Does moonlight increase predation risk? Meta-analysis reveals divergent responses of nocturnal mammals to lunar cycles

1. The risk of predation strongly affects mammalian population dynamics and community interactions. Bright moonlight is widely believed to increase predation risk for nocturnal mammals by increasing the ability of predators to detect prey, but the potential for moonlight to increase detection of predators and the foraging efficiency of prey has largely been ignored. Studies have reported highly variable responses to moonlight among species, calling into question the assumption that moonlight increases risk. 2. Here, we conducted a quantitative meta-analysis examining the effects of moonlight on the activity of 59 nocturnal mammal species to test the assumption that moonlight increases predation risk. We examined patterns of lunarphilia and lunarphobia across species in relation to factors such as trophic level, habitat cover preference, and visual acuity. 3. Across all species included in the meta-analysis, moonlight suppressed activity. The magnitude of suppression was similar to the p...