Oosthuizen Tasha, Oosthuizen Maria K, Pillay Neville
School of Animal, Plant and Environmental Sciences, University of Witwatersrand Johannesburg South Africa.
Department of Zoology and Entomology University of Pretoria Hatfield South Africa.
Ecol Evol. 2025 May 21;15(5):e71237. doi: 10.1002/ece3.71237. eCollection 2025 May.
Small mammals are prey to a range of predators and consequently use environmental cues, such as light, to assess the level of predation risk in their environment. The lunar cycle significantly influences the fear landscape for prey species because their risk level varies with visibility. We conducted small mammal surveys in two communities in close proximity to each other on a peri-urban site in South Africa. We investigated the abundance, composition and diversity of these communities across the lunar cycle and seasons. As predicted, we trapped the highest number of individuals and species on new moon nights, which have low light levels and thus indicate a reduced perceived predation risk. Winter showed a higher abundance compared to the other seasons, which could be explained by a decline in naturally available resources in winter. We captured more individuals and species on one site compared to the other site, largely because of the different microhabitats in the two sites; one site had a lower density of trees and more bare soil areas. Our study provides the first evidence of the impact the lunar cycle has on small mammal communities in southern Africa. Based on our findings of decreased activity of small mammals under increased lunar visibility, we hypothesise that small mammal communities in southern Africa will be negatively affected by the increased occurrence of artificial light at night, which could have wider ecosystem impacts.
小型哺乳动物是多种捕食者的猎物，因此它们利用光照等环境线索来评估其所处环境中的捕食风险水平。月相周期对猎物物种的恐惧环境有显著影响，因为它们的风险水平会随着能见度的变化而变化。我们在南非一个城郊地区两个彼此相邻的群落中开展了小型哺乳动物调查。我们研究了这些群落在月相周期和不同季节中的数量、组成及多样性。正如预期的那样，我们在新月之夜捕获到的个体和物种数量最多，新月之夜光照水平低，这表明被捕食风险的感知降低。与其他季节相比，冬季的数量更为丰富，这可能是由于冬季自然可利用资源减少所致。与另一个地点相比，我们在一个地点捕获到了更多的个体和物种，这主要是因为两个地点的微生境不同；一个地点树木密度较低，裸土面积更大。我们的研究首次证明了月相周期对南部非洲小型哺乳动物群落的影响。基于我们在月相可见度增加时小型哺乳动物活动减少的研究结果，我们推测南部非洲的小型哺乳动物群落将受到夜间人造光增加的负面影响，这可能会对更广泛的生态系统产生影响。
