The bushtit is a small songbird found along the west coast of North America. Measuring only 4-6 inches in length and weighing less than half an ounce, the bushtit inhabits a variety of wooded habitats. Understanding the preferred habitat of the bushtit provides insights into where these busy little birds can be found.
What kind of habitat do bushtits prefer?
Bushtits prefer open woodlands with a mix of oak, pine, and other trees. They are found in oak woodlands, pine-oak woodlands, mixed evergreen forests, and parks and yards with trees. Their favored habitats have a sparse or open understory, allowing them to freely move and forage for food. Dense, brushy areas are avoided.
In oak woodlands, bushtits forage in the canopies of oak trees like coast live oak, California black oak, canyon oak, and blue oak. Pine-oak woodlands populated with ponderosa pine, Jeffrey pine, Coulter pine, and other conifers are also occupied. Along the coast, Monterey pine trees provide habitat.
In mixed evergreen forests, bushtits inhabit trees like Douglas fir, incense cedar, white fir, California bay laurel, tanbark oak, and madrone. The understory of these forests is open, not overgrown.
Bushtits frequent both native habitats and landscaped parks, yards, and gardens with trees. Ornamentals like crape myrtle, olive, and fruit trees are visited.
What vegetation and food sources are preferred?
Bushtits seek out certain vegetation that provides food sources, nesting sites, and protection.
Foraging primarily occurs on the outer branches and twigs of trees and shrubs. Bushtits glean insects and spiders from the leaves and bark. They also feed on flower nectar, pollen, seeds, and fruit found in trees.
Vegetation with ample lichens, mosses, and hanging Spanish moss provides an abundance of arthropod prey for bushtits to pick off. Evergreen trees decked with Usnea lichens, for instance, make excellent foraging sites.
Trees and shrubs with leaves, needles, and twigs that offer cavities and crevices for nests are favored, including oak, pine, willow, and juniper. Dense foliage also provides shelter from predators and harsh weather.
What is the range of the bushtit habitat?
The bushtit inhabits open woodlands along the entire west coast of North America. Their habitat range extends from southern British Columbia in Canada to Baja California in Mexico.
In the United States, bushtits live along the coasts of Washington, Oregon, and California. They occupy coastal mountain ranges like the Olympics, the Cascades, the Siskiyous, and the Sierra Nevada. Their range extends east into Nevada, Arizona, and New Mexico.
In California, bushtits are found throughout the state in appropriate habitats except for the Central Valley, Mojave Desert, and high mountains. Coastal areas, the Coast Ranges, foothills of the Sierra Nevada, and other wooded regions are inhabited.
The mild climate of coastal California provides excellent year-round habitat. Birds also live in sheltered inland woodlands like those in the San Bernardino and San Jacinto Mountains. At higher elevations, seasonal migration may occur.
What are the elevation ranges?
Bushtits reside from sea level up to elevations around 9,800 ft (3,000 m). In California and Oregon, they primarily occupy elevations below 6,000 ft (1,830 m).
Along the coast, bushtits inhabit sea level areas in coastal forests and scrub. Inland along mountain ranges, they live between 2,000-5,000 ft (610-1,525 m) in oak and pine woodlands.
At the highest elevations between 5,000-9,800 ft (1,525-3,000 m), bushtits inhabit mixed coniferous forests of fir, pine, and cedar. These high elevations are reached in the Cascades, Sierra Nevada, Transverse Ranges, and other ranges.
Mild coastal areas provide the most favorable habitat. But bushtits extend into cooler, snowier areas along the length of California and beyond. their range is limited by harsh winters, deep snow, and lack of vegetation at the highest peaks.
When do they migrate and where do they winter?
Bushtits are non-migratory over most of their range and remain in their breeding habitat year-round. Seasonal movements are limited and poorly understood.
In northern parts of their range like British Columbia, bushtits may migrate short distances south and west to winter. But most birds in Washington, Oregon, and California are permanent residents.
Along the coast and at lower inland elevations, bushtits stay put throughout the year. At higher elevations in mountains, they may move to lower slopes and canyons in fall and winter. But substantial migration does not occur.
In colder interior mountains like the Sierra Nevada, bushtits may vacate breeding areas and move to lower foothills. But males often remain as year-round residents, even where winter conditions are harsh.
With plentiful food and mild climate, coastal southern California provides ideal year-round habitat. Bushtits are abundant permanent residents in coastal areas and inland mountains and valleys.
Do they stay in the same regions or return to the same sites?
Bushtits exhibit strong site fidelity, remaining in the same general area year-round and often returning to the same nesting sites. They forage over a fixed area or home range.
Pairs occupy and defend a territory of around 4 to 10 acres against other bushtits. Much of this area consists of unused space, with an inner core area of about 1 acre that contains active foraging trees and nesting sites.
Bushtits loyally stick to their established territory, only wandering farther during harsh weather when food is scarce. They do not migrate and will stubbornly try to tough out cold winters.
Nesting sites in particular trees or shrubs are often reused for many years. Bushtits maintain and add to elaborate nests over consecutive seasons. Though nesting trees may be used annually, a new nest is still constructed each year.
Birds exhibit strong loyalty to nesting sites and mate for life. This site fidelity helps pairs reunite on territory early in the breeding season to reuse nests in familiar trees or bushes.
How do they adapt to winter weather and lack of resources?
Bushtits survive winter through behavioral and physiological adaptations:
– Join Large Mixed Flocks: Bushtits gather in large flocks of up to 50-100 birds consisting of different species. Flocking provides protection from predators and cold.
– Switch Food Sources: They eat more plant foods like seeds and berries when insect prey is scarce. Flocks sweep areas and exploit any food found.
– Store Food: Some seeds and insects are wedged into bark crevices to create scattered caches. Bushtits can retrieve these stored morsels during lean times.
– Enter Torpor: Bushtits can lower body temperature and metabolism to conserve energy overnight when roosting. This short-term torpor helps them survive frigid nights.
– Fluff Feathers: Fluffing feathers creates an insulating air layer against the skin. This trap of body heat aids survival in freezing temperatures.
– Nest Together: Group winter roosting in cavities, nest boxes, and foliage provides shared warmth that boosts survival during cold spells.
Summary
In summary, the bushtit inhabits open, mixed woodlands along the Pacific Coast and Interior West at elevations up to 9,800 feet. Found in oak, pine, evergreen, and mixed forests, it prefers trees and shrubs that offer food sources, nesting sites, and shelter. The bushtit’s range extends from Canada to Mexico, including coastal and inland mountains in Washington, Oregon, and California. Mild coastal areas provide ideal year-round habitat. Bushtits are non-migratory but may move to lower elevations in winter. They exhibit strong loyalty to nesting territories and habitat. Behavioral and physiological adaptations help bushtits survive cold winters. Understanding the habitat needs of bushtits provides insights into their distribution and adaptability.
