show all 10 contributors for this article] (2024). Studying wolf flight responses during experimental approaches using fine-scale GPS and accelerometer data. Full text in Research Archive
• Eriksen, Ane; Zimmermann, Barbara; Kirchner, Theresa Margret; Evans, Alina & Mathisen, Karen Marie (2024). Elg i endring. Full text in Research Archive
• Eriksen, Ane; Lorand, Charlotte Muguette Renée; Versluijs, Erik; Chimienti, Marianna; Devineau, Olivier & Bouet, Lea [Show all 10 contributors for this article] (2024). Eksperimentelle nærmøter med ulv – oppdatering og framtidige planer. Full text in Research Archive
• Lorand, Charlotte Muguette Renée; Eriksen, Ane; Devineau, Olivier; Bouet, Lea; Chimienti, Marianna & Wikenros, Camilla [Show all 9 contributors for this article] (2024). The secret lives of wolves: Predicting behaviors in wild wolves approached by humans, using collar-mounted accelerometers and a model calibrated in captivity. Full text in Research Archive
• Zimmermann, Barbara; Sand, Håkan; Ausilio, Giorgia; Wikenros, Camilla; Eriksen, Ane & Wabakken, Petter (2024). Ikke lett å være elg. Full text in Research Archive
• Lorand, Charlotte Muguette Renée & Eriksen, Ane (2024). Short-term controlled disturbances - How to make them work for wolf-human coexistence. Full text in Research Archive
• Eriksen, Ane & Lorand, Charlotte (2023). Oppdatering om eksperimentelle nærmøter med ulv - nye forsøk og framtidige planer. Full text in Research Archive
• Ausilio, Giorgia; Wikenros, Camilla; Sand, Håkan; Devineau, Olivier; Eriksen, Ane & Wabakken, Petter [Show all 10 contributors for this article] (2023). Environmental and anthropogenic features mediate human hunting risk and wolf predation risk for moose. Full text in Research Archive
• Zimmermann, Barbara; Ausilio, Giorgia; Sand, Håkan; Wikenros, Camilla; Eriksen, Ane & Wabakken, Petter [Show all 7 contributors for this article] (2023). Moose at risk: Scandinavian biotagging research on impacts of predation, harvest and climate change. Full text in Research Archive
• Zimmermann, Barbara; Wikenros, Camilla; Mathisen, Karen Marie; Ausilio, Giorgia; Sand, Håkan & Hellbaum, Paige [Show all 12 contributors for this article] (2023). Elgforvaltning i grenseland. Full text in Research Archive
• Mayer, Martin; Furuhovde, Erlend; Nordli, Kristoffer; Ausilio, Giorgia; Eriksen, Ane & Evans, Alina [Show all 8 contributors for this article] (2023). Efficiency and disturbance effects of drone versus ground approaches to monitor moose. Full text in Research Archive
• Ausilio, Giorgia; Sand, Håkan; Wikenros, Camilla; Aronsson, Malin; Milleret, Cyril Pierre & Nordli, Kristoffer [Show all 11 contributors for this article] (2023). Effects of large carnivores, hunter harvest and climate on the survival of calves in a partially migratory moose population. Full text in Research Archive
• Zimmermann, Barbara; Wabakken, Petter & Eriksen, Ane (2023). Carnivore exclosures to protect sheep: Experiences and effects on wildlife. Full text in Research Archive
• Zimmermann, Barbara; Ausilio, Giorgia; Sand, Håkan; Wikenros, Camilla; Eriksen, Ane & Wabakken, Petter [Show all 7 contributors for this article] (2023). Moose at risk: Scandinavian biotagging research on impacts of predation, harvest and climate change. Full text in Research Archive
• Zimmermann, Barbara; Mathisen, Karen Marie; Hellbaum, Paige; Ausilio, Giorgia; Sand, Håkan & Wikenros, Camilla [Show all 12 contributors for this article] (2023). Contrasting management goals for a transboundary moose population in Scandinavia. Full text in Research Archive
• Ausilio, Giorgia; Zimmermann, Barbara; Mathisen, Karen Marie; Eriksen, Ane; Wabakken, Petter & Wikenros, Camilla [Show all 7 contributors for this article] (2023). Effekter av varg och andra faktorer på älgförekomst och betesskador. Full text in Research Archive
• Zimmermann, Barbara; Sand, Håkan; Wikenros, Camilla; Eriksen, Ane & Wabakken, Petter (2022). Uneven spatial and temporal distribution of predation inside wolf territories challenges moose management. Full text in Research Archive
• Eriksen, Ane (2022). Juridisk og biologisk evaluering av den norske delen av den skandinaviske ulvebestanden - oppsummering og konklusjoner fra workshop 5.-6. mars 2020. Full text in Research Archive
• Zimmermann, Barbara; Wikenros, Camilla; Aronsson, Malin; Eriksen, Ane; Mathisen, Karen Marie & Persson, Jens [Show all 8 contributors for this article] (2022). Viltforvaltning på tvers av grensen: Ny lærdom fra GRENSEVILT prosjektet. Jakt og Fiske i Hedmark. ISSN 1891-1471. Full text in Research Archive
• Sand, Håkan; Zimmermann, Barbara; Berg, Erik; Bramorska, Beata; Eriksen, Ane & Wikenros, Camilla [Show all 10 contributors for this article] (2022). Trekkmønster hos grenseelg – konsekvenser for forvaltningen. Hjorteviltet. ISSN 1502-3729. Full text in Research Archive
• Zimmermann, Barbara; Mathisen, Karen Marie; Ausilio, Giorgia; Sand, Håkan; Wikenros, Camilla & Eriksen, Ane [Show all 13 contributors for this article] (2022). Motsatte norske og svenske mål for felles elgbestand. Hjorteviltet. ISSN 1502-3729. Full text in Research Archive
• Talleraas, Simen Moflag; Kalén, Crister; Zimmermann, Barbara; Franklin, Oskar; Evans, Alina & Eriksen, Ane [Show all 7 contributors for this article] (2022). How does bilberry affect the availability and use of bilberry forage for moose? Full text in Research Archive
• Wikenros, Camilla; Zimmermann, Barbara; Eriksen, Ane; Falkevik, Maria; Lund, Pia K. & Løken, Øivind [Show all 10 contributors for this article] (2021). GRENSEVILT 2 – forvaltningssamarbeit og effekter av vindkraft. Hjorteviltet. ISSN 1502-3729. Full text in Research Archive
• Wikenros, Camilla; Zimmermann, Barbara; Eriksen, Ane; Persson, Jens; Sand, Håkan & Wabakken, Petter (2021). GRENSEVILT 2 – forvaltningssamarbeid og effekter av vindkraft. Hjorteviltet. ISSN 1502-3729. Full text in Research Archive
• Eriksen, Ane (2021). Eksperimentelle nærmøter med ulv. Full text in Research Archive
• Eriksen, Ane (2021). Eksperimentelle nærmøter med ulv - pågående studier. Full text in Research Archive
• Wikenros, Camilla; Månsson, Johan; Maartmann, Erling; Eriksen, Ane; Wabakken, Petter & Zimmermann, Barbara (2021). Publisher Correction: Impact of a recolonizing, cross-border carnivore population on ungulate harvest in Scandinavia (Scientific Reports, (2020), 10, 1, (21670), 10.1038/s41598-020-78585-8). Scientific Reports. 11(1). doi: 10.1038/s41598-021-89263-8. Full text in Research Archive
• Wikenros, Camilla; Zimmermann, Barbara; Sand, Håkan; Månsson, Johan; Maartmann, Erling & Eriksen, Ane [Show all 7 contributors for this article] (2021). Så påverkar vargen älgobs och avskjutning. Svensk Jakt. ISSN 0039-6583. p. 30–32. Full text in Research Archive
• Wikenros, Camilla; Zimmermann, Barbara; Sand, Håkan; Månsson, Johan; Maartmann, Erling & Eriksen, Ane [Show all 7 contributors for this article] (2020). Sett og felt elg i forhold til ulveforekomst i Norge og Sverige. Hjorteviltet. ISSN 1502-3729. Full text in Research Archive
• Eriksen, Ane (2020). Assessment of the Norwegian part of the Scandinavian wolf population, phase 1: Workshop summary. Full text in Research Archive
• Eriksen, Ane; Wabakken, Petter & Maartmann, Erling (2020). Så nært kommer de ulven. [TV]. NRK Dsgsrevyen. Full text in Research Archive
• Eriksen, Ane; Wabakken, Petter & Maartmann, Erling (2020). På sporet af ulven. [TV]. Danmarks Radio. Full text in Research Archive
• Zimmermann, Barbara; Sand, Håkan; Wikenros, Camilla; Eriksen, Ane & Wabakken, Petter (2020). Å dele utbyttet med ulven: Jakt- og predasjonstrykk på elg i ulverevir i Skandinavia. Hjorteviltet. ISSN 1502-3729. Full text in Research Archive
• Zimmermann, Barbara; Sand, Håkan; Wikenros, Camilla; Eriksen, Ane & Wabakken, Petter (2020). Ujevn fordeling av ulvens uttak av elg i ulverevir påvirker jaktuttaket lokalt. Hjorteviltet. ISSN 1502-3729. Full text in Research Archive
• Eriksen, Ane (2019). Stasjonære ulvers bevegelser i forhold til hus og veier. Full text in Research Archive
• Eriksen, Ane (2019). Ulvekonflikten i lys av ulvens sosiale organisering og årssyklus. Full text in Research Archive
• Eriksen, Ane (2019). Ulvers bevegelser i forhold til menneskelig bosetting og aktivitet. Full text in Research Archive
• Eriksen, Ane (2019). Eksperimentelle nærmøter med ulv - pågående studier. Full text in Research Archive
• Eriksen, Ane (2019). Hvordan reagerer ulv på mennesker. [Radio]. NRK Østlandssendingen. Full text in Research Archive
• Eriksen, Ane; Zimmermann, Barbara; Wikenros, Camilla; Mathisen, Karen Marie; Wabakken, Petter & Sand, Håkan [Show all 8 contributors for this article] (2019). Grensevilt – reduksjon av grensebarrierer for skandinavisk viltforvaltning. Hjorteviltet. ISSN 1502-3729. Full text in Research Archive
• Eriksen, Ane (2019). Glimt fra viltforskningen på Evenstad. Full text in Research Archive
• Eriksen, Ane (2019). A standardized method for experimental human approaches on wolves. Full text in Research Archive
• Eriksen, Ane; Versluijs, Erik; Fuchs, Boris; Zimmermann, Barbara; Wabakken, Petter & Bouet, Lea [Show all 16 contributors for this article] (2019). A standardized method for conducting and analysing experimental human approaches on wolves. Full text in Research Archive
• Zimmermann, Barbara; Sand, Håkan; Wikenros, Camilla; Wabakken, Petter & Eriksen, Ane (2019). The asymmetric share of moose as prey for humans and wolves. Full text in Research Archive
• Eriksen, Ane & Evans, Alina (2018). Bjørnens levevis og hi i Gutulia. Full text in Research Archive
• Eriksen, Ane; Zimmermann, Barbara; Sunde, Peter; Gorini, Lucrezia; Wabakken, Petter & Evans, Alina [Show all 13 contributors for this article] (2018). Wolf responses to experimental approaches by humans along a gradient of anthropogenic impact: A pilot study. Full text in Research Archive
• Eriksen, Ane (2018). Grensevilt. Full text in Research Archive
• Eriksen, Ane (2018). Nærmøter med ulv - et pilotprosjekt. Full text in Research Archive
• Eriksen, Ane (2018). Den skandinaviske ulven: Ulvens år, bestandsutvikling og skadepotensiale. Full text in Research Archive
• Eriksen, Ane; Zimmermann, Barbara; Wabakken, Petter; Sanchez, David Carricondo; Sand, Håkan & Wikenros, Camilla (2018). Wolf movement relative to human structures during natal dispersal. Full text in Research Archive
• Zimmermann, Barbara; Wabakken, Petter; Eriksen, Ane; Mathisen, Karen Marie; Wikenros, Camilla & Sand, Håkan [Show all 8 contributors for this article] (2018). GRENSEVILT. Reduksjon av grensebarrierer for skandinavisk viltforvaltning. Interreg-prosjekt 2018-2020. Full text in Research Archive
• Zimmermann, Barbara; Wabakken, Petter; Eriksen, Ane; Sanchez, David Carricondo; Versluijs, Erik & Sand, Håkan [Show all 7 contributors for this article] (2018). Wolf tracks at the doorstep: A one-year cycle of wolf behavior close to houses in Scandinavia. Full text in Research Archive
• Wabakken, Petter; Maartmann, Erling; Eriksen, Ane; Zimmermann, Barbara; Flagstad, Øystein & Liberg, Olof [Show all 8 contributors for this article] (2018). Betydningen av ulvens spredningsmønster for tap av bufe, tamrein og hund i Norge. Full text in Research Archive
• Nordli, Kristoffer; Zimmermann, Barbara; Wabakken, Petter & Eriksen, Ane (2018). On the way to independence - Ebbing cohesion in Scandinavian wolf family groups. Full text in Research Archive
• Eriksen, Ane; Wabakken, Petter; Maartmann, Erling & Zimmermann, Barbara (2017). Do brown bears plan for breakfast? Den site selection for easy access to ungulates in spring. Full text in Research Archive
• Wabakken, Petter; Eriksen, Ane; Maartmann, Erling; Zimmermann, Barbara; Flagstad, Øystein & Liberg, Olof [Show all 8 contributors for this article] (2017). Wolf depredation on livestock, semi-domestic reindeer and domestic dogs in Norway. Full text in Research Archive
• Zimmermann, Barbara; Wabakken, Petter; Eriksen, Ane; Sand, Håkan & Wikenros, Camilla (2017). Who is outside the door? Wolf movement in relation to human settlements. Full text in Research Archive
• Eriksen, Ane (2017). From backyard songbirds to outback bears (and backyard wolves). Full text in Research Archive
• Eriksen, Ane (2016). Sangfugler – fuglesang, fuglekasser, og glimt fra forskning vha. eksperimentell kryssfostring. Full text in Research Archive
• Eriksen, Ane; Wabakken, Petter; Dahl, E.; Fremming, Odd Reidar; Gundersen, Hege & Bichsel, M. [Show all 11 contributors for this article] (2011). Atferdsstudier og glimt fra forskning ved langtidsovervåkning - hubro og vånd i et kystlandskap uten mink. Full text in Research Archive
• Eriksen, Ane & Grydeland, Ivar (2010). Hvem er jeg…? [Internet]. Nrk.no - Vitenskap og teknologi. Full text in Research Archive
• Eriksen, Ane & Slagsvold, Tore (2010). Are mothers models for song learning - an experimental study on great tits. Full text in Research Archive Show summary

  In songbirds, it is assumed that males learn songs from their father and conspecific male neighbours. We studied if the mother may play a role as well. Great tits Parus major were experimentally cross-fostered to blue tits Cyanistes caeruleus in the wild, and vice versa. In both species, cross-fostered males sang a combination of conspecific and heterospecific song, demonstrating an effect of early learning. Due to sexual misimprinting, cross-fostering resulted in pairings between the two species, providing an opportunity to see how species and gender of parent influence song learning. Great tit males reared by a great tit male and a blue tit female included blue tit song in their repertoires. To control for the possibility that they had learned blue tit songs from their cross-fostered great tit fathers, males reared by great tit pairs in which the father had been cross-fostered served as controls. None of these sang blue tit song, revealing an effect of the social mother on song acquisition. In great tits, the female rarely sings, and so it is possible that the juveniles select the male neighbours to be used as song tutors based on the neighbours’ resemblance to their (foster) mother as well as father.

• Eriksen, Ane (2010). Verdt å vite spesial. [Radio]. NRK P2. Full text in Research Archive
• Wikenros, Camilla; Zimmermann, Barbara; Sand, Håkan; Månsson, Johan; Maartmann, Erling & Eriksen, Ane [Show all 7 contributors for this article] (2010). Effect of predation on hunting quotas, hunter observations and moose harvest in two countries with an increasing wolf population during 22 years. Full text in Research Archive
• Eriksen, Ane (2009). Fuglesang - trenger fugler å lære? [Radio]. Verdt å vite, NRK P2. Full text in Research Archive
• Eriksen, Ane; Slagsvold, Tore & Lampe, Helene M. (2009). Adult song learning – are pied flycatchers open-ended learners? Full text in Research Archive
• Eriksen, Ane; Lampe, Helene M. & Slagsvold, Tore (2008). Song learning and sexual misimprinting in cross-fostered great tits. Full text in Research Archive
• Eriksen, Ane; Lampe, Helene M. & Slagsvold, Tore (2007). Interspecific cross-fostering affects song acquisition but not mate choice in pied flycatchers. Full text in Research Archive
• Eriksen, Ane; Wabakken, Petter; Zimmermann, Barbara; Andreassen, Harry Peter; Arnemo, Jon Martin & Gundersen, Hege [Show all 13 contributors for this article] (2006). Activity patterns of predator and prey: Wolf and moose in South-Eastern Norway. Full text in Research Archive
• Ausilio, Giorgia; Zimmermann, Barbara; Sand, Håkan; Wikenros, Camilla; Eriksen, Ane & Wabakken, Petter [Show all 12 contributors for this article] (2023). Gränsöverskridande älgförvaltning - Ekologiska förutsättningar. Universitetet i Innlandet. ISSN 9788283804089. Full text in Research Archive Show summary

  Gjensidige påvirkninger mellom rovdyr og byttedyr formes av flere ulike faktorer inklusive type landskap de lever i og rovdyrenes jaktmetode. I landskap påvirket av mennesker kan disse interaksjonene endres av aktiviteter som jakt, skogbruk og andre typer av arealbruk. I Skandinavia har jakt blitt den største dødsårsaken for elg (Alces alces) i det siste århundret, men med tilbakekomsten av store rovdyr slik som bjørn (Ursus arctos) og ulv (Canis lupus) i de seneste årene blir dødsrisikoen nå fordelt på flere kilder. Målet med denne studien var å 1) beskrive habitatet på de plassene der elg ble skutt av jegere i jaktsesongen, og der elg ble drept av ulv både i og etter jaktsesongen, for å finne ut om risikoen for å dø av de to årsakene var koblet til spesifikke habitatstyper; 2) undersøke om habitatvalget til GPS-merket elg påvirkes av fordelingen av jakt- og predasjonsrisiko i tid og rom; og 3) beregne dødeligheten hos elgkalver sommer- og vinterstid i forhold til risiko fra jakt, store rovdyr (ulv og bjørn) og andre miljøvariabler. Vi fant at plassene der elg ble skutt skilte seg fra plassene der elg ble drept av ulv på mange ulike måter som var koblet til habitat i form av alder og type skog, elgtetthet og nærhet til bebyggelse. I neste steg koblet vi disse resultatene til habitatvalget til GPS-merket elg. I jaktsesongen unngikk elgene habitat med høy jaktrisiko på dagtid, mens deres habitatvalg nattestid ikke var koblet til risiko for å bli skutt. Etter jaktsesongen fantes det ingen kobling mellom elgenes habitatvalg og jaktrisiko, hverken på dagtid eller nattestid. Derimot valgte GPS-elgene habitat med høyere risiko for ulvepredasjon både på dagtid og nattestid i og etter jaktsesongen. Dødeligheten hos elgkalver sommerstid varierte signifikant mellom de tre ulike studieårene, men var ikke relatert til risiko for ulvepredasjon, bjørnetetthet, eller klima- eller miljøvariabler. I vinterperioden var kalvedødeligheten positivt koblet til snødybde og andelen hogstflater og ungskog innenfor ulverevir, samt til habitat med økt jaktrisiko. Oppsummert viser disse resultatene at selv om risikoene fra både jakt og ulvepredasjon varierte i tid og rom, så responderte elgene atferdsmessig hovedsakelig på den sterkere og mer forutsigbare dødelighetskilden; jakt. Disse resultatene er sannsynligvis en effekt av at jakt er den dominerende dødsårsaken, som funksjonelt har erstattet predasjon fra ulv og bjørn på elg i løpet av det siste århundret i Skandinavia.

• Wikenros, Camilla; Zimmermann, Barbara; Eriksen, Ane; Esselin, Anders; Falkevik, Maria & Løken, Øivind [Show all 9 contributors for this article] (2023). GRENSEVILT 2 - Slutrapport till Interreg Sverige-Norge. Universitetet i Innlandet. ISSN 9788283804058. Full text in Research Archive Show summary

  Indre Skandinavia kjennetegnes av et sammenhengende barskogområde med store viltbestander (naturarv) som preger regionens skogbruk og jakt (kulturarv). Til tross for at naturressursene er grenseoverskridende, forvaltes og utnyttes de ulikt på hver sin side av administrative grenser. Det fører til interessekonflikter og ugunstige forvaltningsmodeller og forvaltningsenheter som ikke tar hensyn til dyrenes økologi. Vindkraftutbygging har akselerert i Indre Skandinavias barskogområder, uten at man er klar over konsekvensene for viltbestander generelt og på tvers av forvaltningsregioner spesielt. Det er et stort behov for forvaltningsrelevant kunnskap som tilrettelegger for og forbedrer grenseoverskridende samarbeid. GRENSEVILT 2 (2020-2022) er en oppfølging av prosjektet GRENSEVILT 1 (2017-2021). Ny kunnskap og ressursgruppens arbeid førte til et uttrykt ønske fra forvaltningen, grunneiere og interesseorganisasjoner i Sverige og Norge om en konkretisering av samarbeidet samt økt kunnskapsinnhenting som underlag for samarbeidet. GRENSEVILT 2 hadde som overordnet mål å øke samordningen av viltforvaltning på tvers av grensen og i områder under press fra menneskelige inngrep. Projektet har hatt to delmål med fokus på å forstå forvaltningsmessige og biologiske forutsetninger for å oppnå et bedre forvaltningssamarbeid, og å forstå effekter av vindkraftutbygging på vilt og jakt. Prosjektets arbeid mot de to delmålene har hatt to hovedkomponenter: 1) oppbygging av et forskningsbasert, forvaltningsrelevant kunnskapsgrunnlag, og 2) nettverks- og kommunikasjonsarbeid på ulike nivåer. GRENSEVILT 2 følger Interregs prosess til å skape regional merverdi gjennom å bli kjent med hverandre, dele kunnskap, og finne fram til felles, grenseoverskridende løsninger. Prosjektgruppen bestod av forskere og forvaltere fra Norge og Sverige, samt en prosessleder. I GRENSEVILT 2 prosjektet har vi lagt en struktur for regionalt samarbeid på tvers av grensen. Vi har økt forståelsen av forvaltningsmessige, metodiske og økologiske forutsetninger for samarbeid i elgforvaltningen. Gjennom scenariediskusjoner, oppbygging av en felles kartløsning, og ny kunnskap har prosjektet diskutert nye adaptive forvaltningsmodeller som tar hensyn til elgens vandringer på tvers av grensen og ulike interesser knyttet til skog, jakt, elg, ulv og jerv. GRENSEVILT 2 har tatt fram mer kunnskap om effekter av den stadig økende utbygging av vindkraft i Indre Skandinavias felles skogressurser. Forflytningsdata fra elg, ulv og jerv merket med GPS-halsbånd samt elgmøkktellinger ble analysert for å øke forståelsen av hvordan slike tekniske inngrep i skoglandskapet kan påvirke atferden og områdebruken til ville dyr. Vi har også kartlagt jaktuttaket av elg lokalt og jegernes opplevelse av vindkraftutbyggingen. Under hele prosjekttiden har vi hatt et nært samarbeid med ressursgruppen, som var satt sammen av norske og svenske representanter fra forvaltningen, grunneiere, næringslivet, forskningen og interesseorganisasjoner. Denne gruppen hadde en avgjørende rolle i prosjektet med en tett møteplan og fortløpende prosessledelse. Kommunikasjon var helt sentralt for å kunne nå vårt hovedmål om økt samordning av viltforvaltningen og vi har fulgt en kommunikasjonsplan under prosjektets gang. I GRENSEVILT 2 utnyttet vi strukturene som ble bygget i GRENSEVILT 1 (hjemmeside, Facebook-side, kontaktnett for nyhetsbrev, mediakontakter, lokale, regionale og nasjonale fagfora for foredrag) men har også arbeidet med andre kommunikasjonskanaler (kartfortellinger og film). I tillegg har vi forberedt innholdet i den planlagte internasjonale forsknings- og forvaltningskonferansen «Wolves Across Borders» som avholdes i mai 2023.

• Zimmermann, Barbara; Wikenros, Camilla; Eriksen, Ane; Sand, Håkan; Wabakken, Petter & Bernardi, Cecilia Di [Show all 14 contributors for this article] (2023). Vilt i vind - Pilotstudier om vindkraftutbyggingens påvirkninger på elg, ulv, jerv og elgjegere. Universitetet i Innlandet. ISSN 9788283804096. Full text in Research Archive Show summary

  Abstract As part of the green transition, substantial wind power development is currently taking place in Scandinavia. The establishment of wind power plants leads to environmental changes in the form of logging, infrastructure such as turbines, transformers, and power lines, and a new or improved road network. The turbines and rotor blades generate noise and flicker from reflected sunlight and shade, and result in increased mortality in birds. In addition, there may be a risk of ice throw from the turbines. Little is known about wind power development effects on wildlife and hunting in Scandinavia. In the GRENSEVILT 2 project, we had the opportunity to carry out pilot studies on the possible effects of wind power development on moose, wolves, wolverines, and moose hunting, partly due to the construction of Kjølberget Wind Power Plant at the Norwegian side of the national border in northern Finnskogen area during 2019-2021. Moose pellet counts at the Kjølberget Wind Power Plant indicated a possible negative effect of the construction work that took place in the summer of 2021 on the distribution of moose. This pattern coincides with the area use of the two GPS-marked moose cows that both had their summer areas at the power plant. One stayed away from the turbines in 2021 and the other was most often in close proximity to the turbines at night and in late autumn when the construction work was over. As for wolves, in order to assess the extent to which wind turbines can be expected to affect the wolf's habitat use we investigated whether areas with planned wind power development within the range of the Scandinavian wolf population coincide with important wolf habitat. We found that planned turbine locations were on the periphery as well as in the activity centers of the wolves, and that there was greatest overlap between planned turbine locations and the wolf activity centers during the denning period. The overlap was slightly less late in the summer, and least in the winter. In the lack of access to GPS-collared wolverines that overlapped with planned or established wind power plants, we analyzed the elevation use of GPS-collared wolverines in areas without wind power plants. Reproducing females during the denning period preferred higher elevations, and their dens were most often at the highest elevations within their home ranges. However, this selection for higher elevation areas was not reflected in a disproportionate use of areas with more wind, and the average wind speed in areas selected by wolverines was below what is considered sufficient for wind power development. Nevertheless, our preliminary conclusions are that the wolverine as a species, and especially in potential breeding areas, should be highly topical with regard to future assessments of impact of land-based wind power development in the Scandinavian countryside. We conducted a web-based, anonymous survey aimed at a selection of hunters in Värmland and Dalarna counties in Sweden, and five municipalities in the far east of Innlandet county in Norway. A total of 656 hunters responded. The results show that many hunters perceive wind turbines on or adjacent to their own hunting grounds as significantly negative for both the hunting performance and the nature experience associated with moose hunting. A clear majority of those questioned had a negative attitude towards the continued development of wind power in general, and this negative attitude became even more evident when it came to development on or in proximity to their own hunting grounds. Our results also indicate that there is a stronger negative attitude towards wind power development in general among the Norwegian than the Swedish hunters. An analysis of hunting statistics from moose management areas at wind power plants indicated a low number of moose shot in hunting areas with many turbines and in close proximity to wind power plants, especially during the construction phase. As possible reasons, we discuss reduced moose density in close proximity to wind power plants because moose avoid these areas, and/or reduced harvest because hunters choose to hunt less in areas with wind power plants. In large moose management areas, the effect of wind power plants on moose harvest was less pronounced, and other factors, such as density of wolves and bears, had a larger impact. Our pilot studies point to a great need for research to uncover the effects of wind power development on wildlife and hunting. This requires long-term studies with a before-during-after design, including studies on the behavioral and physiological responses of wild animals to wind power development.

• Wikenros, Camilla; Zimmermann, Barbara; Sand, Håkan; Eriksen, Ane; Wabakken, Petter & Bernardi, Cecilia Di (2022). Avskjutning av älg över tid och rum – effekter av rovdjur och skogsbruk. Sveriges Lantbruksuniversitet. ISSN 9789157699428. Full text in Research Archive
• Zimmermann, Barbara; Wikenros, Camilla; Eriksen, Ane; Aronsson, Malin; Ausilio, Giorgia & Mathisen, Karen Marie [Show all 10 contributors for this article] (2022). GRENSEVILT – reduksjon av grensebarrierer for skandinavisk viltforvaltning. Sveriges Lantbruksuniversitet. ISSN 9789157699398. Full text in Research Archive
• Wikenros, Camilla; Zimmermann, Barbara; Aronsson, Malin; Eriksen, Ane; Mathisen, Karen Marie & Persson, Jens [Show all 8 contributors for this article] (2022). GRENSEVILT – slutrapport till Interreg Sverige-Norge. Sveriges Lantbruksuniversitet. ISSN 9789157699381. Full text in Research Archive
• Zimmermann, Barbara; Mathisen, Karen Marie; Ausilio, Giorgia; Sand, Håkan; Wikenros, Camilla & Eriksen, Ane [Show all 20 contributors for this article] (2022). Elgvandringer i grenseland med følger for skogbruk, jakt og rovdyr. Sveriges Lantbruksuniversitet. ISSN 9789157699411. Full text in Research Archive
• Sand, Håkan; Zimmermann, Barbara; Berg, Erik; Bramorska, Beata; Eriksen, Ane & Wikenros, Camilla [Show all 10 contributors for this article] (2022). Vandringsmönster hos GPS-försedda älgar i GRENSEVILT – konsekvenser för förvaltningen. Sveriges Lantbruksuniversitet. ISSN 9789157699404. Full text in Research Archive
• Eriksen, Ane; Willebrand, Maria Hörnell; Zimmermann, Barbara; Wikenros, Camilla; Åkesson, Mikael & Backer, Inge Lorange [Show all 16 contributors for this article] (2020). Assessment of the Norwegian part of the Scandinavian wolf population, phase 1. Høgskolen i Innlandet. Full text in Research Archive
• Sand, Håkan; Mathisen, Karen Marie; Ausilio, Giorgia; Gicquel, M; Wikenros, Camilla & Månsson, Johan [Show all 10 contributors for this article] (2019). Kan forekomst av ulv redusere elgbeiteskader og øke tettheten av løvtrær? Utredning om ulv og elg del 4. Universitetet i Innlandet. ISSN 9788283800876. Full text in Research Archive Show summary

  Store rovdyr har nylig kommet tilbake til flere områder hvor de tidligere var utryddet, og dette har kastet nytt lys over deres potensielle effekter på biologisk mangfold og økosystemfunksjoner. Særlig effektene på lavere nivå i næringskjeden har fått mye oppmerksomhet. Store rovdyr kan påvirke vekst hos planter og biologisk mangfold, gjennom deres påvirkning på planteeteres tetthet og atferd (tri-trofiske kaskadeeffekter). Vi har undersøkt hypotesen om tri-trofiske kaskadeeffekter i det skandinaviske økosystemet, ved å fokusere på ulv, elg og planter som er viktige for elg, nemlig furu, og fire høyt selekterte løvtrær; rogn, osp, selje og eik (ROSE). Vi har belyst denne problemstillingen ved bruk av tre ulike datasett fra Norge og Sverige, hvor tetthet av elgmøkkhauger, beiteskader på furu, og tetthet av ROSE har blitt registrert over 1-13 år. Vi har fokusert på de seks fylkene i Sverige som har jevnlig forekomst av ulverevir, og områdene innenfor og like i nærheten av ulvesonen i Norge. Vi har analysert hvordan forekomst og tetthet av elg, beiteskader og tetthet av ROSE, varierer innenfor/utenfor ulverevir, og med antall år ulverevir har vært etablert i et område, i tillegg til en rekke andre miljøvariabler. Tetthet av elg og beiteskader viste enten ingen sammenheng med ulverevir, eller en svak økning innenfor ulverevir. Tetthet av ROSE viste oftest lavere tetthet innenfor ulverevir, men effekten var svak og varierte mellom datasett. Ulverevir forklarte generelt en veldig liten del av variasjonen i elgtetthet, beiteskader og ROSE. I stedet var hogstklasse, dekningsgrad av furu, bjørk og gran, avstand til eller tetthet av skogsbilveier, forekomst av gammelt elgbeite, høyde over havet og snødybde mye viktigere for å forklare variasjonen i elgtetthet, beite og ROSE. Vi fant heller ingen endring i habitatvalg hos elg, og dermed ingen støtte for en endring i atferd hos elg, avhengig av tilstedeværelse av ulv. Vi konkluderer med at våre resultater ikke gir støtte til hypotesen om at gjenkomst av ulv til Skandinavia fører til tri-trofiske kaskadeeffekter, med redusert beitetrykk på viktige plantearter. Våre resultat støtter ideen om at store rovdyr vil ha lavt potensiale for effekter på andre trofiske nivåer i områder med sterk menneskelig påvirkning, noe som er typisk for de områdene hvor store rovdyr nå kommer tilbake. Grunnen til dette er mest sannsynlig høyt jakttrykk på både rovdyr og byttedyr, og intensivt skogbruk og landbruk som gir grunnlag for høye byttedyrtettheter.

• Sand, Håkan; Wikenros, Camilla; Zimmermann, Barbara; Eriksen, Ane; Holen, Frode & Wabakken, Petter (2019). Predasjonsmønster hos enslige stasjonære ulver og ulver på vandring. Utredning om ulv og elg del 3. Høgskolen i Innlandet. Full text in Research Archive
• Liberg, Olof; Sand, Håkan; Wabakken, Petter; Wikenros, Camilla; Zimmermann, Barbara & Eriksen, Ane (2019). Beräkningar av beskattning av den Skandinaviska vargpopulationen 2020. Grimsö Wildlife Research Station, Department of Ecology, Swedish University of Agricultural Sciences. Full text in Research Archive
• Wikenros, Camilla; Zimmermann, Barbara; Sand, Håkan; Månsson, Johan; Maartmann, Erling & Eriksen, Ane [Show all 7 contributors for this article] (2019). Tildelt, sett og felt elg i forhold til ulveforekomst i Norge og Sverige. Utredning om ulv og elg del 1. Universitetet i Innlandet. ISSN 9788283800814. Full text in Research Archive Show summary

  Predasjon fra store rovdyr og jakt er de to viktigste faktorene som styrer dynamikken i mange hjorteviltpopulasjoner verden over. Gjenetableringen av ulv på den skandinaviske halvøya har møtt hard motstand fra mange hold, der ett argument har vært at ulveforekomst resulterer i en nedgang i elgstammen og reduserer det mulige jaktuttaket. Elgen er det viktigste byttedyret for ulven hele året, og ulvepredasjonen gjelder i hovedsak dyr som ellers kunne ha blitt felt under jakt. I denne rapporten presenterer vi hvordan ulven påvirker elgstammen og hvordan dette i sin tur påvirker avskytningen av elg i ulvens viktigste utbredelsesområde i Skandinavia ved å sammenligne områder uten og med ulik grad av ulveforekomst. Studien omfatter flere ulike datasett hvorav det mest omfattende spenner over en 32-års periode (fra 1986 i Norge og fra 1995 i Sverige til 2017). De mest detaljerte studiene av ulveforekomstens effekt på antall og sammensetning av kvoter, fellinger og observerte dyr ble gjennomført på data fra de seks siste årene. Vi har også sammenstilt hvilke jaktstrategier som er blitt utnyttet i den allmenne forvaltningen av elg og i forhold til forekomsten av ulv. Resultatet av denne studien viser at det har vært betydelig variasjon i avskytningen av elg i både Norge og Sverige de siste tiårene. En del av denne variasjonen kan forklares av den voksende ulvestammen. Utviklingen i elgstammen målt ved kvoter, fellinger og observerte dyr, samt effekten av ulv på disse variablene er likevel ulik mellom de to landene. Dette kan delvis forklares ved forskjeller i jaktstrategi, men også ved metodologiske ulikheter i innsamlingen av data. Denne studien viser at en endring i antall observerte dyr ett eller flere år ofte resulterte i en tilsvarende forandring i jaktuttaket neste år. Forekomst av ulv påvirket både antall og sammensetning av jaktuttak og observerte dyr. Det viste seg at ulven hadde en langtidseffekt på felte dyr per areal, mens påvirkningen på kjønns- og alderssammensetningen i sett elg var mer kortvarig. Data fra begge land viste at så vel kvoter som fellinger avtok den siste seksårs-perioden, og var koplet til ulveforekomst. Flertallet av analysene viste også at andre faktorer i kombinasjon med ulveforekomst har stor betydning for variasjonen i kvoter, felling og observerte dyr. Slike faktorer er breddegrad og andel kulturlandskap. Dette viser at endringer i både elgstammens størrelse, sammensetning og tilhørende jaktuttak styres av en kombinasjon av flere faktorer, som forvaltningsstrategi (jaktuttakets størrelse og sammensetning) og livsmiljø der predasjon fra store rovdyr er viktige elementer. Økt forekomst av ulv i Norge resulterte i at man kombinerte to jaktstrategier: 1. Man forsøkte å maksimere antallet felte dyr ved å øke andelen kalv i avskytningen. 2. Man reduserte jakttrykket på hunndyr i den hensikt å øke deres andel i populasjonen, altså skape en mer produktiv stamme. De samme strategier kunne observeres i Sverige, med den forskjell at andelen felte kalver de siste seks år var høyere enn i Norge, og uavhengig av om det fantes ulv. Dette viser at man i begge land innførte tiltak for å redusere den totale dødeligheten i elgstammen (redusert felling) så vel som for å maksimere produktiviteten (redusert felling av hunndyr). Den observerte andelen kalv i avskytningen tyder på at man uavhengig av ulveforekomst fant et kompromiss mellom å maksimere antall felte dyr og mengde kjøtt. Denne strategien var uavhengig (Sverige) eller ble styrket av den voksende ulvebestanden (Norge).

• Zimmermann, Barbara; Wikenros, Camilla; Sand, Håkan; Eriksen, Ane & Wabakken, Petter (2019). Elg i ulverevir: Predasjon og elgjakt. Utredning om ulv og elg del 2. Universitetet i Innlandet. ISSN 9788283800838. Full text in Research Archive Show summary

  I Skandinavia er ulvebestanden regulert av jakt. Dette medfører at ulvens påvirkning på byttedyrbestandene begrenses sammenlignet med uregulerte rovviltbestander og hovedsakelig konsentreres til områder med stasjonære, revirhevdende flokker og par. En måte å beregne effekten av ulvens predasjon på elgbestanden sammenlignet med jaktuttaket er å ta utgangspunkt i det enkelte ulverevir og beregne omfanget av ulvens predasjon ut fra kunnskap om ulvens predasjonstakt, størrelsen på reviret og elgtettheten. I den første delen av denne studien analyserer vi hvordan ulike elg- og ulverelaterte faktorer påvirker variasjonen i ulvens predasjonstrykk (andel av elgbestanden som tas av ulv) mellom ulike revir, samt hvordan dette henger sammen med eksisterende data for jaktuttak på revirnivå. I den andre delen av denne studien undersøker vi ulvenes tidsbruk innenfor sine revir og hvordan denne geografisk sammenfaller med fordelingen av 1) ulvedrepte byttedyr (elg) funnet i felt, samt 2) jaktuttaket og elgobservasjoner mellom de ulike jaktenhetene som inngår i reviret. Predasjonstrykket fra ulv på elgbestander i ulike ulverevir hadde ingen tydelig sammenheng med tetthet av elg, ulveflokkens størrelse, eller hvor ofte en ulveflokk tok elg (predasjonstakt). Derimot var predasjonstrykket sterkt avhengig av den kombinerte effekten av revirets størrelse og elgtetthet, som til sammen utgjør hvor mange elger som finnes i reviret. Omfanget av predasjonstrykket ble beregnet til gjennomsnittlig 7 – 8% av elgbestanden og varierte mellom 2 – 12% mellom revir. Motsvarende var jakttrykket beregnet til gjennomsnittlig 15 – 19%, med en variasjon på 8 – 33% mellom revir. Sett over hele året var jakttrykket gjennomsnittlig 2.4 – 3.5 ganger høyere enn predasjonstrykket, men jakttrykket var konsentrert til en kort periode i jakttiden, mens predasjonstrykket fordelte seg mer regelmessig over hele året. Jakttrykket hadde ikke noen sammenheng med antall elg i reviret eller predasjonstrykket, noe som tyder på at den kombinerte effekten av ulv og jakt ikke er kompensatorisk. En sammenligning av predasjonstrykket fra ulv og bjørn på elg i Alaska med dødeligheten fra jakt, ulv og bjørn i Skandinavia tyder på at en mindre andel av elgbestanden i Skandinavia dør årlig. Delstudie to viste 1) at ulvene fordeler tiden sin ulikt i de ulike delene av reviret, 2) at denne ujevne fordelingen blir spesielt sterk på sommeren i revir der ulvene har ynglet, 3) at fordelingen av ulvedrepte elger er ujevn og følger fordelingen av ulvenes områdebruk, men 4) at den ujevne fordelingen av ulvedrepte elger, i motsetning til ulvenes tidsbruk, ikke kan forklares med om ulvene har ynglet eller ikke, eller av årstid. En konsekvens av ulvenes ujevne områdebruk i reviret er at antallet felte elger per jaktareal var lavere i deler av reviret der ulvene tilbragte mer tid og der ulvene drepte flere elger. I gjennomsnittet var jaktuttaket 24% lavere i områder som ble mye brukt av ulv, sammenlignet med områder der ulvene tilbragte lite tid. Andelen felte kalver var hele 41% lavere i områder med høy sommeraktivitet sammenlignet med områder med lav sommeraktivitet, mens forskjellen i andelen felte kalver var på 33% mellom høy- og lavaktivitetsområder for hele året. Resultatene viser at det finnes en variasjon i jaktuttaket innenfor reviret som delvis kan forklares av ulvens områdebruk. Derimot fant vi ikke noen negativ sammenheng mellom sett elg per jegertime og ulvenes områdebruk eller fordeling av ulvedrepte elger. I noen tilfeller ble det til og med sett flere elger i områder med mye ulveaktivitet. Dette tyder på at det råder en kompleks sammenheng mellom ulvenes fordeling, predasjon, jaktuttak og sett elg i tid og rom på den geografiske skalaen av et ulverevir.

• Wabakken, Petter; Zimmermann, Barbara; Eriksen, Ane; Maartmann, Erling; Nordli, Kristoffer & Sanchez, David Carricondo [Show all 8 contributors for this article] (2018). Sesongkonflikter mellom mennesker og ulv i områder med snø og trekkelg: Ulv i Slettåsreviret, 2009-2018. Høgskolen i Innlandet. ISSN 9788283800760. Full text in Research Archive
• Nordli, Kristoffer; Zimmermann, Barbara; Wabakken, Petter; Eriksen, Ane; Sanchez, David Carricondo & Maartmann, Erling [Show all 8 contributors for this article] (2018). Ulvevalpers flokksamhold og områdebruk i Skandinavia. Utredning om ulv og bosetting del 2. Universitetet i Innlandet. ISSN 9788283800708. Full text in Research Archive Show summary

  English: The basic social unit in wolves consists of the territory-marking pair, and together with their offspring from the contemporary and/or previous litters they form a family group, commonly referred to as the wolf pack. The family group's grouping behavior and movement pattern depends on the wolves' year cycle. Observations in Scandinavia from long-term series of GPS data, and the National Monitoring Program indicates that the overall cohesion of the pack gradually dissolves during the winter. Using 15 years of data distributed over 17 pack years, 21 adult breeding pairs and 30 pups with simultaneous GPS positioning, we investigated wolf pack cohesion and pup dispersal from January to early July. We investigated the cohesion by using a regressive non-linear time series analysis (GAMM) with an added interaction term on time adjusted to appropriate reference levels. The cohesion was strongest in early winter but declining over time, characterized by wolf pups becoming increasingly independent from the rest of their family group, before most pups (75%) eventually disperse in the spring before 14 months of age. The distance between litter siblings and between pups and parents became significantly different from zero during the mating season and remained significant to after the birth of the subsequent litter. Overall the predicted variation in cohesion between siblings and between pups and their parents was large. In other words, pups could be separated from their parents and other siblings already in early winter, though not so often or over shorter time periods than later in winter-spring. In cases when the pups were separated from the parents, the pups’ habitat selection could be characterized as elusive, more concealed and further away from human infrastructure. Our results are a strong contrast to the common belief that members of a wolf pack allegedly operate as a strictly synchronized unit. This also may have implications for the annual wolf monitoring program in terms of calculating the number of wolves and reproductions, and for the planning and implementation of an ethical and effective license hunt on Scandinavian wolf family groups in the future.

• Eriksen, Ane; Zimmermann, Barbara; Wabakken, Petter; Sanchez, David Carricondo; Sand, Håkan & Wikenros, Camilla (2018). Spredningsulvers bevegelser i forhold til menneskelig infrastruktur. Utredning om ulv og bosetting del 3. Universitetet i Innlandet. ISSN 9788283800722. Full text in Research Archive Show summary

  English: We present the first telemetry study of the habitat use of dispersing wolves in Scandinavia. During dispersal, young wolves enter unfamiliar areas, and their travel routes often follow natural as well as anthropogenic landscape corridors such as valleys and roads. With average dispersal distances of 225 km (males) and 154 km (females), dispersing wolves can theoretically appear anywhere on the Scandinavian peninsula. During the period 2003-2017, 31 wolves were GPS collard inside their natal territories, and followed during part of or the entire period of natal dispersal. We used step selection functions and conditional logistic regressions to evaluate the movement of dispersing wolves relative to human settlement and infrastructure, during different seasons and times of day, and during displacement and at so-called clusters. We also looked for changes over time since the wolves left their natal territories. Based on the assumption that young dispersing wolves are inexperienced, relatively poor hunters, travel across large distances and into unfamiliar areas, we expected that these wolves would often get close to human settlements. We also expected that they would use roads for efficient transportation, but that they would adjust their activity in time and space to avoid encounters with humans. Finally, we expected that the proximity to human activity would decrease over time as the dispersing wolves got older, gained experience and became better hunters. Our results show that the dispersing wolves were generally evasive towards human infrastructure and avoided proximity to settlements, high building densities, and open areas. The dispersing wolves were particularly evasive when moving to places where they would spend longer periods of time at day beds or consuming food. During transportation the wolves selected higher densities of forest roads, seemingly regardless of season and time of day. During nocturnal transportation bouts they did not avoid main roads. Consistent with earlier studies we interpret this as the wolves using roads for efficient travel. The dispersing wolves showed stronger avoidance of roads, buildings and open areas during day than during night, probably to avoid humans. Their movement relative to human infrastructure was stable throughout the first nine months after leaving the natal territory. Our findings regarding the movement of dispersing wolves is consistent with existing knowledge about wolf behavior toward human infrastructure, and we did not find evidence that dispersing wolves as a group seek human activity more than resident wolves do. Nevertheless, we saw cases of individual dispersing wolves appearing in areas with very high levels of human activity, inside settlements and near large traffic arteries. Our interpretation of these results is that dispersing wolves generally avoid humans in the same way as resident wolves, and that e.g. roads are mainly used when the likelihood of encountering humans is low. Even so, wolves traveling across long distances will often have to cross major roads or densely populated areas where the risk of detection by humans is high.

• Zimmermann, Barbara; Wabakken, Petter; Eriksen, Ane; Maartmann, Erling; Sanchez, David Carricondo & Versluijs, Erik [Show all 8 contributors for this article] (2018). Slettåsulvenes atferd i forhold til menneskelig bosetting gjennom et helt år. Utredning om ulv og bosetting del 6. Universitetet i Innlandet. ISSN 9788283800784. Full text in Research Archive Show summary

  Etter at Slettåsulvene i 2009 etablerte revir i et område som har vært tomt for ynglende ulv i trolig over hundre år, har det vært en vedvarende konflikt om ulvers atferd i forhold til bosetting. Slettåsulvene ble av lokalt bosatte oppfattet som nærgående, og det var grunnen til at forvaltningen merket lederparet og fire valper med GPS-halsbånd i januar-februar 2017. Det Skandinaviske Ulveforskningsprosjektet SKANDULV fikk i oppdrag å analysere de regelmessige GPS-posisjonene tatt hver time eller hver fjerde time, studere ulvenes atferd ved å oppsøke posisjoner i felt og kartlegge fordelingen av elg og rådyr om vinteren og sommeren ved hjelp av systematiske møkktellinger. Vi har søkt etter kadaverrester og ulvespor på 45 % av alle 4-timersposisjoner til de voksne ulvene tatt i perioden 13.1.2017–10.1.2018. I området som Slettåsulvene brukte som revir gjennom 2017 (880 km2) er menneskelig bosetting konsentrert langs ved Osensjøen, i fire tettsteder og noen spredte enkelthus i de lavereliggende, tørre områdene, mens hytter finnes hovedsakelig enten lavt eller høyt i terrenget. Om vinteren var elgen konsentrert i atskilte områder, ofte nære hus, mens elgfordelingen var jevnere gjennom sommeren. Vi fant lite rådyrmøkk, nær hus om vinteren og langt fra hus om sommeren. Lederparet i Slettåsflokken oppholdt seg gjennomsnittlig nærmere hus enn forventet fra tilgjengelig habitat om vinteren, spesielt nattestid og i områder med høy elgtetthet, trolig for å jakte. Under yngling valgte ulvene stort sett hi- og valpeplasser langt fra bebyggelse, trolig for å unngå menneskelig forstyrrelse, men de fortsatte å jakte elg nærmere hus enn forventet, trolig fordi elgkyrne valgte kalvingshabitat i slike områder. Om høsten (oktober-november) valgte ulvene å jakte og oppholde seg langt fra bebodde hus, trolig for å unngå menneskelig forstyrrelse under elgjakt eller som en konsekvens av elgens habitatvalg. Når fjorårsvalpene gikk atskilt fra de voksne før utvandring fra oppvekstreviret, holdt de seg gjennomsnittlig lenger unna hus enn foreldreparet på samme tidspunkt, trolig fordi de ikke fulgte med på de voksnes jaktturer eller fordi de var mer varsomme overfor menneskelig forstyrrelse. Vi konkluderer med at sporobservasjoner av Slettåsulvene nær bebodde hus trolig skyldtes ulvenes jaktatferd i områder med god tilgang til elg og rådyr, og at ulvene passerte hus mens de jaktet eller var på vei mellom dagleie og kadaver heller enn at de oppholdt seg ved hus over lenger tid.

• Sanz-Perez, Ana; Milleret, Cyril Pierre; Fernandez, Andres Avelino Ordiz; Uzal, Antonio; Sanchez, David Carricondo & Eriksen, Ane [Show all 11 contributors for this article] (2018). Oppvekstrevirets effekt på habitatvalg hos voksne ulver. Utredning om ulv og bosetting del 4. Universitetet i Innlandet. ISSN 9788283800746. Full text in Research Archive Show summary

  English: We investigated whether the degree of natal exposure to anthropogenic influences could explain some of the variation in the selection of habitat with regard to anthropogenic factors in Scandinavian wolves. In the first part of the study we tested whether anthropogenic influences in the natal habitat might affect the choice of a breeding territory. Because dispersal distance may influence habitat similarity between natal and established territories, and mammals often show male-biased dispersal, we investigated the importance of dispersal distance and sex, and we tested alternative methods for defining habitat availability. In the second part of the study we evaluated whether the natal habitat may affect the habitat selection of wolves within their established territories, and we tested two competing hypotheses. A) Wolves exposed to a high degree of human activity in the natal territory may avoid human-related features within their established territory. B) Wolves exposed to a high degree of human activity in the natal territory may select for human related features in the established territory because of a certain degree of adaptation or habituation to human activity. We found that female, and to a smaller degree male wolves with short dispersal distances established in natal-like habitat types, regardless of the definition of habitat availability and habitat similarity. This was not the case for wolves that dispersed longer distances. We also found weak but consistent statistical evidence that wolf pairs in which the female had dispersed from a natal territory with a high degree of anthropogenic influence tended to select areas further away from humans within their established territory. The effects of the natal territory of the males was less clear. Part of the background for this evaluation was a concern among people living in wolf areas that wolves growing up in areas with high anthropogenic influence would seek human activity. On the contrary, our results suggest that wolves that have been exposed to larger degrees of anthropogenic influence in the natal territory may avoid proximity to human settlements and infrastructure inside their established territories. Our methodological approach may be useful for the continued wolf research and management in Scandinavia and elsewhere, both for the monitoring of whether wolves’ response to exposure to humans changes following changes in the wolf population or in the patterns of human settlement, but also to compare the response of wolves in Scandinavia to those in other parts of Europe, in which wolves are recolonizing areas of much higher anthropogenic influence.

• Liberg, Olof; Sand, Håkan; Wabakken, Petter; Wikenros, Camilla; Zimmermann, Barbara & Eriksen, Ane (2018). Beräkningar av beskattning av den Skandinaviska vargpopulationen. Grimsö Wildlife Research Station, Department of Ecology, Swedish University of Agricultural Sciences. Full text in Research Archive
• Sanchez, David Carricondo; Zimmermann, Barbara; Wabakken, Petter; Eriksen, Ane; Maartmann, Erling & Sanz-Perez, Ana [Show all 8 contributors for this article] (2018). Individuell atferd hos ulv overfor menneskelig infrastruktur i Skandinavia. Høgskolen i Innlandet. ISSN 9788283800678. Full text in Research Archive Show summary

  Ulv er kjent til å være en habitatgeneralist med ynglende bestander i mange ulike typer habitat fra arktiske strøk, boreale skoger, åpne landbruksområder og til tettbefolkede områder i varme strøk. En viktig faktor for ulvens habitatvalg er tilgang til byttedyr, og flere studier har vist at i områder hvor menneskelig infrastruktur overlapper med tilgang til byttedyr, utnytter ulven natten for å jakte. Ikke bare ytre faktorer kan påvirke ulvers habitatvalg. Ulveindivider har ulik personalitet formet av nedarvede og lærte egenskaper, og det kan derfor forventes en stor variasjon i hvordan ulike individer oppfører seg overfor menneskelig infrastruktur. Vi kategoriserte Skandinaviske ulvers individuell atferd langs en gradient fra unnvikende til oppsøkende, der unnvikende betyr unngåelse av infrastruktur og oppsøkende betyr preferanse for eller større bruk av infrastruktur enn forventet fra tilgjengeligheten. Vi brukte GPS-posisjoner fra 55 forsknings- og forvaltningsmerkede ulver i tidsperioden 2001-2017 i individuelle stegvalganalyser for å beskrive habitatvalget for hvert individ, for deretter å teste om variasjonen i habitatvalget kan forklares med årstid, tid på døgnet, alder, kjønn og andre individ- og revirspesifikke egenskaper. Ulvene viste oftest ikke noe spesiell seleksjonsmønster eller var unnvikende overfor infrastruktur, og oppsøkende atferd var sjeldent, med et unntak: mer enn halvparten av ulvene viste en oppsøkende atferd overfor skogsbilveier, trolig for bruk til energieffektiv forflytning. Ulvene foretrakk områder med veldig lav bygningstetthet. På dagtid var ulvene mer unnvikende, trolig for å unngå møter med folk, og på natten var de mindre unnvikende eller mer oppsøkende, trolig for å jakte på byttedyr. Ulvene, og spesielt tispene, var mer unnvikende på sommeren, trolig for å skjerme valpene på hi- og valpeplassene fra menneskelig forstyrrelse. Om vinteren var ulvene mindre unnvikende eller mer oppsøkende, trolig for å jakte elg og rådyr som oppholdt seg nær menneskelig infrastruktur når det er snødekke. Ulvene nord i norsk ulvesone og tilgrensende områder var mer oppsøkende enn ulvene lenger sør, trolig som en effekt av elgfordelingen i dalbunnene vinterstid i områder med elgtrekk. Vi fant ikke noe tydelig effekt av ulike individers eller flokkers særegenhet på deres atferdsmønster og antar derfor at ulvene i Skandinavia utviser en stor grad av fleksibilitet og tilpasningsevne i deres atferd overfor menneskelig infrastruktur.

• Wabakken, Petter; Maartmann, Erling; Eriksen, Ane; Zimmermann, Barbara; Flagstad, Øystein & Liberg, Olof [Show all 8 contributors for this article] (2017). Ulv som skadegjører på bufe, tamrein og hund i Norge: skadehistorikk og skadepotensiale i forhold til ulvens spredningsmønster. Universitetet i Innlandet. ISSN 9788283800036. Full text in Research Archive Show summary

  Since the reestablishment of the wolf population in Scandinavia during the 1980s, there have been conflicts related to the coexistence of wolves and people, mostly regarding loss of livestock and dogs, people’s fear, and competition for moose. To reduce conflicts, knowledge about wolf dispersal patterns is essential for management policies, but has thus far been studied very little. This is a first quantitative assessment of the history of, and potential for, livestock depredation by wolves in Norway. We have analyzed the dispersal patterns of Scandinavian wolves born in 1) fully Norwegian territories associated with today’s wolf zone, 2) trans-border territories, and 3) Swedish territories, respectively. Based on the established dispersal patterns, we analyzed wolf occurrence and potential for livestock depredation in Norway in general, as well as in the following regions: 1) Southern Norway outside of Hedmark County and the wolf zone, 2) Hedmark County, west of the Glomma River, and 3) Hedmark, east of Glomma and north of the wolf zone. Depredation on free-ranging domestic sheep is the major conflict concerning wolves and livestock in Norway. With the exception of two municipalities west of Oslo, there are no freeranging sheep in the wolf zone, and we conclude that young, solitary, dispersing wolves that immigrate to regions outside the wolf zone pose the greatest potential damage to free-ranging sheep in Norway. During the past 31 years, 2/3 of all wolf-killed sheep in Norway were in Hedmark County, and Rendalen Municipality in particular is suffering extensive and chronic losses, despite extensive culling of wolves. Most of the wolves immigrating to potential conflict areas in Southern Norway are born in Sweden. This is particularly true for those immigrating to Southern Norway outside of Hedmark and the wolf zone; among 56 wolves, 55 were Swedish-born, three were born in trans-border territories, and none were from the 41 wolf litters registered in fully Norwegian wolf territories associated with the wolf zone. Wolves from fully Norwegian territories east of Glomma almost always dispersed east into our neighboring countries. Only one out of 40 wolves which during a 20-year period were culled in Norway in direct association with attacks on livestock during the grazing season had dispersed from a fully Norwegian wolf territory associated with the wolf zone. We therefore conclude that the number of litters in fully Norwegian wolf territories seems to be of minimal importance for the extent of depredation on free-ranging sheep in Southern Norway as long as the reproductions happen in association with the wolf zone. Free-ranging cattle still graze both inside and outside the wolf zone, but the densities and the extent of wolf predation are low. During the period of 1995-2017, 113 dogs were classified as killed by wolves in Norway. The vast majority of these (107 dogs) were killed inside the wolf zone and/or inside Norwegian wolf territories. Resident, territorial wolves seem to be responsible for most of the attacks on dogs. Nevertheless, we found no relationship between the number of wolves or wolf territories in Norway and the number of dogs killed per year. Many territories had no attacks on dogs at all. Wolves in packs and pairs are an important factor in moose management, but the substantial decrease in moose populations in recent years in counties without resident wolves illustrates that factors other than wolves may be of major importance.

• Zimmermann, Barbara; Wabakken, Petter; Eriksen, Ane; Maartmann, Erling; Holen, Frode & Dahl, Espen R. [Show all 13 contributors for this article] (2017). Atferdsstudier på ulv i Slettås- og Osdalsreviret: Foreløpige resultater fra feltperioden januar–februar 2017. Høgskolen i Innlandet. ISSN 9788283800005. Full text in Research Archive Show summary

  Ulver i Slettåsreviret har i flere år blitt beskrevet som nærgående av lokalbefolkningen og media. Fem individer av flokken ble derfor merket med GPS-halsbånd i januar 2017, samtidig som ni ulver fra naboflokken i Osdalsreviret også ble GPS-merket. Det Skandinaviske Ulveforskningsprosjektet SKANDULV har deretter, med noen dagers forsinkelse for ikke å forstyrre, fulgt opp ulvene i felt for å kartlegge deres atferd og forflytningsmønster. Vi har oppsøkt de fleste plassene hvor ulvene har stoppet opp. Slike plasser karakteriseres av klynger med GPS-posisjoner, såkalte clustere, og i kombinasjon med sporsnø er det ofte mulig å se ulvenes atferd i slike områder. For de to ulveflokkene ble det etter fortløpende GIS-analyser undersøkt til sammen 5827 ulveposisjoner (83% av alle heltimesposisjonene) i felt, hvorav 5729 (98%) av posisjonene var fordelt klumpvis på totalt 362 clustere. Undersøkte GPS-posisjoner representerte en periode på 160 og 301 døgn for medlemmer av henholdsvis Slettåsflokken og Osdalsflokken, og GPS-posisjonene ble undersøkt av 7 peroner til sammen 67 dager i felt i perioden 7. februar – 2. mars 2017. På henholdsvis 8 (5%) og 14 (7%) clustere i Slettås- og Osdalsreviret fant vi rester etter elg som etter all sannsynlighet var drept av ulv, og på et cluster i Slettås var det rester etter det som kan ha vært en liten hund. Clustere med elgkadaver i Slettåsreviret lå gjennomsnittlig 1434 m (SE = 825 m) fra nærmeste bebodde hus. Dessuten ble matrester, ofte fra åteplasser, funnet på 12 clustere i Slettåsreviret. Denne typen cluster lå gjennomsnittlig nærmere bebodde hus enn andre typer av clustere. Det nærmeste matrester-cluster var på en åteplass besøkt av ulv 46 m fra hus. En foreløpig analyse av Slettåsulvenes GPS-posisjoner viser at ulvene foretrakk å bruke områder mellom 500 – 2000 m fra bebodde hus. Sett i forhold til andel areal med forskjellige avstander til bebodde hus brukte ulvene de nærmeste 500m fra hus mindre enn forventet på dagtid og omtrent som forventet om natten. Av de totalt 3095 posisjonene med 1-timesintervaller i Slettåsreviret var 21 (0,7%) nærmere enn 50 m fra bebodde hus, samtlige tatt om natten. Den nærmeste heltimesposisjonen påvist på dagtid var 98 m fra et hus. Den korte studieperioden begrenser muligheten til å trekke allmenne konklusjoner om ulvenes atferd, men vi kan se fra forflytningsmønsteret og clusterfunnene at mat trolig er en avgjørende faktor for ulvenes arealbruk. Fordelingen av elg i vinterkonsentrasjonsområder nær hus, men også tilgang til menneskeskapte åteplasser og dyp snø i høyden synes på denne årstiden å forklare mye av ulvenes forflytningsmønster. For en helhetlig konklusjon, økt allmenn kunnskap og framtidig adaptiv forvaltning av ulv er et anbefalt minimum å sammenligne Slettås- og Osdalsulvenes arealbruk med tilgjengelig tidligere års materiale fra ulver som er GPS-merket og observert i mer enn 50 andre Skandinaviske ulverevir.

• Eriksen, Ane; Slagsvold, Tore & Lampe, Helene M. (2011). Song learning in oscine songbirds : Tutor choice, timing, and the relationship with sexual imprinting. Universitetet i Oslo. Full text in Research Archive Show summary

  Birdsong is a species-specific signal that is used in mate attraction and intrasexual competition. This thesis concerns song acquisition in two oscine songbird species, the great tit Parus major and the pied flycatcher Ficedula hypoleuca. It addresses questions such as how free-living songbirds choose their song tutors and whether learning of foreign songs can take place in adult birds, and it looks into the relationship between song learning and sexual imprinting. This was done using a method of experimental, interspecific cross-fostering, in which eggs were swapped between nests of different species. Great tits were cross-fostered to blue tits Cyanistes caeruleus, and pied flycatchers were cross-fostered to great tits and blue tits. In oscine songbirds, young males have to learn their song from adult conspecifics, and a mechanism is needed to ensure that they choose song tutors of the right species. Early laboratory studies proposed the existence of an innate auditory template facilitating the recognition and memorization of conspecific song. However, in a number of species, males reared by heterospecifics have been found to copy songs of the foster species and thereby become mixed singers. To account for such heterospecific song learning, it has been suggested that familiarization with the social father before independence guides the choice of song tutors. However, under natural conditions, young males may grow up without a social father. A study on captive zebra finches Taeniopygia guttata has demonstrated effects of the social mother on song learning. Based on this finding, I propose a mechanism of mothermediated tutor choice, suggesting that experience with the social mother as well as the father guides the choice of song tutor in oscine songbirds. Great tits cross-fostered to blue tits include blue tit song in their repertoires. They also get sexually misimprinted, and occasional heterospecific pairs are formed between cross-fostered great tits and cross-fostered blue tits. I tested the hypothesis of mother-mediated tutor choice by letting great tits grow up with a blue tit foster mother and a great tit foster father. Males of this treatment included blue tit song in their repertoires. To control for the possibility that the males had learned the blue tit song directly from their cross-fostered fathers, we also recorded song from great tit males that were reared by conspecifics, but whose fathers had been cross-fostered to blue tits. None of these males sang blue tit song, suggesting an effect of the social mother. However, cross-fostered great tit males mated to blue tits may sing more blue tit song than those mated to great tits. Our samples were too small to separate between heterospecific song learning resulting from mother-mediated tutor choice and from exposure to blue tit song in the repertoire of the father. Song learning shares a number of characteristics with sexual imprinting. I investigated the relationship between these two processes in great tits. I exposed cross-fostered great tit males to playback of great tit song and blue tit song inside their territory. Males that showed sexual interest in blue tit females were more likely to respond with blue tit song to playback than males that showed interest only in conspecific females. This suggests that different degrees of misimprinting may have parallel effects on song learning and sexual preferences in cross-fostered great tit males. Furthermore, the response to territorial intruders seemed to be affected by social interactions: Cross-fostered males currently associated with blue tits increased their response to playback of blue tit song whereas males currently associated with great tits increased their response to playback of great tit song through the season. I also studied the effect of social rearing condition on song learning in pied flycatchers. Cross-fostered pied flycatchers do not seem to get sexually misimprinted. However, I found that pied flycatcher males reared by blue tits or great tits became mixed singers, uttering a combination of pied flycatcher song and the foster species’ song. Furthermore, males reared with nest mates of the foster species included tit song in a higher proportion of strophes than did cross-fostered males reared with conspecific nest mates. Hence, in pied flycatchers, growing up with heterospecific foster parents and nest mates caused a mixed choice of song tutors without affecting their mate preferences. Some songbird species are open-ended learners and retain the ability to learn new songs throughout their lives. However, to demonstrate that a species is a true open-ended learner, it is necessary to make sure that the elements learned as adults have not been heard and possibly memorized by the birds at an early age. I performed a playback experiment to test whether the pied flycatcher is a true open-ended learner. I exposed pied flycatcher males to playback of song containing syllables that were unknown to the study area. Among the 20 subjects, one yearling and two older males had learned a foreign syllable type, supporting the hypothesis that pied flycatchers are true open-ended learners. Pied flycatcher song is believed to serve mostly for mate attraction, and possible functions of adult song learning are to increase the repertoire size and to increase syllable sharing with neighbours. The subjects showed no increase in either of these parameters after the treatment. An alternative adaptive value of adult song learning in pied flycatchers may rather be to pick up particularly attractive song elements.

• Storaas, Torstein; Pedersen, Simen; Pedersen, Simen; Andreassen, Harry P.; Arnemo, Jon Martin & Dötterer, Michael [Show all 22 contributors for this article] (2008). Effekter av ulv på elgbestanden : da ulven kom og forsvant fra Koppangkjølen Effects of wolves on moose : when the wolf came and went from Koppangkjølen. Høgskolen i Hedmark. ISSN 9788276716474. Full text in Research Archive Show summary

  Fra 1997 til 2005 hevdet ulv revir på Koppangkjølen i Stor-Elvdal og Rendalen kommuner, Hedmark Fylke. Vi fulgte elgbestanden i området gjennom SETT ELG, takseringer fra helikopter og ved hjelp av radiomerkede elger. Vi har SETT ELG-data fra alle årene og gode data fra helikoptertakseringer og radiomerkede elger særlig fra 1999¿2001. Særlig mot slutten ble datainnsamlingen begrenset av prosjektøkonomien. Ulvenes antall og revirgrenser ble hver vinter kartlagt ved sporing på snø, og i 2004 ble tilleggsinformasjon innsamlet ved GPS-merking av både den revirhevdende tispa og hannen. Vi har beregnet det økonomiske tapet for jaktrettshaverne ved ulvens uttak av elg og analysert utviklingen av både reelle og potensielle inntekter fra småviltjakt og hytteutleie i ulvereviret. Basert på ulike deler av innsamlet datamateriale har vi produsert studentoppgaver på bachelor-, master- og ph.d.-nivå, i tillegg til diverse populærartikler og vitenskapelig publiserte arbeider. Her presenterer vi de viktigste resultatene fra de forskjellige arbeidene for å gi en samlet oversikt over hva vi lærte fra perioden med ulv på Koppangkjølen. During 1997 to 2005 a wolf territory was situated at Koppangkjølen in Stor-Elvdal and Rendalen municipalities, Hedmark County. We monitored the moose population in the area using a hunters¿ observation index called OBSERVED MOOSE, helicopter surveys, and by radiomarking moose. We have OBSERVED MOOSE data from all the years and good helicopter survey data and information from radiomarked moose, especially from 1999¿2001. Data collection was restricted in the later years by the project budget.The wolf pack numbers and territory boundaries were monitored each winter by snow tracking. In 2004 we got additional data by radiomarking both the female and male wolf territory holders. We estimated the landowner¿s economic loss by wolves killing moose and analyzed the development of the income from small game hunting and cabin renting within the wolf territory. Based on different parts of the data collected, our project has produced Bachelor-, Master-, and Ph.D.-theses, in addition to several popular articles and scientific papers. Herein we present the main results from our work and summarize the most important findings from the period with wolves at Koppangkjølen.

• Storaas, Torstein; Pedersen, Simen; Andreassen, Harry Peter; Arnemo, Jon Martin; Dötterer, Michael & Eriksen, Ane [Show all 21 contributors for this article] (2008). Effekter av ulv på elgbestanden: da ulven kom og forsvant fra Koppangkjølen. Høgskolen i Hedmark. ISSN 9788276716474. Full text in Research Archive Show summary

  English: During 1997 to 2005 a wolf territory was situated at Koppangkjølen in Stor-Elvdal and Rendalen municipalities, Hedmark County. We monitored the moose population in the area using a hunters’ observation index called OBSERVED MOOSE, helicopter surveys, and by radiomarking moose. We have OBSERVED MOOSE data from all the years and good helicopter survey data and information from radiomarked moose, especially from 1999–2001. Data collection was restricted in the later years by the project budget.The wolf pack numbers and territory boundaries were monitored each winter by snow tracking. In 2004 we got additional data by radiomarking both the female and male wolf territory holders. We estimated the landowner’s economic loss by wolves killing moose and analyzed the development of the income from small game hunting and cabin renting within the wolf territory. Based on different parts of the data collected, our project has produced Bachelor-, Master-, and Ph.D.-theses, in addition to several popular articles and scientific papers. Herein we present the main results from our work and summarize the most important findings from the period with wolves at Koppangkjølen. Within the Koppang wolf territory, a summer population of about 700 moose increased to more than 1 100 individuals due to migration in winter. The wolf pack size varied between 2 and 11 wolves. Of 135 radiomarked adult moose observed over 505 observed moose years, only 2 moose were classified as probably killed by wolves. However, many unmarked calves and yearlings were killed. It proved difficult to estimate exactly how many moose the wolves killed based on different indirect study methods on moose. The calf losses also increased with larger wolf packs and lower winter temperatures. The two years with good comparable data, we got inaccurate and varying estimates by the different methods with point estimates ranging from 62–175 moose per year. In our models we used a mean annual predation of 115 moose. This fits well with the yearly loss of 100–130 moose per wolf pack estimated by The Scandinavien wolf project (SKANDULV) by following GPS-marked wolves. Over 8 years, this mean level of predation would probably give a total loss of just below 1000 moose. Our models showed that the moose population would decrease dramatically with this level of predation if traffic accidents and harvest remained constant. Most likely, the predation on moose was even higher in the years when the wolf pack was at its largest and we had the best data. However, predation estimates based on OBSERVED MOOSE during these years were biased by a change in local harvest and hunting practices as a result of the wolf pack presence and the landowners’ interest in not reducing the moose population. Therefore, we based our estimate for these years on helicopter surveys, radiomarked moose and OBSERVED MOOSE from before the change in hunting practice, and estimated a mean predation loss of 160 moose a year within the wolf territory. If predation was this high in every year, the total loss would approach 1300 moose. When the old wolf female disappeared, the new territorial pair used a much larger area, and as a result the losses to wolves inside the old territory at Koppangkjølen were probably lower. A wolf pack hunts prey within its territory boundaries. However, as Koppangkjølen is a wintering area for migrating moose, the wolves could also kill moose that summered outside the territory when they moved into the territory during winter. We observed that the migrating cows lost a larger proportion of their calves in winter than cows resident year-round within the wolf territory. We also observed that the moose behaved slightly differently on supplementary feeding sites inside and outside the wolf territory. This indicates that local moose behavior may be affected by experience of wolf presence. The loss of moose to wolves is probably diluted across a larger area, neighboring the wolf territory because the wolves killed many calves of migrating moose. Furthermore net calf production was lower inside the territory and we suggest there was greater immigration than emigration, especially of young bulls. Our models indicated that the immigration of calf-loosing moose during winter reduced the losses to wolves of the resident moose population considerably. It proved difficult to estimate the loss of moose to wolves from hunter harvest data before and after the wolves established and disappeared. From the harvest data in the wolf territory 5 years before the wolves established, it seems as if the landowners reduced the harvest by 250 moose and that this reduction was sufficient to increase the moose population during the wolf period. However, the moose at Koppangkjølen is managed in 6 different management units with sometimes differing spatial and temporal goals. To determine the real losses during the wolf period, the harvest must be compared to the current goals of each management unit. In Koppang management unit (ca 1/6 of the wolf territory) the land owners reduced the harvest over 8 years by more than 300 moose to achieve their management goal of maintaining the population size. The other management units reduced their harvest by less. As the hunting practice and harvest changed inside the wolf territory, the hunter-based information from OBSERVED MOOSE also changed, most likely biasing the information. Hunter-based statistics on harvest and OBSERVED MOOSE are crude tools that have to be used with care to estimate losses to wolves. From our experience we conclude that moose losses to wolves will best be achieved by intensive studies of GPS-collared predators. As the local moose harvest was reduced, the calf losses to wolves were distributed over a larger area than the wolf territory because of wintering migration, and immigration was greater than emigration, the winter moose population within the wolf territory was not reduced despite many moose being killed by wolves. Thus the browsing pressure on pine plantations was not reduced. Because damage on forest regrowth may be substantial in high moose density areas, when wolves establish in an area we need models to predict when it is economically worth reducing the moose harvest and stabilizing the moose population, or on the contrary, when it will be best to reduce the moose population and invest in forest regeneration. If the mean annual wolf predation was as high as the years we had most wolves and best data, the wolf pack during the 8 year period reduced the income from moose hunting by 13 million NOK and gave a potential loss of 3 million from small game hunting and cabin renting. If so, total losses for the landowners within the wolf territory over 8 years may be close to 16 million NOK, with an annual loss of approximately 2 million NOK compared to the income if the wolves had settled in some other area. To reduce widespread illegal killing, and to achieve sustainable management and higher acceptance of wolves locally, a management strategy for the regional and national authorities could be to (after negotiations) also generously pay the local landowners and municipalities for economic losses other than loss of domestic animals where resident wolves are protected.

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