Meeting Abstract

P1.28  Sunday, Jan. 4  The comparative ecology of Norops lemurinus (Sauria; Polychrotidae) on the islands of Cayo Menor and Cayo Mayor of the Cayos Cochinos archipelago of Honduras. LOGAN, Michael L*; MONTGOMERY, Chad E; BOBACK, Scott M; REED, Robert N; CAMPBELL, Jonathan A; University of Texas at Arlington; Truman State University; Dickinson College; United States Geological Survey; University of Texas at Arlington mlogan@uta.edu

In Honduras, Norops lemurinus (Sauria; Polychrotidae) is distributed along the Atlantic versant of the mainland and on the Caribbean island system consisting of the Bay Islands and Cayos Cochinos archipelagos. In the Cayos Cochinos, N. lemurinus occurs on two islands, Cayo Menor and Cayo Mayor. The abiotic and biotic environment of these islands differs noticeably from the mainland, while the environments of each island differ from each other to a lesser degree. To examine the potential morphological, ecological, and physiological correlates of these differences in environment, we sampled lizards from both islands, measuring 15 morphometric variables, 13 habitat variables, and field active body temperatures. Additionally, we measured upper thermal tolerance and evaporative water loss for the Cayo Menor population, and compared our results to previously published data for mainland populations. After correcting for snout-to-vent-length, Cayo Menor males had greater mass and dewlap diameter, while females did not differ in any morphological character examined. When males and females were pooled, perch width and temperature at perch site were greater on Cayo Mayor. Additionally, lizards on Cayo Menor were found at greater distances from open environments (areas with breaks in canopy cover). Observed differences in morphology, physiology, and habitat use can perhaps be explained by differences in temperature and rainfall regimes, habitat availability, and niche relationships with potential competitors.