Squirrel Nests

Once the leaves have fallen, you may notice a large ball of leaves about thirty feet above the ground and close to the trunk of a tree.  This is most likely a drey, a squirrel’s nest.  The drey starts as a ball of small branches harvested while the leaves are still green.  Because the tree has not begun the process of losing its leaves for the winter, they remain attached throughout the winter.  This outer layer serves both as camouflage and waterproofing.  The inner chamber of the drey is lined with items such as moss, lichens, grass, feathers, and fur for warmth and comfort.  The single entrance will generally be concealed and face the trunk.

Squirrels typically build two or more dreys and will abandon one if it is discovered by predators or infested with parasites such as lice or fleas.  Squirrels breed twice a year, generally in June and January.  Many squirrels will choose to den in a tree cavity rather than a leaf drey during the winter and kittens (or pups, depending on who you ask) born in cavities are about 60% more likely to survive.  If not breeding two or more squirrels may share a drey for warmth.  This collection of squirrels, by the way, is called a scurry.