Efficacy of Sampling Techniques for Determining Species Richness Estimates of Reptiles and Amphibians

Abstract

The ability to detect reptiles and amphibians is influenced by environmental and behavioural variables and detection probabilities, but studies to determine herpetofauna species richness often employ only a small number of sampling techniques, primarily drift fence arrays, visual encounter surveys, and coverboards (i.e. primary techniques). However, using only two or three sampling techniques can underestimate species richness. To evaluate the efficacy of sampling methodologies in determining the species richness of herpetofauna, we employed 11 different sampling techniques. We hypothesized that adding standardized road searches, polyvinyl chloride (PVC) piping grids, line transects, auditory surveys (i.e. secondary techniques), opportunistic encounters, aquatic funnel traps, crayfish traps and basking traps (i.e. tertiary techniques) would better portray species richness. Observed species richness (Sabs, species physically detected or observed), Chao2 estimates of species richness (S), unique species captured (i.e. species detected by only one technique), cost, and cost‐per‐species‐captured for individual techniques and categories (i.e. primary, secondary and tertiary) were used to determine efficacy. Primary capture methodologies detected 13 species (S = 14). Secondary and tertiary sampling techniques captured 18 and 24 species, respectively (S = 29 and 25). All sampling methodologies combined captured 33 species for a Chao2 estimate of 34. More unique species were captured by tertiary techniques than by primary or secondary methodologies. Costs for primary techniques were much higher than for secondary and tertiary methodologies. To better determine species richness, we recommend that future research incorporate multiple sampling methodologies in addition to more common techniques.