Li Han, Wilkins Kenneth T
Department of Biology, University of North Carolina Greensboro, Greensboro, NC 27412, USA.
Department of Biology, Baylor University, Waco, TX 76798, USA.
Biology (Basel). 2022 May 27;11(6):829. doi: 10.3390/biology11060829.
Predators respond to the increase of prey by aggregation in space or foraging more often. However, foraging habitat suitability limits predators' responses. For nocturnal insectivorous bats, artificial light at night (ALAN) can trigger insect prey aggregation. It is not clear how ALAN might affect predator-prey relationships in the urban setting, where urban bats could have adapted to the city, and novel spatial complexity introduced by man-made objects might alter foraging habitat suitability. We strategically selected sites to represent different levels of ALAN and spatial complexity. We recorded bat commuting and foraging activities and collected aerial insects to examine how ALAN and spatial complexity affected bat-insect relationships. We found that insect biomass was positively correlated with ALAN, but was not affected by spatial complexity. Large-sized big brown bats and hoary bats positively responded to change of prey in open sites whereas small-sized eastern red bats and silver-haired bats positively responded in cluttered sites, suggesting that the impact of ALAN could vary when ALAN is coupled with urban spatial complexity. Our study demonstrates that foraging habitat suitability can alter which species might benefit from ALAN. Predator-prey relationships in cities are complex, but general ecological principles still apply in novel urban ecosystems.
捕食者会通过在空间上聚集或更频繁地觅食来应对猎物数量的增加。然而，觅食栖息地的适宜性限制了捕食者的反应。对于夜间食虫蝙蝠来说，夜间人造光（ALAN）会引发昆虫猎物的聚集。目前尚不清楚在城市环境中，ALAN会如何影响捕食者与猎物的关系，在城市中，城市蝙蝠可能已经适应了城市环境，而人造物体引入的新空间复杂性可能会改变觅食栖息地的适宜性。我们策略性地选择了代表不同ALAN水平和空间复杂性的地点。我们记录了蝙蝠的往返和觅食活动，并收集了空中昆虫，以研究ALAN和空间复杂性如何影响蝙蝠与昆虫的关系。我们发现昆虫生物量与ALAN呈正相关，但不受空间复杂性的影响。大型的大棕蝠和霜蝠在开阔地带对猎物的变化有积极反应，而小型的东部红蝠和银毛蝠在杂乱的地带则有积极反应，这表明当ALAN与城市空间复杂性相结合时，ALAN的影响可能会有所不同。我们的研究表明，觅食栖息地的适宜性可以改变哪些物种可能从ALAN中受益。城市中的捕食者与猎物关系很复杂，但一般的生态原则在新的城市生态系统中仍然适用。
