The rock horned lizard, also known as the Ditmars’ horned lizard, has the distinction of disappearing from scientists’ view for well over half a century. First discovered by herpetologist Leonhard Stejneger in 1898, the species wasn’t observed again for about 70 more years. We’ve been learning more about this species to ensure it thrives for centuries to come, and you’re helping.
With your clicks, trivia participation, shopping for a cause, and direct donations, you’ve helped support our partner Greater Good Charites’ Global Discovery Expeditions (GDE) program. This program aims to protect threatened biodiversity hotspots by taking the first step toward conservation: surveying these landscapes and recording the species that live there.

This effort has recently expanded to Vietnam, which is believed to contain nearly 1 in 10 of the world’s animal species. However, GDE began its work within unique mountain “islands” surrounded by deserts and grasslands, called the Madrean Sky Islands. This is where more than 7,000 plant and animal species, including the Ditmars’ horned lizard, can be found.
HELP PROTECT THE MADREAN SKY ISLANDS
GDE survey groups have been traveling to the Sky Islands – located in the southwestern United States and northwestern Mexico – for more than 10 years. The trips have largely focused on the Mexican state of Sonora, where this special ecosystem is particularly rich with biodiversity but is at risk due to ranching and mining.

During these trips, the survey teams – which consist of scientists from both Mexico and the United States – have recorded the Ditmars’ horned lizard multiple times. This work is necessary to better understand the species, about which there is limited knowledge. In fact, the IUCN Red List currently says there is deficient data on its population.
There’s also limited knowledge on how it reproduces, which is why we’re working with GGC and Zoo Miami on a new breeding program. The goal is to ensure that there are individual lizards to release into the wild should their numbers fall, to answer important questions scientists still have about topics like their reproduction, and to raise awareness about the species with zoo visitors.

The most recent trip to Sonora helped find four lizards that will become part of the program.
Your support has helped these important scientific studies continue. Thank you! If you’d like to continue to support survey trips to the Madrean Sky Islands, click here!
Keep scrolling to see photos, all taken by Greater Good Charities, from the most recent trip.






