LAUSR

I assess the impact of interspecific competition on species' post‐glacial range expansions into previously glaciated areas. I hypothesize that expansion of one species (the founder) after the last glacial maximum (LGM) into areas that were glaciated has hindered expansion of its competitor (the latecomer). If true, I predict that range and niche sizes of two congeners are more disproportionate within the previously glaciated areas (i.e. the areas of post‐glacial expansion) than within areas that were not glaciated. I also predict that niche partitioning is reduced within previously glaciated areas. If true, range and climatic niche overlap of two congeners is smaller in the previously glaciated areas than in non‐glaciated areas.