From steps to home range formation: species‐specific movement upscaling among sympatric ungulates

Abstract

Summary Animals move to interact with the environment in order to find food resources and cover. Intrinsic characteristics affecting feeding and antipredatory strategies likely shape variation in movement patterns and home range formation between individuals, populations and species. Browsing herbivores selectively forage on patchily distributed resources in areas with more canopy cover, whereas mixed feeders and grazers feed on more open grasslands and tend to aggregate as an antipredatory strategy. We therefore predicted that at small temporal scales, browsers will show greater net displacements (i.e. typical of searching patterns) than mixed feeders or grazers; but at larger temporal scales, we expect the opposite pattern, since gregarious species will need to use larger areas to feed the whole herd. We also predicted that the feeding/antipredatory strategy will determine the behavioural responses to other environmental factors. To test this, we compared spatial movement patterns at multiple scales (from 20‐min intervals to annual home ranges) of three sympatric, similar‐sized, alpine ungulates which differ in their feeding/antipredatory strategy: roe deer (solitary browsers), mouflon (gregarious grazers) and chamois (intermediate feeders in smaller groups). We used location data from GPS‐collared females of the three species in the French Alps. As predicted, we found that multi‐scale spatial patterns depended on the feeding/antipredatory strategy. Browsers foraged within smaller range areas, searching back and forth. Mixed feeders and, especially, grazers covered larger areas, presumably to satisfy herd needs. The feeding/antipredatory strategies also determined the interspecific variability in behavioural responses to factors such as maternal status, weather, habitat type or human disturbance, supporting our hypothesis. Exploring interspecific variability, we showed how movement behaviour and home range formation vary substantially, even among species within the same guild. This mechanism might be important to maintain intra‐guild multi‐species associations and increase biodiversity, through contributing to niche segregation and, thus, coexistence.

Migration in geographic and ecological space by a large herbivore

“…In contrast, higher proportions of forest may provide increased shelter and protection for resident roe deer (Tablado et al. ), emphasizing the importance of the ratio of costs and benefits of migration. Interestingly, Tablado et al.…”

“…Interestingly, Tablado et al. () found that roe deer concentrate their movement in fairly small areas selecting higher quality food and are able to forage optimally due to their solitary social system. Thus, if fine‐scale forage diversity is sufficiently high in resident ranges, residency may be the more beneficial tactic for this small browser.…”

“…Because variation in NDVI was higher for migrants, likely due to migration to higher elevations with more diverse and less continuous cover types, we assume that overall forage heterogeneity was higher for migrants, allowing them to be more selective. In contrast, higher proportions of forest may provide increased shelter and protection for resident roe deer (Tablado et al 2016), emphasizing the importance of the ratio of costs and benefits of migration. Interestingly, Tablado et al (2016) found that roe deer concentrate their movement in fairly small areas selecting higher quality food and are able to forage optimally due to their solitary social system.…”

“…In contrast, higher proportions of forest may provide increased shelter and protection for resident roe deer (Tablado et al 2016), emphasizing the importance of the ratio of costs and benefits of migration. Interestingly, Tablado et al (2016) found that roe deer concentrate their movement in fairly small areas selecting higher quality food and are able to forage optimally due to their solitary social system. Thus, if fine-scale forage diversity is sufficiently high in resident ranges, residency may be the more beneficial tactic for this small browser.…”

Revisiting the functional response in habitat selection for large herbivores: a matter of spatial variation in resource distribution?

“…This species is so a particularly relevant model to seek for a functional response vis-à-vis a continuously distributed resource variable, which can be characterized by both a mean value and a spatial variation. We leveraged a unique combination of three large data sets on habitat characteristics (distribution, composition, and biomass of plant communities) defined through remote sensing and field sampling (Duparc et al 2012;Duparc 2016), individual habitat use obtained by GPS collars (Tablado et al 2016), and diet, determined using DNA barcoding (Bison 2015;Thuiller et al 2017). More specifically, we determined the shape of the functional response by comparing habitat selection patterns among individuals from several subpopulation units monitored throughout the growing season.…”