How to best manage genetic structure presents a frequent dilemma in endangered species conservation. In 2020, Fresno Chaffee Zoo received emergency permission to found a captive colony of Blunt-nosed Leopard Lizards (BNLL, Gambelia sila) from Panoche Plateau, Fresno County, CA. We began with 5 founders in 2020 and added two additional animals from Panoche Plateau in 2021, with an average kinship equivalent to half-sibs. Although animals successfully reproduced in captivity, reproductive rates declined over time, raising the possibility of ongoing inbreeding depression. In 2024, we collected three additional animals from a nearby population in Little Panoche Valley (LPV) which were crossed with Panoche Plateau-derived animals in our captive colony in 2025. We compared hatching success, post-hatching survival, hatchling morphology, and hatchling growth curves of animals resulting from pure-plateau crosses and outcrosses. Surprisingly, we could not detect any differences between lizards resulting from these different crosses. This result suggests that outcrossing at this level may provide few direct fitness costs or benefits. Given the known risk of inbreeding depression for closely-related vertebrates and lack of evidence for a cost to outcrossing, outcrossing is expected to result in a net conservation benefit for Panoche BNLL.

Dr. Rory Telemeco is Director of Conservation Science at Fresno Chaffee Zoo and lead scientist for the zoo’s Blunt-nosed Leopard Lizard Conservation Project. Rory received his PhD in Ecology and Evolutionary Biology from Iowa State University and his MS and BS degrees in Biology from the University of Central Oklahoma, with a research year at the University of Sydney. Before joining the zoo, Rory completed post-docs at the University of Washington and Auburn University, and was an Assistant Professor of Biology at Fresno State University. Rory is broadly interested in ecological and evolutionary responses of organisms (especially reptiles) to changing environments and using this information to improve conservation management.