Data from: Climate and local abundance in freshwater fishes

Identifying factors regulating variation in numbers of individuals among
populations across a species' distribution is a fundamental goal in
ecology. A common prediction, often referred to as the abundant-centre
hypothesis, suggests that abundance is highest near the centre of a
species' range. However, because of the primary focus on the
geographical position of a population, this framework provides little
insight into the environmental factors regulating local abundance. While
range-wide variation in population abundance associated with environmental
conditions has been investigated in terrestrial species, the relationship
between climate and local abundance in freshwater taxa across
species' distributions is not well understood. We used GIS-based
temperature and precipitation data to determine the relationships between
climatic conditions and range-wide variation in local abundance for 19
species of North American freshwater fishes. Climate predicted a portion
of the variation in local abundance among populations for 18 species. In
addition, the relationship between climatic conditions and local abundance
varied among species, which is expected as lineages partition the
environment across geographical space. The influence of local habitat
quality on species persistence is well documented; however, our results
also indicate the importance of climate in regulating population sizes
across a species geographical range, even in aquatic taxa.