HARLINGEN, Texas (ValleyCentral) — The endangered Aplomado falcon is slowly being restored to its historic range in South Texas, but this season the number of falcons has declined for the second year in a row.

The rare falcon vanished from South Texas some 75 years ago due to habitat loss, egg collecting, and the advent of harmful pesticides.

Brian Mutch, Biologist with the Peregrine Fund’s Aplomado Falcon Program, recently wrapped up this year’s banding of young falcons in the Rio Grande Valley.

“We have seen a decline the last couple of years. This year it looks like down here in the Valley, there is going to be probably about five fewer pairs than last year,” he said.

In 1978 the Peregrine Fund initiated a captive breeding program with nestlings collected from several populations in Mexico, and in 2003 began releasing falcons into South Texas wildlands.

Paul Jurgens, Peregrine Fund’s Vice-president of Conservation for Domestic Programs, notes the Aplomado restoration effort has been challenging.

“They are the last falcon on the endangered species list, and recovery has been a challenge,” said Jurgens.

The Aplomado restoration effort peaked in 2006 at 42 pairs scattered along the coast from the Rio Grande to Matagorda Island with as many as 21 pairs nesting at one time in the Rio Grande Valley.

This year, while only a dozen pair were counted in the RGV, those 12 birds raised 20 young, mostly in secure artificial nest platforms.

While egg collecting is no longer rampant, and the harmful pesticide DDT was banned 50 years ago, coastal prairie habitat loss continues to threaten the Aplomados recovery.

“The future of the falcon is secure, but as to what level, how many pairs and such, that remains to be seen. And it is all dependent on the amount of habitat that is available to them,” said Jurgens.