Interspecific abundance-occupancy relationships of British mammals and birds: is it possible to explain the residual variation?

The majority of studies concerning positive interspecific abundance-occupancy relationships have used broad-scale and microcosm data to test the occurrence and correlates of the relationship to determine which of the proposed mechanisms give rise to it. It has been argued recently that studying the residual variation about abundance-occupancy relationships is a more logical analysis and may yield faster progress in identifying the relative roles of the mechanisms. However, to date this approach has been largely unsuccessful. Here we test if fundamental species traits such as the status (native and introduced), habitat and trophic group of mammal and bird species may explain any of the residual variation about their respective abundance-occupancy relationships.