How to test habitat selection at the home range scale: A resampling randomwindows technique

Habitat selection studies at the home range scale involve testing whether a n animal selects a particular spatial arrangement of habitats within a land scape. We propose a technique based on comparing the landscape pattern indi ces (LPIs) of observed home ranges with those of a large sample of random w indows. In order to determine the appropriate, size of the windows, we exam ined how this variable influences LPIs in a 138-km(2) boreal forest block w here clearcuts were prevalent. Square random windows of three different siz es (289, 729, and 1156 ha) yielded similar habitat composition proportions but very different values for many of the other LPIs. When compared with va lues computed for the entire landscape as a single window, most LPIs except composition were very different in the random windows. An example of a com parison between marten (Martes americana Turton), home ranges (n = 11) and square random windows (n = 100) in our study area is given, showing a stron g selection for mosaics containing more forest (> 30 years), fewer open reg enerating stands, and a larger amount of core area in forest. We conclude t hat computing LPI values for the entire landscape as a single window is ina ppropriate for testing habitat selection at the home range scale, and that windows of similar size as the home ranges should be used instead.