Effects of destructive collecting practices on reptiles: A field experiment

A basic tenet of wildlife management is that acceptable harvest methods should have little impact on populations other than eliminating or reducing the number of surplus individuals. We evaluated whether collectors who use destructive methods to harvest individual animals threaten reptile populations in Arizona, USA. Destructive methods usually involve permanent damage to cracks and crevices in rock outcrops that provide moist, cool shelter sites for reptiles. We surveyed 80 rock outcrops in an area slated for development. We treated half of the rock outcrops by imitating the activities of collectors using pry bars to overturn rocks and break open cracks, and we then resurveyed the rock outcrops. Multivariate repeated-measures analysis revealed that damaged rock outcrops support fewer reptiles than undamaged outcrops. We also observed species, sex, age-class, and seasonal effects due to treatment. To combat the growing problem of habitat destruction from reptile harvest, we recommend protection of rock outcrops and education of reptile collectors.