ROAD SURVEYS FOR TURTLES: CONSIDERATION OF POSSIBLE SAMPLING BIASES

.—Herpetofaunal surveys often rely on observations obtained via road cruising. The ease with which many speciesof amphibians and reptiles can be observed on roads makes this a useful technique. However, road surveys have inherentlimitations and biases, particularly for turtles. Observations of turtles along roads are likely biased towards large, adultfemale freshwater turtles on nesting forays and male terrestrial turtles that typically have a large home range. Turtles mayalso use roadsides as habitat and their presence on roads may not necessarily be reflective of their abundance in adjacentnatural habitats. Researchers who use road surveys to examine demographic parameters of a turtle population (e.g., sexratio or age class structure), or to describe a turtle community (e.g., species richness) should consider these biases in theirconclusions and explicitly note the role of road cruising in data collection.