News Release

Breeding program for endangered blunt-nosed leopard lizards announced

The blunt-nosed leopard lizard was listed as an endangered species at the state and federal level in the mid 1960s.
Newly hatched blunt-nosed leopard lizard. Photo by Mark Halvorsen and courtesy of BLM.
Hatching blunt-nosed leopard lizard. Photo by Mark Halvorsen and courtesy of BLM.

Information in this article was provided by the Bureau of Land Management


The Bureau of Land Management announced that officials at Fresno Chaffee Zoo, Fresno State University, Bureau of Land Management, California Department of Fish and Wildlife and U.S. Fish and Wildlife Service are involved in a joint conservation effort to recover the endangered blunt-nosed leopard lizard.

To support the recovery of the  species, the partners developed a captive breeding plan in late 2020. Between July 2020 and July 2021, six adult blunt-nosed leopard lizards were collected from Panoche Hills to serve as founders for a breeding program. The BLM said research and data coming out of the breeding program will help with the goal of eventually increasing the lizard population. The news release states that habitat loss is the primary cause of reduced numbers.

The Bureau said that during the next five years, Fresno Chaffee Zoo, together with their agency partners, will continue a breeding effort to increase the population for eventual release in the Panoche Hills.

As part of this effort, Fresno Chaffee Zoo has successfully hatched 19 lizards in a captive breeding program, the first a first for the species, with the long-term goal of releasing them to their native habitat.

“Each and every animal serves an important role in our ecosystem, so it’s imperative to conserve species in their natural habitats,” said Fresno Chaffee Zoo General Curator Lyn Myers. “These 19 individuals represent a chance to ensure that blunt-nosed leopard lizards will be around for generations to come. The work that we are doing and the knowledge gained will help blunt-nosed leopard lizards both at our Zoo and in their natural habitat.”

According to the Bureau of Land Management the blunt-nosed leopard lizard was listed as an endangered species at the state and federal level in the mid 1960s. Endemic to central California, the lizard is in danger of extinction throughout its range.

“The species decline is directly associated with habitat loss. Blunt-nosed leopard lizards are only found in the San Joaquin Desert of central California, within the San Joaquin Valley and adjacent foothills [including Panoche Valley], as well as the Carrizo Plain and Cuyama Valley,” the release said.

Panoche Valley in San Benito County. Photo by Annette Teng and available through Creative Commons.
Panoche Valley in San Benito County. Photo by Annette Teng and available through Creative Commons.

The Bureau said these lizards inhabit sparsely vegetated areas. The lizard uses rodent burrows for coverage from the harsh desert heat and is known to pounce on prey. The blunt-nosed leopard lizard is a relatively large lizard with a long tail; long, powerful legs; and a short, blunt snout. Adult males typically range in size from 3.4 to 4.7 inches in length, excluding their tail, and females are about 3.4 to 4.4 inches in length, excluding tail.

Darker than other leopard lizards, blunt-nosed leopard lizards vary in color and pattern on their backs. Their background color ranges from yellowish or light gray-brown to dark brown, depending on the surrounding soil color and vegetation. Habitat disturbance, destruction, and fragmentation are the greatest threats to blunt-nosed leopard lizard populations.

For more than a decade, the Bureau has been closely monitoring this lizard on public lands it manages in the Panoche Hills, bordering the San Joaquin Valley. The Bureau seasonally closes the Panoche Hills to vehicle access during mating season and designated it as an Area of Critical Environmental Concern. The Bureau has invested significant resources to document the population decline by employing innovative survey methods using scat to identify the DNA of individual lizards.

“The Bureau of Land Management is excited to see our commitment to the blunt-nosed leopard lizard move the needle towards recovery,” explains Bureau Central Coast Field Office Wildlife Biology Program Lead Dr. Mike Westphal. “Collectively, we can do so much more together as partners to conserve this population and hopefully many other imperiled species in the future.”

Lizards were caught in the Panoche Hills in 2020 for the breeding program.

“This captive breeding program is essential for recovering the blunt-nosed leopard lizard in the Panoche Hills. By raising the lizards in a controlled environment, we can improve their chances of survival when they are released into the wild. The species is on a better path because of this collaboration,” said U.S. Fish and Wildlife Service’s Sacramento Fish and Wildlife Office Field Supervisor Michael Fris.

The Bureau added that successfully breeding this species for the first time in captivity has provided valuable data on and insight into the species, including the number of eggs female lizards lay per clutch, length of breeding season, and length of incubation period. Partners will use this information to project future breeding estimates and expectations. Each year, the partners hope to release young lizards back to the Panoche Hills.

“The goal of this joint effort is the eventual re-creation of a self-sustaining population of blunt-nosed leopard lizards in the Panoche Hills,” the release said. “The partners have outlined a goal of more than 50 females whose ancestors were born on the plateau, successfully reproducing each year for three consecutive years. All released individuals will be monitored to assess their survival and further breeding in their natural habitat.”

“This exciting partnership has rapidly responded to save a critically imperiled population of an endangered species. At the same time, we are also learning about important elements of the blunt-nosed leopard lizard’s life history which will assist in recovery efforts for the entire species. A wonderful benefit of this partnership is that residents of the San Joaquin Valley can learn about a rare and fascinating local California endemic species from Fresno Chaffee Zoo,” said California Department of Fish and Wildlife Regional Manager Julie Vance.

The current breeding season for the blunt-nosed leopard lizard adult colony at Fresno Chaffee Zoo has ended and will begin again in spring 2022.



BenitoLink Staff