Stoats can range over enormous areas, which are very hard to document. One might comment that the huge home ranges of the New Zealand and Scottish males might be possible only because these stoats are relatively large, except that the small males studied by Lisgo (1999) in Alberta maintained home ranges averaging 150 ha. At the other extreme, the small stoats of Ontario and Switzerland have home ranges nearer in size to those of common weasels (Table 8.1).
By comparing all these stories, from repeated studies done both in their natural homelands and in New Zealand, we can make a few secure generalizations about spacing behavior of stoats.
1. The home ranges of males are larger than those of females, and members of each sex mostly do not use the same ground at the same time; both differences are likely to be correlated with the different hunting strategies of the two sexes, which in turn is linked (but not directly) to the difference in their average body sizes (Chapter 4) and diets (Chapter 5).
2. In both sexes, home range sizes are determined by an interaction between body size and prey density; stoats of all sizes need larger home ranges when prey are scarce.
3. Stoats are perpetually hungry and may need to hunt at any time of the day or night. Theory predicts that the home ranges of predators should be large and have the least overlap when prey are scarce, but still be able to support a healthy predator population (Carpenter & MacMillen 1976; Powell 1987; Powell 1994). But because home ranges are not a fixed character in stoats, some exceptions to these generalizations (Alterio 1998) are always to be expected.
Was this article helpful?