For backyard naturalists, Eastern fox squirrels are one of Colorado’s easiest and most entertaining species to watch. They are active during the day year-round. While other tree squirrel species stick to wild areas, fox squirrels are right at home in urban and suburban settings. They love places where trees are widely spaced and the understory is open and can be found along the cottonwood-lined creeks on Colorado’s eastern plains and in foothill pine forests.
Fox squirrels are medium-sized tree squirrels with long, furry tails. They vary in color, but most commonly the reddish-brown fur is tipped with grayish-brown, giving these squirrels a frosted look. The fur on their belly is always lighter in color. Fox squirrels have very sharp claws and powerful hind legs and are excellent climbers. They take to the trees when danger threatens. They are impressive jumpers, jumping as much as fifteen feet from branch-to-branch. They frequently chase each other up and down trees and across yards and clearings. Their long bushy tails help them balance when running, jumping, and walking.
Eastern fox squirrels use tree holes for nesting and raising their young. Where tree holes are scarce, they build nests of leaves and twigs high up in larger trees. Leaf nests have a side entrance and are lined with shredded material. Each squirrel usually maintains three to six active nests.
Fox squirrels are omnivores, eating everything from seeds, nuts and plant parts to insects, birds, and carrion. Their diet depends on what is available in the area in which they live. Unfortunately, backyard birdfeeders are often a favorite target of these squirrels. They are "scatter hoarders", which means that they hide small amounts of food in various locations and go back to find it later.
Fox squirrels communicate many ways. They use a variety of sounds, including barks, chatters, distress screams, and high-pitched whines. They use scent marks. They also communicate through behavior. They will, for example, threaten one another by standing upright and flicking their tail over their back.
Courtship between males and females is very complex and dramatic, and so is the conflict among males to establish dominance in the neighborhood. Females can begin to have babies at six months old and have one or two litters per year. Babies are born naked and develop fur after two weeks. They open their eyes at about one month and begin to climb about the tree when they are seven or eight weeks old. They can climb down to the ground at about ten weeks. When they first emerge, young squirrels forage with their mother, learning how to eat various foods, and getting into all kinds of mischief. They are independent by the fall of their first year.
If you are ready to watch fox squirrels, you probably won’t have to travel far. No equipment needed. Even without a pair of binoculars you can see plenty of squirrelly behavior. Check your backyard, local parks, or any area with scattered, deciduous trees.