The Use of Automated Data-Acquisition Techniques in Monitoring Amphibian and Reptile Populations

A major problem associated with herpetological surveys and monitoring programs is that environmental variation affects animal activity and, thus, our ability to determine the presence and abundance of amphibians and reptiles. This paper discusses how automated data-acquisition techniques can be used to quantify the relationships between environmental variation and animal activity and thereby improve surveys and monitoring programs. Two major issues are addressed: (1) how to describe temporal and spatial variation in the physical environment, and (2) how to measure the activity patterns of free-ranging animals. We use an automated weather station to gather environmental data and techniques such as radiotelemetry and audio recording to determine activity patterns. Combining environmental and activity data helps optimize where, when, and under what conditions to sample. We illustrate our approach with data on the effects of environmental variation on the activity patterns of rubber boas (Charina bottae) and on the calling activity of southwestern toads (Bufo microscaphus) .