Bird of the Month: Bushtit
Written by Andy McCormick
Andy McCormick, Volunteer and Former Board President of Eastside Audubon
A western specialty, the Bushtit, weighing only 5 grams, is a tiny gray bird that travels in flocks when not breeding.
Bushtits are energetic, small gray puffballs with long tails. They are highly social birds that spend most of their life in the company of other Bushtits. They interact freely with each other and even during the breeding cycle when they break up into pairs for nesting, members of the flock will visit the nests of other Bushtits, and other members will participate in cooperative breeding (Sloane).
There are two regional forms of Bushtits that differ slightly in appearance. The coastal group has a brown cap that contrasts with the gray body. An interior group seen mostly east of the Sierra Nevada is all light gray with the crown matching the color of the back. In both groups the upper parts are darker than the chest and belly. Males have a dark eye; females have a light-colored eye. Photos, videos, and vocalizations of Bushtits may be found at the Macaulay Library.
Bushtit
Scientific Name: Psaltriparus minimus
Length: 4.5”
Wingspan: 6”
Weight: 0.19 oz (5.3 g)
AOU Alpha Code: BUSH
FLOCKING FAMILIES
Bushtits are almost never seen alone. When not breeding, Bushtit families stay together and travel in flocks, which can expand in numbers during fall. Families merge, and flocks commonly grow to 20 or even 40 members. As the flock forages in trees and shrubs, the members interact continuously by emitting a series of soft chip calls and tsee tsee notes. When they enter a tree, Bushtits will spread over its entirety in a seemingly haphazard manner making short hops from branch to branch. They are nimble enough to perch on the smallest branches while searching for larvae and insects. Once ready to move on, they leave a tree in a ragged single file, presenting a convenient way for birders to get an accurate count of the flock size. Their strong group behavior can continue even on cold nights when Bushtits will huddle together.
Bushtits are the sole North American representative of the family of long-tailed tits, and it is the only member of the genus Psaltriparus, from the Greek psaltria, a female harp player, referencing the bird’s song, and parus, Latin for titmouse, another small gray bird. The species epithet minimus is another reference to the Bushtit’s small size (Holloway). A tit is any small bird. This term is used more commonly in Eurasia and Africa than in the Americas.
SOCK NEST
In spring, Bushtit flocks break up and pairs build a tightly-woven sock-shaped nest hanging from a tree branch eight or more feet from the ground. The nest is composed of grass, moss, spider webs, lichen, and twigs and lined with animal hair and feathers. Nest can sometimes reach a foot in length. Usually, 5-7 eggs are deposited which both parents incubate for about 12 days. Sometimes both parents sleep in the nest at night (Kaufman). Once hatched, the young are fed by parents for another two weeks until the young leave the nest. Many Bushtits will have two broods per year. During breeding they are tolerant of having other Bushtits close-by and females may mate with a different male for the second brood. Some members of the flock may visit other nests and participate in cooperative breeding with some non-breeding males and juveniles acting as extra helpers caring for and brooding the young.
STATUS AND DISTRIBUTION
The Bushtit is common throughout open woodland and brushy habitat, including some oak-pine, and oak-juniper woodlands. It also breeds in coastal chaparral from Southern British Columbia to the mid-level mountain regions of Mexico and Central America. It avoids open desert regions. The population of Bushtits is stable, and it is considered a bird of least concern. It is typically a resident bird within its range which has expanded to the north and west (Sloane). In mountainous regions, Bushtits will migrate to lower elevation in winter.
Photo credit Mick Thompson.
References available upon request from amccormick@eastsideaudubon.org.