Conservation genetics and population structure of Chiricahua leopard frogs in New Mexico, Arizona and Mexico

Collaborator: Dr. Melanie Culver, School of Natural Resources, University of Arizona

The Chiricahua leopard frog (Rana chiricahuensis) occurs at elevations of 3,281 to 8,890 feet in central and southeastern Arizona; west-central and southwestern New Mexico; and the sky islands and Sierra Madre Occidental of northeastern Sonora and northwestern Chihuahua, Mexico. The range of the species is split into two disjunct parts - the northern populations along the Mogollon Rim in Arizona east into the mountains of the west-central New Mexico, and the southern populations in southeastern Arizona, southwestern New Mexico, and Mexico. Genetic analysis suggests the northern populations may be an undescribed, distinct species.

Chiricahua leopard frog populations have declined precipitously throughout Arizona and New Mexico since the species was listed as threatened in 2002. Due primarily to drought and chytridiomycosis (a fungal skin disease), the number of likely extant populations has declined by 27-33% in the last 4 years. Thirty-five years ago, Chiricahua leopard frogs were well-distributed in often robust populations throughout their range in Arizona and New Mexico. The species was known historically from over 400 localities, but is now considered likely extant at only 36-59 sites in Arizona and 30-35 in New Mexico (77-84% percent decline in total).

Molecular genetic analyses using microsatellite and mitochondrial DNA markers, to quantify genetic relationships among populations, metapopulations, and recovery units. This work should also help define genetic diversity within populations and metapopulations, and the need for augmentation. Results will also be used for future population viability analysis.