BFL: Species Account: Red-faced Warbler

RED-FACED WARBLER

Red-faced Warbler (Cardellina rubrifrons)

Distribution

Breeding: Breeds at high elevations from central Arizona east to western Red-faced Warbler range map New Mexico through the Pacific slope and adjacent interior of Mexico from Sonora to Durango. Casual in southern California, where it may breed, and central and southeastern New Mexico; also sight reports from southern Nevada and Texas.

Winter: Winters in the highlands of Mexico from Sinaloa and Durango south to Guatemala, El Salvador, and Honduras.

Breeding habitat

Breeds at high elevation, generally from 6,550-9,200 feet (2,000-2,800 meters), in montane fir, pine, and open pine-oak forests. Also in more mesic sites such as stream and snowmelt drainages that include conifers such as Douglas fir, spruce, and/or deciduous vegetation such as quaking aspen and canyon maple mixed with conifers. On the Mogollon Rim, northern Arizona, this species is particularly abundant in steep canyons but also occurs in flatter terrain.

Conservation status

This warbler is of high conservation importance, because of its very restricted and patchy breeding distribution and its dependence on montane coniferous forests. Populations are not well monitored, and precise habitat or area requirements are poorly known.

Description

Male: The brilliant red on the forehead, throat, and sides of neck give this species its colorful name. Black on the crown and sides of the face, gray on the back, white underneath. White patches on the nape and the rump are sometimes seen.

Female: Similar to adult male, but red is slightly paler.

Juvenile: Gray-brown above with a whitish rump and two buffy wing bars. Head and breast are brown, the belly is gray.

Vocalizations

Songs: A clear and energetic series of thin, variable notes ending with one or more downward slurred notes, wi tsi-wi tsi-wi si-wi-si-whichu. The number and arrangement of notes are highly variable. A flight song has also been noted.

Calls: A sharp chup or tchip. Adult pair members "chip" to maintain contact with each other during all stages of nesting; adults also seem to use the same call to maintain contact with both nestlings and fledglings. Adults give a harsh call to scold predators, especially when near the nest or young.

Foraging strategy

Birds glean on outer branches of trees; sally for aerial prey, spiraling downward in pursuit of flying insects; occasionally hovers to glean insects from foliage.

Diet

Insectivorous, taking caterpillars, flies, and bees during the breeding season.

Behavior and displays

Hops on ground when examining possible nest sites and while picking up nesting material.

The male establishes, defends, and advertises an all-purpose territory, within which both male and female feed. Male chases conspecifics while establishing territory and, much less often, when at the boundaries of territory. Once territory is established, male seems to spend more time chasing and displacing intruders than disputing territory boundaries or ownership. The female defends the territory against other females.

Socially monogamous with 1 pair/territory, but neighboring males often sneak onto territories to solicit extra-pair copulations. Male closely guards mate before and during nest-building. Unlike in most other species in which mate-guarding has been described, guarding continues after egg laying into the incubation period.

Copulation attempts can be initiated by either sex and seem to change with stage of breeding. While a female is prospecting for nest sites, male solicits copulations on the ground where the female is searching. A male quivers his wings in a typical begging response with head up and tail spread as he circles the female. During nest building, both pair members solicit copulations.

Courtship

No information.

Nesting

Nest site: Nest is a small depression on the ground, either scraped out or naturally occurring, on a slope in the open, or at the base of woody plants. Sometimes a roof, provided by a woody plant stem, log, dirt and forbs, grass, or rock, conceals the nest. The female chooses the site, often accompanied and guarded by male as she prospects.

Height: Nest placed on ground.

Nest: The outer layer of the cup-shaped nest is constructed from pieces of bark, particularly aspen, also dead maple leaves or pine needles. Inner layers are made of grass; bowl is often lined with animal hair.

Eggs: 4-5, rarely 6, occasionally 3 late in season. The eggs are white and finely speckled with brown or chestnut, often with a wreath of thicker speckling and blotches near the larger end.

Incubation period: Only the female incubates, sitting tightly on the nest and flushing only when danger is near the nest. She then performs distraction displays, such as wing fluttering on ground, as she leaves.

Nestling period: Young are altricial, with closed eyes and naked except for gray down on capital tracts. Both parents feed young starting at hatching day. Young open eyes at day 4, feathers begin breaking the sheath at day 6.

Fledgling period: Young leave the nest at day 12. Upon departure young can fly only 30-50 feet (10-15 meters) as the tail is about half-grown and wings only three-quarters developed. From a nearby bush, the parents wait with food and watch as nestlings fledge, feeding each after departure. Young separate immediately upon fledging and do not associate for the first few weeks. The young beg from and are fed by parents, although they begin foraging for themselves after a few days.

Broods: No information.

Cowbird Parasitism: Rare Brown-headed Cowbird host.