Audubon Zoo Releases Rarest Snakes in the United States

Three representatives of the rarest snake species in the United States were released into the wild thanks to partners from around the country. Three Louisiana pine snakes were released by Audubon Zoo and the United States Forestry Service (USFS) in the Kisatchie National Forest on September 19, 2019.

Hatched at the Jacksonville Zoo and Gardens in 2017 and then transferred to Audubon Zoo in 2018 for head-starting, or rearing to larger sizes that would be less vulnerable to predation prior to their release, these three individuals play a critical role in the recovery of this disappearing species. With around 200 individuals estimated to be left in the wild, Louisiana pine snakes (Pituophis ruthveni) are classified as endangered by the IUCN. Audubon Zoo’s release follows the release of an additional 22 Louisiana pine snakes earlier this month that were hatched at Memphis Zoo and Fort Worth Zoo.

Restricted to longleaf pine habitat in just a few isolated locations in western Louisiana and eastern Texas, the Louisiana pine snake has experienced widespread population declines over the past century and is now considered to be the rarest snake in the United States. Its disappearance has been associated with the decline of the longleaf pine ecosystem due to poor land management practices including fire suppression and large-scale timber production. Today, the species is found on only a handful of tiny, fragmented parcels of land.

A managed population of the Louisiana pine snake was established in AZA-accredited zoos in 1984. In 2000, a Species Survival Plan (SSP), led by Memphis Zoo, was created to maintain an assurance colony of this imperiled species and carefully manage the zoo population by ensuring that all planned breeding maximizes genetic diversity in the population. Four main breeding facilities participate in this program, including Memphis Zoo, Ellen Trout Zoo, Fort Worth Zoo, and Audubon Zoo. Zoo Atlanta, Phoenix Zoo, and the Jacksonville Zoo and Gardens are also involved in the program, maintaining a few adult animals for breeding purposes.

“In addition to the three head-started individuals that were recently released, Audubon Zoo has also successfully hatched a total of 113 Louisiana pine snakes since 1997,” said Audubon Zoo’s Curator of Herpetology Robert Mendyk. “While many of these animals have been held back to become future breeders for the program or transferred to other participating facilities for rearing, a total of 14 individuals hatched at Audubon Zoo have been released into the wild in Louisiana to date.”

The Kisatchie National Forest in western Louisiana is one of the few remaining places that Louisiana pine snakes remain in the wild. On September 19, field partners from USFS and staff from Audubon Zoo’s herpetology department made the journey to this remote location to release these three snakes.

Before the snakes were released, staff measured body length and weight and took photographs and notes on each individual snake’s body condition and any identifiable features. The snakes are equipped with microchips that store identifiable information, which enable USFS biologists to track their movements and survivorship over time. These microchips are checked one last time before the snakes are released down holes or the burrows of pocket gophers, a primary food source of the species.

As one of the four main conservation breeding and rearing facilities for the Louisiana pine snake, Audubon Zoo’s continued involvement in this conservation program is vital to the success of recovery efforts. Audubon Zoo looks forward to continuing its important work with this imperiled native species while working closely with partnering zoos and wildlife agencies.