In 1995, the recovery team tried releasing a group of Attwater’s chicks bred in captivity into the wild, keeping them at first for 14 days in an outdoor pen, so that they could acclimate to their new environment, and then sending them out on their own into the prairie grasses.

But right away there were problems. On the eighth day after the chicks were freed, all 15 perished.

“We suspect it was probably an issue of they didn’t know where to go get water,” Mr. Rossignol said. “They were dying of what seemed like dehydration and just exposure.”

For the next releases, the team made sure that water was available. But several years later, they checked one of the acclimation pens and found that the young chicks inside had been decapitated. A great horned owl had apparently swooped in and frightened the chicks. Mr. Rossignol said the chicks may have stuck their heads up through the netting, only to have them lopped off by the owl.

After that, a second layer of netting was added. But it did nothing to protect the birds from the ensuing drought. When a bird died in a release pen, it spread botulism to the other chickens that had pecked at the carcass, killing many of them.

Even getting the birds to breed in captivity was far from easy.

The Houston Zoo, one of four organizations participating in the breeding program, set up pens on the grounds of NASA’s Johnson Space Center. “I like to joke that I get to take care of endangered species that are protected by armed guards,” said Hannah Bailey, the zoo’s curator of birds and natural encounters.

At first, the zoo kept a male-and-female pair of prairie chickens in each pen and placed visual barriers between the enclosures. But the eggs laid by the females were unfertilized.

“It’s a female-choice situation,” Ms. Bailey said. “The males display on the leks, and the females choose which male is best looking or fittest or whatever weird thing Attwater’s prairie hens find attractive.”