Ecomorphological differences allow species to coexist within communities, as animals with different morphological characters are likely to use distinct niches, hence reducing interspecific competition. Ecomorphological studies have highlighted the role of e.g. bill size and shape in passerines (Newton 1967), body size in amphibians, reptiles, insects and rodents (Barbault 1992), canine diameter in carnivores (Pimm and Gittleman 1990), neck height and/or incisor arcade structure in herbivorous mammals (Gordon and Illius 1988, Du Toit 1990). Because competition for food has long been a keystone of community ecology, it is not surprising that ecomorphological studies have often focussed on characters related to animal's foraging habits.