The spatial structure of habitat selection by caribou (Rangifer tarandus caribou) in Newfoundland: new multi-scaled approaches with applications to limiting factors

Habitat selection is a multi-scaled phenomenon. Selection depends on the scales perceived by organisms, while our ability to detect selection depends on analytical scale. Traditional studies of habitat selection have been limited by the use of discrete, arbitrary scales, because a quantitative basis has not existed for evaluating how animals perceive the availability of habitat. I developed new approaches based on common geostatistical and spatial analyses that use continua to represent multi-scaled winter habitat selection by caribou (Rangifer tarandus) from the perspective of the organisms, letting their responses define the scales of analysis. Caribou responded most strongly at the feeding area level, at distances up to 13 km, and at scales of patchiness of about 1 ha. Although habitat selection among levels of behaviour was hierarchical, caribou selected habitat variables across overlapping scale domains, suggesting that limiting factors were not hierarchically constrained. My results implicate habitat heterogeneity as an underlying cause of multi-scaled habitat selection