The effect of snow depth on movement rates of GPS-collared moose

During deep snow conditions, wildlife must balance between minimizing movements to conserve energy while seeking high amounts of browse to gain the energy. Knowledge of how snow begins to hinder their movements is therefore vital when predicting their wintertime behavior. We assessed the phenomenon with moose. Movement data from 122 GPS-collared moose were integrated with snow depth data from designated measurement stations. The effects of increasing snow depths on moose movement rates were then modeled with spline regression. The study was conducted in Finland, between 2009 and 2011. The moose were known for their sex and for the presence of calf at heel. On average, the movement rates decreased sharply until snow depths of ca. 30–40 cm, after which further significant decreases were not seen. The movement rates decreased from several kilometers per day to less than 500 m per day. Moose in the northernmost study area with the deepest snow covers moved as much as the moose in the other areas with less snow. Although we saw differences in the movement rates between males and females, differences between individuals were markedly higher than those caused by sex or a calf at heel. Moose are keystone species whose heavy browsing, especially during winter, can have profound effects on vegetation and forest regeneration. As snow covers in large parts of the boreal zone are predicted to decrease due to warming climate, the wintertime movements of moose and how they affect the local vegetation will remain relevant questions.

Habitat Selection by Brown Bears with Varying Levels of Predation Rates on Ungulate Neonates

In northern Eurasia, large carnivores overlap with semi-domestic reindeer (Rangifer tarandus) and moose (Alces alces). In Scandinavia, previous studies have quantified brown bear (Ursus arctos) spring predation on neonates of reindeer (mostly in May) and moose (mostly in June). We explored if habitat selection by brown bears changed following resource pulses and whether these changes are more pronounced on those individuals characterised by higher predatory behaviour. Fifteen brown bears in northern Sweden (2010–2012) were fitted with GPS proximity collars, and 2585 female reindeers were collared with UHF transmitters. Clusters of bear positions were visited to investigate moose and reindeer predation. Bear kill rates and home ranges were calculated to examine bear movements and predatory behaviour. Bear habitat selection was modelled using resource selection functions over four periods (pre-calving, reindeer calving, moose calving, and post-calving). Coefficients of selection for areas closer to different land cover classes across periods were compared, examining the interactions between different degrees of predatory behaviour (i.e., high and low). Bear habitat selection differed throughout the periods and between low and high predatory bears. Differences among individuals’ predatory behaviour are reflected in the selection of habitat types, providing empirical evidence that different levels of specialization in foraging behaviour helps to explain individual variation in bear habitat selection.

There’s no place like home — site fidelity by female moose (Alces alces) in central Ontario, Canada

Site fidelity is thought to provide increased fitness through familiarity with the distribution of forage, protective cover, breeding and offspring rearing sites, and predators. For moose (Alces alces (Linnaeus, 1758)), previous research has documented fidelity at varying spatial scales. Our objective was to build on this knowledge and assess fidelity by adult female moose in two areas of central Ontario, Canada (Algonquin Provincial Park (APP) and Wildlife Management Unit 49 (WMU49)). We used global positioning system data to generate mean weekly locations for collared moose, then measured the distance between paired weekly locations among consecutive years to evaluate site fidelity. We tested for effects of study area, biological season, moose age, and reproductive status using generalized linear mixed models. Moose demonstrated stronger site fidelity in WMU49, an area with more anthropogenic disturbance, than the protected area, APP. Fidelity was weakest in the winter, but was similar among other seasons and was independent of maternal age and the presence of a calf. Our study highlights the need to consider the scale of site fidelity relative to habitat management. Actions aimed at supporting moose populations might benefit more by protecting habitat classes selected by moose rather than specific sites used by individuals.