Species Abundance and Biomass Distributions
in Freshwater Turtles
RICHARD C. VOGT 1 and JOSÉ-LUIS VILLARREAL BENITEZ 2
1 Estación de Biología Tropical Los Tuxtlas, Instituto de Biología UNAM,
A.P. 91, San Andres Tuxtla, Veracruz, C.P. 95700 México / email: Dickturtle@aol.com
2 Matamoros No. 10, Catemaco, Veracruz, C.P. 95780 México
ABSTRACT: Species abundance has been used to infer interspecific patterns in resource partitioning. However, these patterns can differ from those predicted by the distribution of species abundance, depending on the relationship within the communities between the abundance of a species and its body size. In many groups, the largest species in the community tend to have lower population densities than smaller ones. Many theories have tried to explain the patterns of species abundance in terms of resource use, by studying the ways that species partition the resources of the community. In this article we explore four patterns of turtle abundance and diversity with specific hypotheses; although the data are preliminary, they suggest many ideas useful for the conservation of chelonians. Our primary conclusion is that turtle species with relatively small body sizes have been more successful; however, the smallest turtles are not very successful. Further research should be done to assess the significance of this pattern to the conservation of turtles throughout the world.