Bird of the Week: Yellow-rumped Warbler

Photograph by Emily Turteltaub Nelson

Species: Yellow-rumped Warbler, Setophaga coronata

Family: Parulidae

Sign: Capricorn  

Favorite hobby: Entomology 

Dear reader, 

The Yellow-rumped Warbler is the first warbler I ever learned to identify. Like the sparrow and sandpiper species, warblers are a grouping of birds that are difficult to get the hang of differentiating at first, but become distinctive with time. Of the sprawling Parulidae, or New World Warbler, family, the Yellow-rumped Warbler is surely the most ubiquitous in the US, the Pacific Northwest being largely a breeding region for them with small pockets of year-round, nonbreeding, and migratory. They hang  around in Oregon during the winter when most warblers have made the journey to warmer places. In the summer, Yellow-rumped Warblers are insect eaters, which they catch by hunting them in the bark of trees as they climb them vertically or flitting out from a branch to catch passing insects like a flycatcher. Like the Cedar Waxwing, they enjoy berries and fruit in the winter, and flock in Bayberry shrubs, Junipers, and Dogwoods. One of the primary reasons Yellow-rumped Warblers winter so much further north than other warblers is that their digestive systems are uniquely suited to fruits, unlike the majority of their family. They are asserted as the most versatile of warblers in their foraging, switching their diets between the spring and summer and fall and winter. They have also been spotted using even more interesting techniques to acquire insects than a flycatcher style, including picking insects off of seaweed, skimming the surfaces of bodies of water, plucking them off of spider webs, and browsing manure for flies. You could never say a Yellow-rumped Warbler is not resourceful!

Yellow-rumped Warblers are small birds, and received their name from the patch of yellow on their back above their tail. They also have streaks of yellow on their sides, throat, and the top of their heads. Further, they are a medium gray, have speckled black on their breasts, and white primary coverts on their wings. They can be a little duller in the winter, with a bit more brown instead of gray. In different regions in the U.S., however, Yellow-rumped Warblers look quite different. Warblers are some of the birds with the most contentious relationship with species distinction: the Myrtle Yellow-rumped Warbler and Audubon’s Yellow-rumped Warbler used to be distinctive species of warblers, but were separated in the last century into the former Eastern subspecies and latter Western subspecies. There are two other forms as well, the Black-fronted and Goldman’s Warblers, that reside respectively in Chihuahua and Durango, Mexico, and a small region of Guatemala and Chiapas, Mexico. There is contention around these species classifications, as many believe that the Yellow-rumped Warbler should be split up into its four species, discarding the overarching classification.

There is a possibility in the future that the Audubon’s and Myrtle Warbler might reemerge. Like many of the debates over species and subspecies of birds, there seems to be no end to the complicated process of classification. Regardless, the Yellow-rumped Warbler continues to be a lovely, flitting inhabitant of the canyon and the wider Reed campus. Look out for them in the conifers, where they make their nests, or in fruit-laden trees with their flock.