Estimation of snowshoe hare population density from turd transects

We counted the number of snowshoe hare (Lepus americanus) fecal pellets on 50 quadrats of 0.155 m2 on each of six areas near Kluane Lake, Yukon Territory, once a year from 1977 to 1983. On four of these areas we livetrapped hares once a month and estimated population density from the Jolly–Seber model. Average hare density for the year was linearly related to fecal pellet counts (r = 0.94) over the range 0–10 hares/ha. Mean turd counts also are related to the variance of these counts by Taylor's power law with exponent 1.30, indicating a clumped pattern in turd deposition. Fecal pellet counts provide a quick and accurate method for snowshoe hare censuses on an extensive scale.

Territory size and ownership in red squirrels: response to removals

We monitored size and ownership of red squirrel territories in the southwestern Yukon during the summer following a year of abundant cone crop. Territory boundaries were determined by observing marked individuals. Six individuals and two groups (four individuals per group) were removed to test the hypothesis that the position of territory boundaries are determined by intruder pressure. Removed squirrels were replaced by juveniles or by breeding females which had given up their former territories to their offspring. Replacement occurred within hours of the removal and territory boundaries of the new squirrels were not significantly different from those of the original territory owners. Neighbouring territorial residents did not expand their territories to occupy all or part of the vacated area. The location of territory boundaries were not affected by intruder pressure.