Aplomado Falcon had one of its best nesting seasons on record this year.

The beautiful dark-bellied falcon occurs across much of South and Middle America, and in the first decades of the 20th century, it could commonly be observed in Texas, southern New Mexico, and southeastern Arizona. The bird largely disappeared from the United States after the 1930s, however, and by the late 1950s it was considered extirpated in the country.

The causes of the decline remain mysterious. Overgrazing by domestic livestock and brush encroachment likely played roles, but so, too, may have egg collecting and the government’s campaign to eradicate prairie dogs using strychnine. The falcon was designated as endangered in February 1986.

Eager to reestablish a population in the Aplomado’s historic U.S. range, biologists with the Peregrine Fund, supported by the U.S. Fish and Wildlife Service, opted to raise birds in captivity and then release them into the wild. The tactic had already proved effective with Peregrine Falcons and was showing success with Bald Eagles.

A number of release sites on the Texas Gulf coast were evaluated between 1985 and 1987 before the program was focused on Laguna Atascosa National Wildlife Refuge, near Brownsville, and Matagorda Island, near Corpus Christi.

Since then, more than 1,500 young Aplomado Falcons have been set free in South Texas, and falcons have also been released in West Texas and New Mexico. Evidence of success came in 1995, when captive-reared Aplomados bred in the wild for the first time. By 2007, the reintroduced falcons had fledged more than 244 young.

This summer, Peregrine Fund biologists announced that they had recorded no fewer than 37 territorial pairs and 93 individual falcons along the Texas coast in 2016, some of the highest totals to date. The goal of the federal recovery plan is a self-sustaining population of 60 pairs in the U.S.

Birding Veracruz.

Kettle as big as Texas.

Captive-bred Florida Grasshopper Sparrows make conservation history.

See photos of Peregrine Falcon.

A version of this article appeared in the October 2016 issue of BirdWatching.

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