With its bright yellow plumage and distinctive black cap, the Wilson’s Warbler (Cardellina pusilla) is a favorite migrant to spot! This small, energetic songbird is a delight as it flits through shrubs and low branches in search of insects. Named after the ornithologist Alexander Wilson, this warbler is a neotropical migrant, spending its breeding season in northern North America and wintering in Central America. 

Wilson’s Warblers are tiny birds, measuring about 4.3–4.7 inches (11–12 cm) in length and weighing only 0.2–0.3 ounces (6–10 g). Their rounded bodies, thin pointed bills, and constant movement make them easy to distinguish. Males are recognized by their bright yellow body and black cap, while females lack the distinct black cap and are a slightly duller shade of yellow.

Habitat

Wilson’s Warblers prefer moist, shrubby habitats, especially near streams and wetlands. They breed in boreal forests, montane regions, and willow thickets across North America. During migration, they can be found in a wide variety of habitats, including gardens, parks, and woodlands, before reaching their wintering grounds in Mexico and Central America.

Food Preferences

Wilson’s Warblers primarily feed on insects and other small invertebrates. They are expert foragers, gleaning caterpillars, beetles, spiders, and flies from leaves and branches. Occasionally, they will hover briefly to catch flying insects. While they rarely visit feeders, providing native plants that attract insects can help draw them to your yard.

Mating and Raising Young

During the breeding season, males sing a quick, chattering song to defend their territory and attract mates. Courtship involves males chasing females through dense vegetation, displaying their agility and persistence. Once paired, females construct a well-hidden, cup-shaped nest close to the ground, often in dense undergrowth or among the roots of trees.

Females lay 3–6 eggs, which they incubate for 10–13 days. Once hatched, the nestlings are fed a diet of insects by both parents. Young Wilson’s Warblers grow quickly and fledge within 8–10 days, gaining independence soon after as they prepare for migration.

Attracting and Spotting Wilson’s Warblers

Though they rarely visit feeders, you can attract Wilson’s Warblers by creating a bird-friendly habitat with native plants, shrubs, and a water source. Providing a dense understory mimics their natural habitat, making them more likely to stop by during migration.

If you want to spot a Wilson’s Warbler, listen for their distinctive, chattering song and watch for their quick, darting movements through low shrubs and trees. They are often found near water, so checking riparian areas during spring and fall migration can increase your chances of seeing one.

Conservation Concerns

Wilson’s Warblers face threats from habitat loss, particularly in their wintering grounds and along migration routes. Deforestation, climate change, and collisions with glass buildings all contribute to population declines. Protecting their breeding and wintering habitats, along with promoting bird-friendly building designs, can help conserve these vibrant songbirds.

 

Do you have a favorite memory of spotting a Wilson’s Warbler?

As discussions continue about renaming birds that currently bear people’s names, what alternative name would you suggest for the bright little Wilson’s Warbler? Share your thoughts social media!