Data from: 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 presence of a predator in experimental studies of foraging rodents (13.6% and 18.7% suppression, respectively). Contrary to the expectation that moonlight increases predation risk for all prey species, however, moonlight effects were not clearly related to trophic level and were better explained by phylogenetic relatedness, visual acuity, and habitat cover. 4. Moonlight increased the activity of prey species that use vision as their primary sensory system and suppressed the activity of species that primarily use other senses (e.g., olfaction, echolocation), and suppression was strongest in open habitat types. Strong taxonomic patterns underlay these relationships: moonlight tended to increase primate activity, whereas it tended to suppress the activity of rodents, lagomorphs, bats, and carnivores. 5. These results indicate that visual acuity and habitat cover jointly moderate the effect of moonlight on predation risk, whereas trophic position has little effect. While the net effect of moonlight appears to increase predation risk for most nocturnal mammals, our results highlight the importance of sensory systems and phylogenetic history in determining the level of risk.

1. 捕食风险强烈影响哺乳动物的种群动态与群落互作。人们普遍认为，明亮的月光会通过提升捕食者发现猎物的能力，增加夜行性哺乳动物面临的捕食风险，但月光可能提升猎物对捕食者的察觉能力以及猎物的觅食效率这一点，却在很大程度上被忽视了。已有研究报道不同物种对月光的响应差异极大，这使得“月光会提升捕食风险”这一假设受到质疑。2. 本研究通过开展定量元分析，检验月光提升捕食风险这一假设：分析了月光对59种夜行性哺乳动物活动量的影响，并探究了不同物种的趋月性与避月性模式，及其与营养级、栖息地遮蔽偏好、视觉敏锐度等因素的关联。3. 在元分析纳入的所有物种中，月光均会抑制其活动量。这种抑制效应的强度，与觅食啮齿类实验研究中捕食者存在时的抑制效应相当（分别为13.6%和18.7%的活动量抑制）。然而，与“月光会提升所有猎物物种的捕食风险”这一预期相悖的是，月光的效应与营养级并无显著关联，而系统发育亲缘关系、视觉敏锐度与栖息地遮蔽更能解释该效应。4. 以视觉作为主要感官系统的猎物物种，其活动量会因月光而提升；而主要依赖其他感官（如嗅觉、回声定位）的物种，活动量则会被月光抑制，且这种抑制效应在开阔生境类型中最为显著。这些关联背后存在显著的分类学模式：月光往往会提升灵长类的活动量，却会抑制啮齿类、兔形目、蝙蝠与食肉目动物的活动量。5. 本研究结果表明，视觉敏锐度与栖息地遮蔽共同调控月光对捕食风险的影响，而营养级的影响则微乎其微。尽管月光的净效应似乎会提升多数夜行性哺乳动物面临的捕食风险，但我们的研究结果凸显了感官系统与演化历史在决定风险水平方面的重要性。