Tufted Titmouse

The tufted titmouse (Baeolophus bicolor) is a small songbird from North America, a species in the tit and chickadee family (Paridae). The black-crested titmouse, found from central and southern Texas southward,^[2] was included as a subspecies but now is considered a separate species, Baeolophus atricristatus.^[3]

Taxonomy

The genus name Baeolophus translates to small crested and is a compound of the Ancient Greek words βαιός: baiós—"small", and λόφος: "lόphοs"—crest. The species name bicolor means two-colored.

Description

Measurements:^[4]

Length: 5.5–6.3 in (14–16 cm)
Weight: 0.6–0.9 oz (17–26 g)
Wingspan: 7.9–10.2 in (20–26 cm)

These small birds have a white front and grey upper body outlined with rust colored flanks. Other characteristics include their black foreheads and the tufted grey crest on their heads.^[5] In juveniles, the black forehead is greatly diminished such that they may be confused with the oak titmouse (although their ranges do not overlap). Males tend to be larger than females.^[6]

The song of the tufted titmouse is usually described as a whistled peter-peter-peter, although this song can vary in approximately 20 notable ways.^[7]

Distribution and habitat

Its habitat is deciduous and mixed woods as well as gardens, parks, and shrublands. Although the tufted titmouse is non-migratory and originally native to the Ohio and Mississippi River basins, factors such as bird feeders have caused these birds to occupy a larger territory across the United States and stretching into Ontario and Quebec in Canada.^[5]^[6]^[8] During the second half of the 20th century and into the 21st century, the species' range has been expanding northwards.^[4]

Behavior and ecology

The tufted titmouse gathers food from the ground and from tree branches, frequently consuming a variety of berries, nuts, seeds, small fruits, insects, and other invertebrates.^[9] Caterpillars constitute a major part of its diet during the summer. This species is also a regular visitor to bird feeders.^[10] Its normal pattern is to scout a feeder from cover, fly in to take a seed, then fly back to shelter to consume the morsel, though caching is also very common.^[9]^[11]

The titmouse can demonstrate curiosity regarding humans and sometimes will perch on a window ledge and seem to be peering into the house. It may also cling to the window frames and walls of buildings seeking prey in wasp and hornet nests.^{[citation needed]}

Titmice are very vocal and will respond to sounds of agitation in other birds.^[4] This species readily forms small flocks, known as troupes or banditries, which often associate with chickadees and other passerines when foraging.^[12]

Breeding

Tufted titmice nest in a hole in a tree, either a natural cavity, a human-made nest box, or sometimes an old woodpecker nest.^[13] They line the nest with soft materials, sometimes plucking hair from a live animal such as a dog.^[14] If they find snake skin sheds, they may incorporate pieces into their nest.^[15] Eggs measure under 1 inch (2.5 centimetres) long and are white or cream-colored with brownish or purplish spots.^[16] Eggs have an incubation period of 12–14 days; titmice will then remain nestlings for 15–16 days.^[4]

The lifespan of the tufted titmouse is approximately 2.1 years, although it can live for more than ten years.^[17] On average, these birds will have a clutch size of five to seven eggs.^[18] Unlike many birds, the offspring of tufted titmice will often stay with their parents during the winter and even after the first year of their life.^[19] Sometimes, a bird born the year before will help its parents raise the next year's young.^[20]

Tufted titmice will occasionally hybridize with the black-crested titmouse; the hybridization range is very narrow, however, because of genetic differences.^[6]

Status

From 1966 to 2015 the tufted titmouse population has increased by more than 1.5% per year throughout the northeastern U.S.^[21] The current breeding population is estimated to be approximately 8 million.^[4]