Yellow-Rumped Warbler

The Yellow-Rumped Warbler seems to be the bird of a thousand faces. Browse through the photos on the Cornell Lab of Ornithology's identification page ^[1] and you'll see different birds in an array of color—striking slate grays, deep blacks, soft browns—all threaded together with a common theme: yellow.

So, why the fashion show? One reason is because the males and females look different, and as the seasons change, so do their colors. Yellow-Rumped Warblers also come in several sub-species, each with a distinct look. In the United States, there are two: the Myrtle and the Audubon's.^[2]

This bird, perched daintily on a branch, is a Myrtle. 

Myrtles and Audubon's were considered different species until 1973, and they have some differences.^[3] Myrtles are more common in the east, while Audubon's are more common in the west. Breeding Myrtles also have white throats, as compared to the bold yellow of the Audubon's.^[4]

But enough about differences. What do they have in common?

Both birds have yellow butts.^[4] (At least, a little. It's like a spot of yellow.) Yellow can also be found on their sides where the chest meets the wing—you can see this on the Myrtle above.^[4, 5]. And importantly, where their ranges meet, they will interbreed, one reason the species were combined.^[3] Enter the Myrtle x Audubon's, an intergrade warbler with characteristics of both sub-species.^{[1, 6]}

One other cool thing about the Yellow-Rumped Warbler is what it eats. In the summer, it mostly snacks on insects, but in the winter, it switches to berries.^[5] The Myrtle got its name is because it loves myrtle berries.^[7] This is a special trait, since other warblers can't eat the wax in the fruit. ^[8] You'll also find it munching on fruit from poison ivy!^[5]

I haven't observed too many Yellow-Rumped Warblers while knowing what I was looking at. (I identified the one above at home.) However, from what I have seen and read, I like how they seem bright and independent. A 1940 copy of Pearson's Birds of America described the Myrtle as moving "with more deliberation than is characteristic of many members of this essentially restless and somewhat nervous family" (p. 129).^[7]

I also think the fact that they can eat berries from poison ivy and loved one food so much that a sub-species is named after it is pretty cool. If you were nicknamed after your favorite food, what would it be? 

Another Yellow-Rumped Warbler from a different day.
You can just faintly see the splash of yellow on its rump.

The Details:

Common Name: Yellow-Rumped Warbler

Scientific Name: Setophaga coronata

Order: Passeriformes

Family: Parulidae

Seen: In a tree near a lake (top photo) and hopping around on twigs near a pipe in freshwater (bottom photo)

Month: November 2023 (top photo) and February 2024 (bottom photo)

Range: Together, all of the Yellow-Rumped Warbler sub-species (including those not mentioned in this post) cover an impressive range across the United States, Canada, Mexico, and beyond.^[9] If you live in the contiguous U.S., the Yellow-Rumped Warbler's range will likely reach your state while it's in one of its phases: breeding, non-breeding, or migratory. Take a look at its range map on the Cornell Lab's website to see where it travels.

Learn More About Yellow-Rumped Warblers:

1. Cornell Lab of Ornithology. (n.d.). Yellow-Rumped Warbler: Identification. All About Birds.
2. American Bird Conservancy. (n.d.). Yellow-Rumped Warbler.
3. Tennessee Wildlife Resources Agency. (n.d.). Yellow-Rumped Warbler.
4. Kaufman, K. (2000). Field guide to birds of North America. Hillstar Editions.
5. Missouri Department of Conservation. (n.d.). Yellow-Rumped Warbler.
6. Sibley, D. A. (2000). The Sibley guide to birds. Chanticleer Press.
7. Pearson, T. G. (Ed.). (1940). Birds of America. Garden City Publishing Company. 
8. Cornell Lab of Ornithology. (n.d.). Yellow-Rumped Warbler: Overview. All About Birds.
9. Cornell Lab of Ornithology. (n.d.). Yellow-Rumped Warbler: Range map. All About Birds.