| American bushtit | |
|---|---|
 | |
| MaleP. m. californicus | |
 | |
| FemaleP. m. californicus | |
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Passeriformes |
| Family: | Aegithalidae |
| Genus: | Psaltriparus Bonaparte, 1850 |
| Species: | P. minimus |
| Binomial name | |
| Psaltriparus minimus (Townsend, 1837) | |
 | |
TheAmerican bushtit, or simplybushtit (Psaltriparus minimus), is a socialsongbird belonging to themonotypic genusPsaltriparus. It is one of the smallestpasserines in North America and it is the only species in thefamilyAegithalidae found in theAmericas; the other eleven species occur inEurasia.[2]
The American bushtit's distinguishing characteristics are its tiny size, its plump and large head, and its long tail.[3] Its range stretches fromVancouver in Canada, south through theWestern United States, via theGreat Basin, the lowlands and foothills ofCalifornia, the highlands ofMexico, toGuatemala.[3] Bushtits usually inhabit mixed openwoodlands, which containsoaks and a scrubbychaparral understory. They can also be found residing in gardens and parks.[3] Their food source is smallinsects, primarily,spiders inmixed-species feeding flocks.[4]
Thesharp-shinned hawk and otherraptorsprey upon American bushtits.[5] Bushtits live inflocks of 10 to 40 birds and family members sleep together in their large, hanging nest duringbreeding season. Once theoffspring develop wings that are developed enough to fly, they leave the nest and sleep onbranches. Bushtits display a unique behavior as adult males are typically the helpers that assist and raise thenestlings; hence it has intrigued manynaturalists for its interesting breeding and mating patterns.[4]
The name "bushtit" has its earliest known origins in theLatin wordParus, which stands for titmouse. Thetit intitmouse comes from theOld Icelandic wordtitr, meaning something small.[6]
Thescientific nameParus minimus was given to the bushtit when it wasoriginally described in 1837 by American naturalist and ornithologistJohn Kirk Townsend, where he reported that the species inhabited theforests of theColumbia River.[7][8] It is now the only species placed in the genusPsaltriparus that was introduced in 1850 by theFrench naturalistCharles Lucien Bonaparte.[9][2] The genus namePsaltriparus combines the name of the genusPsaltria that was introduced byCoenraad Temminck in 1836 for thepygmy bushtit, withParus that was introduced byCarl Linnaeus in 1758 for the tits.[10]
Tensubspecies recognized:[2]
| Subspecies | Authority | Breeding range |
|---|---|---|
| Psaltriparus minimus saturatus | Ridgway, 1903 | Southwest Canada and the Northwest United States |
| Psaltriparus minimus minimus | Townsend, JK, 1837 | Coastal Western United States |
| Psaltriparus minimus melanurus | Grinnell & Swarth, 1926 | Southwest United States and North Baja California |
| Psaltriparus minimus grindae | Ridgway, 1883 | South Baja California |
| Psaltriparus minimus californicus | Ridgway, 1884 | South-central Oregon to South-central California |
| Psaltriparus minimus plumbeus | Baird, SF, 1854 | West-central, South United States and North-central Mexico |
| Psaltriparus minimus dimorphicus | Van Rossem &Hachisuka, 1938 | South-central United States and North-central Mexico |
| Psaltriparus minimus iulus | Jouy, 1894 | West and Central Mexico |
| Psaltriparus minimus personatus | Bonaparte, 1850 | South-Central Mexico |
| Psaltriparus minimus melanotis | Hartlaub, 1844 | South Mexico and Guatemala |
The subspeciesP. m. melanotis was previously considered as a separate species due to their black ears.[11]
With a length of 100–110 mm (3.9–4.3 in) and a weight of 4.5–6 g (0.16–0.21 oz), the American bushtit is one of the smallestpasserines in North America.[3][12] It is mostly gray-brown, with a largehead, shortneck, longtail, and small, stubbybeak. American bushtits have different characteristics based on theirsex andhabitats. The male has dark brown to black eyes while the adult female has yellow eyes. Additionally, bushtits resident near thecoast 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 inTexas. 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 | 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 (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 (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. |  |
| Female (Pacific) | As the male, but with pale yellow eyes. |  |
| Female (Interior) | They display grayer crowns and brown cheeks with pale yellow eyes. |  |
| 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. |
Bushtits usually inhabit mixed openwoodlands, which containsoaks and a scrubbychaparral understory. It can also be found residing in gardens and parks.[3] It lives under thehighland parts ofMexico and thewestern United States toVancouver, via theGreat Basin, thelowlands andfoothills ofCalifornia, southern Mexico, andGuatemala.[3]
The American bushtit has an active and social demeanor.[3] This species formsflocks of 10 to 40 individuals of various species, includingchickadees andwarblers, toforage for tinyinsects andspiders inmixed-species environment. Group members frequently communicate with one another through brief calls.[3]
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 1.25–7.5 m, rarely to 15 m.[3][14]
Female bushtits lay plain white ovaleggs in batches of 4-10, but bothparents share the responsibility ofincubation for 11–13 days. The egg is 13.7 mm long and 10 mm wide.[12] Once thechickshatch, both the male and female bushtits coorperate to feed and care for them for 14–18 days. They can raise 1-2broods a year, and oldersiblings from the first brood may assist in feeding the next.[14][15]
During thebreeding season, male and female bushtits form pairs, actively participate innest-building, and both engage in rearing the young. They are aided by other adult males who bring food to the nestingpair'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 breedingprocess.[15] If they are disturbed in the early nesting stages, they may abandon their nesting attempt and potentially seek a differentmate.[14]
