Flying Free
Mustang Island helps in recovery of Aplomado falcons.
By Melissa Gaskill
Mustang Island State Park is well-known for bird life, with more than 400 species documented within its boundaries. The coastal park has played a key role in the recovery of one of those species, the endangered Aplomado falcon.
These birds of prey bear bold facial stripes, bright yellow legs and a long tail. Once common in dry grasslands of the Southwest, the species had nearly disappeared in Texas by the 1930s. In 1977, the Chihuahuan Desert Institute at Alpine began a captive breeding program using wild birds from Mexico. The nonprofit Peregrine Fund took over and expanded the program in the 1980s. Captive-reared birds were released on private land and later Laguna Atascosa National Wildlife Refuge and Matagorda Island. From 1993 to 2013, 997 birds were released into the wild at 27 Texas sites, with at least 37 pairs producing nearly 100 young as a result.
In summer 2012 and 2013, the Texas Parks and Wildlife Department, Peregrine Fund and the U.S. Fish and Wildlife Service released 65 captive-bred falcons at Mustang Island State Park.
Aplomado falcons use nests that other birds have abandoned, according to park interpreter Eric Ehrlich. Conservationists took advantage of that quirk, installing 65 artificial nests along the Texas coast, including in and around the park. These platforms have woven sticks and a roof and bars to protect chicks from predators like owls.
A pair of falcons has used one of the nesting sites, which is visible from Texas Highway 361 about 2 miles north of the main park entrance, each of the 12 years Ehrlich has been at Mustang Island. Typically, he says, in this type of habitat, Aplomado falcons would roost in yucca, which stand about 7 feet tall when mature.
Falcon pairs hunt together, one flying low to flush small birds from the grass and the other hovering up higher to pounce on the prey. In winter, Ehrlich has seen pairs hunting near the dunes on the beach side of the park and around Fish Pass, a cut on the bay side. People sometimes see the falcons perched on the power lines along the highway or around the pond next to the park headquarters building. “You have to be lucky,” he says. “They have a wide hunting range, mostly over grasslands with no roads. You just have to catch them flying over.” Even that isn't easy, as the birds are extremely agile fliers.
Tim Anderson at the U.S. Fish and Wildlife Service says the best time to observe the falcons is nesting season, which typically runs from late February to early July. Human activity can disturb nesting birds, though. A safe viewing distance is at least 200 yards, so getting a good look requires binoculars or a scope.
A nesting pair requires roughly 2,000 acres of nearly treeless coastal prairie and salt marsh. Much of this habitat has been lost because of invasive brush, suppression of naturally occurring fires, industrial development and ditches that drain marshes. Controlled burns and other work have restored native coastal prairie in the park. This work and the nesting sites are giving the endangered birds a brighter future.
