Atle Mysterud

• Belsare, Aniruddha V.; Millspaugh, Joshua J.; Mason, J.Russ; Sumners, Jason; Viljugrein, Hildegunn & Mysterud, Atle (2021). Getting in front of chronic wasting disease: Model-informed proactive approach for managing an emerging wildlife disease. Frontiers in Veterinary Science.  ISSN 2297-1769.  7:608235, s 1- 6 . doi: 10.3389/fvets.2020.608235
• Mysterud, Atle; Viljugrein, Hildegunn; Rolandsen, Christer Moe & Belsare, Aniruddha V. (2021). Harvest strategies for the elimination of low prevalence wildlife diseases. Royal Society Open Science.  ISSN 2054-5703.  8 . doi: 10.1098/rsos.210124 Vis sammendrag

  The intensive harvesting of hosts is often the only practicable strategy for controlling emerging wildlife diseases. Several harvesting approaches have been explored theoretically with the objective of lowering transmission rates, decreasing the transmission period or specifically targeting spatial disease clusters or high-risk demographic groups. Here, we present a novel model-based approach to evaluate alternative harvest regimes, in terms of demographic composition and rates, intended to increase the probability to remove all infected individuals in the population during the early phase of an outbreak. We tested the utility of the method for the elimination of chronic wasting disease based on empirical data for reindeer (Rangifer tarandus) in Norway, in populations with (Nordfjella) and without (Hardangervidda) knowledge about exact disease prevalence and population abundance. Low and medium harvest intensities were unsuccessful in eliminating the disease, even at low prevalence. High-intensity harvesting had a high likelihood of eliminating the disease, but probability was strongly influenced by the disease prevalence. We suggest that the uncertainty about disease prevalence can be mitigated by using an adaptive management approach: forecast from models after each harvest season with updated data, derive prevalence estimates and forecast further harvesting. We identified the problems arising from disease surveillance with large fluctuations in harvesting pressure and hence sample sizes. The elimination method may be suitable for pathogens that cause long-lasting infections and with slow epidemic growth, but the method should only be attempted if there is a low risk ofreinfection, either by a new disease introduction event (e.g. dispersing hosts) or due to environmental reservoirs. Our simulations highlighted the short time window when such a strategy is likely to be successful before approaching near complete eradication of the population.

• Ytrehus, Bjørnar; Asmyhr, Maria Gulbrandsen; Hansen, Helge; Nilsen, Erlend Birkeland; Mysterud, Atle; Strand, Olav; Tranulis, Michael A.; Våge, Jørn; Kapperud, Georg; Madslien, Knut Ivar Engesæter; Rueness, Eli Knispel & Wasteson, Yngvild (2021). Handlingsrommet etter påvisning av skrantesyke (Chronic Wasting Disease, CWD) på Hardangervidda – grunnlag for fremtidige forvaltningsstrategier. Vitenskapelig uttalelse fra Vitenskapskomiteen for Mat og Miljø (VKM).. VKM Report.  ISSN 2535-4019.  2021(1), s 1- 122
• Aikens, Ellen O.; Mysterud, Atle; Merkle, Jerod A.; Cagnacci, Francesca; Rivrud, Inger Maren; Hebblewhite, Mark; Hurley, Mark A.; Peters, Wibke Erika Brigitta; Bergen, Scott; De Groeve, Johannes; Dwinnell, Samantha P.H.; Gehr, Benedikt; Heurich, Marco; Hewison, A.J. Mark; Jarnemo, Anders; Kjellander, Petter; Kröschel, Max; Licoppe, Alain; Linnell, John Durrus; Merrill, Evelyn H.; Middleton, Arthur D.; Morellet, Nicolas; Neufeld, Lalenia; Ortega, Anna C.; Parker, Katherine L.; Pedrotti, Luca; Proffitt, Kelly M.; Saïd, Sonia; Sawyer, Hall; Scurlock, Brandon M.; Signer, Johannes; Stent, Patrick; Sustr, Pavel; Szkorupa, Tara; Monteith, Kevin L. & Kauffman, Matthew J. (2020). Wave-like patterns of plant phenology determine ungulate movement tactics. Current Biology.  ISSN 0960-9822.  30(17), s 3444- 3449 . doi: 10.1016/j.cub.2020.06.032 Fulltekst i vitenarkiv. Vis sammendrag

  Animals exhibit a diversity of movement tactics [1]. Tracking resources that change across space and time is predicted to be a fundamental driver of animal movement [2]. For example, some migratory ungulates (i.e., hooved mammals) closely track the progression of highly nutritious plant green-up, a phenomenon called ‘‘green-wave surfing’’ [3–5]. Yet general principles describing how the dynamic nature of resources determine movement tactics are lacking [6]. We tested an emerging theory that predicts surfing and the existence of migratory behavior will be favored in environments where green-up is fleeting and moves sequentially across large landscapes (i.e., wave-like green-up) [7]. Landscapes exhibiting wave-like patterns of greenup facilitated surfing and explained the existence of migratory behavior across 61 populations of four ungulate species on two continents (n = 1,696 individuals). At the species level, foraging benefits were equivalent between tactics, suggesting that each movement tactic is fine-tuned to local patterns of plant phenology. For decades, ecologists have sought to understand how animals move to select habitat, commonly defining habitat as a set of static patches [8, 9]. Our findings indicate that animal movement tactics emerge as a function of the flux of resources across space and time, underscoring the need to redefine habitat to include its dynamic attributes. As global habitats continue to be modified by anthropogenic disturbance and climate change [10], our synthesis provides a generalizable framework to understand how animal movement will be influenced by altered patterns of resource phenology.

• Johansson, Maria; Mysterud, Atle & Flykt, Anders (2020). Livestock owners’ worry and fear of tick‑borne diseases. Parasites & Vectors.  ISSN 1756-3305.  13(331) . doi: 10.1186/s13071-020-04162-7 Fulltekst i vitenarkiv.
• Loe, Leif Egil; Liston, Glen E.; Pigeon, Gabriel; Barker, Kristin; Horvitz, Nir; Stien, Audun; Forchhammer, Mads C.; Getz, Wayne M.; Irvine, Robert Justin; Lee, Aline Magdalena; Movik, Lars K.; Mysterud, Atle; Pedersen, Åshild Ønvik; Reinking, Adele K.; Ropstad, Erik; Trondrud, Liv Monica; Tveraa, Torkild; Veiberg, Vebjørn; Hansen, Brage Bremset & Albon, Steve D. (2020). The neglected season: Warmer autumns counteract harsher winters and promote population growth in Arctic reindeer. Global Change Biology.  ISSN 1354-1013.  27(5), s 993- 1002 . doi: 10.1111/gcb.15458 Fulltekst i vitenarkiv. Vis sammendrag

  Arctic ungulates are experiencing the most rapid climate warming on Earth. While concerns have been raised that more frequent icing events may cause die-offs, and earlier springs may generate a trophic mismatch in phenology, the effects of warming autumns have been largely neglected. We used 25 years of individual-based data from a growing population of wild Svalbard reindeer, to test how warmer autumns enhance population growth. Delayed plant senescence had no effect, but a six-week delay in snow-onset (the observed data range) was estimated to increase late winter body mass by 10%. Because average late winter body mass explains 90% of the variation in population growth rates, such a delay in winter-onset would enable a population growth of r = 0.20, sufficient to counteract all but the most extreme icing events. This study provides novel mechanistic insights into the consequences of climate change for Arctic herbivores, highlighting the positive impact of warming autumns on population viability, offsetting the impacts of harsher winters. Thus, the future for Arctic herbivores facing climate change may be brighter than the prevailing view. body mass, climate change, fitness, GPS, movement ecology, plant phenology, Rangifer, snow, space use, ungulates

• Madslien, Knut Ivar Engesæter; Stubsjøen, Solveig Marie; Viljugrein, Hildegunn; Ytrehus, Bjørnar; Solberg, Erling Johan; Kapronczai, Luciene; Mysterud, Atle; Godfroid, Jacques; Janz, David M. & Cattet, Marc (2020). Hair cortisol concentration and body mass in moose (Alces alces) infested with deer keds (Lipoptena cervi). Journal of Wildlife Diseases.  ISSN 0090-3558.  56(3), s 687- 692 . doi: 10.7589/2019-07-185
• Mysterud, Atle; Benestad, Sylvie L.; Rolandsen, Christer Moe & Våge, Jørn (2020). Policy implications of an expanded chronic wasting disease universe. Journal of Applied Ecology.  ISSN 0021-8901.  s 1- 5 . doi: 10.1111/1365-2664.13783 Vis sammendrag

  1. International policy for the management of wildlife disease(s) plays an important role for concerted action, and changes to policy should be evidence-based and updated as new evidence accumulates. Management of chronic wasting disease (CWD), the prion disease affecting cervids, is based on its highly contagious nature relative to most other prion diseases. These management actions are particularly invasive, with considerable biological and economic consequences. 2. A novel type of CWD has been discovered in moose Alces alces and red deer Cervus elaphus, with prions restricted to the central nervous system (CNS). Prions in tissue outside the CNS are an indication of the contagiousness of a prion disease. As such, for this novel type of CWD, there is a lower likelihood of horizontal transmission under natural conditions. Furthermore, infected individuals were older (mean 15 years), and cases appeared with limited clustering in space and time; hence, with no indication of an epidemic outbreak. 3. Policy implications. The annual harvest of approximately 4 million cervids in Europe each year generates considerable cultural and economic value. ‘Stamping out’ policies would be inefficient and inappropriate to control diseases with no horizontal transmission among live animals, and banning the export of meat from a region after detection of a positively tested animal would make little sense in the case of sporadic disease. The novel type of chronic wasting disease (CWD) with epidemiological characteristics clearly different from ‘classical’ and contagious CWD calls for differentiated management strategies to avoid unnecessarily invasive actions. cervids, chronic wasting disease, disease management, EU-policy, moose, red deer, sporadic prion disease, TSE regulation

• Mysterud, Atle; Hopp, Petter; Alvseike, Kristin Ruud; Benestad, Sylvie L.; Nilsen, Erlend Birkeland; Rolandsen, Christer Moe; Strand, Olav; Våge, Jørn & Viljugrein, Hildegunn (2020). Hunting strategies to increase detection of chronic wasting disease in cervids. Nature Communications.  ISSN 2041-1723.  11, s 1- 11 . doi: 10.1038/s41467-020-18229-7 Fulltekst i vitenarkiv. Vis sammendrag

  The successful mitigation of emerging wildlife diseases may involve controversial host culling. For livestock, ‘preemptive host culling’ is an accepted practice involving the removal of herds with known contact to infected populations. When applied to wildlife, this proactive approach comes in conflict with biodiversity conservation goals. Here, we present an alternative approach of ‘proactive hunting surveillance’ with the aim of early disease detection that simultaneously avoids undesirable population decline by targeting demographic groups with (1) a higher likelihood of being infected and (2) a lower reproductive value. We applied this harvesting principle to populations of reindeer to substantiate freedom of chronic wasting disease (CWD) infection. Proactive hunting surveillance reached 99% probability of freedom from infection (<4 reindeer infected) within 3–5 years, in comparison to ~10 years using ordinary harvest surveillance. However, implementation uncertainties linked to social issues appear challenging also with this kind of host culling

• Mysterud, Atle; Rauset, Geir Rune; Van Moorter, Bram; Andersen, Roy; Strand, Olav & Rivrud, Inger Maren (2020). The last moves: The effect of hunting and culling on the risk of disease spread from a population of reindeer. Journal of Applied Ecology.  ISSN 0021-8901.  57, s 2509- 2518 . doi: 10.1111/1365-2664.13761 Fulltekst i vitenarkiv. Vis sammendrag

  1. Hunting and culling are frequently used to combat infectious wildlife diseases. The aim is to markedly lower population density in order to limit disease transmission or to eradicate the host. Massive host culling can yield a trade-off when combating wildlife disease; it follows that intrusive actions may have unintended behavioural side effects, leading to the geographic spread of disease. The manner in which such excessive hunting and culling of hosts can affect the movement and dispersion of cervids has not been studied. 2. In this study, we quantified the behaviour (daily movements and habitat use) and dispersion of GPS-marked reindeer (n = 24) before and during the eradication of an entire population (>2,000 reindeer) infected with chronic wasting disease (CWD) in Norway. We compared behaviour and dispersion during 10 ordinary hunting seasons (2007–2016), an extended hunting season (2017) and marksmen culling (2017/2018). 3. Seasonality had a major impact on movements. Reindeer movements during the early hunting season (20 August–20 September) did not increase the overall movements compared to that in the pre-hunt season (20 July–19 August), while extended hunting into October (as in 2017) and marksmen culling from November to February markedly increased daytime movements relative to that normally observed in this time of the year. Towards the end of the eradication, the remaining reindeer sought refuge at restricted high-elevation areas with limited forage production. Reindeer used novel areas towards the perimeter of the range, but active herding during culling stopped one herd from leaving the CWD zone. 4. Synthesis and applications. With emerging wildlife diseases, host culling is becoming a more frequently used tool for managers in Europe. Our study highlights the potential trade-off between combating disease transmission within a population and the risk of geographic spread. Such insight is important to design mitigation measures, such as perimeter fencing or herding, to avoid the risk of the geographic spread of disease in cases of severe and economically important wildlife diseases. cervids, chronic wasting disease, disease ecology, disease management, host culling, movement ecology, spatial organization, unintended side effects

• Mysterud, Atle; Rivrud, Inger Maren; Gundersen, Vegard; Rolandsen, Christer Moe & Viljugrein, Hildegunn (2020). The unique spatial ecology of human hunters. Nature Human Behaviour.  ISSN 2397-3374.  4, s 694- 701 . doi: 10.1038/s41562-020-0836-7 Fulltekst i vitenarkiv.
• Mysterud, Atle; Strand, Olav & Rolandsen, Christer Moe (2020). Embracing fragmentation to save reindeer from disease. Conservation Science and Practice (CSP).  ISSN 2578-4854.  2, s 1- 4 . doi: 10.1111/csp2.244 Fulltekst i vitenarkiv. Vis sammendrag

  Space demanding mammalian species, such as reindeer, are in decline worldwide due to habitat loss and fragmentation. Policy to restore connectivity of reindeer habitat is now put to an abrupt halt in several areas because of an outbreak of Chronic Wasting Disease in Norway, and replaced with deliberate fragmentation of the landscape by enhancing barrier effects of linear structures.

• Mysterud, Atle; Ytrehus, Bjørnar; Tranulis, Michael A.; Rauset, Geir Rune; Rolandsen, Christer Moe & Strand, Olav (2020). Antler cannibalism in reindeer. Scientific Reports.  ISSN 2045-2322.  10, s 1- 7 . doi: 10.1038/s41598-020-79050-2 Fulltekst i vitenarkiv. Vis sammendrag

  Prion diseases constitute a class of invariably fatal and degenerative encephalopathies. Chronic Wasting Disease (CWD) is a contagious prion disease among cervids, which is spreading and causing marked population declines in USA and Canada. The first outbreak of CWD in Europe was discovered in a reindeer population in Norway in 2016. In the worst-case scenario with continental-wide spreading of CWD in Eurasia, an annual harvest of around 4 million cervids is at stake only in Europe, with huge economic and cultural significance. An in situ origin of CWD was suspected, and it appear urgent to identify the likely cause to prevent future emergences. Here, we document the novel phenomenon of extensive antler cannibalism prior to shedding among reindeer in the CWD-infected population. The extent of antler cannibalism increased over the last decades when CWD emerged, and included ingestion of vascularized antlers. Ingestion of tissues from conspecifics is a risk factor for the emergence of prion diseases, where the presence of extensive antler cannibalism opens the intriguing possibility of a ‘Kuru-analogue’ origin of CWD among the reindeer in Europe. Based on general insight on pathology of prion diseases and strain selection processes, we propose an hypothesis for how contagious CWD may emerge from sporadic CWD under the unique epidemiological conditions we document here. More research is required to document the presence of prions in reindeer antlers, and whether antler cannibalism actually led to a strain selection process and the emergence of a contagious form of CWD from a sporadic form of CWD.

• Van Moorter, Bram; Engen, Steinar; Fryxell, John M.; Panzacchi, Manuela; Nilsen, Erlend Birkeland & Mysterud, Atle (2020). Consequences of barriers and changing seasonality on population dynamics and harvest of migratory ungulates. Theoretical Ecology.  ISSN 1874-1738.  13, s 595- 605 . doi: 10.1007/s12080-020-00471-w Fulltekst i vitenarkiv.
• De Groeve, Johannes; Cagnacci, Francesca; Ranc, Nathan; Bonnot, Nadège C.; Gehr, Benedikt; Heurich, Marco; Hewison, A.J. Mark; Kroeschel, Max; Linnell, John Durrus; Morellet, Nicolas; Mysterud, Atle; Sandfort, Robin & Van De Weghe, Nico (2019). Individual Movement - Sequence Analysis Method (IM-SAM): characterizing spatio-temporal patterns of animal habitat use across landscapes. International Journal of Geographical Information Science (IJGIS).  ISSN 1365-8816.  s 1- 23 . doi: 10.1080/13658816.2019.1594822 Fulltekst i vitenarkiv. Vis sammendrag

  We present methodological advances to a recently developed framework to study sequential habitat use by animals using a visually-explicit and tree-based Sequence Analysis Method (SAM), derived from molecular biology and more recently used in time geography. Habitat use sequences are expressed as annotations obtained by intersecting GPS movement trajectories with environmental layers. Here, we develop IM-SAM, where we use the individual reference area of use as the reference spatial context. To assess IM-SAM’s applicability, we investigated the sequential use of open and closed habitats across multiple European roe deer populations ranging in landscapes with contrasting structure. Starting from simulated sequences based on a mechanistic movement model, we found that different sequential patterns of habitat use were distinguished as separate, robust clusters, with less variable cluster size when habitats were present in equal proportions within the individual reference area of use. Application on real roe deer sequences showed that our approach effectively captured variation in spatio-temporal patterns of sequential habitat use, and provided evidence for important behavioral processes, such as day-night habitat alternation. By characterizing sequential habitat use patterns of animals, we may better evaluate the temporal trade-offs in animal habitat use and how they are affected by changes in landscapes. Sequence dissimilarity; dendrogram; ungulates; spatio-temporal habitat use; mechanistic movement model

• Debeffe, Lucie Isabelle; Rivrud, Inger Maren; Meisingset, Erling L. & Mysterud, Atle (2019). Sex-specific differences in spring and autumn migration in a northern large herbivore. Scientific Reports.  ISSN 2045-2322.  9, s 1- 11 . doi: 10.1038/s41598-019-42639-3 Fulltekst i vitenarkiv. Vis sammendrag

  Ongoing global warming is now affecting migratory cycles in a large variety of taxa in seasonally variable environments. Disruption of migratory systems can cause population decline and affect ecosystem function across the globe. It is therefore urgent to understand the drivers of migration and how the different fitness limitations of the sexes affect migration, but studies seldom considered the full annual cycle. We analysed the annual migration cycle of 237 red deer (Cervus elaphus) in Norway and investigate how different seasonal limitations affected the variation in a suite of migration characteristics. We found fundamental differences in migration phenology between seasons, and migratory traits were much more variable in males. Spring migratory movements were characterized by longer distance roamed, lower speed, lasted longer, more frequent use of stopovers, timing was more synchronized and coincided with onset of plant growth, and with higher daily activity levels. Timing of autumn migration was more variable and not closely related to cease of plant growth. Our study emphasizes the benefits of studying the full annual cycle to gain further insight into the migration process, and how understanding the limitations of the full annual migration process of both sexes is critical for conservation purposes.

• Hagge, Jonas; Müller, Jörg; Bässler, Claus; Biebl, Samantha Susanne; Brandl, Roland; Drexler, Matthias; Gruppe, Axel; Hotes, Stefan; Hothorn, Torsten; Langhammer, Peter; Stark, Hans; Wirtz, Roland; Zimmerer, Veronika & Mysterud, Atle (2019). Deadwood retention in forests lowers short-term browsing pressure on silver fir saplings by overabundant deer. Forest Ecology and Management.  ISSN 0378-1127.  451, s 1- 7 . doi: 10.1016/j.foreco.2019.117531 Fulltekst i vitenarkiv.
• Hofman, M. P. G.; Hayward, M.W.; Heim, Morten; Marchand, P.; Rolandsen, Christer Moe; Mattisson, Jenny; Urbano, F.; Heurich, M.; Mysterud, Atle; Melzheimer, J.; Morellet, N.; Voigt, U.; Allen, B.L.; Gehr, B.; Rouco, C.; Ullmann, W.; Holand, Øystein; Jørgensen, Nicolai Hermann; Steinheim, Geir; Cagnacci, F.; Kroeschel, M.; Kaczensky, Petra; Buuveibaatar, B.; Payne, J.C.; Palmegiani, I.; Jerina, K.; Kjellander, P.; Johansson, Ö.; LaPoint, S.; Bayrakcismith, R.; Linnell, John Durrus; Zaccaroni, M.; Jorge, M.L.S.; Oshima, J.E.F.; Songhurst, A.; Fischer, C.; Mc Bride Jr., R.T.; Thompson, J.J.; Streif, S.; Sandfort, R.; Bonenfant, Christophe; Drouilly, M.; Klapproth, M.; Zinner, D.; Yarnell, R.; Stronza, A.; Wilmott, L.; Meisingset, Erling L.; Thaker, M.; Vanak, A.T.; Nicoloso, S.; Graeber, R.; Saïd, S.; Boudreau, M.R.; Devlin, A.; Hoogesteijn, R.; May-Junior, J.A.; Nifong, J.C.; Odden, John; Quigley, H.B.; Tortato, F.; Parker, D.M.; Caso, A.; Perrine, J.; Tellaeche, C.; Zieba, F.; Zwijacz-Kozica, T.; Appel, C.L.; Axsom, I.; Bean, W.T.; Cristescu, B.; Périquet, S.; Teichman, K.J.; Karpanty, S.; Licoppe, A.; Menges, V.; Black, K.; Scheppers, T.L.; Schai-Braun, S.C.; Azevedo, F. C.; Lemos, F.G.; Payne, A.; Swanepoel, L.H.; Weckworth, B.V.; Berger, A.; Bertassoni, A.; McCulloch, G.; Šustr, P.; Athreya, V.; Bockmuhl, D.; Casaer, J.; Ekori, A.; Melovski, D.; Richard-Hansen, C.; van de Vyver, D.; Reyna-Hurtado, R.; Robardet, E.; Selva, N.; Sergiel, A.; Farhadinia, M.S.; Sunde, P.; Portas, R.; Ambarli, H.; Berzins, R.; Kappeler, P.M.; Mann, G.K.; Pyritz, L.; Bissett, C.; Grant, T.; Steinmetz, R.; Swedell, L.; Welch, R.J.; Armenteras, D.; Bidder, O.R.; González, T.M.; Rosenblatt, A.; Kachel, S. & Balkenhol, N. (2019). Right on track? Performance of satellite telemetry in terrestrial wildlife research. PLOS ONE.  ISSN 1932-6203.  14:e0216223(5), s 1- 26 . doi: 10.1371/journal.pone.0216223 Fulltekst i vitenarkiv. Vis sammendrag

  Satellite telemetry is an increasingly utilized technology in wildlife research, and current devices can track individual animal movements at unprecedented spatial and temporal resolutions. However, as we enter the golden age of satellite telemetry, we need an in-Depth understanding of the main technological, species-specific and environmental factors that determine the success and failure of satellite tracking devices across species and habitats. Here, we assess the relative influence of such factors on the ability of satellite telemetry units to provide the expected amount and quality of data by analyzing data from over 3,000 devices deployed on 62 terrestrial species in 167 projects worldwide. We evaluate the success rate in obtaining GPS fixes as well as in transferring these fixes to the user and we evaluate failure rates. Average fix success and data transfer rates were high and were generally better predicted by species and unit characteristics, while environmental characteristics influenced the variability of performance. However, 48% of the unit deployments ended prematurely, half of them due to technical failure. Nonetheless, this study shows that the performance of satellite telemetry applications has shown improvements over time, and based on our findings, we provide further recommendations for both users and manufacturers.

• Jaarsma, Ryanne I.; Sprong, Hein; Takumi, Katsuhisa; Kazimirova, Maria; Silaghi, Cornelia; Mysterud, Atle; Rudolf, Ivo; Beck, Relja; Foldvari, Gabor; Tomassone, Laura; Groenvelt, Margit; Everts, Reinard R.; Rijks, Jolianne M.; Ecke, Frauke; Hörnfeldt, Birger; Modrý, David; Majerová, Karolina; Votýpka, Jan & Estrada-Peña, Agustin (2019). Anaplasma phagocytophilum evolves in geographical and biotic niches of vertebrates and ticks. Parasites & Vectors.  ISSN 1756-3305.  12, s 1- 17 . doi: 10.1186/s13071-019-3583-8 Fulltekst i vitenarkiv.
• Loe, Leif Egil; Pigeon, Gabriel; Albon, Steve D.; Giske, Pernille Andrine Eriksdatter; Irvine, R. Justin; Ropstad, Erik; Stien, Audun; Veiberg, Vebjørn & Mysterud, Atle (2019). Antler growth as a cost of reproduction in female reindeer. Oecologia.  ISSN 0029-8549.  189(3), s 601- 609 . doi: 10.1007/s00442-019-04347-7 Fulltekst i vitenarkiv. Vis sammendrag

  The costs of reproduction are important in shaping individual life histories, and hence population dynamics, but the mechanistic pathways of such costs are often unknown. Female reindeer have evolved antlers possibly due to interference competition on winter-feeding grounds. Here, we investigate if variation in antler size explains part of the cost of reproduction in late winter mass of female reindeer. We captured 440 individual Svalbard reindeer a total of 1426 times over 16 years and measured antler size and body mass in late winter, while presence of a ‘calf-at-heel’ was observed in summer. We found that reproductive females grew smaller antlers and weighed 4.3 kg less than non-reproductive females. Path analyses revealed that 14% of this cost of reproduction in body mass was caused by the reduced antler size. Our study is therefore consistent with the hypothesis that antlers in female Rangifer have evolved due to interference competition and provides evidence for antler growth as a cost of reproduction in females. Antler growth was constrained more by life history events than by variation in the environment, which contrasts markedly with studies on male antlers and horns, and hence increases our understanding of constraints on ornamentation and life history trade-offs.

• Mysterud, Atle; Bleka, Øyvind; Nielsen, Anders; Steinheim, Geir; Yoccoz, Nigel Gilles & Storvik, Geir Olve (2019). Climate and synchrony of lamb body mass, In Jon Olaf Olaussen (ed.),  Contributions in natural resource economics. Festschrift to Anders Skonhoft.  Fagbokforlaget.  ISBN 9788245024715.  9.  s 183 - 197
• Mysterud, Atle & Edmunds, David R. (2019). A review of chronic wasting disease in North America with implications for Europe. European Journal of Wildlife Research.  ISSN 1612-4642.  65(26), s 1- 13 . doi: 10.1007/s10344-019-1260-z Fulltekst i vitenarkiv.
• Mysterud, Atle; Heylen, Dieter J. A.; Matthysen, Erik; Garcia, Aïda Lopez; Jore, Solveig & Viljugrein, Hildegunn (2019). Lyme neuroborreliosis and bird populations in northern Europe. Proceedings of the Royal Society of London. Biological Sciences.  ISSN 0962-8452.  286(1903), s 1- 10 . doi: 10.1098/rspb.2019.0759 Fulltekst i vitenarkiv.
• Mysterud, Atle; Madslien, Knut Ivar Engesæter; Viljugrein, Hildegunn; Vikøren, Turid; Andersen, Roy; Guere Calderon, Mariella Evelyn; Benestad, Sylvie Lafond; Hopp, Petter; Strand, Olav; Ytrehus, Bjørnar; Røed, Knut; Rolandsen, Christer Moe & Våge, Jørn (2019). The demographic pattern of infection with chronic wasting disease in reindeer at an early epidemic stage. Ecosphere.  ISSN 2150-8925.  10(11), s 1- 11 . doi: 10.1002/ecs2.2931 Fulltekst i vitenarkiv. Vis sammendrag

  Infection patterns linked to age and sex are crucial to predict the population dynamic effects of diseases in long-lived species. How such demographic patterns of infection arise is often multifactorial, although the cause is commonly seen as a combination of immune status as well as variation in pathogen exposure. Prion diseases are particularly interesting, as they do not trigger an adaptive immune response; hence, differences in pathogen exposure linked to behavior could be the prime determinant of the pattern of infection. In cervids, the fatal prion disease, chronic wasting disease (CWD), is spreading geographically, with economic and cultural consequences in affected areas in North America, and all infected individuals eventually die from disease-associated sequelae if they live long enough. Understanding the causes of the demographic pattern of infection with CWD is therefore urgent but is limited by the fact that reported data primarily come from related deer species in North America. The recent (detected 2016) emergence of CWD among wild alpine reindeer (Rangifer tarandus) in Norway with a different social organization, that is, no home range behavior and no matrilineal female groups, offers an opportunity to advance our understanding of how behavior influences the infection patterns. Testing of 1081 males and 1278 females detected 19 animals positive for abnormal prion protein in brain and/or lymphatic tissues. No calves and only one male yearling were infected, with the remaining positives being adults (representing 1.5% of adult males and 0.5% of adult females). We found a strong sex-biased infection pattern in reindeer (with infection 2.7 times more likely in adult males), which is similar to the results reported in mule deer and white-tailed deer. The hazard of being detected as positive increased with age in males. There was no close genetic relatedness among positive animals. The results were consistent with the within-group contact of males being a possible major route of transmission. We discuss the demographic pattern of infection with CWD in view of the lack of stable home range behavior and other key behavioral traits of reindeer relevant to understanding pathogen exposure in general. irect contact; disease ecology; environmental reservoirs; pathogen exposure; population dynamics; prions; social organization; transmission.

• Mysterud, Atle; Stigum, Vetle Malmer; Jaarsma, Ryanne I. & Sprong, Hein (2019). Genospecies of Borrelia burgdorferi sensu lato detected in 16 mammal species and questing ticks from northern Europe. Scientific Reports.  ISSN 2045-2322.  9, s 1- 8 . doi: 10.1038/s41598-019-41686-0 Fulltekst i vitenarkiv.
• Mysterud, Atle; Stigum, Vetle Malmer; Linløkken, Harald Kolstad; Herland, Anders & Viljugrein, Hildegunn (2019). How general are generalist parasites? The small mammal part of the Lyme disease transmission cycle in two ecosystems in northern Europe. Oecologia.  ISSN 0029-8549.  190(1), s 115- 126 . doi: 10.1007/s00442-019-04411-2 Fulltekst i vitenarkiv.
• Mysterud, Atle; Strand, Olav & Rolandsen, Christer Moe (2019). Efficacy of Recreational Hunters and Marksmen for Host Culling to Combat Chronic Wasting Disease in Reindeer. Wildlife Society Bulletin (WSB).  ISSN 0091-7648.  43(4), s 683- 692 . doi: 10.1002/wsb.1024 Fulltekst i vitenarkiv. Vis sammendrag

  Most populations of large mammals in developed countries are managed by human hunting, but there are surprisingly few empirical studies about the benefits and limitations of using recreational hunters to achieve specific management objectives. In particular, the extensive host culling required to markedly reduce population densities to combat some wildlife diseases may conflict with the management aims of landowners and hunters. This is particularly acute in the case of chronic wasting disease (CWD) in cervids, which has now emerged in reindeer (Rangifer tarandus) in Norway. We analyzed the relative efficacy of approximately 1,000 recreational hunters and 30 professional marksmen during the eradication of the entire CWD‐infected population of >2,000 reindeer in Norway. The government changed a series of legislation that would normally limit the efficacy of recreational hunters; these changes were linked to the duration of the hunting season, the specificity and size of the quotas, and spatial access rights. Efforts were taken to reduce both the searching time (hunters were given information on herd whereabouts) and handling time (helicopter aid for transport) of the recreational hunters. We compared 1) recreational hunting under ordinary legislation (up to 2016), 2) recreational hunting with less legislation (2017), and 3) culling by marksmen that were allowed to use both snowmobile and helicopter. Despite all of the changes in legislation, harvest by recreational hunters only increased from 241–316 during 2014–2016 to 582 reindeer in 2017 and was below management targets, while marksmen culled 1,399 reindeer, with a daily average and maximum offtake well above that of the hunters. The hunters shot more animals in the early season and during weekends. Offtake by both the hunters and marksmen were equally negatively affected by fog, which reduced visibility. We discuss the relative merits of using hunters and marksmen for wildlife control in general and limits to how legislation can increase offtake. We highlight the need for more research into how the use of marksmen comes with a cost in terms of social conflict. © 2019 The Authors. Wildlife Society Bulletin published by Wiley Periodicals, Inc. on behalf of The Wildlife Society. cervids, chronic wasting disease, disease ecology, disease management, host culling, hunting legislation, searching and handling times.

• Mysterud, Atle; Viljugrein, Hildegunn; Solberg, Erling Johan & Rolandsen, Christer Moe (2019). Legal regulation of supplementary cervid feeding facing chronic wasting disease. Journal of Wildlife Management.  ISSN 0022-541X.  83(8), s 1667- 1675 . doi: 10.1002/jwmg.21746 Fulltekst i vitenarkiv.
• Rivrud, Inger Maren; Frank, Shane; Bischof, Richard; Mysterud, Atle; Steyaert, Sam; Hertel, Anne Gabriela; Hagen, Snorre; Eiken, Hans Geir; Swenson, Jon & Zedrosser, Andreas (2019). Heritability of head size in a hunted large carnivore, the brown bear (Ursus arctos). Evolutionary Applications.  ISSN 1752-4571.  12(6), s 1124- 1135 . doi: 10.1111/eva.12786 Fulltekst i vitenarkiv. Vis sammendrag

  Wild animal populations experience selection pressures from both natural and anthropogenic sources. The availability of extensive pedigrees is increasing along with our ability to quantify the heritability and evolvability of phenotypic traits and thus the speed and potential for evolutionary change in wild populations. The environment may also affect gene expressions in individuals, which may in turn affect the potential of phenotypic traits to respond to selection. Knowledge about the relationship between the genetic and environmental components of phenotypic variation is particularly relevant, given ongoing anthropogenically driven global change. Using a quantitative genetic mixed model, we disentangled the genetic and environmental components of phenotypic variance in a large carnivore, the brown bear (Ursus arctos). We combined a pedigree covering ~1,500 individual bears over seven generations with location data from 413 bears, as well as data on bear density, habitat characteristics, and climatic conditions. We found a narrow‐sense heritability of 0.24 (95% CrI: 0.06–0.38) for brown bear head size, showing that the trait can respond to selection at a moderate speed. The environment contributed substantially to phenotypic variation, and we partitioned this into birth year (5.9%), nonadditive among‐individual genetic (15.0%), and residual (50.4%) environmental effects. Brown bear head circumference showed an evolvability of 0.2%, which can generate large changes in the trait mean over some hundreds of generations. Our study is among the first to quantify heritability of a trait in a hunted large carnivore population. Such knowledge about the degree to which species experiencing hunting can respond to selection is crucial for conservation and to make informed management decisions. We show that including important environmental variables when analyzing heritability is key to understanding the dynamics of the evolutionary potential of phenotypic traits.

• Rivrud, Inger Maren; Meisingset, Erling L.; Loe, Leif Egil & Mysterud, Atle (2019). Future suitability of habitat in a migratory ungulate under climate change. Proceedings of the Royal Society of London. Biological Sciences.  ISSN 0962-8452.  286(1899) . doi: 10.1098/rspb.2019.0442 Fulltekst i vitenarkiv. Vis sammendrag

  With climate change, the effect of global warming on snow cover is expected to cause range expansion and enhance habitat suitability for species at their northern distribution limits. However, how this depends on landscape topography and sex in size-dimorphic species remains uncertain, and is further complicated for migratory animals following climate-driven seasonal resource fluctuations across vast landscapes. Using 11 years of data from a partially migratory ungulate at their northern distribution ranges, the red deer (Cervus elaphus), we predicted sex-specific summer and winter habitat suitability in diverse landscapes under medium and severe global warming. We found large increases in future winter habitat suitability, resulting in expansion of winter ranges as currently unsuitable habitat became suitable. Even moderate warming decreased snow cover substantially, with no suitability difference between warming scenarios. Winter ranges will hence not expand linearly with warming, even for species at their northern distribution limits. Although less pronounced than in winter, summer ranges also expanded and more so under severe warming. Summer habitat suitability was positively correlated with landscape topography and ranges expanded more for females than males. Our study highlights the complexity of predicting future habitat suitability for conservation and management of size-dimorphic, migratory species under global warming.

• Stigum, Vetle Malmer; Jaarsma, Ryanne I.; Sprong, Hein; Rolandsen, Christer Moe & Mysterud, Atle (2019). Infection prevalence and ecotypes of Anaplasma phagocytophilum in moose Alces alces, red deer Cervus elaphus, roe deer Capreolus capreolus and Ixodes ricinus ticks from Norway. Parasites & Vectors.  ISSN 1756-3305.  12, s 1- 8 . doi: 10.1186/s13071-018-3256-z Fulltekst i vitenarkiv.
• Williamsen, Linda; Pigeon, Gabriel; Mysterud, Atle; Stien, Audun; Forchhammer, Mads C. & Loe, Leif Egil (2019). Keeping cool in the warming Arctic: thermoregulatory behaviour by Svalbard reindeer (Rangifer tarandus platyrhynchus). Canadian Journal of Zoology.  ISSN 0008-4301.  97(12), s 1177- 1185 . doi: 10.1139/cjz-2019-0090 Fulltekst i vitenarkiv. Vis sammendrag

  In animals with long generation times, evolution of physiological and morphological traits may not be fast enough to keep up with rapid climate warming, but thermoregulatory behaviour can possibly serve as an important buffer mitigating warming effects. In this study, we investigated if the cold-adapted Svalbard reindeer (Rangifer tarandus platyrhynchus (Vrolik, 1829)) used cool bed sites as a thermoregulatory behaviour in the summer. We recorded habitat variables and ground temperature at 371 bed sites with random “control” sites 10 and 100 m distant. Using case-control logistic regression, we found that reindeer selected bed sites on cool substrates (snow and mire), as well as cold, dry ground on days with warm ambient temperatures, while they avoided such sites on cold days. Selection of both cool substrates and cool ground did not depend on age or sex. The study was conducted in an environment where neither predatory threat nor insect harassment influenced bed site selection. Our findings suggest that the thermal landscape is important for habitat selection of cold-adapted Arctic ungulates in summer. Thus, behavioural strategies may be important to mitigate effects of climate change, at least in the short term. bed site, behavioural buffering, climate change, habitat selection, snow, ungulates, Svalbard reindeer, Rangifer tarandus platyrhynchus.

• Tucker, Marlee A.; Böhning-Gaese, Katrin; Fagan, William F.; Fryxell, John M.; Van Moorter, Bram; Alberts, Susan C.; Ali, Abdullahi H.; Allen, Andrew M.; Attias, Nina; Avgar, Tal; Bartlam-Brooks, Hattie; Bayarbaatar, Buuveibaatar; Belant, Jerrold L.; Bertassoni, Alessandra; Beyer, Dean; Bidner, Laura; van Beest, Floris M.; Blake, Stephen; Blaum, Niels; Bracis, Chloe; Brown, Danielle; de Bruyn, P.J. Nico; Cagnacci, Francesca; Calabrese, Justin M.; Camilo-Alves, Constança; Chamaillé-Jammes, Simon; Chiaradia, Andre; Davidson, Sarah C.; Todd, Dennis; DeStefano, Stephen; Diefenbach, Duane; Douglas-Hamilton, Iain; Fennesy, Julian; Fichtel, Claudia; Fiedler, Wolfgang; Fischer, Christina; Fischoff, Ilya; Fleming, Christen H.; Ford, Adam T.; Fritz, Susanne A.; Gehr, Benedikt; Goheen, Jacob R.; Gurarie, Eliezer; Hebblewhite, Mark; Heurich, Marco; Hewison, A.J. Mark; Hof, Christian; Hurme, Edward; Isbell, Lynne A.; Janssen, René; Jeltsch, Florian; Kaczensky, Petra; Kane, Adam; Kappeler, Peter M.; Kauffman, Matthew; Kays, Roland; Kimuyu, Duncan; Koch, Flavia; Kranstauber, Bart; LaPoint, Scott; Leimgruber, Peter; Linnell, John Durrus; López-López, Pascual; Markham, A. Catherine; Mattisson, Jenny; Medici, Emilia Patricia; Mellone, Ugo; Merrill, Evelyn; De MirandaMourao, Guilherme; Morato, Ronaldo G; Morellet, Nicolas; Morrison, Thomas A.; Díaz-Muñoz, Samuel L.; Mysterud, Atle; Nandintsetseg, Dejid; Nathan, Ran; Niamir, Aidin; Odden, John; OHara, Robert Brian; Oliveira-Santos, Luiz Gustavo R.; Olson, Kirk A.; Patterson, Bruce D.; De Paula, Rogerio Cunha; Pedrotti, Luca; Reineking, Björn; Rimmler, Martin; Rogers, Tracey L.; Rolandsen, Christer Moe; Rosenberry, Christopher S.; Rubenstein, Daniel I.; Safi, Kamran; Saïd, Sonia; Sapir, Nir; Sawyer, Hall; Schmidt, Niels Martin; Selva, Nuria; Sergiel, Agnieszka; Shiilegdamba, Enkhtuvshin; Silva, João Paulo; Singh, Navinder; Solberg, Erling Johan; Spiegel, Orr; Strand, Olav; Sundaresan, Siva; Ullmann, Wiebke; Voigt, Ulrich; Wall, Jake; Wattles, David; Wikelski, Martin; Wilmers, Christopher C.; Wilson, John W.; Wittemyer, George; Zięba, Filip; Zwijacz-Kozica, Tomasz & Mueller, Thomas (2018). Moving in the Anthropocene: Global reductions in terrestrial mammalian movements. Science.  ISSN 0036-8075.  359(6374), s 466- 469 . doi: 10.1126/science.aam9712 Fulltekst i vitenarkiv.
• Bischof, Richard; Bonenfant, Christophe; Rivrud, Inger Maren; Zedrosser, Andreas; Friebe, Andrea; Coulson, Tim; Mysterud, Atle & Swenson, Jon (2018). Regulated hunting re-shapes the life history of brown bears. Nature Ecology and Evolution.  ISSN 2397-334X.  2(1), s 116- 123 . doi: 10.1038/s41559-017-0400-7 Fulltekst i vitenarkiv. Vis sammendrag

  Management of large carnivores is among the most controversial topics in natural resource administration. Regulated hunting is a centrepiece of many carnivore management programmes and, although a number of hunting effects on population dynamics, body-size distributions and life history in other wildlife have been observed, its effects on life history and demography of large carnivores remain poorly documented. We report results from a 30-year study of brown bears (Ursus arctos) analysed using an integrated hierarchical approach. Our study revealed that regulated hunting has severely disrupted the interplay between age-specific survival and environmental factors, altered the consequences of reproductive strategies, and changed reproductive values and life expectancy in a population of the world’s largest terrestrial carnivore. Protection and sustainable management have led to numerical recovery of several populations of large carnivores, but managers and policymakers should be aware of the extent to which regulated hunting may be influencing vital rates, thereby reshaping the life history of apex predators.

• Büntgen, Ulf; Galvan, Juan D.; Mysterud, Atle; Krusic, Paul J.; Hulsmann, Lisa; Jenny, Hannes; Senn, Josef & Bollmann, Kurt (2018). Horn growth variation and hunting selection of the Alpine ibex. Journal of Animal Ecology.  ISSN 0021-8790.  87(4), s 1069- 1079 . doi: 10.1111/1365-2656.12839 Fulltekst i vitenarkiv.
• Couriot, Ophélie; Hewison, A. J. Mark; Saïd, Sonia; Cagnacci, Francesca; Chamaillé-Jammes, Simon; Linnell, John Durrus; Mysterud, Atle; Peters, Wibke Erika Brigitta; Urbano, Ferdinando; Heurich, Marco; Kjellander, Petter; Nicoloso, Sandro; Berger, Anne; Sustr, Pavel; Kroeschel, Max; Soennichsen, Leif; Sandfort, Robin; Gehr, Benedikt & Morellet, Nicolas (2018). Truly sedentary? The multi-range tactic as a response to resource heterogeneity and unpredictability in a large herbivore. Oecologia.  ISSN 0029-8549.  187(1), s 47- 60 . doi: 10.1007/s00442-018-4131-5 Fulltekst i vitenarkiv. Vis sammendrag

  Much research on large herbivore movement has focused on the annual scale to distinguish between resident and migratory tactics, commonly assuming that individuals are sedentary at the within-season scale. However, apparently sedentary animals may occupy a number of sub-seasonal functional home ranges (sfHR), particularly when the environment is spatially heterogeneous and/or temporally unpredictable. The roe deer (Capreolus capreolus) experiences sharply contrasting environmental conditions due to its widespread distribution, but appears markedly sedentary over much of its range. Using GPS monitoring from 15 populations across Europe, we evaluated the propensity of this large herbivore to be truly sedentary at the seasonal scale in relation to variation in environmental conditions. We studied movement using net square displacement to identify the possible use of sfHR. We expected that roe deer should be less sedentary within seasons in heterogeneous and unpredictable environments, while migratory individuals should be seasonally more sedentary than residents. Our analyses revealed that, across the 15 populations, all individuals adopted a multi-range tactic, occupying between two and nine sfHR during a given season. In addition, we showed that (i) the number of sfHR was only marginally influenced by variation in resource distribution, but decreased with increasing sfHR size; and (ii) the distance between sfHR increased with increasing heterogeneity and predictability in resource distribution, as well as with increasing sfHR size. We suggest that the multirange tactic is likely widespread among large herbivores, allowing animals to track spatio-temporal variation in resource distribution and, thereby, to cope with changes in their local environment. Migration · Residency · Sub-seasonal functional home range · Plasticity · Roe deer

• Festa-Bianchet, Marco & Mysterud, Atle (2018). Hunting and evolution: theory, evidence, and unknowns. Journal of Mammalogy.  ISSN 0022-2372.  99(6), s 1281- 1292 . doi: 10.1093/jmammal/gyy138 Fulltekst i vitenarkiv.
• Gaudry, William; Gaillard, J.-M.; Saïd, S.; Bonenfant, Christophe; Mysterud, Atle; Morellet, Nicolas; Maryline, Pellerin & Calenge, Clément (2018). Same habitat types but different use: evidence of context-dependent habitat selection in roe deer across populations. Scientific Reports.  ISSN 2045-2322.  8(1), s 1- 13 . doi: 10.1038/s41598-018-23111-0 Fulltekst i vitenarkiv.
• Hertel, Anne Gabriela; Bischof, Richard; Langval, Ola; Mysterud, Atle; Kindberg, Jonas; Swenson, Jon & Zedrosser, Andreas (2018). Berry production drives bottom-up effects on body mass and reproductive success in an omnivore. Oikos.  ISSN 0030-1299.  127(2), s 197- 207 . doi: 10.1111/oik.04515 Fulltekst i vitenarkiv. Vis sammendrag

  Obligate herbivores dominate studies of the eff ects of climate change on mammals, however there is limited empirical evidence for how changes in the abundance or quality of plant food aff ect mammalian omnivores. Omnivores can exploit a range of diff erent food resources over the course of a year, but they often rely on seasonally restricted highly nutritious fruiting bodies during critical life stages. Brown bears Ursus arctos in Sweden are dependent on berries for fattening before entering hibernation. We used a ten-year time series to evaluate the eff ect of temperature and snow on annual variation in berry abundance and how this variation aff ected bears. We found marked interannual variation in berry production of bilberry Vaccinium myrtillus and lingonberry V. vitis-idaea , that we could attribute in part to temperature during plant dormancy and flowering and precipitation during fruit ripening. Both, autumn weights of female bears and spring weights of yearling bears increased linearly with bilberry abundance. When bilberry abundance was low, lightweight female bears had a lower reproductive success than females in better condition. Th is eff ect vanished when food abundance was above average, indicating that lightweight females could compensate for their initial weight during good bilberry years. Our study highlights the importance of considering individuals ’ dynamic responses to variation in food availability, which leave some more vulnerable to food shortage than others. Individual life-history heterogeneity in response to resource variation likely aff ects long-term population recruitment. Our fi ndings emphasize that Scandinavian bears can be dependent on a single food resource during a critical period of the year and are therefore less resilient to environmental change than expected for an omnivore. Future climate scenarios predict ambiguous trends for weather covariates that aff ected crucial stages of berry phenology, preventing a clear prognosis of how climate change may aff ect long-term bilberry production.

• Meisingset, Erling L.; Loe, Leif Egil; Brekkum, Øystein; Bischof, Richard; Rivrud, Inger Maren; Lande, Unni Støbet; Zimmermann, Barbara; Veiberg, Vebjørn & Mysterud, Atle (2018). Spatial mismatch between management units and movement ecology of a partially migratory ungulate. Journal of Applied Ecology.  ISSN 0021-8901.  55(2), s 745- 753 . doi: 10.1111/1365-2664.13003 Fulltekst i vitenarkiv. Vis sammendrag

  1. Population-level management is difficult to achieve if wildlife routinely crosses administrative boundaries, as is particularly frequent for migratory populations. However, the degree of mismatch between management units and scales at which ecological processes operate has rarely been quantified. Such insight is vital for delimiting functional population units of partially migratory species common in northern forest ecosystems. 2. We combined an extensive dataset of 412 GPS-marked red deer (Cervus elaphus) across Norway with information on the size and borders of two administrative levels, the governmental level (municipality) and landowner level (local management units, LMUs), to determine the timing and scale of mismatch between animal space use and management units. We analysed how landscape characteristics affected the use of management units and the timing and likelihood of crossing borders between them, in an effort to delineate more appropriate units in various landscapes. 3. Median municipality size could potentially cover 70% of female and 62% of male annual ranges, while only 12% and 4% of LMUs were expansive enough to accommodate migratory routes in females and males, respectively. Red deer migrate along elevational gradients and are more likely to find both suitable lowland winter habitat and higher summer habitat within management units with variable topography. Consistent with this, the likelihood of border crossing decreased with increasing diversity of elevations. 4. Synthesis and applications. We demonstrate a considerable mismatch between animal space use and management units. Far-ranging movements and frequent administrative border crossings during autumn migration coincides with the period of active management (hunting season). Our study also highlights that, due to extensive movements of males, coordination of management aims may provide a more realistic avenue than increasing sizes of local management units. A more general insight is that the degree of mismatch between range use and management units depends on the season and landscape type. This needs to be accounted for when delimitating functional population units of migratory populations.

• Mysterud, Atle & Rolandsen, Christer Moe (2018). Fencing for wildlife disease control. Journal of Applied Ecology.  ISSN 0021-8901.  56(3), s 519- 525 . doi: 10.1111/1365-2664.13301 Fulltekst i vitenarkiv.
• Mysterud, Atle; Stigum, Vetle Malmer; Seland, Ingrid Vikingsdal; Herland, Anders; Easterday, William Ryan; Jore, Solveig; Østerås, Olav & Viljugrein, Hildegunn (2018). Tick abundance, pathogen prevalence, and disease incidence in two contrasting regions at the northern distribution range of Europe. Parasites & Vectors.  ISSN 1756-3305.  11 . doi: 10.1186/s13071-018-2890-9 Fulltekst i vitenarkiv.
• Peters, Wibke; Hebblewhite, Mark; Mysterud, Atle; Eacker, Daniel; Hewison, A.J. Mark; Linnell, John Durrus; Focardi, Stefano; Urbano, Ferdinando; De Groeve, Johannes; Gehr, Benedikt; Heurich, Marco; Jarnemo, Anders; Kjellander, Petter; Kröschel, Max; Morellet, Nicolas; Pedrotti, Luca; Reinecke, Horst; Sandfort, Robin; Sönnichsen, Leif; Sunde, Peter & Cagnacci, Francesca (2018). Large herbivore migration plasticity along environmental gradients in Europe: life-history traits modulate forage effects. Oikos.  ISSN 0030-1299.  s 1- 14 . doi: 10.1111/oik.05588
• Prager, Katrin; Lorenzo-Arribas, Altea; Bull, Hans; Kvernstuen, Mikkel Slaaen; Loe, Leif Egil & Mysterud, Atle (2018). Social constraints in cross-boundary collaborative deer management. Ecology & society.  ISSN 1708-3087.  23(4), s 1- 33 . doi: 10.5751/ES-10549-230429 Fulltekst i vitenarkiv.
• Rivrud, Inger Maren; Sivertsen, Therese Ramberg; Mysterud, Atle; Åhman, Birgitta; Støen, Ole-Gunnar & Skarin, Anna (2018). Reindeer green-wave surfing constrained by predators. Ecosphere.  ISSN 2150-8925.  9(5) . doi: 10.1002/ecs2.2210 Fulltekst i vitenarkiv. Vis sammendrag

  Migratory large herbivores in seasonal environments are known to follow the onset of new growth during spring, so‐called green‐wave surfing. This ensures prolonged access to forage with an optimal balance between forage quality and quantity. Many studies have focused on herbivores’ ability to follow the spring flush, but without considering potential constraints to surfing the green wave. The presence of predators is likely to be such a limitation, which could force herbivores to deviate from the optimal movement patterns in terms of forage access. We compared how well 319 reindeer (Rangifer tarandus) from seven different populations followed the green‐up at different population densities of brown bear (Ursus arctos). We found that reindeer at higher bear densities selected movement paths with lower access to high‐quality forage and deviated more in time from following the peak of the green wave, thus missing out on valuable forage. In addition, reindeer generally moved faster at higher bear densities, but this pattern was more consistent in forest habitats. Our results indicate that reindeer are forced to deviate from following the spring flush and alter their movement pattern in areas with high bear densities, which may lead to reduced body condition for reindeer experiencing high predation risk. With the recent recolonization of large carnivores in northern ecosystems, it is critical to understand the direct and indirect effects of predators on large herbivores in order to assess effects on population dynamics and potentially cascading consequences on ecosystem function.

• Viljugrein, Hildegunn; Hopp, Petter; Benestad, Sylvie Lafond; Nilsen, Erlend Birkeland; Våge, Jørn; Tavornpanich, Saraya; Rolandsen, Christer Moe; Strand, Olav & Mysterud, Atle (2018). A method that accounts for differential detectability in mixed samples of long-term infections with applications to the case of Chronic Wasting Disease in cervids. Methods in Ecology and Evolution.  ISSN 2041-210X.  s 1- 12 . doi: 10.1111/2041-210X.13088 Fulltekst i vitenarkiv. Vis sammendrag

  1. Surveillance of wildlife diseases is logistically difficult, and imperfect detection is a recurrent challenge for disease estimation. Using citizen science can increase sample sizes, but it is associated with a cost in terms of the anatomical type and quality of the sample. Additionally, biological tissue samples from remote areas lose quality due to autolysis. These challenges are faced in the case of emerging Chronic Wasting Disease (CWD) in cervids. 2. Here, we develop a stochastic scenario tree model of diagnostic sensitivity, allowing for a mixture of tissue sample types (lymph nodes and brain) and qualities while accounting for different detection probabilities during the CWD infection, lasting 2-3 years. We apply the diagnostic sensitivity in a Bayesian framework, enabling estimation of age-class-specific true prevalence, including the prevalence in latent, recently infected stages. We provide a simulation framework to estimate the sensitivity of the surveillance system (i.e., the probability of detecting the infection in a given population), when detectability varies among individuals due to different disease progression. 3. We demonstrate the utility of our framework by applying it to the recent emergence of CWD in a European population of reindeer. We estimated apparent CWD prevalence at 1.2 % of adults in the infected population of wild reindeer, while the true prevalence was 1.6 %. The sensitivity estimation of the CWD surveillance was performed in an adjacent small (~500) and a large (~10,000) reindeer population, demonstrating low certainty of CWD absence. 4. Our method has immediate application to the mandatory testing for CWD in EU countries commencing in 2018. Similar approaches that account for latent stages and a serial disease progression in various tissues with a temporal pattern of diagnostic sensitivity may enhance the estimation of the prevalence of wildlife diseases more generally. Bayesian estimation methods, surveillance, wildlife diseases, diagnostic sensitivity, test sensitivity, chronic wasting disease, prevalence, prions, PrP CWD

• Apollonio, Marco; Belkin, Vladimir V.; Borkowski, Jakub; Borodin, Oleg I.; Borowik, Tomasz; Cagnacci, Fransesca; Danilkin, Aleksey A.; Danilov, Peter I.; Faybich, Andrey; Ferretti, Francesco; Gaillard, Jean Michel; Hayward, Matt; Heshtaut, Pavel; Heurich, Marco; Hurynovich, Aliaxandr; Kashtalyan, Alexander; Kerley, Graham I. H.; Kjellander, Petter; Kowalczyk, Rafał; Kozorez, Alexander; Matveytchuk, Sergey; Milner, Jos M.; Mysterud, Atle; Ozoliņš, Jānis; Panchenko, Danila V.; Peters, Wibke; Podgórski, Tomasz; Pokorny, Boštjan; Rolandsen, Christer Moe; Ruusila, Vesa; Schmidt, Krzysztof; Sipko, Taras P.; Veeroja, Rauno; Velihurau, Pavel & Yanuta, Gregoriy (2017). Challenges and science-based implications for modern management and conservation of European ungulate populations. Mammal Research.  ISSN 2199-2401.  62(3), s 209- 217 . doi: 10.1007/s13364-017-0321-5 Fulltekst i vitenarkiv. Vis sammendrag

  Wildlife management systems face growing challenges to cope with increasingly complex interactions between wildlife populations, the environment and human activities. In this position statement, we address the most important issues characterising current ungulate conservation and management in Europe. We present some key points arising from ecological research that may be critical for a reassessment of ungulate management in the future. Ecosystem . Population sustainability . Science-basedmanagement .Wildlifemanagement .Adaptive management

• Büntgen, Ulf; Greuter, Lucie; Bollmann, Kurt; Jenny, Hannes; Liebhold, Andrew; Galván, J. Diego; Stenseth, Nils Christian; Andrew, Carrie Joy & Mysterud, Atle (2017). Elevational range shifts in four mountain ungulate species from the Swiss Alps. Ecosphere.  ISSN 2150-8925.  8(4), s 1- 15 . doi: 10.1002/ecs2.1761 Fulltekst i vitenarkiv.
• Debeffe, Lucie Isabelle; Rivrud, Inger Maren; Brekkum, Øystein; Meisingset, Erling L. & Mysterud, Atle (2017). Implications of the forage maturation hypothesis for activity of partially migratory male and female deer. Ecosphere.  ISSN 2150-8925.  8(12), s 1- 16 . doi: 10.1002/ecs2.2050 Fulltekst i vitenarkiv. Vis sammendrag

  Partial migration is common in a large variety of taxa in seasonally variable environments. Understanding the mechanisms underlying migration is important, as migration affects individual fi tness. Migratory herbivores bene fi t from delayed forage maturation and hence higher food quality during migra- tion and at their summer range, termed the forage maturation hypothesis (FMH). The link between diet quality and rumination time allows migrants eating a higher quality diet to spend less time on rumination, and they can thus allocate more time to additional feeding. However, such an argument implicitly assumes that deer are energy maximizers, while studies have reported also time minimization strategies under risk of predation. Male and female distributions are limited by different factors linked to both body size differ- ences and reproductive strategies, but there is no study investigating differences in activity pattern accord- ing to the individual migratory patterns for male and female deer. We here unify the FMH with the hypotheses predicting sex-speci fi c time allocation strategies. To test predictions of sex-speci fi c activity of resident and migratory red deer ( Cervus elaphus ), we analyzed activity data of 286 individuals that were fi tted with GPS collars from a population in western Norway. While migrants were more active during the migration itself, we found no differences in activity pattern between migrant and resident deer during the main growth season, neither in terms of proportion of daily time active nor in terms of daily mean movement speed, thus rejecting that deer were energy maximizers. Overall, we found that females were more active during the main growth season even after controlling for body size differences. These patterns are consistent with patterns predicted from sexual segregation theory linked to the reproductive strategy hypothesis. Our study highlights how the understanding of migration can be advanced by considering it in the context of different reproductive strategies of males and females.

• Lone, Karen; Mysterud, Atle; Gobakken, Terje; Odden, John; Linnell, John Durrus & Loe, Leif Egil (2017). Temporal variation in habitat selection breaks the catch-22 of spatially contrasting predation risk from multiple predators. Oikos.  ISSN 0030-1299.  126(5), s 624- 632 . doi: 10.1111/oik.03486/full Vis sammendrag

  Predator avoidance depends on prey being able to discern how risk varies in space and time, but this is made considerably more complicated if risk is simultaneously present from multiple predators. Th is is the situation for an increasing number of mammalian prey species, as large carnivores recover or are reintroduced in ecosystems on several continents. Roe deer Capreolus capreolus in southern Norway illustrate a case in which prey face two predators with contrasting patterns of predation risk. Th ey face a catch-22 situation: spatially avoiding the risk from one predator (lynx Lynx lynx in dense habitat) implies exposure to the other (hunters in open habitat). Using GPS-data from 29 roe deer, we tested for daily and seasonal variation in roe deer selection for habitat with respect to the habitats ’ year-round average risk level. Generally, roe deer altered their habitat selection between night and day in a pattern consistent with being able to avoid predicted risk from the nocturnal lynx during night and predicted risk from human hunters during day. However, seasonal variation in habitat selection only partially corresponded with the predicted seasonal variation in risk. Whereas roe deer avoided areas with high risk from hunters more strongly during the hunting season than in other seasons, there was a lack of selection towards areas and time periods lowering the risk of lynx predation during winter. It seems likely that the risk of starvation and thermal stress constrain roe deer habitat selection during this energetically challenging season with cold temperatures, snow cover and limited natural forage. Th e habitat selection pattern of roe deer fi ts thus only partly with the two contrasting risk gradients they face. Adjusting risk-avoidance behavior temporally can be an adaptive response in the case of several predators whose predation patterns diff er in space and time.

• Mysterud, Atle; Jore, Solveig; Østerås, Olav & Viljugrein, Hildegunn (2017). Emergence of tick-borne diseases at northern latitudes in Europe: a comparative approach. Scientific Reports.  ISSN 2045-2322.  7 . doi: 10.1038/s41598-017-15742-6 Fulltekst i vitenarkiv.
• Mysterud, Atle; Vike, Brit Karen; Meisingset, Erling L. & Rivrud, Inger Maren (2017). The role of landscape characteristics for forage maturation and nutritional benefits of migration in red deer. Ecology and Evolution.  ISSN 2045-7758.  7(12), s 4448- 4455 . doi: 10.1002/ece3.3006 Fulltekst i vitenarkiv. Vis sammendrag

  Large herbivores gain nutritional benefits from following the sequential flush of newly emergent, high- quality forage along environmental gradients in the landscape, termed green wave surfing. Which landscape characteristics underlie the environmental gradi-ent causing the green wave and to what extent landscape characteristics alone explain individual variation in nutritional benefits remain unresolved questions. Here, we com-bine GPS data from 346 red deer (Cervus elaphus) from four partially migratory popula-tions in Norway with the satellite- derived normalized difference vegetation index (NDVI), an index of plant phenology. We quantify whether migratory deer had access to higher quality forage than resident deer, how landscape characteristics within sum-mer home ranges affected nutritional benefits, and whether differences in landscape characteristics could explain differences in nutritional gain between migratory and resident deer. We found that migratory red deer gained access to higher quality forage than resident deer but that this difference persisted even after controlling for land-scape characteristics within the summer home ranges. There was a positive effect of elevation on access to high- quality forage, but only for migratory deer. We discuss how the landscape an ungulate inhabits may determine its responses to plant phenol-ogy and also highlight how individual behavior may influence nutritional gain beyond the effect of landscape.

• Ossi, Federico; Gaillard, Jean Michel; Hebblewhite, Mark; Morellet, Nicolas; Ranc, Nathan; Sandfort, Robin; Kroeschel, Max; Kjellander, Petter; Mysterud, Atle; Linnell, John Durrus; Heurich, Marco; Soennichsen, Leif; Sustr, Pavel; Berger, Anne; Rocca, Michele; Urbano, Ferdinando & Cagnacci, Francesca (2017). Plastic response by a small cervid to supplemental feeding in winter across a wide environmental gradient. Ecosphere.  ISSN 2150-8925.  8(1), s 1- 17 . doi: 10.1002/ecs2.1629 Fulltekst i vitenarkiv.
• Peters, Wibke Erika Brigitta; Hebblewhite, Mark; Mysterud, Atle; Spitz, Derek; Focardi, Stefano; Urbano, Ferdinando; Morellet, Nicolas; Heurich, Marco; Kjellander, Petter; Linnell, John Durrus & Cagnacci, Francesca (2017). Migration in geographic and ecological space by a large herbivore. Ecological Monographs.  ISSN 0012-9615.  87(2), s 297- 320 . doi: 10.1002/ecm.1250 Fulltekst i vitenarkiv. Vis sammendrag

  Partial migration, when only part of the population migrates seasonally while the other part remains resident on the shared range, is the most common form of migration in ungulates. Migration is often defined by spatial separation of seasonal ranges and consequently, classification of individuals as migrants or residents is usually only based on geographic criteria. However, the underlying mechanism for migration is hypothesized to be movement in response to spatiotemporal resource variability and thus, migrants are assumed to travel an “ecological distance” (ED) or shift their realized ecological niches. While ecological and geographic distances should be related, their relationship may depend on landscape heterogeneity. Here, we tested the utility of ecological niche theory to both classify migratory individuals and to understand the underlying ecological factors for migratory behavior. We developed an integrative approach combining measures in geographic and ecological niche space and used this to classify and explain migratory behavior of 71 annual roe deer (Capreolus capreolus) movement trajectories in five European study areas. First, to assess the utility of the ED concept for classifying migratory behavior, we tested whether roe deer sought the same ecological conditions year-round or moved to different ecological conditions by measuring the annual ED travelled and the seasonal niche overlap using multivariate statistics. Comparing methods to classify migrants and residents based on geographic and ecological niche space, we found that migratory roe deer switched between seasons both in geographic and in ecological dimensions. Second, we tested which seasonal ecological factors separated resident from migrant niches using discriminant analysis and which broad-scale determinants (e.g., spatiotemporal forage variation and population density) predicted migration probability using generalized linear models. Our results indicated that factors describing forage and topographic variability discriminated seasonal migrant from resident niches. Determinants for predicting migration probability included the temporal variation (seasonality) and also the spatial variability of forage patches. Last, we also found suggestive evidence for a positive relationship between population density and migration probability. By applying the ecological niche concept to the study of partial migration in ungulates, our work underlines that partial migration is a form of behavioral plasticity. Key words: behavioral plasticity; Capreolus capreolus; ecological distance; large herbivores; niche switching; Normalized Difference Vegetation Index; partial migration; realized niche; spatiotemporal variation; ungulates

• Austrheim, Gunnar; Speed, James David Mervyn; Evju, Marianne; Hester, Alison; Holand, Øystein; Loe, Leif Egil; Martinsen, Vegard; Mobæk, Ragnhild; Mulder, Jan; Steen, Harald; Thompson, Des B.A. & Mysterud, Atle (2016). Synergies and trade-offs between ecosystem services in analpine ecosystem grazed by sheep – An experimental approach. Basic and Applied Ecology.  ISSN 1439-1791.  17(7), s 596- 608 . doi: 10.1016/j.baae.2016.06.003 Fulltekst i vitenarkiv. Vis sammendrag

  Domestic livestock drives ecosystem changes in many of the world’s mountain regions, and can be the dominant influenceon soil, habitat and wildlife dynamics. Grazing impacts on ecosystem services (ES) vary according to densities of sheep, butan ES framework accounting for these is lacking. We devised an experiment to evaluate synergies and trade-offs of ESs andcomponents of biodiversity affected by sheep density at the alpine landscape scale in southern Norway. We examined the effectsof increased (80 per km2), decreased (0 per km2) and maintained sheep densities (25 per km2) on ‘supporting’, ‘regulating’and ‘provisioning’ services and biodiversity (plants, invertebrates and birds). Overall, ESs and biodiversity were highest atmaintained sheep density. Regulating services, including carbon storage and habitat openness, were particularly favoured bymaintained densities of sheep. There was no overall decline in ESs from maintained to increased sheep densities, but severalservices, such as runoff water quality, plant productivity and carbon storage, declined when grazing increased. Our study providesexperimental evidence for a positive effect of grazing on ES, but only at maintained low sheep densities. By identifying ESand biodiversity components that are traded-off at decreased and increased grazing, our study also demonstrates some of thenegative impacts on ecosystems that can occur in mountain regions if management does not regulate herbivore densities. Herbivory; Ecosystem services; Livestock; Management; Optimal stocking levels; Overgrazing; Threshold

• Cagnacci, Francesca; Focardi, Stefano; Ghisla, Anne; Van Moorter, Bram; Merril, Evelyn H.; Gurarie, Eliezer; Heurich, Marco; Mysterud, Atle; Linnell, John Durrus; Panzacchi, Manuela; May, Roelof Frans; Nygård, Torgeir; Rolandsen, Christer Moe & Hebblewhite, Mark (2016). How many routes lead to migration? Comparison of methods to assess and characterize migratory movements. Journal of Animal Ecology.  ISSN 0021-8790.  85(1), s 54- 68 . doi: 10.1111/1365-2656.12449 Fulltekst i vitenarkiv. Vis sammendrag

  Summary 1. Decreasing rate of migration in several species as a consequence of climate change and anthropic pressure, together with increasing evidence of space-use strategies intermediate between residency and complete migration, are very strong motivations to evaluate migration occurrence and features in animal populations. 2. The main goal of this paper was to perform a relative comparison between methods for identifying and charact erizing migration at the individual and population level on the basis of animal location data. 3. We classified 104 yearly individual trajectories from five populations of three deer species as migratory or non-migratory, by means of three methods: seasonal home range overlap, spatio-temporal separation of seasonal clusters and the Net Squared Displacement (NSD) method. For migr atory cases, we also measured timing and distance of migration and resi- dence time on the summer range. Finally, we comp ared the classification in migration cases across methods and populations. 4. All methods consistently identified migration at the population level, that is, they coherently dis- tinguished between complete or almost complete migr atory populations and partially migratory populations. Ho wever, in the latter case, methods co heren tly classified only about 50% of the sin- gle cases, that is they classified differently at the individual-animal level. We therefore infer that the compariso n of methods may help point to ‘less-stereo typed ’ cases in the residency -to-migration continuum. For ca ses consistently classified by all methods, no signifi cant differences were found in migration distance, or residence time on summer ranges. Timing of migration estimated by NSD was ea rlier than by the other two methods, both for spring and autumn migrations. 5. We suggest three steps to identify improper inferences from migration data and to enhance understanding of intermedia te space-use strategies. We recommend (i) classifying migration behaviours using more than one method, (ii) performing sensitivity analysis on method parame- ters to identify the extent of the differences and (iii) investigating inconsistently classified cases as these may often be ecologically interest ing (i.e. less-stereotyped migratory behaviours). adehabitat, hom e range overlap, movement patterns, Net Squared Displacement, red deer, reindeer, residence behaviour, roe deer, spatial clusters

• Diekert, Florian Klaus; Richter, Andries Peter; Rivrud, Inger Maren & Mysterud, Atle (2016). How constraints affect the hunter's decision to shoot a deer. Proceedings of the National Academy of Sciences of the United States of America.  ISSN 0027-8424.  113(50), s 14450- 14455 . doi: 10.1073/pnas.1607685113
• Hertel, Anne Gabriela; Steyaert, Sam; Zedrosser, Andreas; Mysterud, Atle; Lodberg-Holm, Hanna Kavli; Gelink, Henriette Wathne; Kindberg, Jonas & Swenson, Jon (2016). Bears and berries: species-specific selective foraging on a patchily distributed food resource in a human-altered landscape. Behavioral Ecology and Sociobiology.  ISSN 0340-5443.  70(6), s 831- 842 . doi: 10.1007/s00265-016-2106-2 Fulltekst i vitenarkiv. Vis sammendrag

  When animals are faced with extraordinary energyconsuming events, like hibernation, finding abundant, energy-rich food resources becomes particularly important. The profitability of food resources can vary spatially, depending on occurrence, quality, and local abundance. Here, we used the brown bear (Ursus arctos) as a model species to quantify selective foraging on berries in different habitats during hyperphagia in autumn prior to hibernation. During the peak berry season in August and September, we sampled berry occurrence, abundance, and sugar content, a proxy for quality, at locations selected by bears for foraging and at random locations in the landscape. The factors determining selection of berries were species specific across the different habitats. Compared to random locations, bears selected locations with a higher probability of occurrence and higher abundance of bilberries (Vaccinium myrtillus) and a higher probability of occurrence, but not abundance, of lingonberries (Vaccinium vitis-idaea). Crowberries (Empetrum hermaphroditum) were least available and least used. Sugar content affected the selection of lingonberries, but not of bilberries. Abundance of bilberries at random locations decreased and abundance of lingonberries increased during fall, but bears did not adjust their foraging strategy by increasing selection for lingonberries. Forestry practices had a large effect on berry occurrence and abundance, and brown bears responded by foraging most selectively in mature forests and on clearcuts. This study shows that bears are successful in navigating human-shaped forest landscapes by using areas of higher than average berry abundance in a period when abundant food intake is particularly important to increase body mass prior to hibernation. Significance statement Food resources heterogeneity, caused by spatial and temporal variation of specific foods, poses a challenge to foragers, particularly when faced with extraordinary energy-demanding events, like hibernation. Brown bears in Sweden inhabit a landscape shaped by forestry practices. Bilberries and lingonberries, the bears’ main food resources in autumn prior to hibernation, show different temporal and habitat-specific ripening patterns. We quantified the bears’ selective foraging on these berry species on clearcuts, bogs, young, and mature forests compared to random locations. Despite a temporal decline of ripe bilberries, bears used locations with a greater occurrence and abundance of bilberries, but not lingonberries. We conclude that bears successfully navigated in this heavily human-shaped landscape by selectively foraging in highreturn habitats for bilberries, but did not compensate for the decline in bilberries by eating more lingonberries.Bilberry . Brown bear . Lingonberry . Movement trajectories . Optimal foraging . Sugar content

• Hertel, Anne Gabriela; Zedrosser, Andreas; Mysterud, Atle; Støen, Ole-Gunnar; Steyaert, Sam & Swenson, Jon (2016). Temporal effects of hunting on foraging behavior of an apex predator: Do bears forego foraging when risk is high?. Oecologia.  ISSN 0029-8549.  182, s 1019- 1029 . doi: 10.1007/s00442-016-3729-8 Fulltekst i vitenarkiv. Vis sammendrag

  Avoiding predators most often entails a food cost. For the Scandinavian brown bear (Ursus arctos), the hunting season coincides with the period of hyperphagia. Hunting mortality risk is not uniformly distributed throughout the day, but peaks in the early morning hours. As bears must increase mass for winter survival, they should be sensitive to temporal allocation of antipredator responses to periods of highest risk. We expected bears to reduce foraging activity at the expense of food intake in the morning hours when risk was high, but not in the afternoon, when risk was low. We used fine-scale GPS-derived activity patterns during the 2 weeks before and after the onset of the annual bear hunting season. At locations of probable foraging, we assessed abundance and sugar content, of bilberry (Vaccinium myrtillus), the most important autumn food resource for bears in this area. Bears decreased their foraging activity in the morning hours of the hunting season. Likewise, they foraged less efficiently and on poorer quality berries in the morning. Neither of our foraging measures were affected by hunting in the afternoon foraging bout, indicating that bears did not allocate antipredator behavior to times of comparably lower risk. Bears effectively responded to variation in risk on the scale of hours. This entailed a measurable foraging cost. The additive effect of reduced foraging activity, reduced forage intake, and lower quality food may result in poorer body condition upon den entry and may ultimately reduce reproductive success.

• Loe, Leif Egil; Hansen, Brage Bremset; Stien, Audun; Albon, Steve D.; Bischof, Richard; Carlsson, Anja M.; Irvine, Justin; Meland, Morten; Rivrud, Inger Maren; Ropstad, Erik; Veiberg, Vebjørn & Mysterud, Atle (2016). Behavioral buffering of extreme weather events in a high-Arctic herbivore. Ecosphere.  ISSN 2150-8925.  7(6) . doi: 10.1002/ecs2.1374 Fulltekst i vitenarkiv. Vis sammendrag

  As global warming advances, there is a growing concern about the impact of extreme weather events on ecosystems. In the Arctic, more frequent unseasonal warm spells and rain-on- snow events in winter cause changes in snow-pack properties, including ground icing. Such extreme weather events are known to have severe effects across trophic levels, for instance, causing die-offs of large herbivores. However, the extent to which individuals and populations are able to buffer such events through behavioral plasticity is poorly understood. Here, we analyze responses in space use to rain-on- snow and icing events, and their fitness correlates, in wild reindeer in high-Arctic Svalbard. Range displacement among GPS-collared females occurred mainly in icy winters to areas with less ice, lower over-winter body mass loss, lower mortality rate, and higher subsequent fecundity, than the departure area. Our study provides rare empirical evidence that mammals may buffer negative effects of climate change and extreme weather events by adjusting behavior in highly stochastic environments. Under global warming, behavioral buffering may be important for the long-term population persistence in mobile species with long generation time and therefore limited ability for rapid evolutionary adaptation. Arctic; climate; GPS; ice; ideal-free distribution; migration; movement; Rangifer tarandus platyrhynchus; space use; Svalbard; Svalbard reindeer; time-to-event analysis.

• Loe, Leif Egil; Rivrud, Inger Maren; Meisingset, Erling L.; Bøe, Silje; Hamnes, Martine; Veiberg, Vebjørn & Mysterud, Atle (2016). Timing of the hunting season as a tool to redistribute harvest of migratory deer across the landscape. European Journal of Wildlife Research.  ISSN 1612-4642.  62(3), s 315- 323 . doi: 10.1007/s10344-016-1004-2
• Mabille, Geraldine; Stien, Audun; Tveraa, Torkild; Mysterud, Atle; Brøseth, Henrik & Linnell, John Durrus (2016). Mortality and lamb body mass growth in free-ranging domestic sheep – environmental impacts including lethal and non-lethal impacts of predators. Ecography.  ISSN 0906-7590.  39(8), s 763- 773 . doi: 10.1111/ecog.01379 Vis sammendrag

  The management and recovery of large predator populations in areas where human persecution has driven them to ecological extinction requires a solid understanding of the effects of both predation and food limitation on prey populations. We used 11 yr of data on reported losses among 17.3 million free-ranging sheep Ovis aries in the Norwegian farming industry to elucidate the relative roles of climate, vegetation characteristics, sheep densities, lamb body mass and densities of predators and alternative prey on the number of lambs and ewes lost on summer pastures. We first examined whether predator densities predicted autumn lamb body mass through possible impacts of predators on body growth (non-lethal effects) but found no evidence for such effects in our study system. This might be due to weak anti-predator behavioral responses in domesticated sheep. However, autumn lamb body mass was predicted by both sheep density and winter and spring weather conditions, probably through food availability. Losses of both lambs and ewes were positively and strongly related to the density of Eurasian lynx Lynx lynx , wolverine Gulo gulo and brown bear Ursus arctos. In addition, food availability and spring weather conditions were associated to losses of lambs, while precipitation in May predicted losses of ewes. There was little evidence for interaction effects of predator species on losses, suggesting that most of the effects of the predators were additive to each other. Given the strong effect of predator densities on sheep losses, we conclude that changing livestock husbandry practices towards a system that actively protects sheep and/or active management of predator densities may be necessary to reduce sheep losses where predators are recolonizing.

• Mysterud, Atle & Austrheim, Gunnar (2016). The role of individual traits and environmental factors for diet composition of sheep. PLOS ONE.  ISSN 1932-6203.  11(1), s 1- 12 . doi: 10.1371/journal.pone.0146217 Fulltekst i vitenarkiv.
• Mysterud, Atle; Easterday, William Ryan; Stigum, Vetle Malmer; Aas, Anders Bjørnsgard; Meisingset, Erling L. & Viljugrein, Hildegunn (2016). Contrasting emergence of Lyme disease across ecosystems. Nature Communications.  ISSN 2041-1723.  7 . doi: 10.1038/ncomms11882 Fulltekst i vitenarkiv. Vis sammendrag

  Global environmental changes are causing Lyme disease to emerge in Europe. The life cycle of Ixodes ricinus, the tick vector of Lyme disease, involves an ontogenetic niche shift, from the larval and nymphal stages utilizing a wide range of hosts, picking up the pathogens causing Lyme disease from small vertebrates, to the adult stage depending on larger (non-transmission) hosts, typically deer. Because of this complexity the role of different host species for emergence of Lyme disease remains controversial. Here, by analysing long-term data on incidence in humans over a broad geographical scale in Norway, we show that both high spatial and temporal deer population density increase Lyme disease incidence. However, the trajectories of deer population sizes play an overall limited role for the recent emergence of the disease. Our study suggests that managing deer populations will have some effect on disease incidence, but that Lyme disease may nevertheless increase as multiple drivers are involved.

• Mysterud, Atle; Madslien, Knut; Herland, Anders; Viljugrein, Hildegunn & Ytrehus, Bjørnar (2016). Phenology of deer ked (Lipoptena cervi) host-seeking flight activity and its relationship with prevailing autumn weather. Parasites & Vectors.  ISSN 1756-3305.  9(95), s 1- 6 . doi: 10.1186/s13071-016-1387-7 Fulltekst i vitenarkiv. Vis sammendrag

  Background: The deer ked (Lipoptena cervi) is an ectoparasite on cervids that has invaded large parts of Norway, Sweden and Finland during recent decades. During their host-seeking flight activity, the adult deer keds constitute a considerable nuisance to people and limit human outdoor recreation. The bites of the deer ked can cause long-lasting dermatitis in humans. Determining the pattern of flight activity during autumn is hence important. Methods: Data on flight phenology was gathered by walking along transects in the forest in two counties of Norway during 2009–2013, counting the number of host-seeking keds. We analysed how the flight activity of deer keds varied depending on date and prevailing weather during autumn. Results: The best model of flight activity included both date and temperature, both as nonlinear terms. Host-seeking deer keds were observed from early August to mid-November with a marked peak in late September. Number of host-seeking keds declined with temperatures falling below the mean, but did not increase much at above mean temperatures. The pattern of flight phenology was similar across the two counties and five years. Conclusions: Parasitic arthropods may be strongly affected by prevailing weather during off-host periods. Our study shows an estimated positive effect of temperature on deer ked flight activity mainly for below mean temperatures in late autumn, while the effect of temperature on flight activity in early autumn was weak. The pattern of host-seeking flight activity during late, rather than early autumn, is hence more likely to change with ongoing climate change, with a predicted increase in duration of the host-seeking period. Keywords: Deer ked, Invading parasites, Climate, Temperature, Moose, Phenology

• Qviller, Lars; Viljugrein, Hildegunn; Loe, Leif Egil; Meisingset, Erling L. & Mysterud, Atle (2016). The influence of red deer space use on the distribution of Ixodes ricinus ticks in the landscape. Parasites & Vectors.  ISSN 1756-3305.  9 . doi: 10.1186/s13071-016-1825-6 Fulltekst i vitenarkiv. Vis sammendrag

  Background: Many wingless ectoparasites have a limited capacity for active movement and are therefore primarily dependent on hitchhiking on their hosts for transportation. The distribution of the tick Ixodes ricinus is expected to depend mainly on transportation by hosts and tick subsequent survival in areas where they drop off. In Europe, the most important hosts of adult female I. ricinus are cervids. The extensive space use of large hosts provides a much larger dispersal potential for I. ricinus than that of smaller mammalian hosts. We aim to determine the contribution of red deer (Cervus elaphus) space use on the spatial distribution of I. ricinus, after accounting for landscape factors. Methods: We analysed the spatial distribution of I. ricinus with generalised mixed effects models (GLMMs) based on data from extensive field surveys of questing density in two coastal regions in Norway, from which home range data from 73 red deer with GPS collars were available. Red deer home ranges were derived using the kernel method to identify areas most frequently used by deer. We first fitted a baseline model with tick questing densities relative to landscape features that are likely to affect local climate conditions and hence, survival. We then added deer space use variables to the baseline model with only landscape variables to test whether areas more frequently used by red deer had higher questing tick densities. Results: Questing I. ricinus density was predicted by several landscape features, such as elevation, distance to the fjord and topographic slope. In addition, we found that areas more heavily used within the red deer home ranges, correlated with higher questing tick densities. Increased effects of deer space use were additive to the landscape model, suggesting that correlations were more than just shared landscape preferences between deer and ticks. Conclusions: Our results imply that the distribution of I. ricinus is controlled by a complex set of factors that include both local conditions related to landscape properties that affect survival and how the large host population redistributes ticks. In particular, we have provided evidence that the local distribution of large hosts, with their extensive space use, redistributes ticks at the local scale.

• Rivrud, Inger Maren; Bischof, Richard; Meisingset, Erling L.; Zimmermann, Barbara; Loe, Leif Egil & Mysterud, Atle (2016). Leave before it's too late: Anthropogenic and environmental triggers of autumn migration in a hunted ungulate population. Ecology.  ISSN 0012-9658.  97(4), s 1058- 1068 . doi: 10.1890/15-1191.1

Se alle arbeider i Cristin

• Rolandsen, Christer Moe; Våge, Jørn; Hopp, Petter; Benestad, Sylvie L.; Viljugrein, Hildegunn; Solberg, Erling Johan; Andersen, Roy; Strand, Olav; Vikøren, Turid; Madslien, Knut Ivar Engesæter; Tarpai, Attila; Fremstad, Jørn; Veiberg, Vebjørn; Heim, Morten; Holmstrøm, Frode & Mysterud, Atle (2021). Kartlegging og overvåking av skrantesjuke (Chronic Wasting Disease - CWD) 2020. NINA rapport. 1983. Vis sammendrag

  Denne rapporten oppsummerer arbeidet som er gjennomført i 2020 for å kartlegge forekomsten av CWD, etter at sykdommen ble påvist hos villrein og elg i 2016. Den oppsummerer også totalt antall hjortedyr som er testet i perioden 2016-2020. I 2020 ble 22 527 hjortedyr testet for CWD, og myndighetenes mål om testing av 22 000 hjortedyr ble dermed nådd. I løpet av året ble det påvist ett tilfelle av klassisk CWD hos en 8 år gammel villreinbukk på Hardangervidda og ett nytt tilfelle av atypisk CWD hos en 17 år gammel elgku i Steinkjer kommune. Totalt er det i perioden 2016-2020 påvist klassisk CWD hos 20 villrein, og atypisk CWD hos sju elgkyr og ei hjortekolle. Prøvetakingen i 2020 omfattet som tidligere både hjerneprøve og lymfeknuter (primært svelglymfeknuter). Av de innsamlede prøvene inneholdt 72 % begge vevstypene. Dette er noe lavere enn i 2019 og 2018 med henholdsvis 78 % og 80 %. Selv om det har vært god oppslutning om prøveinnsamlingen og det er et høyt antall testede dyr, er det utfordringer med dårlig kvalitet på en god del prøver og det er problemer med mangelfull registrering. For eksempel var 3 % av prøvene ikke merket med kommune eller område, 2 % manglet informasjon om art, og for 9 % av ville hjortedyr manglet informasjon om prøven kom fra jakt eller fallvilt. I 2020 ble det testet i overkant av 20 % av registrerte fallvilt av viltlevende hjortedyr, noe som er en lavere andel enn ønsket. I gjennomsnitt ble over 80 % av felte villrein i de ulike villreinområdene testet, men bare for 67 % av disse ble det sendt inn både hjerne og lymfeknute. Med prøver fra både lymfeknute og hjerne vil det ta kortere tid å få kunnskap om forekomst og prevalens i områder med smitte og vi kan raskere sannsynliggjøre fravær av CWD i områder uten smitte. Fremover er det viktig å avklare om klassisk CWD forekommer i andre områder, og særlig i områder nær Nordfjella og Hardangervidda. Et stort antall prøver er dessuten viktig for å øke kunnskapen om forekomsten av atypisk CWD hos hjortedyr. Kunnskapen som er ervervet så langt viser at det er viktig å kjenne alder på dyrene. Dette gjelder både for klassisk og atypisk CWD. Hjorter og elger fra Fennoskandia med påvist atypisk CWD har vært gamle dyr. Det er derfor fortsatt ønskelig å aldersbestemme hjortevilt i utvalgte områder de neste årene, både fallvilt og dyr som felles under jakta. Med bedre kunnskap om aldersfordelingen kan vi med større sikkerhet beregne forekomst av atypisk CWD, og eventuelt også klassisk CWD, i ulike bestander.

• Andersen, Oddgeir; Rolandsen, Christer Moe; Kaltenborn, Bjørn Petter & Mysterud, Atle (2020). Befolkningens vurdering av myndighetenes tiltak mot skrantesjuke. Resultater fra en spørreundersøkelse knyttet til uttaket av villreinstammen i Nordfjella sone 1. NINA rapport. 1653. Vis sammendrag

  I denne rapporten har vi undersøkt befolkningens syn på de tiltak som har blitt iverksatt for å bekjempe skrantesjuke. Vi ser spesielt på i hvilken grad de føler at myndighetene har gitt god nok informasjon og grad av tillit til de institusjoner som har vært delaktige i prosessen og forvaltningen av skrantesjuke. Dette ble gjort gjennom en spørreundersøkelse til tre intervjuutvalg som besto av personer bosatt i (1) Nordfjellaregionen, (2) Hardangerviddaregionen og (3) landet ellers. Flere har hørt mye eller veldig mye om skrantesjuke jo nærmere Nordfjella man kommer, og andelen er ganske høy (52 %) for hele utvalget sett under ett. I Nordfjellaregionen er det 9 % som svarer at de ikke har hørt om skrantesjuke, mens tilsvarende tall for landet ellers er 30 %. To av tre i landet ellers svarer at de har tillit til at forskerne har god nok kunnskap om skrantesjuke til å gi myndighetene gode råd. Andelen avtar jo nærmere Nordfjella man kommer, hvor om lag halvparten (48 %) mener dette. I landet ellers var det et flertall som var enig (69 % helt eller delvis enige) i beslutningen om å avlive all villrein i Nordfjella sone 1, mens i Nordfjellaregionen var det 40 % som var helt eller delvis enige. I landet ellers var 81% helt eller delvis enige i at det var riktig av myndighetene å handle raskt, mens det i Nordfjella var 49 % som mente dette. Nærmere 2 av 3 (64 %) i landet ellers var helt eller delvis enige i at myndighetene har håndtert situasjonen på en god måte, mens 38 % mente det samme i Nordfjella. Det var stor enighet i alle intervjuutvalgene (75-88 %) om at SNO sine profesjonelle jegere er velegnet til å foreta uttak av dyr når det gjelder smitterisiko. En noe lavere andel svarte at vanlige jegere er velegnede til å foreta alle typer uttak av hjortedyr, men fortsatt var det stor overvekt som sa seg helt eller delvis enig (62-73 %). De tre viktigste faktorene som medførte økende aksept for beslutningen om å avlive all villrein i Nordfjella sone 1 var: (1) Om man føler å ha fått tilstrekkelig med informasjonen av myndighetene. Litt over halvparten (57 %) mener myndighetene har gitt publikum tilstrekkelig informasjon, og de regionale forskjellene er ikke store. (2) Grad av tillit til nasjonale institusjoner som har vært delaktige i prosessen, og (3) bosted til informantene. Aksept for beslutningen om å avlive all villrein i Nordfjella sone 1 er økende med økende avstand fra Nordfjella. Tilliten til de ulike institusjonene som var involvert i prosessen som førte til vedtaket om sanering av villreinstammen var over middels god med skårverdier på ± 4 på en skala fra 1-5. Vår analyse indikerer at de to viktigste faktorene som påvirker tilliten til nasjonale institusjoner er om folk føler de har fått tilstrekkelig med informasjon og deres bosted. Tilliten øker med økende enighet i at myndighetene har informert tilstrekkelig, men er likevel mindre i Nordfjellaregionen enn i Hardangerviddaregionen og landet ellers. Samtidig viser analysene at grad av enighet og tillit påvirkes av flere forhold hvorav en av de viktigste er om folk føler de har fått tilstrekkelig med informasjon. Dette samsvarer godt med erfaringer fra USA hvor sykdommen har vært kjent i flere tiår, og hvor erfaringene viser viktigheten av å ha en veloverveid prosess med involvering av ulike interessegrupper som vil bli påvirket. I tillegg til biologisk kompetanse er derfor solid samfunnsvitenskapelig kompetanse helt nødvendig for å opprettholde tillit og minimere konflikter i fremtidige, kontroversielle naturforvaltningssaker.

• Rivrud, Inger Maren; Rolandsen, Christer Moe; Rauset, Geir Rune; Kvasnes, Mikkel Andreas Jørnsøn; Mysterud, Atle & Solberg, Erling Johan (2020). Hjorteviltpåkjørsler i Norge: Årsaksforhold, lokalisering, risiko og datakvalitet. NINA rapport. 1806.
• Rolandsen, Christer Moe; Våge, Jørn; Hopp, Petter; Benestad, Sylvie Lafond; Viljugrein, Hildegunn; Solberg, Erling Johan; Ytrehus, Bjørnar; Andersen, Roy; Strand, Olav; Vikøren, Turid; Madslien, Knut Ivar Engesæter; Tarpai, Attila; Fremstad, Jørn; Veiberg, Vebjørn; Heim, Morten; Holmstrøm, Frode & Mysterud, Atle (2020). Kartlegging og overvåking av skrantesjuke (Chronic Wasting Disease - CWD) 2016-2019. NINA rapport. 1818. Vis sammendrag

  Denne rapporten oppsummerer arbeidet som er gjennomført i 2019 for å kartlegge forekomsten av CWD, etter at sykdommen ble påvist hos villrein og elg i henholdsvis mars og mai 2016. Den oppsummerer også totalt antall hjortedyr som er testet i perioden 2016-2019. I 2019 ble 30 147 hjortedyr testet for CWD, og dermed ble myndighetenes mål om testing av 30 000 hjortedyr nådd. I 2019 ble det påvist to nye tilfeller av atypisk CWD, først hos en 20 år gammel elgku i Selbu kommune og senere hos en 12 år gammel elgku i Sigdal kommune. Totalt er det nå påvist atypisk CWD hos seks elgkyr og ei hjortekolle. Klassisk CWD er fortsatt kun funnet hos villrein fra sone 1 i Nordfjella villreinområde 2016-2018. Prøvetakingen i 2019 omfattet som i 2018 og tidligere, både hjerneprøve og lymfeknuter (primært svelglymfeknuter). Begge vevstypene var inkludert i 78 % av de innsamlede prøvene. Dette er omtrent på samme nivå som i 2018 (80 %). I det store og hele har innsamlingen vært preget av god oppslutning. Selv om det er tilfredshet med det høye antall testede dyr, er det utfordringer med innsendt vev av mangelfull kvalitet og med mangelfull registrering. For eksempel var 1,9 % av prøvene ikke merket med kommune eller område, 1,5 % manglet informasjon om art, og for 10,9 % av ville hjortedyr manglet informasjon om prøven kom fra jakt eller fallvilt. Andel fallvilt som er prøvetatt er lavere enn ønsket. Fremover er det spesielt viktig å avklare om klassisk CWD er tilstede i andre områder, og særlig i områdene nær Nordfjella. Et stort antall prøver er dessuten viktig for å utrede graden av smittsomhet for de tilfellene med CWD hos elg og hjort med atypiske karakteristika. Hos disse kan ikke smittestoff påvises i lymfeknutene. Dette til sammenlikning med CWD hos villrein, der man finner prioner også i lymfatisk vev. Kunnskapen vi har ervervet de tre siste årene viser hvor viktig det er å kjenne til alderen på dyrene som testes for CWD. Dette gjelder både for klassisk og atypisk CWD. Hjorten og elgene fra Fennoskandia med påvist atypisk CWD har vært gamle hunndyr. Som følge av denne kunnskapen, er det de neste årene ønskelig å aldersbestemme et større antall av hjorteviltet som testes for CWD, enn hva som er gjort tidligere. For fallvilt av elg, hjort, rådyr og rein er det aldri gjennomført systematiske aldersbestemmelser basert på tannsnitt. Fallvilt representerer en viktig risikogruppe for å avdekke sykdom i viltbestander. Med bedre kunnskap om aldersfordelingen hos fallvilt og felte dyr, vil det med større sikkerhet kunne beregnes forekomst av atypisk CWD, og eventuelt også klassisk CWD, dersom denne skulle dukke opp i nye bestander. I de neste 23 årene av kartleggingsprogrammet har NINA og Veterinærinstituttet derfor foreslått økt omfang på aldersanalyser av dyr som testes for CWD, både av fallvilt og dyr felt under jakt. Dette vil kunne gi et bedre kunnskapsgrunnlag for fremtidig kartlegging av CWD. I 2020 har myndighetene redusert målet om antall prøver fra 30 000 til 22 000. Dette skyldes i hovedsak at Mattilsynet i flere områder vil redusere testingen av tamrein fordi det her allerede har blitt testet et så høyt antall dyr tidligere år. Antall prøver av viltlevende elg og hjort som felles under jakt samt testing av slakt av oppdrettshjort, skal opprettholdes på omtrent samme nivå som i 2019. For fallvilt av både ville og tamme hjortedyr, er målet å få inn prøver fra så mange som mulig, kun med unntak av de som blir funnet så lenge etter dødstidspunktet at prøven ikke er egnet til undersøkelser.

• Atmeh, Kamal; Loison, Anne; Morellet, Nicolas; Hewison, A. J. Mark; Marchand, P.; Garel, Mathieu; Solberg, Erling Johan; Heim, Morten; Sæther, Bernt-Erik; Herfindal, Ivar; Mysterud, Atle; Meisingset, Erling L.; St-Laurent, Martin-Hugues & Péron, Guillaume (2019). Tell me how large ungulates move - I will tell you how they mate and reproduce..
• Rolandsen, Christer Moe; Våge, Jørn; Hopp, Petter; Benestad, Sylvie Lafond; Viljugrein, Hildegunn; Solberg, Erling Johan; Ytrehus, Bjørnar; Andersen, Roy; Strand, Olav; Vikøren, Turid; Madslien, Knut Ivar Engesæter; Tarpai, Attila; Fremstad, Jørn; Veiberg, Vebjørn; Heim, Morten & Mysterud, Atle (2019). Kartlegging av skrantesjuke (CWD) i 2016-2018. NINA rapport. 1711. Vis sammendrag

  Skrantesjuke (Chronic Wasting Disease - CWD) ble oppdaget hos villrein (Rangifer tarandus) og elg (Alces alces) våren 2016, og hos hjort (Cervus elaphus) høsten 2017. Dette var første gang sykdommen ble påvist i Europa. CWD forårsakes av opphopning av feilfoldede prionproteiner i hjernen og nervesystemet. Den klassiske formen for CWD er smittsom, alltid dødelig, og har evne til å spre seg mellom hjortedyrarter. Alvorlighetsgraden av denne sykdommen medførte at Mattilsynet og Miljødirektoratet initierte et storstilt nasjonalt prøvetakingsarbeid fra hjortedyr. Norsk institutt for naturforskning (NINA) og Veterinærinstituttet fikk ansvaret for å organisere innsamlingsarbeidet og gjennomføre nødvendige analyser av det innsamlede materialet. Ved utgangen av 2017 var det analysert prøver fra 35 794 individer. Flere funn av klassisk (smittsom) CWD hos villrein fra sone 1 i Nordfjella villreinområde, medførte statlig vedtak om å skyte ut hele denne delbestanden. Dette ble gjennomført vinteren 2017/2018. Ved inngangen til 2018 var det registrert 13 tilfeller av CWD hos villrein, tre tilfeller hos elg og ett tilfelle hos hjort. Tilfellene hos elg og hjort ble klassifisert som atypisk CWD. Dette er en type av sykdommen som trolig oppstår spontant, primært hos eldre individer, og som antas å ikke være smittsom, eller i så fall, ikke i samme grad som klassisk CWD. Innsamlingsarbeidet i 2018 avdekket ytterligere seks funn av klassisk CWD hos villrein. Alle disse stammet fra den statlige fellingen i Nordfjella sone 1. Det ble også funnet en elgku med atypisk CWD i Flesberg kommune i Buskerud. Arbeidet med å kartlegge forekomsten av CWD hos norske hjortedyr ble ytterligere intensivert i 2018. En medvirkende årsak til opptrappingen var EUs vedtak om å initiere et europeisk kartleggingsprogram. I 2018 ble det organisert innsamling av hjerneprøve og lymfeknuter fra elg, hjort og villrein felt under ordinær jakt i 125 kommuner, 21 villreinområder, og viltbehandlingsanlegg spredt rundt i landet. Innsamlingen ble utført av jegere på felte dyr. I tillegg ble alle landets kommuner bedt om å samle prøver fra fallvilt fra alle hjorteviltarter. Det ble også tatt prøver av slaktet tamrein fra 65 av landets 83 reinbeitedistrikter og fra annet oppdrettet hjortevilt (hjort, dåhjort). Myndighetenes mål for 2018 var prøver fra 30 000 individer. Formålet med innsamlingen var å få mer kunnskap om forekomst og geografisk utbredelse av CWD i Norge. Takket være en formidabel innsats fra jegere og representanter fra kommuner, villreinnemder, villreinutvalg, fjelloppsyn m.m., ble innsamlingsarbeidet i 2018 svært vellykket. Totalt ble det samlet inn og analysert prøver fra 33 656 hjortedyr. Av dette stammet prøvene fra 16 400 individer felt under jakt, 12 461 individer fra slaktet tamrein og 3743 individer fra fallvilt. I tillegg stammet 1052 prøver fra individer med ukjent opprinnelse. Prøvetakingen i 2018 omfattet både hjerneprøve og lymfeknuter (primært svelglymfeknuter). Over 80 % av de innsamlede prøvene inneholdt begge vevstypene. Dette er en vesentlig økning fra tidligere år. I 2018 har det også vært utøvd betydelig innsats fra Miljødirektoratet, Veterinærinstituttet og NINA med tilrettelegging av funksjonelle merkesystemer og løsninger for innsamling av individdata, rapportering av analyseresultater og informasjonsvirksomhet. Eksisterende løsninger fungerer godt, og sørger for god sporbarhet og rask resultatformidling. Det er imidlertid fortsatt forbedringspotensial med hensyn til ufullstendig merking av prøver og fortsatt utfordringer med varierende kvalitet på hjerneprøver som sendes inn. I 2019 er det myndighetens mål å opprettholde omfanget av overvåkingen på samme nivå som i 2018. Dette vil gjøres innenfor rammer definert av Mattilsynet og Miljødirektoratet.

• Solberg, Erling Johan; Rivrud, Inger Maren; Nilsen, Erlend Birkeland; Veiberg, Vebjørn; Rolandsen, Christer Moe; Meisingset, Erling L. & Mysterud, Atle (2019). Bestandsreduksjon av elg og hjort i Nordfjella-regionen i perioden 2019-2020. Forslag til avskytingsstrategier. NINA rapport. 1667.
• Hopp, Petter; Viljugrein, Hildegunn; Benestad, Sylvie Lafond; Våge, Jørn; Rolandsen, Christer Moe & Mysterud, Atle (2018). Evaluating freedom of chronic wasting disease in wild reindeer populations accounting for differential sensitivity during the course of infection.
• Mysterud, Atle; Kjørstad, Morten Andre; Meisingset, Erling L.; Rolandsen, Christer Moe; Solberg, Erling Johan & Strand, Olav (2018). Derfor merker vi dyr med GPS. Hjorteviltet.  ISSN 1502-3729.  28, s 20- 23
• Mysterud, Atle; Kjørstad, Morten Andre; Meisingset, Erling L.; Rolandsen, Christer Moe; Solberg, Erling Johan & Strand, Olav (2018). Merking gir verdifull informasjon. Nationen.  ISSN 0805-3782.
• Mysterud, Atle; Linnell, John Durrus & Odden, John (2018). Pattedyrene beveger seg mye mindre nær folk.. Aftenposten (morgenutg. : trykt utg.).  ISSN 0804-3116.
• Mysterud, Atle & Rolandsen, Christer Moe (2018). A reindeer cull to prevent chronic wasting disease in Europe. Nature Ecology and Evolution.  ISSN 2397-334X.  s 1- 3 . doi: 10.1038/s41559-018-0616-1
• Mysterud, Atle; Tranulis, Michael A. & Røed, Knut (2018). Skrantesyke hos villrein går ikke over av seg selv.. Aftenposten (morgenutg. : trykt utg.).  ISSN 0804-3116.
• Rolandsen, Christer Moe; Våge, Jørn; Hopp, Petter; Benestad, Sylvie Lafond; Mysterud, Atle; Viljugrein, Hildegunn; Solberg, Erling Johan; Ytrehus, Bjørnar; Strand, Olav; Vikøren, Turid; Madslien, Knut; Tarpai, Attila; Næss, Camilla; Haavardstun, Tom; Veiberg, Vebjørn; Heim, Morten & Rudningen, Kåre (2018). Kartlegging av skrantesjuke (CWD) i 2016 og 2017. NINA rapport. 1522.
• Viljugrein, Hildegunn; Jore, Solveig & Mysterud, Atle (2018). Emergence of tick-borne diseases at Northern latitudes in Europe: a comparative approach.
• Ytrehus, Bjørnar; Grahek-Ogden, Danica; Strand, Olav; Tranulis, Michael A.; Mysterud, Atle; Aspholm, Marina; Jore, Solveig; Kapperud, Georg; Møretrø, Trond; Nesbakken, Truls; Robertson, Lucy; Melby, Kjetil K. & Skjerdal, Olaug Taran (2018). Factors that can contribute to spread of CWD – an update on the situation in Nordfjella, Norway. Opinion of the Panel on biological hazards of the Norwegian Scientific Committee for Food and Environment. VKM Report. 2018:16.
• Ytrehus, Bjørnar; Hansen, Helge; Kapperud, Georg; Mysterud, Atle; Solberg, Erling Johan; Strand, Olav; Tranulis, Michael A.; Asmyhr, Maria Gulbrandsen & Grahek-Ogden, Danica (2018). The background for the management of CWD in Norway – scientific reasoning with high degree of uncertainty.
• Austrheim, Gunnar; Berger, Victoria; Daverdin, Marc; Gebreyohanis, Winta Berhie; Kolstad, Anders Lorentzen; Speed, James David Mervyn; Venete, Aurel M A; Hegland, Stein Joar; Meisingset, Erling L.; Mysterud, Atle & Solberg, Erling Johan (2017). SustHerb - towards sustainable herbivore management.
• Hansen, Helge; Kapperud, Georg; Mysterud, Atle; Solberg, Erling Johan; Strand, Olav; Tranulis, Michael A.; Ytrehus, Bjørnar; Gulbrandsen, Maria; Grahek-Ogden, Danica; Eckner, Karl Fredrich; Lassen, Jørgen Fr; Narvhus, Judith; Nesbakken, Truls; Robertson, Lucy; Rosnes, Jan Thomas; Skjerdal, Taran; Skjerve, Eystein; Vold, Line & Wasteson, Yngvild (2017). CWD in Norway – a state of emergency for the future of cervids (Phase II). Opinion of the panel on Biological Hazards. VKM Report. 2017:09. Fulltekst i vitenarkiv.
• Hopp, Petter; Mysterud, Atle; Benestad, Sylvie Lafond; Vikøren, Turid & Viljugrein, Hildegunn (2017). Skrantesyke. Resultater av overvåkingen 2016.
• Kjørstad, Morten Andre; Bøthun, Siri; Gundersen, Vegard; Holand, Øystein; Madslien, Knut; Mysterud, Atle; Nerhoel, Ingrid; Punsvik, Tor; Røed, Knut; Strand, Olav; Tveraa, Torkild; Tømmervik, Hans; Ytrehus, Bjørnar & Veiberg, Vebjørn (red.) (2017). Miljøkvalitetsnorm for villrein. Forslag fra en ekspertgruppe. NINA rapport. 1400. Vis sammendrag

  Bakgrunn og oppdrag Miljødirektoratet har etter oppdrag fra Klima- og miljødepartementet (KLD) oppnevnt en uav- hengig ekspertgruppe for utvikling av en miljøkvalitetsnorm for villrein. Norge er pålagt et spesielt internasjonalt ansvar for bevaring av villrein. Det overordnede målet er at villreinen, og de 23 ulike delbestandene, forvaltes på en slik måte at internasjonale forpliktelser overholdes, og at nasjonale målsettinger om ivaretagelse av levedyktige bestander innen økologisk fungerende leveområder nås (naturmangfoldloven § 5). Villreinen er en krevende art å forvalte. Den har en tilpasning til ekstremt vekslende sesongmes- sige beiteforhold som innebærer en ekstensiv arealbruk. Vinterstid innebærer det beiting på sår- bare og seintvoksende lavressurser. Det sesongmessige trekket mellom ulike beiteområder skjer i et fjellandskap der tilgjengelig areal blir stadig mindre og mer oppdelt hovedsakelig pga. økende grad av menneskelige inngrep og forstyrrelser. Forvaltningen av villreinen har derfor hovedsa- kelig handlet om a) å balansere reinstammen i forhold til de naturlige beiteressurser gjennom bestandsforvaltning og jakt, og b) å sikre villreinen leveområder i konkurranse med infrastruktur og ferdsel gjennom arealforvaltning. Villreinforvaltningen påvirker og påvirkes derfor av energi-, nærings- og infrastrukturutvikling samt nye rekreasjonstrender i bruk av fjellområdene. I tillegg står vi ovenfor nye utfordringer som klimaendringer og utbrudd av sykdommer. Ekspertgruppa har vurdert kunnskapsgrunnlaget om villrein generelt og for de 23 villreinområ- dene, samt identifisert måleparametere for tilstand og påvirkningsfaktorer. Klassifiseringssystem I ekspertgruppas mandat ble det understreket at klassifiseringssystemet for miljøkvalitetsnormen ikke burde være mer komplisert enn nødvendig. Det ble enighet om en tredelt skala (God, Mid- dels og Dårlig) med en fargeangivelse og -betydning med en klar «trafikklysanalogi». En finere inndeling ville gitt inntrykk av en større presisjonsgrad og detaljkunnskap enn det ekspertgruppa fant støtte for. Det påpekes at det bør gjøres vurderinger av usikkerhet knyttet både til begrenset kunnskap og naturlig variasjon, særlig i tilfeller der man havner i overgangen mellom Middels og Dårlig tilstand. TABELL NØKKELORD : villrein, miljøkvalitetsnorm, forvaltning, måleparametere, slaktevekt, eldre bukker, kalveproduksjon, genetisk variasjon, meldepliktig sykdom, lavbeiter, menneskelig påvirkning, fokus-område, funksjonsområde KEY WORDS : wild reindeer, environmental quality standard, management, measurement parameters, body mass, calf production, adult males, genetic diversity, notifiable diseases, lichen pastures, human disturbance, focal areas, functional areas

• Munkelien, Fredrik & Mysterud, Atle (2017). The distribution of small mammals and its relationship with ticks in two coastal areas of Norway through a population cycle.
• Mysterud, Atle; Viljugrein, Hildegunn; Hopp, Petter; Rolandsen, Christer Moe & Nilsen, Erlend Birkeland (2017). Utbruddet av skrantesyke er et tidsskille i norsk naturforvaltning. Aftenposten Vitenskap.  ISSN 2464-3033.
• Mysterud, Atle; Viljugrein, Hildegunn & Meisingset, Erling L. (2017). Hjortedyr, flått og Lyme borreliose. Hjorteviltet.  ISSN 1502-3729.  22, s 18- 21
• Linløkken, Harald & Mysterud, Atle (2016). Tick load and infection of tick-borne pathogens in small mammals.
• Loe, Leif Egil; Rivrud, Inger Maren; Meisingset, Erling L.; Bøe, Silje; Hamnes, Martine; Veiberg, Vebjørn & Mysterud, Atle (2016). Tidligere jaktstart fører til økt avskytning i hjortens sommerområder. Hjorteviltet.  ISSN 1502-3729.  s 79- 81
• Martinsen, Vegard; Mulder, Jan; Speed, James David Mervyn; Mysterud, Atle & Austrheim, Gunnar (2016). Grazing & treeline advance in alpine zones: Effects on ecosystem carbon stocks.
• Martinsen, Vegard; Mulder, Jan; Speed, James David Mervyn; Mysterud, Atle & Austrheim, Gunnar (2016). Results of long-term grazing Experiments in Norway - focus on C & N.
• Mulder, Jan; Martinsen, Vegard; Speed, James David Mervyn; Mysterud, Atle & Austrheim, Gunnar (2016). Grazing & treeline advance in alpine zones: Effects on ecosystem carbon stocks.
• Mulder, Jan; Martinsen, Vegard; Speed, James David Mervyn; Mysterud, Atle & Austrheim, Gunnar (2016). Treeline advance in alpine zones: Effects on ecosystem carbon stocks.
• Munkelien, Fredrik & Mysterud, Atle (2016). The distribution of small mammals and its relationship with ticks in two coastal areas of Norway through a population cycle.
• Mysterud, Atle; Viljugrein, Hildegunn & Meisingset, Erling L. (2016). Flåttnytt. Dagens næringsliv.  ISSN 0803-9372. Vis sammendrag

  Flåttbårne sykdommer øker, men ikke bare på grunn av flere hjortedyr. "Forskning viser at..."

• Mysterud, Atle; Viljugrein, Hildegunn & Meisingset, Erling L. (2016). Flåttnytt. Flåttbårne sykdommer øker, men ikke bare på grunn av flere hjortedyr. Dagens næringsliv.  ISSN 0803-9372.  s 29- 29

Se alle arbeider i Cristin