Magne Neby

• Neby, Magne (2026). A proof of concept for linking individual identity to camera traps. Wildlife Biology. ISSN 0909-6396. doi: 10.1002/wlb3.01733. Full text in Research Archive Show summary

  Small mammal movements are difficult to monitor, both visually and with remote tracking devices, due to the animals' small body size and elusive behavior. Cameras deployed at fixed locations can provide continuous, non‐invasive records in natural habitats, yet camera‐derived indices remain sparsely validated and generally do not allow inference at the individual level. In contrast, capture–recapture regimes can provide abundance estimates and individual‐level measures, e.g. marking the individual animals with passive integrated transponder (PIT)‐tags. By combining camera traps with a fixed RFID (radio frequency identification) reader, more information can be extracted than when the methods are used separately. Bank voles Clethrionomys glareolus , with implanted PIT tags, were successfully identified at the individual level using the RFID‐integrated camera trap; however, some visits were recorded by only one method. These mismatches were most consistent with entrance‐level behaviour and camera‐trigger settings, including partial entries, reversals, and repeated movements during the camera's quiet period. Co‐locating a fixed RFID reader with a camera trap provides a way to reconstruct individual encounter histories while simultaneously recording the broader animal community. The system links PIT‐tag identity to camera detections and makes it possible to describe detection mismatches at the individual level. Used together, the two systems can improve interpretation and quality of camera‐based monitoring data of small mammals.

• Neby, Magne (2025). Intraspecific variation in spruce seed palatability perceived by bank voles. Ecological Research. ISSN 0912-3814. 40(5). doi: 10.1111/1440-1703.12559. Full text in Research Archive Show summary

  Mast seeding in Norway spruce (Picea abies) provides an abundant food source for rodents, such as bank voles (Clethrionomys glareolus). While seed quantity effects are well known, intraspecific variation in seed palatability is not. In this study, I tested whether voles show preferences for spruce seeds from different batches of seeds (sampled from different mast years). In controlled trials, voles did not show significant preferences for seeds from different years, suggesting limited variation in seed characteristics detectable by voles. The results support that variations in the small spruce seeds may be primarily a quantitative burst of food (i.e., during mast seeding) rather than a qualitative variation that influences foraging behavior. Understanding these dynamics contributes to our knowledge of resource-driven rodent ecology and the role of mast seeding on granivore behavior.

• Neby, Magne; Ims, Rolf Anker; Kamenova, Stefaniya Kamenova; Devineau, Olivier & Soininen, Eeva Marjatta (2024). Is the diet cyclic phase-dependent in boreal vole populations? Ecology and Evolution. 14(4). doi: 10.1002/ece3.11227. Full text in Research Archive Show summary

  Herbivorous rodents in boreal, alpine and arctic ecosystems are renowned for their multi-annual population cycles. Researchers have hypothesised that these cycles may result from herbivore–plant interactions in various ways. For instance, if the biomass of preferred food plants is reduced after a peak phase of a cycle, rodent diets can be expected to become dominated by less preferred food plants, leading the population to a crash. It could also be expected that the taxonomic diversity of rodent diets in creases from the peak to the crash phase of a cycle. The present study is the first to use DNA metabarcoding to quantify the diets of two functionally important boreal rodent species (bank vole and tundra vole) to assess whether their diet changed sys tematically in the expected cyclic phase-dependent manner. We found the taxonomic diet spectrum broad in both vole species but with little interspecific overlap. There was no evidence of systematic shifts in diet diversity metrics between the phases of the population cycle in either species. While both species' diet composition changed moderately between cycle phases and seasons, these changes were small compared to other sources of diet variation—especially differences between individuals. Thus, the variation in diet that could be attributed to cyclic phases is marginal relative to the overall diet flexibility. Based on general consumer-resource theory, we suggest that the broad diets with little interspecific overlap render it unlikely that herbivore–plant interactions generate their synchronous population cycles. We propose that deter mining dietary niche width should be the first step in scientific inquiries about the role of herbivore–plant interactions in cyclic vole populations.

• Soininen, Eeva M & Neby, Magne (2023). Small rodent population cycles and plants – after 70 years, where do we go? Biological Reviews. ISSN 1464-7931. p. 1–30. doi: 10.1111/brv.13021. Full text in Research Archive Show summary

  Small rodent population cycles characterise northern ecosystems, and the cause of these cycles has been a long-lasting central topic in ecology, with trophic interactions currently considered the most plausible cause. While some researchers have rejected plant–herbivore interactions as a cause of rodent cycles, others have continued to research their potential roles. Here, we present an overview of whether plants can cause rodent population cycles, dividing this idea into four different hypotheses with different pathways of plant impacts and related assumptions. Our systematic review of the existing literature identified 238 studies from 150 publications. This evidence base covered studies from the temperate biome to the tundra, but the studies were scattered across study systems and only a few specific topics were addressed in a replicated manner. Quantitative effects of rodents on vegetation was the best studied topic, and our evidence base suggests such that such effects may be most pronounced in winter. However, the regrowth of vegetation appears to take place too rapidly to maintain low rodent population densities over several years. The lack of studies prevented assessment of time lags in the qualitative responses of vegetation to rodent herbivory. We conclude that the literature is currently insufficient to discard with confidence any of the four potential hypotheses for plant–rodent cycles discussed herein. While new methods allow analyses of plant quality across more herbivore-relevant spatial scales than previously possible, we argue that the best way forward to rejecting any of the rodent–plant hypotheses is testing specific predictions of dietary variation. Indeed, all identified hypotheses make explicit assumptions on how rodent diet taxonomic composition and quality will change across the cycle. Passing this bottleneck could help pinpoint where, when, and how plant–herbivore interactions have – or do not have – plausible effects on rodent population dynamics.

• Neby, Magne; Andreassen, Harry Peter; Milleret, Cyril Pierre; Pedersen, Simen; Tamayo, Ana-Maria Peris & Sanchez, David Carricondo [Show all 8 contributors for this article] (2023). Small rodent monitoring at Birkebeiner Road, Norway. Biodiversity Data Journal. ISSN 1314-2836. 11. doi: 10.3897/BDJ.11.E105914. Full text in Research Archive Show summary

  Northern small mammal populations are renowned for their multi-annual population cycles. Population cycles are multi-faceted and have extensive impacts on the rest of the ecosystem. In 2011, we started a student-based research activity to monitor the variation of small rodent density along an elevation gradient following the Birkebeiner Road, in southeast Norway. Fieldwork was conducted by staff and students at the University campus Evenstad, Inland Norway University of Applied Sciences, which has a long history of researching cyclic population dynamics. The faculty has a strong focus on engaging students in all parts of the research activities, including data collection. Small rodents were monitored using a set of snap trap stations. Trapped animals were measured (e.g. body mass, body length, sex) and dissected to assess their reproductive status. We also characterised the vegetation at trapping sites.

• Sousa, Kaue de; Etten, Jacob van; Neby, Magne & Solberg, Svein Øivind (2023). Climate variability indices for ecological and crop models in R: the climatrends package. Journal of Open Source Software (JOSS). 8(85), p. 1–13. doi: 10.21105/joss.04405. Full text in Research Archive Show summary

  Abiotic factors play an important role in most ecological and crop systems that depend on certain levels of temperature, light and precipitation to initiate important physiological events (Schulze et al., 2019). Understanding how these factors drive the physiological processes is a key approach to provide recommendations for adaptation and biodiversity conservation in applied ecology studies. The package climatrends aims to provide the methods in R (R Core Team, 2020) to compute precipitation and temperature indices that serve as input for climate and crop models (Kehel et al., 2016; van Etten et al., 2019), trends in climate change (Aguilar et al., 2005; de Sousa et al., 2018) and applied ecology (Liu & El-Kassaby, 2018; Prentice et al., 1992).

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• Neby, Magne & Refseth, Per (2025). Millionene som gjør norsk forskning og publisering bedre. Full text in Research Archive
• Neby, Magne (2025). Forskere spiller lotto med skattepengene. Full text in Research Archive
• Neby, Magne & Jørstad, Torbjørn (2024). Frykter ulykker. [Journal]. Hamar Arbeiderblad. Full text in Research Archive
• Neby, Magne & Landgraff, Knut Erik (2024). Vi er på vei inn i et museår. [Journal]. Ringasker Bladet (papir, nett). Full text in Research Archive
• Neby, Magne (2024). High-intensive Monitoring of Subnivean Secrets. Full text in Research Archive
• Neby, Magne (2023). Small mammal population dynamics and research. Full text in Research Archive
• Neby, Magne & Ringlund, Ole Martin (2023). Dette skrev vi om på forskning.no i 2022. [Internet]. INN Nyhetssaker. Full text in Research Archive
• Neby, Magne (2023). Vi ser på celler. Full text in Research Archive
• Neby, Magne (2023). Small mammals in field experiments. Full text in Research Archive
• Neby, Magne (2022). eDNA: What is it and how can we use it for disease surveillance? Full text in Research Archive
• Neby, Magne & Ringlund, Ole Martin (2022). Blir det lite eller mye mus i år? [Internet]. Forskning.no. Full text in Research Archive
• Neby, Magne & Ringlund, Ole Martin (2022). Blir det lite eller mye mus i år? [Internet]. INN Nyhetssaker. Full text in Research Archive
• Neby, Magne (2022). Vole cycle research at HINN. Full text in Research Archive
• Neby, Magne (2022). The role of diet in vole population cycles. Universitetet i Innlandet. ISSN 9788283803334. Full text in Research Archive Show summary

  Smågnagerpopulasjoner med store bestandssvingninger finner vi over hele verden. I denne avhandlingen har jeg inkludert en litteraturstudie om både regelmessige sykluser og mer uregelmessige utbrudd i smågnagerpopulasjoner og som peker på de viktigste problemstillingene å svare på for videre forståelse (Paper I). Smågnagere i boreale, alpine og arktiske økosystem er særlig kjent for sine sykliske populasjonsendringer, hvor både sesongvariasjon og/eller endringer i mattilgang er viktige faktorer. I et observasjonsstudium i de boreale skogene på Evenstad, fant vi en klar sammenheng mellom høyde over havet og hvor mye smågnagere det var i museårene. Smågnagerpopulasjonen hadde et syklisk forløp over hele høydegradienten, men syklusen var tydeligst høyt oppe i liene der det var mer mus i toppåret enn det var nede i dalene og bekreftet slik den viktige rollen vintersesongen spiller (Paper II). En tydelig tetthetsavhengighet om vinteren er forventet ved begrensede ressurser. En systematisk gjennomgang av litteraturen om forholdet mellom smågnagere og planter (Paper III) viste at begrenset mattilgang kan påvirke smågnagernes populasjonstetthet, og at det var best støtte for dette om vinteren. Det var derimot ikke mulig å hverken bekrefte eller avkrefte noen «plantehypothese» på grunn av for få studier med like respons- og forklaringsvariabler. Begge litteraturstudiene (Paper I og Paper III) poengterer viktigheten av at fremtidige studier utforsker videre om det forekommer systematiske endringer i dietten til smågnagerne som kan påvirke deres populasjonsdynamikk. Jeg har forsøkt å belyse nettopp dette ved å ta i bruk DNA-strekkoding (metabarcoding) for å analysere om diettens komposisjon eller diversitet endrer seg systematisk i forhold til sesong og syklusens faser (Paper V). DNA-strekkoding kan dog ikke forventes å reflektere relative proporsjoner av matinntaket nøyaktig (Paper IV). Diettstudien fant stor fleksibilitet i dietten, noe som støtter opp under at det forekommer moderate endringer mellom sesong og faser hos både klatremus Myodes glareolus og fjellmarkmus Microtus oeconomus. Men diettvariasjonen som kan tilskrives syklusenes faser var relativt marginal i forhold til den generelle fleksibiliteten i dietten. Det virker derfor ikke sannsynlig at fasenes diettvariasjon er tilstrekkelig for å drive smågnagerpopulasjonenes særegne dynamikk.

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