January 16, 2013 —
When the winds howl and sleet sheets across the landscape, our fellow feathered residents adapt to challenging conditions in a variety of ways.
Some of the most visible can be observed by paying attention to the trees we see, inspecting their trunks for openings and peering up at their tops for collections of leaves, branches or twigs.
Cavity nesters, such as red-bellied woodpeckers and yellow-bellied sapsuckers, excavate holes in trees, thereby providing shelter and nest sites.
Bird nests are sometimes recycled for use by other species, as well as by fellow birds. As Bernd Heinrich notes in “Winter World,” wood ducks, mergansers and bufflehead ducks utilize old holes drilled by pileated woodpeckers.
Woodpeckers go to great trouble to make new nest cavities each year, he writes. “There is then a yearly progression of fresh empty apartments for flying squirrels, crested flycatchers, barred owls and potentially bats.” Gray squirrels, for example, will often take advantage of such cavities in which to build nests and raise young.
Some birds even create temporary housing intended for one-time usage. Grouse, which typically roost in dense coniferous trees, may excavate tunnels ending in a small cave in insulating snow.