Cornell University, Department of Entomology, 2126 Comstock Hall, Ithaca, NY 14853, USA.
University of Texas Rio Grande Valley, Department of Biology, 1201 W. University Dr., Edinburg, TX 78539, USA.
Environ Entomol. 2023 Jun 16;52(3):510-520. doi: 10.1093/ee/nvad025.
With an increase in human population over the past 30 years, regional land use in south Texas has shifted from grassland and shrubland to a peri-urban matrix. Despite this shift from natural areas to more anthropogenically modified habitats, native red harvester ants (Pogonomyrmex barbatus) have maintained nest sites within parts of these matrices. To determine which habitat characteristics in a peri-urban landscape may play a role in red harvester ant nest site selection, we mapped the location of nests in 2020 and 2021. We then evaluated nest presence and absence relative to elevation, percentage of surrounding impervious surfaces, distance to roadways, and tree canopy cover (using NDVI). For a sub-sample of the study site, we also measured soil moisture and estimated the potential foraging area per colony with Voronoi tessellation. We found that nests were clustered together near high human-use areas such as athletic fields, lawns, sidewalks, and railroad tracks. Nests were more likely to be found in areas with higher elevation and lower tree canopy cover, with no impact from surrounding impervious surfaces or soil moisture. In fact, many nests were observed immediately adjacent to roadways and in paved parking lots. Red harvester ants are highly adept at nesting in disturbed, urbanized matrices, but still appear to be constrained by certain environmental factors like shading, potential flood risk (elevation), and access to food resources (foraging area).
在过去的 30 年中，随着人口的增加，德克萨斯州南部的区域土地利用已经从草原和灌木丛转变为城市周边的基质。尽管这种从自然区域到更多人为改造的栖息地的转变，原生红收获蚁（Pogonomyrmex barbatus）仍然在这些基质的部分区域内维持着巢穴。为了确定城市周边景观中的哪些栖息地特征可能在红收获蚁巢穴选择中发挥作用，我们在 2020 年和 2021 年绘制了巢穴的位置图。然后，我们评估了巢穴的存在和不存在与海拔、周围不透水面的百分比、与道路的距离以及树冠覆盖（使用 NDVI）的关系。对于研究地点的一个子样本，我们还测量了土壤湿度，并使用 Voronoi 镶嵌法估计了每个蚁群的潜在觅食面积。我们发现，巢穴聚集在高人类活动区域附近，如运动场、草坪、人行道和铁轨。在海拔较高、树冠覆盖较低的地区，更容易发现巢穴，而周围不透水面或土壤湿度对其没有影响。事实上，许多巢穴被观察到就在道路旁边和铺砌的停车场中。红收获蚁非常擅长在受干扰的城市化基质中筑巢，但似乎仍然受到某些环境因素的限制，如遮荫、潜在的洪水风险（海拔）和食物资源的获取（觅食面积）。
