6 Rare Rattlesnakes Born At LA Zoo In Conservation Milestone

LOS ANGELES, CA — Six rare New Mexico ridge-nosed rattlesnakes have been born at the Los Angeles Zoo, marking the first successful births under an international conservation breeding program for the threatened species.

A litter of five snakes was born Aug. 18, followed by a single neonate born Monday, the zoo announced Tuesday.

The births are the first for Project Obscurus, a collaborative recovery effort involving zoos, researchers, wildlife agencies and conservation groups in the United States and Mexico.

“This incredible breeding success is a testament to our animal care team’s deep expertise in managing delicate montane pit vipers,” said Byron Wusstig, the zoo’s curator of ectotherms. “These two litters represent a tangible lifeline for a species whose numbers have drastically declined in the U.S.”

The Los Angeles Zoo is the first of the project’s participating institutions to successfully breed the New Mexico ridge-nosed rattlesnake, which is classified as threatened by the U.S. Fish and Wildlife Service.

Project Obscurus was formalized in 2024 and is coordinated by The Rattlesnake Conservancy. Its conservation breeding partners include the Los Angeles Zoo, Arizona-Sonora Desert Museum and San Antonio Zoo.

The effort builds on more than three decades of research and conservation work involving the species in the U.S. and Mexico.

The program is designed to raise young snakes in managed care and eventually bolster struggling wild populations while increasing their genetic diversity.

Unlike many reptiles, New Mexico ridge-nosed rattlesnakes give birth to live young rather than laying eggs.

The six newborn snakes will remain behind the scenes at the Los Angeles Zoo while staff members care for and monitor them. Once the snakes mature and meet appropriate benchmarks, they and their offspring could become candidates for release into native habitat in Arizona or New Mexico.

Considered one of the rarest rattlesnakes in the U.S., the New Mexico ridge-nosed rattlesnake is a small, pale gray to gray-brown pit viper distinguished by its upturned snout.

Its range is limited to portions of the Peloncillo Mountains in Arizona and New Mexico, the Animas Mountains in New Mexico and the Sierra San Luis in the Mexican states of Sonora and Chihuahua.

The snakes live primarily in humid mountain woodlands and some grassy slopes between about 5,000 and 8,000 feet in elevation.

Because the subspecies exists within a small and fragmented range, conservationists say it is particularly vulnerable to severe population declines.