Habitat
Oak Titmice live mostly in warm, open, dry oak or oak-pine woodlands. Many will use scrub oaks or other brush as long as woodlands are nearby. They live in a restricted range, from southwest Oregon to northwest Baja California, with another population in the Cape District of south Baja California. In a few areas they use habitats without oaks. In extreme northern California, Oak Titmice live in western juniper woodlands (the only part of their range where they overlap with the Juniper Titmouse). On San Benito Mountain in central California they live in open pine forests. In the mountains of northwest Baja, they live in pinyon pine woodland. At the eastern edge of their range, they live in pinyon or California juniper mixed with Joshua trees. Back to top
Food
The Oak Titmouse eats seeds and other plant materials as well as insects and other invertebrates, particularly in warmer months. It eats acorns, pine seeds, oats, thistle seeds, poison oak berries, oak and willow catkins, leaf buds, galls, berries, and cultivated cherries. Its invertebrate diet includes leafhoppers, treehoppers, plant lice, aphids, scales, caterpillars, beetles, ants, wasps, flies, and spiders. The Oak Titmouse gleans its prey from bark and foliage, usually less than 30 feet off the ground. It uses its stout bill to peck and probe crevices, chip away bark, and pull apart leaf galls, flowers, acorns, curled dead leaves, and lichens in search of prey. It may also forage on the ground itself, taking its food to an elevated perch with good visibility before eating it (or storing it to retrieve later). For large food items, it holds the item against a branch with its foot and pulverizes it with its bill. Occasionally it catches insects out of the air.Back to top
Nesting
Nest Placement
The female selects the nest site, but the male goes with her as she roams across their breeding territory to inspect sites. She chooses a cavity in a tree up to 40 feet off the ground, preferring natural cavities over woodpecker-excavated ones. Sometimes she may partially excavate the nest herself in soft or rotten wood, or further excavate an existing cavity. Occasionally Oak Titmice nest in stumps, fenceposts, pipes, eaves, or holes in riverbanks. They will also use nest boxes.
Nest Description
The female takes charge of building the nest, taking 4–10 days to finish it. The male accompanies her while she gathers material and he feeds her when she is inside the cavity. Nests are made of grass, moss, hair, and feathers, and may also contain shredded bark, wool, straw, twigs, plant fibers, rope, string, oak blossoms, snakeskin, sycamore seed balls, rootlets, leaves, and wood chips. The nest may be reused in later years, either by the same pair or a different one.
Nesting Facts
| Clutch Size: | 3-9 eggs |
| Number of Broods: | 1-2 broods |
| Egg Length: | 0.6-0.8 in (1.6-2 cm) |
| Egg Width: | 0.5-0.6 in (1.2-1.5 cm) |
| Incubation Period: | 14-16 days |
| Nestling Period: | 16-21 days |
| Egg Description: | White, sometimes speckled with a faint reddish brown. |
| Condition at Hatching: | Undeveloped and helpless. |
Behavior
Oak Titmice flit between branches and trees, flying with a shallow undulating motion. They tend to feed among the woody twigs in the lower canopies of oaks and other trees. They form pair bonds in their first year and mate for life. Both sexes defend territories year-round, meaning they don’t flock in the winter the way many other titmice and relatives do. When defending against an intruding member of its species, the Oak Titmouse raises its crest, quivers its wings, and scolds. Oak Titmice are hunted by mammals, snakes, and other birds, including Western Scrub-Jays, Steller’s Jays, Western Screech-Owls, Northern Pygmy-Owls, and accipiter hawks. Oak Titmice will mob predators, often joining forces with other small birds.Back to top
Conservation
The Oak Titmouse is one of the most common birds in oak woodlands of California, but populations have declined by close to 2% per year between 1966 and 2014, resulting in a cumulative decline of 57%, according to the North American Breeding Bird Survey. Partners in Flight estimates a global breeding population of 500,000, with 89% living in the U.S. and 11% in Mexico. The species rates a 14 out of 20 on the Continental Concern Score. Oak Titmouse is a U.S.-Canada Stewardship species and is on the 2014 State of the Birds Watch List, which lists bird species that are at risk of becoming threatened or endangered without conservation action. The decline of this species is linked to the increase in California's population during the twentieth century (from 1.5 million to more than 30 million people), which has increased pressures on oak woodlands from activities such as timber harvesting, clearing for agriculture, and urban and suburban development. An estimated 80 percent of California’s remaining oak woodlands are privately owned, so landowners can play a crucial role in conservation of this unique habitat.Back to top
Credits
Lutmerding, J. A. and A. S. Love. (2020). Longevity records of North American birds. Version 2020. Patuxent Wildlife Research Center, Bird Banding Laboratory 2020.
North American Bird Conservation Initiative. (2014). The State of the Birds 2014 Report. US Department of Interior, Washington, DC, USA.
Partners in Flight (2017). Avian Conservation Assessment Database. 2017.
Sauer, J. R., J. E. Hines, J. E. Fallon, K. L. Pardieck, Jr. Ziolkowski, D. J. and W. A. Link. The North American Breeding Bird Survey, results and analysis 1966-2013 (Version 1.30.15). USGS Patuxent Wildlife Research Center (2014b). Available from http://www.mbr-pwrc.usgs.gov/bbs/.
Sibley, D. A. (2014). The Sibley Guide to Birds, second edition. Alfred A. Knopf, New York, NY, USA.