Aplomado Falcons

Falco femoralis ssp. septentrionalis

An amazing endangered species success story is that of the Aplomado falcon.

These beautiful birds are most often seen in pairs and will work together to find prey and flush it. Rather than build their own nests, they use stick nests built by other birds. The female will typically lay 2-3 eggs and the young birds will fledge about 4 to 5 weeks after hatching. They feed primarily on small birds, but a variety of insects, crustaceans, small reptiles, and mammals are also prey. Aplomados are fast fliers and in South Texas can typically be seen on the coastal prairie and savannah habitat -- flat open areas with low growing vegetation containing yuccas or mesquite trees. These birds are generally year-round residents within the Lower Rio Grande Valley (Valley).

Once widespread throughout the American Southwest, two remaining pairs of aplomado falcons were known to exist in the 1940s and 50s – one pair near Brownsville, Texas, in 1946 and a pair in Deming, New Mexico, in 1952. A plausible theory regarding the decline of the aplomado in Texas is the over-harvesting of eggs. Historic records indicate the bird was found primarily on the salt prairie between Brownsville and Port Isabel, a popular location for egg collecting in the late 1800s and early 1900s. It is thought the original decline of this falcon species in the Valley was most likely due to over-collection rather than habitat degradation – the problem this species faced in other parts of its United States range. In 1986 the northern subspecies of aplomado falcon was listed as endangered due to its extirpation in the United States and evidence of pesticide contamination and population declines in eastern Mexico.

Today, the aplomado falcon has made a comeback in South Texas due to an aggressive recovery program involving captive breeding and re-introduction efforts. In 1993, releases began on the refuge in partnership with The Peregrine Fund, a non-profit conservation group based in Boise, Idaho. In 1995, the first known United States nest of an aplomado falcon since 1952 was documented near Old Port Isabel Road and Loma Alta, a few miles southwest of the refuge’s Bahia Grande Unit. As of 2004, more than 900 falcons have been released in the Valley, with 25 nesting pairs documented in 2006. Fortunately, the release program in the Valley was deemed a success and efforts shifted to West Texas and New Mexico.

Since then established territories and nesting have been annually documented on the refuge. Continued development within the aplomado’s habitat is a concern, as is the potential for contaminant problems due to the birds foraging in areas treated with pesticides. Refuge staff continues to monitor the birds on the refuge and document nesting and fledgling success as well as contaminant levels.

Facts About Aplomado Falcons

The northern aplomado falcon is a rare, nonmigratory, medium-sized falcon.

It is found in open grasslands ranging from the southwestern United States and Mexico through Central and South America.

It is approximately 12–15 inches long and has a wingspan of about three feet.