The Los Angeles Zoo reported the birth of two litters totaling six New Mexico ridge-nosed rattlesnake pups last month. These represent the first offspring produced under a coordinated recovery initiative involving multiple institutions that began two years earlier, according to LAist.
Byron Wusstig, the zoo’s reptile curator, described the long-term aim as establishing sustainable, genetically diverse populations in the areas of Arizona and New Mexico where the species faces the greatest pressure. The snake, listed as threatened under the Endangered Species Act, occupies isolated mountain habitats in those states and northern Mexico.
The zoo participates in Project Obscurus alongside two other facilities. The scientific name of the snake is Crotalus willardi obscurus. Adults used in the current breeding were originally collected from the Sierra San Luis mountains in Mexico, with pairings arranged roughly one year ago.
Staff replicate seasonal conditions in the animals’ enclosure by adjusting temperature, humidity, and lighting to match the species’ native mountain environment. Summer conditions include the use of sprayers and misters to simulate monsoon rainfall, Wusstig noted.
Rattlesnakes give birth to live young and remain with the neonates for several weeks. The pups consume centipedes along with small portions of mice and quail, while adult meals are prepared frozen and thawed to the correct temperature because the snakes detect prey through heat sensing.
Wusstig observed that the young snakes have been seen basking atop their mother and drinking water that collects on her scales. Project Obscurus participants will determine in the coming months whether the pups are released into the wild or retained for further breeding. The animals are currently held off public view to maintain quarantine protocols.
This report is based on coverage by LAist: https://laist.com/news/climate-environment/los-angeles-zoo-ridge-nosed-rattlesnake-recovery-litter-2026