Caldwell Zoo helping return APCs to Texas coast

Published on Saturday, 29 March 2014 22:40 - Written by Steve Knight

With his ear-like feathers and tail pointed skyward, his gold and fuchsia check feathers ballooned like a squirrel carrying acorns, the Attwater’s prairie chicken was making his best tough-guy look as he began to boom.

It is an annual mating ritual that includes a call that is part irritating seagull and part rhythmic drumming, but as natural sounding as geese honking overhead.

Then the young male began his happy dance, rapidly stomping his feet up and down, stopping only to start calling again.

A hundred and fifty years ago he would have been among a million-bird Attwater’s prairie chicken population along the Texas Gulf Coast. Then he and other males would have started off on barren ground called a lek, strutting their stuff for females that came to watch and picking out their breeding mate.

This bird was one of six breeding pairs at Tyler’s Caldwell Zoo, who along with the Houston, San Antonio and Abilene zoos and Fossil Rim Wildlife Center, are working with the U.S. Fish and Wildlife Service and the Texas Parks and Wildlife Department to return the birds to what is left of their habitat.

On this morning, a bitter, overcast day, his only competition was the other males in separate pens secluded near the zoo’s headquarters. Instead of waiting to be chosen by a female, that was already done for him by officials with the Species Survival Program, an organization that keeps genetics records to determine the best mating pairs. The male only has to wait for the female to become interested.

“I think zoos are all about conservation,” Yvonne Stainback, Curator of Birds & Reptiles at Caldwell Zoo. “These are a Texas species and the most endangered species in Texas, and we hope to get them back out there. Few zoos have a release program to get animals back out in the wild.”

The breeding program started at the zoo in 2005. Success has been measured. Chicks have been produced, but not at the numbers expected. Rearing the young has proven more difficult than expected.

“It seems like there is always something with those birds. The chicks you would think would be easy to raise. You think they would want to eat, but they sometimes won’t eat and they get sick.

“You think back in the day that there were a million of them out there and they made it. But there are not as many of them (in the pens), and we have got a lot of good facilities trying to raise them,” Stainback said.

Attwater’s prairie chickens are in the same family as a barnyard chicken, but in the same subfamily as a grouse.

Throughout most of the year the zoo’s flock is allowed to roam through the pens with the staff watching to see which male prefers which area. Beginning in March the area is divided into separate pens and the males are paired with a female.

“We typically have eggs by the end of March into the first of April. We will start having chicks around May after a 25- or 26-day incubation,” Stainback said.

Once numbering in the millions on six million acres of habitat that stretched from near Corpus Christi into Louisiana and 75 miles inland, today the number of birds in the wild can actually be counted. USFWS officials are currently in the process of this year’s wild bird count. Last year there was only an estimated 66 counted on two sites, the Attwater Prairie Chicken National Wildlife Refuge near Eagle Lake and on private property in Goliad County.

“I have a feeling that we will see an increase in total numbers again this year, just not sure what that is yet. Birds are still at both of the locations this year,” said Terry Rossignol, USFWS recovery plan coordinator for the Attwater’s project.

A third refuge has been created near Texas City, but to date there haven’t been enough birds to begin repopulating it.

The birds were gone from Louisiana by 1919. By 1937 the number in Texas had been reduced to an estimated 8,000. They were listed as endangered in 1967 when just over a thousand remained on what little habitat existed, and by 1996 biologists counted only 42 in the wild.

The decline can be attributed to urban growth and modern farming and cattle ranching that destroyed habitat along the coast. There was also indiscriminate hunting of the birds at the turn of the 20th Century, until a four-day season and 10-bird limit was set in 1929.

Hunting Attwater’s prairie chickens in Texas was completely banned in 1937.

The rush to return the birds to the refuges before they disappear completely is hampered by the limited production. Caldwell Zoo, which funds the majority of its share of the project, is the smallest of the facilities attempting to produce the birds. While the zoo itself can only handle so many pairs, the birds aren’t helping as egg production has been declining.

“The hens used to lay 12, 14 or 16 eggs. They are not laying as many as they used to,” Stainback said. After mortality takes its toll, the zoo may only have 15-20 young-of-the-year birds ready for release in October.

In the wild a clutch of 12 eggs was normal. The birds also only lived two to three years in the wild, but have lived as long as six years in captivity. As they got older, though, egg production diminished.

Still, the program is the bird’s best chance of recovery.

“The Attwater’s prairie chicken captive breeding program is an extremely viable program. This ground-breaking program literally has prevented the Attwater’s from becoming extinct, buying time, so-to-speak, until issues dealing with wild chick survival could be investigated and solutions found,” Rossignol said.

There are also problems once the birds are moved through acclimation pens at the refuge and then released into the wild. One of the biggest issues has been fire ants. The USFWS has seen survival numbers increase on parts of the refuges where major fire ant treatment programs have been conducted. Biologists are working to keep the refuges fire ant free, and by doing so are seeing an increase in insects and invertebrates. Insects and invertebrates are the chicks’ primary food source the first three to four weeks of their life.

Rossignol said Attwater’s numbers in the wild had slowly increased annually from 2007 until the drought year of 2011.

“The extreme drought of 2011 really set us back. The next couple of years will be telling. ... if we can dramatically improve the survival of wild chicks by treating for (red imported fire ants), APC numbers will continue to go up. That’s not to say that we will not experience some bad years, but at least APC numbers will move in a positive direction. Unfortunately, it takes time to bring back a species out of the jaws of extinction,” he noted.