Comparative Winter Habitat Use and Associations among Herbivores in the High Arctic

Abstract

We studied winter habitat use and interspecific associations among large- and medium-sized herbivores on southeastern Victoria Island, Arctic Canada, by documenting the deposition of feces in relation to vegetation. Associations between ptarmigan ( Lagopus spp.), arctic hares ( Lepus arcticus ), caribou ( Rangifer tarandus ), and muskoxen ( Ovibos moschatus ) were assessed using the Jaccard Index (JI) and chi² at two scales, i.e., with 1 m² and 1 ha as sampling units. JI values for species pairs were greater at the larger scale, but chi² revealed significant (positive) associations only at the smaller scale and only between arctic hares and caribou and between arctic hares and ptarmigan. Comparative use of habitats was described with respect to vegetation by canonical correspondence analysis (CCA). Ptarmigan and muskoxen were most strongly correlated with lowland vegetation and caribou with upland vegetation; arctic hares were intermediate. CCA also indicated rather wide separation in the multivariate space, further suggesting distinct patterns of habitat use. The results imply that these species were segregated in their use of resources in this High Arctic environment. Key words: arctic hare, caribou, habitat selection, interspecific relationships, multivariate, muskox, niche, ptarmigan, spatial scale