Eye catching light: Anthropogenic light at night and its evolutionary influence on the avian eye

Variation among avian species in their responses to artificial night lighting was recently linked to differences in dim light vision, but whether dim light vision is under selection from human-caused night lighting is unexplored. Here, we approximated dim light vision using eye geometries from museum specimens of six species collected across 100+ years and sought to determine whether proxies for artificial night lighting were related to within-species variation in dim light vision. We found variation in dim light vision was strongly linked to artificial night lighting proxies for three species and weakly linked for a forth, but the relationship varied by species. This variation is likely related to differences in ecological traits and may also reflect whether artificial night lighting facilitates increased temporal activity or results in physiological costs for each species. These results suggest that altered sensory environments are likely a source of selection shaping the sensory abilities of animals in the anthropocene.