Black-and-white warbler

Mniotilta varia

Photo by A.J. Hand (Connecticut Ornithological Association)

Common name:

black-and-white-warbler (en); riscadinha (pt); paruline noir et blanc (fr); chipe rayado (es); baumläuferwaldsänger (de)

Taxonomy:

Order Passeriformes

Family Parulidae

Range:

This birds breed throughout the eastern United States and much of Canada. They migrate south to winter from southern Florida through the Bahamas, Mexico, Central America, and the Caribbean and into northern South America in Venezuela, Colombia, Ecuador and northern Peru.

Size:

Black-and-white warblers are 11-13 cm long and have a wingspan of 18-22 cm. They weigh 8-15 g.

Habitat:

They breed in mature and second-growth deciduous and mixed forests, requiring large trees and a dense understory. They winter in a variety of forests from high-elevation cloud forests to lowland evergreen and deciduous forests, woodland borders, gardens, and coffee plantations.

Diet:

Black-and-white warblers are insectivorous, gleaning caterpillars, flies, bugs, beetles, borers, spiders, larvae, and egg masses along branches and trunks from the canopy to the ground.

Breeding:

These birds breed in April-August. They build an open cup of dry leaves, grass, bark, and pine needles, lined with fine grasses, horsehair, and moss, usually placed on the ground next to a tree. There the female lays 4-6 white eggs speckled with brown and light purple. The eggs are incubated by the female alone for 10-12 days. The chicks are fed by both parents and fledge 8-12 days after hatching, but remain in the parents' territory for another 2 to 3 weeks.

Conservation:

IUCN status - LC (Least Concern)

This species has a very large breeding range and a global population of 14 million individuals. The population has undergone a small decline over the last 40 years, mostly due to forest fragmentation and increased parasitism by cowbirds. There is also evidence that pesticide use has had a negative effect on this species.