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Tree Cavities

Gray Squirrels Mating & Making Nests

Gray Squirrels have two breeding seasons, one from December – March and another May – July (most females mate in the latter season and only mate once a year).  At this time of year, polygamous male Gray Squirrels are aggressively chasing and checking out females to see if they are in estrus and if they are receptive. (An unreceptive female squirrel lets all suitors know in no uncertain terms – using claws and teeth – that she is not interested.)  Male Gray Squirrels can smell females in estrus as far as half a mile away, so the woods are full of hopeful males these days.

Frequently litters this time of year are born in a tree cavity, while the second, late-summer litter is born in a leaf nest (drey).  Cavities obviously offer more protection from the elements and predators than do leaf nests. Most den cavities have been created by decay, lightning, or woodpeckers and are lined with dry leaves, shredded bark and grasses. (Photo:  Gray Squirrel collecting American Beech leaves to be used as a lining for her cavity nest.)

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