Black-and-white Warbler

If you're strolling along one day and hear what sounds like a squeaky wheel in a tree, you may have stumbled across a Black-and-white Warbler. Their song sounds like "we-see" over and over, like a wheel that could use some oil (have a listen!).^{[1, 2]} But their sound is only one of many ways they are unique.

The Black-and-white Warbler differs from other warblers in many ways. First is how it looks for food. Other warblers like to fly as they hunt, but Black-and-white Warblers prefer to creep along the branches.^[3] Their bill is also longer and more curved than other warblers, great for grabbing insects hiding within crevasses.^[4] They also have a unique migratory schedule. Starting in late March, earlier than many other warblers, they'll migrate by night up to their breeding ranges in the eastern U.S. and southern Canada.^[1,5,6] Their wintering range is generally from Florida on southward.^[4,6]

When I saw this bird, it was doing what it was known for: creeping along the branches, presumably looking for food. They eat a wide range of bugs, including caterpillars, beetles, ants, and more.^[5] It was a beautiful day, and it was fun to guess at where it would pop out next. This bird is a male, which we can tell by its cheeks. For males, the cheek area behind their eyes is completely black.^[7] For females, the feathers there are paler.

When it's time to nest, the female will build a cup-shaped nest at the base of a tree or in a rock or log hollow.^[1] Common building materials include bark and grasses, lined with moss and other soft things.^[1,8] For extra protection, the nest may be covered with leaf litter.^[9] The mother also incubates 4-6 eggs for about a week and a half.^[1,5,8] A writer in the early 1930s observed a pair of nesting Black-and-white Warblers and noted that he did not see the father incubating the eggs, but did observe him occasionally “singing softly near the nest.” ^[10]

Once born, both parents feed the babies.^[5] If a predator comes near, the mother may attempt to distract the predator away from the babies by dragging her wings on the ground.^[1] What a noble parent! Before the babies have even mastered the art of flying, they'll venture out into the big wide world, just under two weeks old.^[5]

Overall, Black-and-white Warblers are very unique, from how they sound to how they feed, travel, and nest. Keep an ear out for a squeaky wheel sound in a tree, and you might find one!
 

The Details: 

Common Name: Black-and-white Warbler

Scientific Name: Mniotilta varia

Order: Passeriformes

Family: Parulidae

Seen: Creeping round the branches of an oak tree.

Month: January '26

Range:  Black-and-white Warblers have a wide range. At various points in the year and their migration schedule, you can find them in Canada all the way down to the northern part of South America.^[7] They are not found in many western states in the U.S. In the U.S., they are typically found from eastern Montana and eastward. However, the Cornell Lab notes that sometimes they can be found wintering in Baja California. The Cornell Lab also has a helpful range map.

Learn More About Black-and-white Warblers:

1. Alsop, F. J. (2002). Birds of North America (American ed.). Dorling Kindersley Limited.
2. Cornell Lab of Ornithology. (n.d.). Black-and-white Warbler: Sounds. All About Birds.
3. Pranty, B., Radamaker, K, & Kennedy, G. (2006). Birds of Florida. Lone Pine.
4. Tennessee Wildlife Resources Agency. (n.d.). Black-and-white Warbler: Mniotilta varia.
5. Kaufman, K. (1996). Lives of North American birds. Houghton Mifflin. 
6. Cornell Lab of Ornithology. (n.d.). Black-and-white Warbler: Range map. All About Birds.
7. Cornel Lab of Ornithology. (n.d.). Black-and-white Warbler: Identification. All About Birds. 
8. Missouri Department of Conservation. (n.d.). Black-and-white Warbler.  
9.  MassWildlife. (2025, May 14). Black-and-white Warbler. Mass.gov. 
10. Smith, W. P. (1934).  Observations of the nesting habits of the Black and White Warbler. Bird-Banding, 5(1), 31-35. https://doi.org/10.2307/4509294