The
Aplomado Falcon, Sentinel of a Vanishing Grassland
There is hardly a more striking and enigmatic bird of prey in the Americas than the Aplomado Falcon. The species disappeared from the American southwest before it was well known or studied and is now attempting to make a comeback.
 Apparently
once found from southeastern Arizona through southern New Mexico
and across south Texas, the species largely disappeared from the
area in the early 1900's. This area included Otero Mesa. The reason
for this rapid and sudden decline is uncertain but several experts
have thought it was related to the collapse of their prey base
during the winter, primarily grassland nesting species that wintered
in huge numbers from southeast Arizona to south Texas.
With the conversion of native grassland to agriculture, many of the same grassland species, which currently use Otero Mesa in winter, also collapsed in numbers. Degradation of Chihuahuan Desert grasslands also plays a role in the decline of this species. While the reason for decline may be due to another cause, there is no doubt of the almost total disappearance of this species from the United States.
In the early 1990's a few started appearing back in the United States, primarily in southern New Mexico. Records have come from Hidalgo County in the far southwest to Eddy County and north to Socorro County. And that includes sightings from Otero Mesa, part of their historic range. A nesting pair has even been found in southwestern New Mexico, the first for the United States in about 50 years. A small colony has been found in adjacent Chihuahua and undoubtedly is the origin of these birds rather than an undetected population that persisted in the United States.
In 1986 the US Fish and Wildlife Service listed the northern subspecies of the Aplomado Falcon as endangered. Grasslands with good densities of birds are vital to the survival (and recovery) of this species. The species prefers open areas with scattered nesting sites (often Yucca) and this certainly described Otero Mesa. There is probably no better grassland in southern New Mexico that is better suited as a recolonization site for this species than Otero Mesa. Among birds, there is no better symbol for Otero Mesa than the Aplomado Falcon, a beautiful yet poorly know species that typifies the decline of grassland species and our attempts to correct that.
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