Implications of skull shape for the ecology and conservation biology of crocodile

Abstract

Each species of crocodile has its own distinct head shape with its own well-adapted capacities for movement, force, strength, and in turn diet and habitat preferences suiting their niche. Different species of crocodilians with overlapping or matching natural ranges (sympatric species) show increased (interspecific) competition with similarity in head shape. Using various skull measurements of all extant crocodilian species, I tried to quantify and describe similarity and dissimilarity in head-shape. I use this information to ascertain the level of competition, and thus impact, the presence of one crocodilian species would have on another. As a result it is possible to predict ratios in which the coexisting species must remain (natural state equilibriums) so that both populations are successful. I applied the found interspecific competition relationships to five known sympatric species pairs and corroborated this method with a comparison to existing population studies. I suggest the derived ratios as guidelines for conservation and management decisions within multi species habitats, where probable impact of one apex predator on another is often unknown, difficult to deduct from ecological studies or underestimated.