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Abstract Foraging behaviors often involve trade‐offs between predation risk and access to forage. Risk‐forage trade‐offs may be particularly acute for maternal female ungulates, whose nutritional needs are high and whose calves are highly vulnerable to predation. In moose, the selection of calving habitat is one way in which females can respond to these trade‐offs. Our objective was to compare among‐individual variation in selected habitat for maternal and nonmaternal female moose during the calving season. We hypothesized that, compared to nonmaternal females, maternal females would exhibit a greater range of variation among individuals, which may signal differential responses to risk‐forage trade‐offs. Meanwhile, we expected nonmaternal females to show comparatively less variation among individuals, consistent with a group primarily maximizing forage intake. To test our hypotheses, we used a path selection framework and a set of continuous remotely sensed map covariates to build predictive models and corresponding spatial predictions for maternal and nonmaternal groups. We then calculated the range of variation among individuals within each group along a relative unitless axis, which we call the “maternal difference index” and define as the divergence of predicted maternal habitat selection from nonmaternal habitat selection. We included 10,080 GPS collar locations for 24 female moose over three consecutive years. Our predictive models had high levels of accuracy (>75%) based both on independent test partitions of a nested cross‐validation and on independent very high frequency (VHF) location data, each including spatial and temporal replication. Both groups of females preferred areas where primary forage species were abundant, diverse, and within foraging height. Habitat selected by the maternal group both overlapped and was broader than habitat selected by the nonmaternal group. Based on the maternal difference index, maternal individuals were less consistent in their habitat selection than nonmaternal individuals. Given that habitat selection behaviors are one way in which animals respond to potential risk‐forage trade‐offs and that maternal individuals in our study differed along a continuum in their selection for primary forage species, we suggest that the concept of maternal trade‐offs, as it relates to habitat selection, is most useful when seen as individually determined and variable, rather than group‐determined and discrete.

The northern bog lemming Synaptomys borealis (NBL) is a rare small mammal that is undergoing a federal Species Status Assessment (SSA) under the US Endangered Species Act. Despite a wide North American distribution, very little is known about NBL dietary or habitat needs, both of which are germane to the resiliency of this species to climate change. To quantify diet composition of NBL in Alaska, we used DNA metabarcoding from 59 archived specimens to describe the taxonomic richness and relative abundance of foods in recent diets. DNA analyses revealed a broad diet composed of at least 110 families and 92 genera of bryophytes (mosses and liverworts), graminoids, fungi, forbs, and woody shrubs. Nine bryophyte genera and Carex sedges composed the largest portions of NBL diets. To quantify habitat preference, we intersected 467 georeferenced occurrence records of NBL in Alaska with remotely sensed land cover classes and used a compositional analysis framework that accounts for the relative abundance of land cover types. We did not detect significant habitat preferences for specific land cover types, although NBL frequently occurred in evergreen forest, woody wetlands, and adjacent to water. Our research highlights the importance of bryophytes, among a high diversity of dietary components, and describes NBL as boreal habitat generalists. Results will inform the current federal SSA by quantifying the extent to which ecological constraints are likely to affect NBL in a rapidly changing boreal environment.

Foraging behaviors often involve trade‐offs between predation risk and access to forage. Risk‐forage trade‐offs may be particularly acute for maternal female ungulates, whose nutritional needs are high and whose calves are highly vulnerable to predation. In moose, the selection of calving habitat is one way in which females can respond to these trade‐offs. Our objective was to compare among‐individual variation in selected habitat for maternal and nonmaternal female moose during the calving season. We hypothesized that, compared to nonmaternal females, maternal females would exhibit a greater range of variation among individuals, which may signal differential responses to risk‐forage trade‐offs. Meanwhile, we expected nonmaternal females to show comparatively less variation among individuals, consistent with a group primarily maximizing forage intake. To test our hypotheses, we used a path selection framework and a set of continuous remotely sensed map covariates to build predictive models and corresponding spatial predictions for maternal and nonmaternal groups. We then calculated the range of variation among individuals within each group along a relative unitless axis, which we call the "maternal difference index" and define as the divergence of predicted maternal habitat selection from nonmaternal habitat selection. We included 10,080 GPS collar locations for 24 female moose over three consecutive years. Our predictive models had high levels of accuracy (>75%) based both on independent test partitions of a nested cross‐validation and on independent very high frequency (VHF) location data, each including spatial and temporal replication. Both groups of females preferred areas where primary forage species were abundant, diverse, and within foraging height. Habitat selected by the maternal group both overlapped and was broader than habitat selected by the nonmaternal group. Based on the maternal difference index, maternal individuals were less consistent in their habitat selection than nonmaternal individuals. Given that habitat selection behaviors are one way in which animals respond to potential risk‐forage trade‐offs and that maternal individuals in our study differed along a continuum in their selection for primary forage species, we suggest that the concept of maternal trade‐offs, as it relates to habitat selection, is most useful when seen as individually determined and variable, rather than group‐determined and discrete. [ABSTRACT FROM AUTHOR]

Abstract Small mammals are under‐represented in conservation research relative to other mammals. We assessed the conservation status of 36 small mammal species in Alaska, USA using the Alaska Species Ranking System (ASRS). We also surveyed taxonomic experts to identify threats, conservation actions, and research priorities for five small mammal species of high conservation priority. The ASRS evaluates species' population status, biological vulnerability, and information needs. According to this ranking system, 86% (n = 31) of species were of moderately high conservation priority. Species of highest priority included three species endemic to Alaska and four bats (Order Chiroptera). Most species (n = 24) had low biological vulnerabilities, but high information needs. Taxonomic experts identified direct and indirect climate change effects as important threats for three of the five species assessed. They listed population monitoring, habitat modeling, genetic diversity, and response to climate change as high priorities for future research. Agencies can use the ASRS with expert elicitation to set priorities for research and monitoring. For example, we highlight the need to monitor population trends, which were unknown or uncertain for all species. Finally, we underscore the importance of accounting for data deficiencies to avoid conflating sparse information with low conservation priority.

Subarachnoid neurocysticercosis can be challenging to recognize, which often leads to a delay in diagnosis. We report 3 cases presenting as chronic headache disorders that highlight the unique manifestations seen with this form of neurocysticercosis and the role that the infectious diseases consultant can play in ensuring a timely diagnosis. [ABSTRACT FROM AUTHOR]

Although travel in deep snow imposes high energetic costs, animals can mitigate these costs through behavioural adaptations. For example, they can select habitats with shallower or more supportive snow. It is less well known, however, if animals select for favourable snow conditions at the scale of the step, i.e., along the travel paths themselves. We snow-tracked grey wolves (Canis lupus L., 1758) over 187 km and used a paired design to compare snow conditions on travel paths to snow 1 m and10 maway. Snow on travel paths was 3.2 cm shallower than measurements1 m away, except when wolves travelled on linear features recently compacted by humans. In those cases, the mean difference in snow depth increased to 17.5 cm. Our analyses suggest that, under natural snow conditions, wolves are limited in the fine-scale differences they can achieve along their travel paths. By creating areas with highly favourable snow conditions, anthropogenic activities drastically change the winter landscape, with potential implications for energetics and predator--prey dynamics. Key words: adaptations, boreal, Canis lupus, grey wolf, carnivore, least cost, morphology, movement path, seismic lines, snow, winter. Si les deplacements dans la neige epaisse imposent de forts couts energetiques, les animaux peuvent attenuer ces couts par des adaptations comportementales. Ils peuvent par exemple selectionner des habitats presentant de la neige moins epaisse ou plus portante. Il n'est cependant pas bien etabli que les animaux selectionnent des conditions de neige favorables a l'echelle du pas, soit le long du trace de leurs deplacements. Nous avons suivi les traces dans la neige de loups gris (Canis lupus L., 1758) sur 187 km et utilise un schema jumele pour comparer les conditionsde la neige le long du trace de deplacements a celles de la neige a 1 m et a 10 m de ce trace. L'epaisseur de la neige le long du trace etait de 3,2 cm inferieure aux epaisseurs mesurees a 1 m, sauf quand les loups se deplacaient le long d'elements lineaires recemment compactes par des humains. Dans ces cas, la difference moyenne d'epaisseur de la neige passait a 17,5 cm. Nos analyses portent a croire que, dans des conditions naturelles d'enneigement, les loups sont limites en ce qui concerne les differences a petite echelle qu'ils peuvent obtenir le long des traces de leurs deplacements. En creant des zones offrant des conditions de neige tres favorables, les activites humaines modifient radicalement le paysage hivernal, ce qui peut avoir des repercussions sur l'utilisation d'energie et la dynamique predateurs--proies. [Traduit par la Redaction] Mots-cles : adaptations, boreal, Canis lupus, loup gris, carnivore, moindre cout, morphologie, trace de deplacement, lignes de sondage sismique, neige, hiver., Introduction In northern regions, the winter season presents particular challenges for wildlife because food becomes scarcer and because thermoregulation and locomotion become costlier. For mammals restricted to life at the [...]

Mammalian predators encounter unique hunting challenges during the winter as snow increases the cost of locomotion and influences predator-prey interactions. Winter precipitation may also affect predators' ability to detect and pursue prey. We investigated the effects of snowfall events on grey wolves (Canis lupus) in a boreal forest ecosystem in northeastern Alberta, Canada. We predicted that wolves would respond to snowfall events by reducing their travel speed and the time they spent travelling. Over the course of two winters, we used remote cameras to identify localized snowfall events and estimate snow depth. We used telemetry data from 17 wolves to calculate travel speed and time spent travelling versus resting. Data were categorized by time of day (night versus day) and time since snowfall events, and analyzed using linear and logistic regression mixed-effects models. We found that wolves were less likely to travel on dates of snowfall events than any date prior to or after an event. Wolves also travelled slower during snowfall events, but only when compared to their travel speed 24 hours before. Effects were most pronounced at night, when movements appeared to be consistent with hunting behavior, and activity levels resumed within 24 hours of a snowfall event. Including snow depth as a variable did not improve model fit. Collectively, our findings suggest that wolves' response is not driven by increased hunting success or by energetic considerations resulting from increased snow depth. Instead, we propose that wolves reduce their activity levels because precipitation dampens hunting success. Snowfall events may impact wolves' ability to detect prey and changes in prey behavior could also lead to decreased encounter rates. We encourage scientists to further investigate the effects of short-term weather events on movement rates and predator-prey interactions.