Gila monsters are endemic to the Sonoran desert and are the only venomous lizards that live in the United States. The Gila monster project at Saguaro National Park was started in 2008 by Dr. Kevin Bonine of the University of Arizona, in part because so little is known about this elusive lizard. This project had several areas of focus. The first was radio tracking, which allowed us to find individual Gila monsters even when they were hidden underground, as they often are. Gila monsters at the park were outfitted with a small radio that can be tracked using a radio receiver. Then, they were located and observed approximately once a week all year round. In addition, to location, we collected data such as temperature, behavior, and nearby plants and other habitat features to help us understand the lifestyle and activities of these lizards.
The second area of focus was genetics. We are learning a great deal from DNA collected from individuals during this study, especially how closely related individuals are from nearby and more distant populations.
Another part of the project involves collecting photographs of all individuals that are seen within or near the Park's boundaries. Like fingerprints, a Gila monster's pattern is unique to each lizard. Therefore, it is possible to identify individuals by the pattern on their bodies. This aspect of the project relies heavily on photographs taken by "citizen scientists", who can be visitors, volunteers, employees, and researchers. Because Gila monsters are venomous, and spend most of their lives underground, finding and photographing them can be challenging. For this reason, we are requesting that if you see a Gila monster in the National Park, please only take its photo from a safe distance! Send it to us, and count yourself as lucky to have spotted one! We will use this photo in our research.
Learn more about what we do with your photos after you send them in and our results!
Take a look and print out our Gila monster brochure!
Last updated: June 4, 2019