Abundance-range size relationships in British birds: is unexplained variation a product of life history?

Positive interspecific relationships between local abundance and geographic range size are a common feature of animal assemblages However, range size typically explains only a moderate proportion of the variation m abundance, begging the question of whether species of differing life history deviate from the underlying relationship in any systematic fashion Using data for the avifauna of Britain, and applying a comparative method to control for the effects of phylogenetic association, we demonstrate that this does not appear to be the case Only adult survivorship, age at independence and incubation period explain significant variation in abundance once range size is controlled for statistically, and then only a few percent There are two probable reasons why this result is contrary to general expectation First, although many life history variables are expected to show simple correlations with abundance or range size It is not obvious how these might relate to variation about the abundance–range size relationship Second, intuitive ideas about the form such variation might take may be seriously confounded by phylogenetic non–independence