Have you spotted these nests in your neighborhood? These are called dreys. Tree squirrels and flying squirrels build them out of leaves, grass, bark, and twigs in the forked branches of trees, when cavity nests aren’t available. A pair of male and female squirrels will often share a drey until the female becomes pregnant, but Dad later leaves to give room to the new babies.
Dreys are much more common today than they were hundreds of years ago. Squirrels— particularly flying squirrels— prefer to nest in the hollow cavities of old trees. These cavity nests keep them much safer from predators, and much warmer in chilly weather. But, since old-growth forests are now rare, squirrels have been forced to adapt to nesting in dreys, where they are 40% more likely to die as babies.
It’s easiest to spot dreys this time of year, when trees are still bare. Do you have dreys in your neighborhood right now?