Historically the aplomado falcon (Falco femoralis) occurred in the United States in Texas, Arizona, and New Mexico. Before the 1900s it was apparently a relatively common raptor in parts of the southwest. Aplomado falcons in the US declined precipitously in the first half of the 20th century, likely due to habitat alteration and finally pesticides, eventually becoming extirpated as a breeding species. It was listed as an endangered species in 1986.
We bred aplomado falcons in captivity at our UCSC breeding facility for reintroduction in Texas, in cooperation with The Peregrine Fund and the Chihuahuan Desert Research Institute. We developed captive husbandry techniques for the species, and conducted initial releases of a total of 24 young in south Texas, leading to the first confirmed nesting in many years. Eventually our breeding stock was transferred to the Peregrine Fund, which has expanded the program of breeding and release.
An interesting aspect of aplomado falcon biology is that unlike many young raptors, natal down of aplomado falcons mirrors the final plumage of the species.