Another colourful bird that visits the Pacific Northwest coastal region is the yellow warbler. This bird is not endemic and may be found anywhere from Alaska to Peru. The male has thin red streaks on its chest and a red cap. It is common throughout the coast, especially found in alder and trembling aspen groves.
The yellow warbler is a small songbird with a thin pointed beak. It is mostly yellow in color and the male has reddish streaks on his chest. The yellow warbler stands around 13 cm in height and has a wingspan of up to 20 cm. The yellow warbler has indistinct yellow wing bars, yellow spots on its tail, and black eyes which are surrounded by indistinct yellow eye-rings.
To distinguish between male and female yellow warblers, you have to observe their chest features. As mentioned above, the male has reddish streaks on his chest and the female has duller coloring with very faint red streaks or no streaks at all.
Young yellow warblers are similar to the adult female, but paler and duller, usually without reddish chest streaks. Their yellow tail spots are reduced and are more faded.
Males arrive on the breeding grounds and claim territory, the females arrive a few days later. Pairs form shortly after the females arrive. The female constructs the nest, usually on a conifer tree branch, although deciduous trees and shrubs are also used. The nest is a small cup of grass, moss, twigs, and rootlets, lined with plant down and feathers, the feathers curve over the rim of the nest, forming a windbreak for the eggs. The female lays up to 5 eggs and incubates them for about 12 days. The male feeds the female at the nest during this time and occasionally will help to incubate them, giving the mom a chance to stretch her wings. After the youngsters leave the nest at around 2 weeks after they hatch, the parents will continue to feed them until they can fly. They can make short flights within a few days of leaving the nest.
The yellow warbler feeds on insects and occasionally fruit. Yellow warblers forage insects and will also catch them on the fly.