ANIMAL BODY-SIZE DISTRIBUTIONS - PATTERNS, MECHANISMS AND IMPLICATIONS

Documenting the shape of the frequency distribution of species body si zes for an animal taxon appears at first sight a straightforward task. However, a variety of patterns has been reported, and a consensus is only now being reached through an understanding of how potential biase s may affect observed shapes of distributions. A new body of evidence suggests that, at large scales, size distributions are right-skewed, e ven on logarithmic axes. If body size distributions can be described w ith certainty, this will allow assessment of the mechanisms proposed t o generate them, and will be an important step towards understanding t he structure and dynamics of animal assemblages.