Happy Mystery Monday! Can you guess what is pictured in photo #1?
The answer to last week’s mystery is the nest of a tree swallow, Tachycineta bicolor, pictured in photo #2.
The nest of tree swallows, Tachycineta bicolor, belongs to a native North American bird and one of the best-studied species on the continent. Though tree swallows are often seen swooping over open, treeless areas near water, their name comes from their habit of nesting in tree cavities. These habitats provide both nesting sites and the flying insects that make up much of their diet.
Tree swallows are cavity nesters, relying on natural holes in dead trees, old woodpecker cavities, or human-made nest boxes. Inside the cavity, the female builds a loose cup of dry grass, pine needles, weed stalks, and rootlets, shaping it with her body until it forms a nest about two to three inches across. She does most of the construction, sometimes taking several days to two weeks to finish.
What makes a tree swallow nest especially distinctive is its feather lining. Males gather many of the feathers, though females collect them too, and early in the nesting season they may even appear to display or play with them. The finished nest may contain feathers from many kinds of birds, including herons, vultures, owls, ducks, woodpeckers, and even domestic birds. This soft lining helps protect the eggs and young, though nest cavities remain vulnerable to predators such as snakes, raccoons, chipmunks, weasels, crows, kestrels, and other wildlife.
Mystery Monday is sponsored by the Spy Newspapers and Adkins Arboretum.