Climate disequilibrium of fishes along elevation and latitudinal gradients: implications for climate tracking

Aim: Differences in realized and fundamental thermal niches can reveal how temperature constrains species distributions. Because climate-induced range shifts assume that temperature influences distribution limits (i.e., climate equilibrium assumption), understanding the factors that determine the realized thermal niche of species is critical for understanding their climate tracking abilities. Location: Thermal niches were evaluated for two scales: Globally (n = 95 species) and across the Great Plains – Rocky Mountain region, U.S.A (n = 28 species) Taxon: Marine and freshwater fishes Results: First, freshwater species were not more likely than marine species to underfill their latitudinal cold-edge limit, despite restricted dispersal in freshwater environments from biogeographic barriers. Second, biological traits of dispersal ability were not associated with patterns of overfilling or underfilling along latitudinal gradients, aside from migratory species being more likely to overfill th...