Habitat quality influences population distribution, individual space use and functional responses in habitat selection by a large herbivore

Abstract

Identifying factors shaping variation in resource selection is central for our understanding of the behaviour and distribution of animals. We examined summer habitat selection and space use by 108 Global Positioning System (GPS)-collared moose in Norway in relation to sex, reproductive status, habitat quality, and availability. Moose selected habitat types based on a combination of forage quality and availability of suitable habitat types. Selection of protective cover was strongest for reproducing females, likely reflecting the need to protect young. Males showed strong selection for habitat types with high quality forage, possibly due to higher energy requirements. Selection for preferred habitat types providing food and cover was a positive function of their availability within home ranges (i.e. not proportional use) indicating functional response in habitat selection. This relationship was not found for unproductive habitat types. Moreover, home ranges with high cover of unproductive habitat types were larger, and smaller home ranges contained higher proportions of the most preferred habitat type. The distribution of moose within the study area was partly related to the distribution of different habitat types. Our study shows how distribution and availability of habitat types providing cover and high-quality food shape ungulate habitat selection and space use.Electronic supplementary materialThe online version of this article (doi:10.1007/s00442-011-2072-3) contains supplementary material, which is available to authorised users.

Telemetry and random‐walk models reveal complex patterns of partial migration in a large marine predator

“…Although previous studies have applied BBMMs to satellite or GPS tracking data (Horne et al 2007, Bjørneraas et al 2012, ours is the first to adapt this tool to electronic presence/absence data. By doing so, we reveal the details of complex partial migration in a large marine top predator, and the environmental conditions that explain them.…”

“…One technique for doing this is Brownian bridge movement models (BBMM), which are stochastic models used to generate utilization distributions (UD) and predict the probability of animals moving between habitats (Horne et al 2007). BBMMs have been used previously to generate expected movement trajectories and thereby estimate home ranges, migration corridors, and the effects of habitat features on movements, but they have not been applied to acoustic monitoring data (e.g., Horne et al 2007, Sawyer et al 2009, Bunnefeld et al 2011, Bjørneraas et al 2012. One of the key issues with studies of partial migration is that the correct spatial and temporal scales must be chosen so that these movements can be observed (Chapman et al 2012a).…”

Large-scale spatiotemporal variation in road mortality of moose: Is it all about population density?

“…1) are typically also characterized by low altitude, less broken topography, and with roads distributed more evenly throughout the moose range. Hence, although moose tend to have smaller home ranges (Bjørneraas et al 2011) and show less seasonal movements in more productive areas (Hjeljord 2001), proportionally more moose are likely to live close to a road in Southeast Norway than in the low density counties further north. We are currently using GPS-collared moose to explore such interactions between moose behavior and landscape characteristics on the risk of MVC.…”

Geographic Cline in the Shape of the Moose Mandible: Indications of an Adaptive Trend

“…Moose exhibit clear sexual size dimorphism as well as behavioral differences in habitat selection, use, and foraging (Nikula et al 2004;Garel et al 2006;Bjørneraas et al 2011;Bjørneraas et al 2012). Barboza and Bowyer (2000) hypothesized that the sexual segregation in dimorphic ungulates is a consequence of the differing life-histories and energetic needs among males (body and antler growth) and females (gestation and lactation).…”

“…We likely have managed only to scratch the surface of the true quantity of the morphological variation and plausible adaptive potential possessed by this species. These features together with the very flexible behavior (e.g., Bjørneraas et al 2011Bjørneraas et al , 2012Eldegard et al 2012;Melin et al 2014) would give at least a partial explanation for the success and extensive range of the moose. …”