Dispersal, niche breadth, and population extinction/colonization ratios predict range size in North American dragonflies

1. Species’ range sizes are shaped by fundamental differences in species’ ecological and evolutionary characteristics, and understanding the mechanisms determining range size can shed light on the factors responsible for generating and structuring biological diversity. Moreover, because geographic range size is associated with a species’ risk of extinction and their ability to respond to global changes in climate and land use, understanding these mechanisms has important conservation implications.
2. Despite hypotheses that dispersal behaviour is a strong determinant of species range areas, few data are available to directly compare the relationship between dispersal behaviour and range size. Here, we overcome this limitation by combining data from a multi-species dispersal experiment with additional species-level trait data that are commonly hypothesized to affect range size (e.g. niche-breadth, local abundance, and body size, etc.). This enables us to examine the relationship between...