This week’s Bird of the Week, compliments of the Weminuche Audubon Society and Audubon Rockies, is the yellow-rumped warbler.
If you live near or visit aspen and mixed conifer forests in our area, you are likely to see this week’s bird — the yellow-rumped warbler. Most common in our area in the spring, summer and fall months, they are widespread across North America, migrating to southern regions or Central America in the winter. As their name implies, they exhibit distinctive yellow patches on the underside of their neck, just below their shoulder, and at the base of their tails, the latter yellow patch giving them the alternative common name butter butts. The rest of their body is gray to black in color with white fringes on the backs of their wings. As with many bird species, males are more distinctively colored than females.
Yellow-rumped warblers are sparrow-sized, but are one of the larger new-world warblers. True generalists in their dietary preferences, they can be observed “sallying” out from tree branches to catch flying insects, but may also dine on more sedentary insects such as grasshoppers, weevils, ants or spiders. When available, they also feed on fruits and berries, including the fruits of bayberry and wax myrtle, which contain waxes that many other bird species are unable to digest. If you have a bird feeder, the best foods to attract them are sunflower seeds, raisins, suet or peanut butter.
Females construct their cup-like nests out of twigs, pine needles and such, with preferred nesting sites on the branches of conifers. They lay up to six eggs per clutch, with one or two broods per year.
While the population numbers of the yellow-rumped warbler are generally stable, a decline was observed from 1966 to 2015. Habitat loss and fragmentation is always a concern for this species, with noted sources of mortality including collisions with radio towers, buildings and other obstructions.
For information on local bird-watching events, visit www.weminucheaudubon.org and www.facebook.com/weminucheaudubon/.