Golden-crowned Warbler

The Golden-crowned Warbler, scientifically known as Basileuterus culicivorus, is a diminutive and vibrant member of the New World warbler family. This species boasts a length of approximately 12.7 cm (5.0 inches) and a weight near 10 grams (0.35 ounces). Its upperparts are a subtle grey-green, while the underparts are a striking bright yellow. The warbler's head is adorned with a grey background, featuring a black-bordered yellow crown stripe. A yellow or white supercilium and a distinct black eyestripe complete its head pattern. Both sexes exhibit similar plumage, though the immature birds are somewhat duller, browner, and lack the full head pattern, retaining only the eyestripe.

Identification Tips

When attempting to identify the Golden-crowned Warbler, look for the characteristic yellow crown stripe bordered by black, as well as the yellow or white supercilium and black eyestripe. The contrast between the grey-green upperparts and bright yellow underparts is also a key feature. Juveniles may be trickier to identify due to their more muted coloration and absence of the full adult head pattern.

Habitat

This warbler is typically found in lowland forests, where it thrives in the dense understory.

Distribution

The Golden-crowned Warbler has a broad range, breeding from Mexico, through Central America, and extending down to northeastern Argentina and Uruguay. It can also be found on the island of Trinidad.

Behaviour

These warblers are insectivorous, feeding primarily on insects and spiders. They exhibit a fascinating defensive behavior when their nest is threatened, with parent birds feigning injury to distract and lead potential predators away from their offspring.

Song & Calls

The Golden-crowned Warbler's song is a high-pitched and thin series of notes, often transcribed as "pit-seet-seet-seet-seet." Its call is a sharp "tsip," which can be heard throughout its habitat.

Breeding

Breeding behavior includes the construction of a domed nest, often situated in a bank or under forest floor debris, such as leaves. These nests are sometimes placed near forest paths for ease of access. The warbler lays a clutch of two to four white eggs, each delicately spotted with rufous markings.

Similar Species

The Golden-crowned Warbler has 13 geographical races that are divided into three groups, which can sometimes be confused with one another. The Central American culicivorus group, or stripe-crowned warbler, closely resembles the general description provided. The southwestern cabanisi group, or Cabanis's warbler, differs with grey upperparts and a white supercilium. The aureocapillus group from the southeast, also known as the golden-crowned warbler, features a white supercilium and an orange-rufous crown stripe. These groups are occasionally considered separate species due to their distinct plumage variations.

Diet and Feeding

The diet of the Golden-crowned Warbler consists mainly of insects and spiders, which they forage for in the understory of their forested habitats.

Conservation status

The IUCN Red List currently classifies the Golden-crowned Warbler as Least Concern, indicating that, at present, there are no immediate threats to its population numbers that would warrant a higher level of conservation concern.