The American bushtit, or simply bushtit (Psaltriparus minimus), is a social songbird belonging to the monotypic genus Psaltriparus. It is one of the smallest passerines in North America and it is the only species in the family Aegithalidae found in the Americas; the other eleven species occur in Eurasia.
The American bushtit's distinguishing characteristics are its tiny size, its plump and large head, and its long tail. Its range stretches from Vancouver in Canada, south through the Western United States, via the Great Basin, the lowlands and foothills of California, the highlands of Mexico, to Guatemala.
The sharp-shinned hawk and other raptors prey upon American bushtits. Bushtits live in flocks of 10 to 40 birds and family members sleep together in their large, hanging nest during breeding season. Once the offspring develop wings that are developed enough to fly, they leave the nest and sleep on branches. Bushtits display a unique behavior as adult males are typically the helpers that assist and raise the nestlings; hence it has intrigued many naturalists for its interesting breeding and mating patterns.
Taxonomy
The scientific name Parus minimus was given to the bushtit when it was originally described in 1837 by American naturalist and ornithologist John Kirk Townsend, where he reported that the species inhabited the forests of the Columbia River. It is now the only species placed in the genus Psaltriparus that was introduced in 1850 by the French naturalist Charles Lucien Bonaparte.
Ten subspecies recognized:
Description
With a length of and a weight of , the American bushtit is one of the smallest passerines in North America. It is mostly gray-brown, with a large head, short neck, long tail, and small, stubby beak. American bushtits have different characteristics based on their sex and habitats. The male has dark brown to black eyes while the adult female has yellow eyes. Additionally, bushtits resident near the coast tend to have a brown "cap" or "crown", while those further inland have a brown "mask" on their face, and those in Mexico and Central America have a black cheek.
Identification
{| class="wikitable"
!Identification
!Description
!
|-
|Male (Pacific)
|Tiny with a chubby appearance, large head, a lengthy tail, and a compact bill. Their feathers are predominantly plain shades of brown and gray, though the specific plumage colors differ based on their geographic location.
| rowspan="1" |thumb|Male 'Pacific' bushtit in Chilliwack, British Columbia.
|-
|Male (Interior)
|Tiny with a long tail and short bill. They display a lighter shade of gray with gray crowns and tan cheeks, whereas those residing near the coast exhibit brown crowns.
| rowspan="1" |thumb|Male 'interior' bushtit in Utah.
|-
|Male (Black-eared)
|Males in southwest Texas to Mexico have a black mask and display a shade of brown. The mask color tends to get darker further to the south.
| rowspan="1" |thumb|Male 'black-eared' bushtit in [[Mexico City.]]
|-
|Female (Pacific)
|As the male, but with pale yellow eyes.
| rowspan="1" |thumb|Female 'Pacific' bushtit in Western Washington state.
|-
|Female (Interior)
|They display grayer crowns and brown cheeks with pale yellow eyes.
| rowspan="2" |thumb|Female in southern Arizona, intermediate between interior and black-eared.
|-
|Female (Black-eared)
|Females in southwest Texas to Mexico have a brown mask and display a shade of light brown. The mask color tends to become darker further to the south.
|}
Behavior
thumb|upright|Congregating on feeder, Tumwater, Washington
Bushtits usually inhabit mixed open woodlands, which contains oaks and a scrubby chaparral understory. It can also be found residing in gardens and parks.
Breeding
Female bushtits lay plain white oval eggs in batches of 4-10, but both parents share the responsibility of incubation for 11–13 days. The egg is 13.7 mm long and 10 mm wide.
During the breeding season, male and female bushtits form pairs, actively participate in nest-building, and both engage in rearing the young. They are aided by other adult males who bring food to the nesting pair's nest. Remarkably, during this time, the entire bushtit family sleeps together in their large, hanging nest, unlike most breeding birds where only one adult typically sleeps on the nest at a time. After the young birds fledge, they move to sleeping on branches.