Red squirrels (Tamiasciurus hudsonicus) defend individual, food-based territories year round. These territories are crucial for overwinter survival, yet some female red squirrels in northern populations bequeath their territories to offspring and search for a new one. Bequeathal involves active, strategic dispersal by breeding females. Our study documents this unusual behavior and investigates its correlates in two red squirrel populations in northern Canada. Thirty percent of breeding females dispersed. Bequeathal was related to breeding date, with late-breeding females more often dispersing, but was not related detectably to female condition or territory quality. As an underlying trade-off, early-born juveniles more likely acquired a territory independently, but early-breeding females lost mass and may have increased their risk of territory loss. We suggest that bequeathal has evolved as a consequence of condition dependence in breeding date coupled with limited resources.

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