The golden-cheeked warbler (Setophaga chrysoparia) is an endangered species of bird that breeds in Central Texas, from Palo Pinto County southwestward along the eastern and southern edge of the Edwards Plateau to Kinney County. The golden-cheeked warbler is the only bird species with a breeding range endemic to Texas.
Description
The golden-cheeked warbler is very striking due to its bright yellow cheeks that are contrasted by its black throat and back. It is also identified by its unique buzzing song emerging from the wooded canyons where it breeds. Golden-cheeked warblers breed in 33 counties in central Texas and are dependent on ashe juniper (blueberry juniper or cedar) for their fine bark strips used as nesting material.
Distribution and habitat
The golden-cheeked warbler can be found in numerous state parks within Texas. These parks include Colorado Bend State Park (SP), Dinosaur Valley SP, Garner SP, Guadalupe River SP, Honey Creek State Natural Area (SNA), Hill Country SNA, Kerr Management Area, Longhorn Cavern SNA, Lost Maples SNA, Meridian SP, Pedernales Falls SP, Possum Kingdom SP, and South Llano River SP.
The golden-cheeked warbler is endemic to Texas and Mexico. Their habitat can range from moist, to dry areas around central and southern Texas. The nesting habitat in the further moist realms can be discovered in tall, closed canopy, compressed, mature stands of ashe juniper (Juniperus ashei) trees along with Texas, shin, live, lacey, and post oak trees. In the drier spheres of Texas, golden-cheeked warblers can be found in upland juniper-oak woodlands off of flat topography. They use ashe juniper bark and spider webs to build their nests. Females lay three to four eggs. When migration and winter hits the habitat stays relatively similar: a variety of short-lived evergreen forests with pines between 3,300 and 8,300 feet.
Migration
Golden-cheeked warblers will only remain in Texas for the breeding season, from March to June. They will migrate with other songbird species along Mexico's Sierra Madre Oriental. By the first week of March, the warblers will return to Texas to breed. During the winter season (November–February), warblers will travel to Guatemala, Nicaragua, Honduras, and Mexico.
Behavior
Warblers only nest in Texas, primarily in juniper trees. However, they have also been found to nest in oak trees and cedar elms. During the winter, warblers seek warmth in Mexico and northern Central America.
After winter habitation, adult male warblers beat their population back to central nesting grounds by about 5 days in order to prepare competing for the attention of female warblers. Male warblers win attention of the females through their "chip" sounds which they also make as a warning call during times of possible danger.
Though male warblers are found either singing or searching for food, females carry the responsibility of nest building as well as keeping the eggs incubated. Warblers only nest once per season, laying between three and four eggs each time, which take an average of twelve days to hatch. Female warblers are considered shy and go more unnoticed compared to the always-singing males.
Warblers typically forage by grabbing insects from foliage and branches (foraging strategy known as gleaning), and by resting at branch edges until the opportunity to snatch insects that fly past (strategy known as sallying).
Diet and feeding
The golden-cheeked warbler is known to feed on various forms of insects and spiders, caterpillars are also noted as a primary source of food during the breeding season. This species is completely insectivorous. The method for catching insects is by plucking them from all surfaces by being able to reach them through flight.
Breeding
Once a female has chosen a mate, she alone builds the nest. The nest is made of strips of juniper bark, rootlets, grasses, cobwebs, cocoons, and can contain animal fur to line to the outer portions of the nest. Nearly all of warbler nests contain juniper bark, and it has been seen that females do not make a nest without the presence of the bark. Golden-cheeked warblers lay 3–4 creamy-white eggs, less than long and wide. Incubation begins one day before the last egg is laid. For approximately the 12 days, the female warbler incubates the eggs. The male may accompany the female when she feeds away from the nest, but does not otherwise aid its partner.