After leaves fall, dense balls of leaves become easier to spot in the branches. Many are dreys built by eastern gray or eastern fox squirrels, although not every clump is a squirrel nest.
Built for survival
A drey begins with a rough framework of twigs. Squirrels layer leaves through the frame and form a protected inner chamber lined with softer plant material. Missouri Department of Conservation describes leaf nests averaging about 40 feet high, though some are much lower.
Leaf nests provide places to rest, escape weather, and sometimes raise young. Squirrels may use more than one nest or cavity within their home range, moving as conditions, food, parasites, or disturbance change.
Drey or tree cavity?
Gray and fox squirrels use both. Tree cavities generally provide better protection from severe weather and predators and are especially important in winter and for nurseries. Leaf nests can be built where cavities are scarce or near a valuable food source.
A stewardship connection
Dreys are a visible reminder that cover comes in many forms. Mature trees, den cavities, connected woodland, and nut-producing species such as oaks, hickories, walnuts, and pecans provide the shelter and food Missouri tree squirrels need.
Steward’s Fact A squirrel may use two or more tree cavities—or a cavity and a leaf nest—at the same time.
Next time you are outdoors after leaf fall, look up. Once you recognize the shape and placement of dreys, you may be surprised by how many have been above you all along.