Department of Biology and Biochemistry, University of Houston, Houston, Texas, 77204-5001, USA.
Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California, 90095, USA.
Ecology. 2022 Jan;103(1):e03556. doi: 10.1002/ecy.3556. Epub 2021 Nov 2.
In sessile organisms such as plants and benthic invertebrates, founding propagules typically suffer extremely high rates of mortality due to both extrinsic and intrinsic factors. Many social insect species share similarities with these groups, but factors influencing early colony survival are relatively unstudied. We used a field experiment to measure the importance of environmental quality relative to intrinsic colony properties in the harvester ant, Pogonomyrmex occidentalis, by monitoring the survival of 584 experimental colonies. We measured survival of transplanted colonies over four months in each of three years (2014-2016) at a site in western Colorado. Colony survival was primarily determined by colony features. Multiple mating by the queen and larger colony size at the time of transplant increased survival, but queen size, maternal lineage and the composition of plant species in the vicinity of the colony did not. Food supplementation increased survival significantly when natural food was scarce, but was not consistently beneficial, in contrast to predictions. Our results emphasize the general importance of rapid growth and early attainment of large size in the survival of sessile species. However, attributes specific to ants that are a consequence of their sociality also strongly affected survival. Colonies with multiply-mated queens were more likely to survive over a wide range of circumstances, highlighting the importance of this trait even at the early stages of colony life.
在植物和底栖无脊椎动物等固着生物中，由于内外因素的影响，最初的繁殖体通常死亡率极高。许多社会性昆虫物种与这些群体有相似之处，但影响早期群体生存的因素相对研究较少。我们通过监测 584 个实验群体的生存情况，利用野外实验来衡量环境质量相对于收获蚁 Pogonomyrmex occidentalis 内在群体特性的重要性。在科罗拉多州西部的一个地点，我们在三年（2014-2016 年）的每个季节中，对移植的群体进行了四个月的生存监测。群体的生存主要取决于群体特征。与预测相反，与其他因素相比，蜂王多次交配和移植时较大的群体规模增加了群体的存活率，而蜂王的大小、母系和群体附近植物物种的组成则没有影响。当天然食物匮乏时，食物补充显著提高了存活率，但并不总是有益的。我们的结果强调了快速生长和早期达到较大体型对固着物种生存的普遍重要性。然而，由于社会性而成为蚂蚁特有属性的特征也强烈影响了其生存。具有多次交配蜂王的群体在更广泛的环境条件下更有可能存活，这突出了即使在群体生活的早期阶段，这种特征的重要性。
