Bird of the Week: Bushtit

Species: Bushtit, Psaltriparus minimus

Family: Aegithalidae

Sign: Aries

Favorite hobby: Group coparenting

Dear reader,

During the recent colder days in Portland, I tend to sit at the dining table working, both because of its convenient proximity to the heater vent, and also for the view that it gives me of the bird feeder on my window and the tall bamboo behind it. Every once in a while, slight movements in the stalks will rouse me from my stupor: a lively flock of bushtits spend a few minutes in the bamboo, flitting around quickly until they decide there is no more food to find in the area and alight to the next backyard of dense shrubbery. Bushtits are seldom alone, almost always moving in groups of their own species, and occasionally other species like warblers, chickadees, and kinglets. 

Bushtits are a small species of passerine that can be found year-round in the Western U.S. and range into Central Mexico as well. They are the only species of their family that reside in the U.S., with the rest of their Aegithalidae brethren being found in Europe and Asia. The family shares the unique trait of making hanging nests, in the form of a pouch or sock, which the Bushtit constructs of moss, spiderwebs, and grasses. This is a very unusual nest construction compared to the bowl-shaped form made of sticks and twigs that other songbirds in the U.S. usually construct. Bushtits all sleep together in their nest, which is another unusual behavior, as in other bird species, usually one adult sleeps in a nest at a time. When their young fledge, they leave the nest and sleep instead on branches. Another interesting aspect of bushtits’ nesting behavior is a breeding pair’s use of ‘helpers,’ usually other adult male birds, that assist in raising their young. Helpers also sleep with the family in their nest. Bushtits’ sociality is constant and important to their everyday activities.

Female and male bushtits are very similar in appearance, both being a light brown-gray, with a slightly darker coloration on the top of their heads. Females have a light iris, while males have a dark one. Plumage varies geographically throughout the U.S.: in Southwest Texas into Mexico, males of the melanotis group have black masks and females have brown masks. Bushtits’ short bills are specialized for eating small insects, which they pick off of the backs of leaves as they forage. They tend to forage and live in open forests and scrubby areas, as well as parks and streamside woods. Essentially, anywhere small insects can be foraged and hanging nests can be built, a bushtit might reside. 

Bushtits do not really have a song in the way that many other birds do. Their sounds consist of a lot of short, high contact calls, and are mostly used to locate flockmates. When mobbing a predator or indicating nesting activities, the calls intensify. This fits in with their very social nesting and foraging behaviors. These social butterflies can be seen in the Canyon, especially in the trees along the bridges, and are more than likely to be flocked with other small passerine species as well.