Variation in herpetofauna detection probabilities: implications for study design

Area of Science:

• Wildlife Ecology
• Conservation Biology
• Herpetology

Background:

• Global biodiversity decline necessitates effective population monitoring strategies.
• Herpetofauna populations are declining worldwide, presenting monitoring challenges.
• Traditional monitoring methods like raw counts are susceptible to detection probability bias.

Purpose of the Study:

• To develop an efficient herpetofauna monitoring program in southern Texas.
• To estimate detection probabilities using an occupancy modeling framework.
• To evaluate the effectiveness of funnel traps, pitfall traps, and cover boards.

Main Methods:

• Data collected using 36 trap arrays over 2105 array-days across two study sites (2015-2016).
• Occupancy modeling applied to estimate detection probabilities for 21 herpetofauna species.
• Comparison of capture efficiencies for funnel traps, pitfall traps, and cover boards.

Main Results:

• Detection probability varied with sampling duration for 10 species and rainfall for 10 species.
• Funnel traps were most efficient for 14 species; pitfall traps for 12 species; cover boards for none.
• Monitoring methods ignoring detection probability introduce significant bias without extensive sampling.

Conclusions:

• Occupancy modeling is crucial for unbiased herpetofauna monitoring.
• Arrays utilizing funnel and pitfall traps are recommended for southern Texas herpetofauna.
• Accurate monitoring informs critical biodiversity management decisions.