Endangered Species

Golden-Cheeked Warbler and Black-Capped Vireo
Chalk Mountain, Texas

Chalk Mountain, with its mixed juniper and hardwood covered “mountains” is a beautiful area.  Those of us who live and own property here love it.  We’re not the only ones who love it.  Two species of Federal and State Endangered birds love it, too.  They are the Golden-Cheeked Warblers and the Black-Capped Vireos.

Golden Cheeked Warbler

The Golden-Cheeked Warbler is a small, migratory songbird with yellow cheeks, a black eye stripe and a black back, throat and cap.  The entire nesting range of the Golden-Cheeked Warbler lies exclusively within 33 counties in central Texas.  Somervell and Erath County are included in this range.  Golden-Cheeks require a mix of vegetation; mature, dense stands of Ashe juniper (cedar) mixed with oak, hackberry, cedar elm and other hardwoods.  The old cedars, at least 20 years old, are necessary, because the Warblers all use strips of cedar bark in building their nests.  The mountains, canyons and draws in the Chalk Mountain area provide excellent habitat for these birds and they are known to nest in the area.  Birders from across the United States and from as far away as Europe have visited the Chalk Mountain area in spring to see the Warblers.  The birds arrive here in March, nest and raise their young (usually laying between three and four eggs).  They usually nest only once during the season.  They then begin their migration back to Mexico in mid-June to July.  Most are gone in August.  The Warblers’ diet consists of insects, such as aphids, beetles, flies, leafhoppers, moths and spiders. Caterpillars are prize food for parents feeding their young.

The Golden-Cheeked Warbler was listed as Endangered in 1990.  The Audubon Society, in a publication titled A March 2006 Report from the National Audubon Society listed the Golden-Cheeked Warbler as one of “Americas Ten Most Endangered Birds.” Habitat loss and fragmentation is reported to be a major cause of a rapidly declining population.

Black Capped Vireo

The Black-Capped Vireo was listed as Endangered in 1987.  These are also small songbirds.  The crown and upper half of the head is black with a partial white eye-ring.  The bill is black and the eye iris is brownish-red. Mature males are olive green above and white below with faint greenish-yellow flanks.  Females are less colorful and their head is a dark slate gray.  The Vireos arrive between mid-March and mid-April.  Males sing to attract females.  Nesting begins in late March or early April and nests are built about “door-knob high”.  Three to four eggs are produced with a first clutch.  Subsequent clutches have fewer eggs.  Migration to Mexico’s western coast beings in July and the Vireos are gone by mid-September.  Vireos require low growing shrubs and open woodlands mixed in a patchwork pattern.  Nesting vegetation must extend all the way to the ground and may grow to six feet in height.  Examples of shrubby plants used for nesting include shin oak, sumac, Texas persimmon, juniper and Texas oak.  Chalk Mountains’ mixture of open grassland and juniper/oak covered hills are very attractive to the Vireos.  As with the Golden-Cheeked Warbler, the Black-Capped diet also consists of insects.

Black-Capped Vireos are also endangered due to habitat loss.  In this case, the loss of the low growing woody cover needed for nesting is the limiting factor.