A COMPARISON OF TRAP EFFECTIVENESS FOR REPTILE SAMPLING

Comparisons of reptile populations require that sampling techniques pr ovide unbiased estimates across habitats and seasons. Use of multiple techniques are frequently suggested to fully sample reptile communitie s. The effects of multiple sampling techniques on measurements and ana lyses of population attributes are limited. This study compared measur ements of abundance based upon drift fences equipped with pitfall and funnel traps to plywood artificial structures in two habitats in the C hihuahuan Desert. Drift fence arrays produced higher abundance estimat es for Cnemidophorus marmoratus (P < 0.001) than artificial structures . Artificial structures attracted more Uta stansburiana on uplands com pared to arroyos (P = 0.045) but this result is biased because of an i nability to distinguish individual animals with plywood artificial hab itat. Provision of water under plywood artificial habitats had no meas urable effect on capture rate. Within drift fence arrays, pitfall trap s captured more C. marmoratus and C. inornatus than funnel traps. Cnem idophorus marmoratus seemed to be susceptible to pitfall trapping duri ng spring (P = 0.058). Uta stansburiana were susceptible to funnel tra pping during spring, but had equal catchability for all other season x method combinations (P = 0.012). Plywood artificial structures produc ed biased abundance estimates for U. stansburiana among habitats. Funn el traps and drift fences alone would produce a seasonal bias for U. s tansburiana whereas pitfall traps and drift fences alone produced a se asonal bias for C. marmoratus.