Scharf Inon, Gilad Tomer, Taichman Yuval, Subach Aziz
School of Zoology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 6997801, Israel.
Biology (Basel). 2021 Jul 8;10(7):635. doi: 10.3390/biology10070635.
Whereas most animals find urban habitats to be inferior to natural habitats, some "urban specialist" species thrive there. Wormlions present such an example. Common in Mediterranean cities, they cluster in thin layers of loose soil below man-made shelters. Wormlions are fly larvae that dig pit-traps in loose soil and hunt small arthropods. Our first aim was to determine whether wormlion pits accumulate next to walls. Wormlion pits were indeed closer to walls than expected by chance at most of the study sites. We examined possible factors behind this apparent preference, combining field observations and experiments, laboratory work, and theoretical analysis. We examined the effect of soil depth, particle size, shade, and prey abundance. Each factor provided a partial explanation for the wormlions' proximity to walls, but none provided an overall explanation. We developed a spatially explicit simulation model, demonstrating under which conditions wall-adjacent positions are favored. Finally, we created artificial microhabitats, and placed wormlions either in the center or next to the wall. The wormlions in the center moved over longer distances than those next to the wall and did so more in the wall's direction. The abundance of walls may help to explain the success of wormlions in urban habitats.
虽然大多数动物认为城市栖息地不如自然栖息地，但一些“城市特化”物种却在那里繁衍生息。蚁狮就是这样一个例子。在地中海城市很常见，它们聚集在人造遮蔽物下方的薄层疏松土壤中。蚁狮是苍蝇的幼虫，它们在疏松土壤中挖掘陷阱捕食小型节肢动物。我们的首要目标是确定蚁狮坑是否会在墙边聚集。在大多数研究地点，蚁狮坑确实比随机分布时更靠近墙壁。我们结合实地观察与实验、实验室工作以及理论分析，研究了这种明显偏好背后可能的因素。我们研究了土壤深度、颗粒大小、遮荫和猎物丰度的影响。每个因素都为蚁狮靠近墙壁提供了部分解释，但都没有提供全面的解释。我们开发了一个空间明确的模拟模型，展示了在哪些条件下墙边位置更受青睐。最后，我们创建了人工微生境，并将蚁狮放置在中心位置或墙边。位于中心的蚁狮移动的距离比墙边的蚁狮更远，而且更多地朝着墙壁的方向移动。墙边的丰富程度可能有助于解释蚁狮在城市栖息地的成功。
