Character displacement as a mechanism for coexistence in moa (Aves: Dinornithiformes)

The moa (Aves: Dinornithiformes) are an extinct group of ratite birds endemic to New Zealand. They were the dominant herbivores prior to human arrival. Analysis of coprolite data showed that moa diet varied little between species in the same area, despite each one being inhabited by three or more moa species. Many hypotheses have been proposed to explain how moa utilised niche partitioning. I aimed to test for evidence of character displacement in body size, which would influence feeding height among other ecologically significant factors. Moa were morphologically diverse in body size, which may have been partly related to displacement. Measurements of femur length and width at midshaft and distal end were taken and used as a proxy for body size. The log-transformed results were then analysed using the V statistic. Results showed that sizes were randomly distributed and not indicative of character displacement. Moa therefore did not evolve character displacement in body size. Niche partitioning may have been accomplished through the evolution of other traits, such as bite dimensions or habitat preferences.