The Neglected Role of Sex-Biased Dispersal in Range-Shift Prediction Under Climate Change

Studies aimed at estimating species response to climate change generally employ correlative species distribution models (SDMs) coupled with dispersal scenarios. However, dispersal distances are generally lacking or nonrepresentative, so researchers typically estimate dispersal distance from allometric relationships. Yet, these estimates ignore the role of sex bias in dispersal—where one sex disperses more than the other—leading to important prediction errors. We collected sex-specific dispersal data for 47 mammal species characterised by different levels of sex bias and projected their distribution under future climate scenarios, either considering or disregarding sex-biased dispersal. Results reveal discrepancies that can be substantial for species with marked sex bias. Given the paucity of sex-specific dispersal data, climate forecasting efforts should cautiously use a range of dispersal scenarios, favouring partial dispersal scenarios that are likely to encompass true species' range shifting abilities. Further research and data collection are crucial for refining predictions and understanding the ecological drivers of sex bias in dispersal across taxa.