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More Luck than Brains: The Opportunistic Discovery of Hatchling Gila Monsters in a Semi-Urban Nest

Repp, Roger A. 9044 N. Valgrind Lane Tucson, Arizona USA

Chiricahua Desert Museum Rodeo, New Mexico USA

Despite the iconic status that the Gila Monster (Heloderma suspectum) maintains as an inhabitant of the deserts of the American Southwest, little is published concerning its reproductive biology, especially most aspects of nesting (e.g., nest location, number of eggs, time of hatching). In late October of 2016, a construction crew digging a footing for a house addition accidentally uncovered five hatchlings that were either still in the egg or had just emerged. I received the phone call from the crew, and was on scene within forty minutes. My close relationship with Dr. Dale DeNardo’s laboratory at Arizona State University allowed collaboration with them and what they have learned through radio-telemetry at their Gila Monster nesting sites in southern Arizona, and the information that was acquired at the dig site. In my presentation I will discuss the physical aspects of the nest itself and metrics of the hatchling Gila Monsters. Preliminary findings indicate that Heloderma suspectum may be the only lizard species to lay their eggs in early summer, hatch in mid fall, overwinter out of the egg, and emerge to become surface active in the spring. The nest that was found in October 2016 is the first to be documented, and we continue to study the hatchlings from that nest, which are being maintained at the DeNardo lab. The color change of the young from whitish-yellow to orange has already been documented, and attention to possible pattern change is being investigated.

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