Distribution of the Gila Monster in Southwestern New Mexico

Giermakowski, J. Tomas

Museum of Southwestern Biology

University of New Mexico

Albuquerque, NM

tomas@unm.edu

Ryan, Mason J.

Terrestrial Wildlife Branch

Arizona Game and Fish Department

Phoenix, AZ

Latella, Ian M.

Museum of Southwestern Biology

University of New Mexico

Albuquerque, NM

The Gila Monster (Heloderma suspectum) is the iconic venomous lizard of the U.S. southwest yet little is known about its distribution in New Mexico. While widespread and relatively common elsewhere, this species is known from only a few scattered and disjunct areas in southwestern New Mexico, and it is categorized as endangered by the New Mexico Department of Game and Fish. Gila Monsters are threatened by multiple factors, including illegal collection for commercial and private trade, habitat fragmentation, changes in land use, and increased temperatures and drought condition from climate change. In the spring and summer of 2017 we conducted surveys throughout four target areas in southwestern New Mexico, identified from previous records and a preliminary model of distribution. While we detected Gila Monsters at all of the four areas, detection probability varied significantly among them; furthermore, these lizards were most prevalent near the Gila River. To evaluate the vulnerability of the populations at a landscape scale, we built suitability models for current and future landscape based on data gathered from various sources. While the potential extent of Gila Monsters occurrences in New Mexico is larger than previously known, our models suggest that occupied areas are likely small and their delineation is complicated by varying detection probabilities thus further sampling is needed to improve model estimates. This will be necessary in designing a comprehensive Gila Monster conservation strategy in New Mexico, where this charismatic lizards future is complicated by the increased pressures from changing climate and the effects of pet-trade harvesting.


Copyright 2018, Biology of Lizards, all rights reserved 
email smithcf@wofford.edu  for usage information 
Logo design, Website design, and content: Chuck Smith 
Website development:
Chuck Smith

photo credits: Will Wells and Jack Goldfarb

Completed registration forms: admins only