Managers report success in restoring endangered bird habitat

An effort to restore habitat for the Black-capped Vireo, an endangered bird native to Central Texas, is yielding results in Travis County.

 

Central Texas contains the only remaining large swaths of habitat suitable for the Black-capped Vireo: open grassy or rocky areas with low, broad-leaved shrubs, where the bird breeds during the spring and summer. The Black-capped Vireo was listed as endangered in 1987, but the City of Austin and the Lower Colorado River Authority seem to have stumbled upon a way to restore it in some areas of Travis County. The tiny bird spends the winter on the Pacific slope of Mexico.

 

At a training event held Thursday at the LCRA headquarters for infrastructure service providers, Bill Reiner, a biologist for the city’s Balcones Canyonlands Preserve Program, said that last spring he and a few colleagues discovered a pair of Black-capped Vireos nesting in shrubs that had grown under a power line along a ridge west and south of Upper Bull Creek Park — an area previously not thought to contain the species. Travis County is a partner in the preservation effort.

 

This spring, less than a quarter-mile away and under the same power line, Reiner discovered another pair of the endangered birds. “The male was a young bird this year so it couldn’t have been the male that established the territory,” said Reiner. “But it could have been the offspring from last year.”

 

The discoveries have bolstered an effort on the part of Reiner and his counterparts at the LCRA to restore Black-capped Vireo habitat in the Greater Austin area. In early February, the city and the LCRA collaborated on a project to plant low shrubs and other vegetation in cleared areas under power lines near where the Black-capped Vireo nests had been spotted, in hopes that the population would spread.

 

“If they produce young next year and the year after that, then maybe their offspring will choose to settle in the new areas the following” year, said Reiner. “That’s depending on whether we get the vegetation to come back to something suitable.”

 

The effort began as a plan to restore habitat for Texas‘ other endangered bird: the Golden-cheeked Warbler, which lives in taller oak and juniper trees. But when it became clear that planting and watering trees of that size would be too costly, the project was put on hold — until the Black-capped Vireos showed up. “We kind of transformed the original plan from restoring Golden-cheek Warbler habitat into trying to create Black-capped Vireo habitat,” Reiner said.

 

The push to restore habitats for these two bird species is part of the Balcones Canyonlands Preservation Plan, a 30-year regional permitting plan meant to protect endangered habitat and wildlife in Central Texas. Administering the plan is a cooperative effort between the City of Austin and Travis County, which are charged with protecting eight endangered species, including the Golden-cheeked Warbler and the Black-capped Vireo.

 

The plan specifically stipulates that 2,000 acres of Black-capped Vireo habitat be established in the BCCP area, although there is currently only about 400 acres of habitat for the bird species.

 

The appearance of Black-capped Vireos west of Upper Bull Creek Park last spring is not the first time a colony has sprung up in a cleared area under power lines. In 1996, stands of scrub junipers and shin oaks were cleared near FM 620 and 4 Points Dr. — an area where Water Treatment Plant 4 was once envisioned — and about five years later a small colony of Black-capped Vireos established territories there. During the winter of 2006-07, the city cleared additional juniper and other vegetation nearby to encourage the colony’s expansion, and last year a Black-capped Vireo pair built a nest and raised young in the new area, according to Reiner. “So, it does work,” he said.