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 familyAegithalidae found in the Americas; the other eleven species occur in Eurasia.[2]
The sharp-shinned hawk and other raptorsprey upon American bushtits.[5] 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.[4]
Etymology
The name "bushtit" has its earliest known origins in the Latin word Parus, which stands for titmouse. The tit in titmouse comes from the Old Icelandic word titr, meaning something small.[6]
The subspecies P. m. melanotis was previously considered as a separate species due to their black ears.[11]
Description
With a length of 100–110mm (3.9–4.3in) and a weight of 4.5–6g (0.16–0.21oz), the American bushtit is one of the smallest passerines in North America.[3][12] 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.[3] This feature does not occur in the northern part of the American bushtits' range and in the United States is confined to near the Mexican border, mainly in Texas. None of the bushtits in that location with the black ear patch are adult females; the majority of them are juvenile males with one or two dark lines on their faces rather than a whole patch.[citation needed] Only from the northeastern Mexican highlands and farther south does the black-eared variant become more prevalent; all males have a full black ear patch, and even mature females have a black arc covering their eyes and typically a black line across them.[13]
Identification
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.
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.
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.
The American bushtit has an active and social demeanor.[3] This species forms flocks of 10 to 40 individuals of various species, including chickadees and warblers, to forage for tiny insects and spiders. Group members frequently communicate with one another through brief calls.[3]
Nesting
Both the males and females work together to construct the hanging nest, which can take up to a month to complete. The nest features a hole near the top that goes down into the nest bowl, and it hangs up to a foot below its anchor point. Using spider webs and plant material, the adults create an elastic sac. Occasionally, they sit inside the nest while it's still being built, which stretches it downward. They cover the outside with fragments of adjacent plants, including the tree the nest is made in, and add insulating materials like feathers, fur, and downy plant debris. All the adults connected to the nest, including the breeding pair and helpers, sleep there when it's in use. Typically, the couple uses the same nest for their second brood of the year. Regarding its placement, the male and female hang spiderwebs from mistletoe or other foliage to test-sites for their nests. Nest locations are typically found on tree trunks or branches, ranging in height from 1.25–7.5m, rarely to 15m.[3][14]
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 13.7mm long and 10mm wide.[12] Once the chickshatch, both the male and female bushtits cooperate to feed and care for them for 14–18 days. They can raise 1-2 broods a year, and older siblings from the first brood may assist in feeding the next.[14][15]
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.[16] 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.[14]
However, bushtits can be sensitive during the breeding process.[15] If they are disturbed in the early nesting stages, they may abandon their nesting attempt and potentially seek a different mate.[14]
↑Bird, Alex (2019-01-24). "Bushtit". Bird Watching Academy. Retrieved 2023-10-22.
Further reading
Skutch, Alexander F. (1960). "Black-eared bush-tit"(PDF). Life Histories of Central American Birds II. Pacific Coast Avifauna, Number 34. Berkeley, California: Cooper Ornithological Society. pp.211–225.
Sloane, Sarah A. (1996). "Incidence and origins of nest supernumeraries at Bushtit (Psaltriparus minimus) nests". Auk. 113: 757–770. doi:10.2307/4088855. JSTOR4088855.
