While visitors watch the animals at Pittsburgh Zoo & PPG Aquarium, a world of research is taking place behind the exhibits.
This week, in a narrow lab behind the snake and reptile enclosures, a veterinarian examined three baby snakes that researchers hope will help the species to slither back from the brink of extinction.
The non-venomous Louisiana pine snakes were hatched at the zoo Sept. 4 as part of a nationwide U.S. Fish and Wildlife Service program to breed the snakes in zoo captivity and introduce them to parts of Texas and Louisiana, where they once thrived.
The species survival program includes 11 U.S. zoos and the Louisiana Department of Wildlife and Fisheries. In a published report, national coordinator Steve Reichling of the Memphis Zoological Garden and Aquarium in Memphis, Tenn., said the Louisiana pine snake is "arguably the most endangered species of snake in North America."
Virtually extinct in their native savannah habitat, there are more pine snakes in captivity than in the wild. Breeding and hatching them is difficult, and failure is common. The successful hatching of three healthy Louisiana pine snakes puts the Pittsburgh Zoo at the vanguard of the species survival program.
"We're proud of the success because it's been two years we've been trying to get this," said Henry Kacprzyk, reptile curator at the Pittsburgh Zoo.
Camouflaged in a distinctive brown pattern, Louisiana pine snakes can reach 5 feet in length. In the wild they eat small mammals, mostly the pocket gophers common to sandy, well-drained, open pine forests on the Texas-Louisiana border. Before sharp population declines during the last half century, the snakes spent much of their time underground in gopher burrow systems, enabling them to survive routine forest fires that killed many of their predators and competition. Habitat loss and the improved suppression of forest fires virtually wiped them out.
Returning the animal to the region's natural food chain is a priority of the Fish and Wildlife Service. But there's a problem. Most snakes produce a clutch of about 20 eggs and while mortality is high, enough survive to propagate the species.
"Louisiana pine snakes produce three to five eggs -- sticky, leathery and about 4 inches," said Mr. Kacprzyk. "These are the largest eggs laid by any snake in the United States and the babies are hatched very large. The biggest of these three is 19 inches. Their size gives them a genetic survival advantage, but the low number of eggs laid puts the snake at a great disadvantage, and that is complicated in captivity."
At the core of the species survival program is a Fish and Wildlife Service computer model that determines the best genetic matches for the 33 adult males and 31 adult females involved in the re-population program. A male and two females reside at the Pittsburgh Zoo.
"We induced hibernation by separating them, cooling them to around 55 degrees, kept them in the dark and didn't feed them," said lead keeper Ray Bamrick. "Then, when they came out of hibernation, they were primed for breeding. It took about three weeks for them to mate."
On July 3, 12 eggs were laid by the two females, and last week three little heads pushed through their leathery sacks. In October the young snakes will be shipped to the Memphis Zoo before stocking in Louisiana.
The Pittsburgh Zoo finances its scientific operations.
"It's part of our mission," said Mr. Kacprzyk. "A lot of people come to the zoo for recreation and education, and certainly that's a big part of what we do. But behind the scenes we're involved in conservation and research projects as well with species from all over the world. It's nice to be involved in a program for right here in the United States."
ON THE WEB
Visit post-gazette.com to watch a video report on the snakes.