Date of Award

Winter 2009

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Biological Sciences

Program/Concentration

Ecological Sciences

Committee Director

Alan H. Savitzky

Committee Member

Frank P. Day

Committee Member

CHristopher A. Binckley

Abstract

The Neotropics is a biologically diverse region that provides man opportunities for ecological and behavioral studies. I utilized the speciose ophidian fauna of central Panama to explore the general ecology of arboreal snakes, the defensive behaviors of the snake community, and the diet of mollusk-eating snakes. I studied arboreal species to understand interspecilic relationships in several morphometric characters and to examine preferences in habitat. There were significant morphometric differences in relative length of jaw, mass, tail length, and size at midbody. The arboreal realm was partitioned among species by distance to ground, distance to water, and diameter of the perch. Correlations were found in some species between body mass or length and distance to the ground and leaf length. Additionally, man arboreal species have been documented to bridge gaps in vegetation, but few studies have investigated this hehavior systematically. I tested average bridging ability of five Neotropical arboreal snakes and investigated morphological elements underlying differences in relative cantilevering ability. I found significant interspecific differences in average and maximum distances bridged. Species with the relative heaviest mass had the lowest cantilever ratios. Defensive behaviors which are employed for protection from predators, also were evaluated. I document interspecific differences in these behaviors at the community level. With knowledge gained from the ophidian community in Panama, I further documented on the defensive behaviors of other New World mollusk-eating snakes. Finally, I studied the diet of selected mollusk-eating snakes. I evaluated fecal samples of Dipsas and Sibon and found that their diet is broader than mollusks alone. In fact, a majority of Dipsas in central Panama were feeding on oligochaetes. Some species of Sibon were feeding on mollusks, whereas others fed primarily on amphibian eggs and oligochaetes. The discovery of a broader diet in these taxa may have conservation implications as populations of amphibians and terrestrial mollusks decline worldwide. The expansion of our knowledge of the natural history, ecology, and behavior of Neotropical snakes has provided information that will be important for future studies of community- and ecosystem-level interactions and for the conservation of the biota of central Panama.

DOI

10.25777/ysd1-2855

ISBN

9781109566314

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