Bushtit

Bushtit
The taxonomic placement of this tiny resident of the West and Southwest has changed over the years. Once thought of as two or even three species, all Bushtits are now considered one. This species has been removed from the titmouse and chickadee family and, together with six Old World species, is now placed in its own family, the long-tailed tits.

Bushtits range from southern British Columbia south through the west and southwestern United States to central Mexico and Guatemala. They are most common in the United States in the West Coast states, especially in the oak woodlands of California's Sacramento Valley and along the coast and in the semiarid scrublands of the Southwest. They also occur in the Rocky Mountains up to 2,440 meters, and in the savannas of the southern Great Plains. Typical habitat includes open deciduous and mixed woodlands with well-spaced trees and shrubs and edge habitats. Outside of the breeding season, they may wander to higher altitudes in montane regions or to desert lowland areas, but they avoid grasslands and the open arid desert. They can also be found in parks and suburban areas, where they are attracted to bird baths.
Bushtit Range Map

Bushtits are highly gregarious and have a complex social system. Outside of the breeding season, which begins as early as mid-January, they travel in flocks of 6 to 60 birds that are created by family groups joining together. Flocks remain stable and may contain the same individuals from year to year. Foraging flocks that glean for insects and spiders travel rapidly through the brush, maintaining contact with high-pitched contact calls. At times, they forage so rapidly that other birds, such as chickadees and wrens that occasionally join them in a mixed-species flock, are left behind. Bushtits roost together among dense branches and huddle closely together on cold nights.

As nesting season begins, the large winter flocks break up as pairs form and establish their nesting territories, usually within the flock's winter range. These territories are not strongly defended, however, and breeding pairs will tolerate other Bushtits feeding in their territory, even allowing them to help construct the nest and incubate and feed the young. Whether this is normal breeding strategy or simply a carryover of social habits is unknown. Flocks of Bushtits, made up of birds that have completed or have not yet begun nesting, can be seen during breeding season.

Bushtit nests are pendant gourd-shaped bags typically between 7 and 12 inches in length. Composed of grass, leaves, and twigs bound together with spider web, these nests are usually lined with plant down, feathers, and hair. The entrance hole is made near the top of the nest at the side of the neck, such that the birds travel down a tube to the bowl of the nest. Nests are often decorated with materials such as flowers, feathers, or lichen.

Description: Bushtits are among the smallest North American birds. They are plain gray-brown above and whitish below washed with gray, buff, or pinkish hues. They have short wings, long tails, and a tiny stubby blackish bill.

Bushtits display geographically variable plumage differences that fall in three groups that were previously considered separate species. The "Common Bushtit," or minimus group, occurs on the West Coast and is distinguished by a brown cap contrasting with the gray back. In the interior West and Southwest, the "Lead-colored Bushtit," or plumbeus group, has a gray cap with brown ear coverts. The most distinctive Bushtits are the "Black-eared Bushtits," or melanotis group, which are found primarily in Mexico. Males have a gray cap, black mask, and white throat and neck, whereas females have variably blackish or gray ear coverts and a grayish throat and neck. There is an intergrade zone between the "Black-eared Bushtits" and "Lead-colored Bushtits" in extreme southern New Mexico, southwestern Texas, and northern Mexico. North of this zone, no adult males show black masks; south of this zone, they all do. Within the zone, the amount of the black on the head is variable.

All females can be distinguished by their whitish eyes, except as juveniles, when their eyes are dark (they pale, however, within a few weeks). Males have dark eyes. Plumage differences between the sexes are very subtle in the "Lead-colored Bushtit"; males show slightly more contrast between the light throat and brownish breast than do females. In the "Common Bushtit," male and female plumage differences are slightly more distinct, and males may show a pinkish wash on the flanks.