Dispersal of Young in Red Squirrels (Tamiasciurus hudsonicus)

Abstract

-To examine how young red squirrels (Tamiasciurus hudsonicus) disperse, I used focal animal observations and radio-telemetry to monitor the activities and movements of six young squirrels from the time they emerged from the nest until they dispersed. Before dispersal, young squirrels spent most of their time within their mothers' territories, which served as natal ranges during the predispersal period. During the dispersing period, young squirrels explored far away from their natal ranges during the day but returned at night until they had established territories of their own. Some young squirrels never displayed this exploratory behavior and eventually claimed territories within their natal ranges. Regardless of whether young squirrels dispersed away from or claimed territories in their natal ranges, they emitted territorial calls significantly more often during the postdispersal period than in the predispersal period. In addition to the six young squirrels that were followed, two other marked young squirrels were sighted in the spring after their birth, and their dispersal distances were calculated. The median dispersal distance for eight young was 100 m, with four remaining in their natal ranges and four dispersing away.