Tree Swallow

Except during the winter, Tree Swallows are abundant  at the Nisqually national wildlife refuge. Erika and I photographed this individual on 26 April 2021. If you see then well, separating Tree from Violet-green swallows is not too difficult. For one thing, the white on the throat does not curl up behind the Tree Swallow’s eye. The messed feathers on this bird gave me pause. This ruffle may be evidence of the bird’s brood patch. If so, this swallow is probably a female, as only they have brood patches (a single, unfeathered, vascularized area used to warm the eggs in the nest). Indeed, with few exceptions and during very cold weather, male Tree Swallows rarely incubate the eggs (Winkler et al. 2020).