Gila Monster. Photo by Chris Lohrengel, 9/2006, Leslie Canyon NWR.

The San Bernardino NWR has been opportunistically collecting data on Gila monsters (Heloderma suspectum) since 2000.  Gila monsters occur in portions of Sonora and Sinaloa in the Republic of Mexico, and in portions of Arizona, New Mexico, California, and Utah in the United States.  The information gathered allows for more insight into these secretive creatures.  These large, venomous lizards appear to be rather uncommon throughout their range, but their exact population status is complicated by the fact that they spend most of their lives underground and very little of their time actively moving through their preferred upland habitat. 

This year refuge staff and volunteers captured 25 individuals with five of them being recaptures.  When an individual is encountered, it is captured, measured, weighed, sexed, photographed, pit-tagged to allow individual identification, and then released at the same site.  Capture sites are recorded and mapped.  Recaptured lizards provide growth and general health information, and can provide information regarding habitat use, individual movement, and home range size.  Such basic population ecology information can easily and economically be gathered by all refuge staff, and the information will ultimately help wildlife managers make more informed decisions regarding this species.  In addition, pit-tagging individuals have the potential to assist with law enforcement investigations involving illegal take, transport, or trade.