Endangered aplomado falcons in southern New Mexico may be stripped of their protections — by the very agency trying to bring the bird back to the state. The U.S. Fish and Wildlife Service is moving forward with a controversial plan to release up to 150 captive-bred aplomado falcons as a "nonessential experimental population."

Because the falcons slated for release are not defined as essential to the species’ survival, they would not be protected as endangered. And their presence would remove protection for any wild falcons already in southern New Mexico, including those on Otero Mesa (HCN, 9/10/01: Gas industry gambles on New Mexico mesa). Endangered species regulations for the raptors have so far helped shield Otero from oil and gas drilling.

Release of the Boise, Idaho-bred birds hinges on whether or not that part of New Mexico hosts an existing population, defined by the Fish and Wildlife Service as two or more breeding pairs.

State and federal biologists say aplomado falcons have been making a comeback but have yet to reach the Service’s threshold — so far, only one breeding pair has been found. Nonetheless, falcon sightings in the area have jumped over the past decades, from just five sightings in the 1980s to more than 25 in the 1990s. Between 2000 and 2004, scientists observed 24 individual birds.

The falcons seen in the state likely originated from a population of aplomados in northern Chihuahua, Mexico, whose range has now expanded into southern New Mexico. Biologists consider the aplomados in New Mexico a contiguous part of this Chihuahuan population, but the Fish and Wildlife Service has drawn the line at the border; it considers the New Mexican birds "transient" and not part of a U.S. population.

The Service considered five different options for aplomados in New Mexico, including releasing falcons with full Endangered Species Act protection or simply letting the birds return on their own. But these options keep falcons classified as endangered, which means more regulation. Elizabeth Slown, an agency spokeswoman, says of the proposed plan: "There is definitely less protection and that is by design … we think that this is a less controversial way to get everyone, including landowners (and ranchers) … supportive of this program." However, the agency acknowledges that, for landowners, compliance with ESA regulations has not proven difficult.

Releasing a nonessential population could help the falcon’s recovery, as long as the "experimental" area does not include locations where falcons have already been spotted, such as Luna and Otero counties, says Kendal Young, a biologist at New Mexico State University. But he believes that the Service is basing its population definition on politics rather than biology: "You can pretty much define a population any way you want to for your given purpose," he says.