ton production. With DDT in their diets, aploma- 

 dos had little chance of reproducing. 



By the early 1990s, though, DDT contamination 

 was in decline, and many species that had been 

 harmed by the pesticide were rapidly recovering in 

 other parts of the U.S. So J. Peter Jenny, Brian D. 

 Mutch, and William R. Heinrich, all biologists with 

 the Peregrine Fund, began looking for pockets of 

 open savanna on the big ranches and wildlife pre- 

 serves of southern Texas. Most promising were tracts 

 near the Gulf Coast, particularly where grasslands 

 were being improved through controlled burning 

 and other methods of brush removal. 



Captive aplomados were first released on a sub- 

 stantial scale in 1993, via a technique invent- 

 ed by European falconers called hacking. Groups of 

 fledgling aplomados were placed in protective, ven- 

 tilated boxes on the tops of wooden towers. Atten- 

 dants covertly placed food in the boxes, then, after 

 a few weeks, opened the boxes so the birds could 

 fledge on their own. Soon the young aplomados 

 were exploring their environs and returning to the 

 tower for food. 



As they did so, however, a potent predator 

 emerged: the great horned owl, a species that had 

 benefited from the centuries-long invasion of 

 thorny brush. New release areas had to be careful- 

 ly screened for owls — ideally, as far from brushy ar- 

 eas as possible. Maturing aplomados posed another, 

 unexpected threat to the newly released young. 

 Once the older falcons learned to be self-sufficient, 

 they dispersed into the landscape, only to return the 

 following year to defend territories close to the 

 hacking towers. There they became aggressive to- 

 ward the young falcons being released. Workers thus 

 had to prospect constantly for new release sites. 



In May 1995, the first wild, productive breeding 

 pair was discovered in southern Texas; since then at 

 least two centers of breeding have emerged. Twen- 

 ty-six breeding pairs now nest in the vicinity of the 

 Laguna Atascosa Wildlife Refuge near Brownsville, 

 and thirteen more pairs nest on Matagorda Island 

 north of Corpus Christi [see map on preceding page]. 

 Both areas make ideal habitats for foraging aploma- 

 dos — the landscapes are vast, open, replete with 

 birdlife, and moderately free of owls. Biologists are 

 cautiously optimistic about the growing aplomado 



Cooperative hunting sequence, similar to one observed in the central Mexican state of San Luis 

 Potosi, is depicted as it unfolds, from left to right, in the schematic diagram. A male aplomado — 

 perched with his mate in an acacia tree — tries to intercept a passing dove, but the dove evades 

 him. The male chases the dove until it takes refuge in a dead acacia. The female enters the tree 

 from below and flushes out the dove; the male, which has been circling, plummets and drives the 

 dove into the grass. The female then dives in for the kill. She carries the dove to the 

 nest tree (a honey mesquite), and deplumes it in an upper branch before feeding it 

 to her three young. 



