Heloderma Population Survey, Rocking K Ranch, Pima County, Arizona 1988

Love, Charles

The Gila Monster (Heloderma suspectum) population on Rocking K Ranch was studied in the field February-June 1988. Observations were made on the other vertebrate taxa during the Heloderma survey period. The objective was to determine population density for Heloderma suspectum on the 5830 acre Ranch. This was accomplished by direct observation of Gila Monsters foraging and in shelters, observation of sign, and, in conjunction with these, the evaluation of habitat with regard to habitat quality for Heloderma suspectum. The yardstick for Heloderma habitat quality on RKR has been calibrated by long-term studies elsewhere in southern Arizona and the Southwest, primarily by the author. These studies have employed mark-recapture population techniques for many years; they also involve radio-telemetry for remote ground-level and underground sensing, employing animal implanted transmitters.