Black-and-white Warbler

Mniotilta varia


Early Spring Date: March 31
Late Spring Date: May 28
Most Frequently Seen: April 27 - May 12

Black-and-white Warblers are one of the most common warblers at Monticello Park in the spring. They start to arrive in mid-April and are seen in good numbers during the last week of April through the middle of May. Their breeding range includes much of the eastern half of the United States, and they prefer deciduous woods near water. They nest in the Washington metro area, but not at Monticello.

Where to See Them in the Park

The Black-and-white Warbler is the only warbler species at Monticello who regularly forages by hopping along the branches and trunks of trees or on logs. Sometimes, Black-and-white Warblers will hop on a branch without seeming to care that people are nearby. They often go into the stream to drink and bathe.

Physical Description


Black-and-white Warbler Male
Male - Photo by Michael Pollack

Black-and-white Warblers look like little escaped convicts as they hop along branches in their striped plumage. Their hind toe is longer than the hind toe of other warbler species, allowing them to move more easily when hopping on trees. They have thicker legs than other warbler species for the same reason.

Black-and-white Warbler Male
Male - Photo by William Young

They have a pointed bill that curves slightly downward. The male has a black cheek.

Black-and-white Warbler Female
Female - Photo by Michael Pollack

The female does not have a black cheek and is not as heavily streaked below.

Vocalizations

The song of the Black-and-white Warbler resembles a squeaky wheel — wee-sa, wee-sa, wee-sa, wee-sa. It is similar to the high-pitched two-part song of the Bay-breasted Warbler, but is usually delivered from lower in the trees.

Hear the songs of the Black-and-white Warbler.

Notes


Black-and-white Warbler Sunning Behavior
Sunning Behavior - Photo by William Young

The Black-and-white Warbler above looks dead, but she was merely sunning herself in the middle of the day at Monticello. Sometimes, birds expose themselves to direct sunlight to try to kill parasites in their feathers. Most birds have no ill effects from feather parasites. In addition to sunning, birds also get rid of parasites by preening, dust bathing, and even rolling in ant swarms — it is thought that the parasites are killed by the formic acid released by the angry ants. More than 200 species of songbirds are known to engage in anting. Sometimes instead of ants, birds will use sumac berries, beetles, and even smoldering cigarette butts.

Origin of Names

Common Names: Black-and-white from the plumage. The New World Warblers were named for their similar appearance to European warblers, to whom they are not related. Most of the New World warblers do not warble (sing continuously with notes that change frequently).
Genus Name: Mniotilta means "moss-plucking", from the way they forage along trees.
Species Name: Varia is Latin for "varied", from the black-and-white plumage.

Black-and-white Warbler video footage

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