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

摘要: Most habitats are distributed heterogeneously in space, forcing animals to move according both habitat characteristics and their needs for energy safety. Animal space use should therefore vary characteristics, a process known as the "functional response" selection. This response has often been tested vis-a-vis proportion of category within areas available individuals. Measuring sought-after resources landscape where they continuously is challenge we posit here that mean availability resource its spatial variation be measured. Accordingly, functional selection these two descriptors mountain herbivore. We hypothesized decrease with value increase variation. Based on GPS data from 50 chamois females actual foodscape (i.e., distribution edible-only biomass landscape), estimated individual ratio (during summer months) at home range level, comparing edible ranges standard deviation range. Chamois being group-living species, accessible were shared by several individuals formed socio-spatial groups (clusters) population. As expected, ratios increased each cluster, but unlike our prediction, was unrelated mean. Selection richer hence did not fade away when more average, result may explained need this capital breeder species accumulate fat-reserve high rate during months. Low could limit chamois, which highlights importance