Golden-winged warbler

Appearance

This is a small warbler, measuring 11.6 cm long, weighing 8–10 g, and having a wingspan range 20 cm. The male has black throat, black ear patch bordered in white, and a yellow crown and wing patch. Females appear similar to males, with a light gray throat and light gray ear patches.

In both sexes, extensive white on the tail is conspicuous from below. Underparts are grayish white and the bill is long and slender. Unlike most warblers, juveniles can be reliably sexed approximately 15 days after fledging.

Naming

The genus name "Vermivora" is from Latin "vermis" "worm", and "vorare", "to devour", and the specific "chrysoptera" is from Ancient Greek "khrusos", "gold", and "pteron", "wing".

Habitat

Golden-winged warblers are neotropical-nearctic migrants, and their habitat selectivity varies seasonally. Golden-winged warblers wintering in Costa Rica select premontane evergreen forest rather than tropical dry forest plant communities. Golden-winged warblers forage in hanging dead leaves, which are often a result of intermediate disturbances to the forest plant community.

During the breeding season, golden-winged warblers nest in shrubland and regenerating forest communities created and maintained by disturbance. This dependency on early-successional plant communities is part of the reason golden-winged warbler populations are declining.

Evolution

Golden-winged warblers are migratory, breeding in eastern North America and wintering in southern Central America and the neighboring regions in Colombia, Venezuela, and Ecuador. They are very rare vagrants elsewhere.

Golden-winged warblers breed in open scrubby areas, wetlands, and mature forest adjacent to those habitats. They lay 3–6 eggs in a concealed cup nest on the ground or low in a bush.

Golden-winged warblers feed on insects, spiders, and caterpillars. They have strong gaping musculature around their bill, allowing them to uncover hidden caterpillars.

Their song is variable, but is most often perceived as a trilled "bzzzzzzz buzz buzz buzz". The call is a buzzy "chip" or "zip".

Male Golden-winged warblers use their brilliant yellow crowns, black throats, and white tail feather patches to signal habitat quality. Birds with more ornate ornaments protect higher quality territories and are typically less aggressive than their less brilliantly-colored conspecifics. However, ornamentation has not been shown to be linked with overall reproductive success. This is likely because golden-winged warblers with less ornamentation likely compensate for this with increased aggression.

Five geotracked golden-winged warblers in Tennessee were observed migrating hundreds of miles south, presumably avoiding tornadic storms, in April 2014. Individuals left prior to the arrival of the storm, perhaps after detecting it due to infrasound.