A ll three tree squirrels build nests of leaves or needles depending on habitat. Fox squirrels eat fruit, nuts and buds, and bury nuts for winter. P redators vary with habits and habitat. Fox squirrels spend some time on the ground and are killed by coyotes and foxes. Magpies, hawks and snakes eat nestlings.
Martens are a major predator on pine squirrels.
The forest-dwelling goshawk eats Abert's squirrels. T ree squirrels have two litters of two to five young, one litter in spring, the other in early summer. Gestation is five weeks for chickarees, and up to seven weeks for their larger cousins.