In social animals, group prey capture could facilitate colonization of new areas with low resource availability. Parawixia bistriata is a colonial spider inhabiting seasonal dry forests and mesic habitats in South America. Individuals capture prey as a group, which allows individuals to broaden their foraging niche by incorporating large prey that cannot be subdued in solitary captures. P. bistriata exhibits two behavioural ecotypes a “dry” (plastic) ecotype which modifies individual’s tendency to capture prey in a group depending on food resources and a “wet” (fixed) ecotype, whose tendency to group prey capture is only modulated by the size of the prey but not by prey availability. By reconstructing the range expansion of the species using phylogeographic and species distribution modelling techniques, we indirectly examined whether group prey capture could have helped P. bistriata in colonization of low resource habitats. Based on cytochrome c oxidase subunit I gene genealogy, we found older populations in northern Cerrado in Brazil with more recent populations located further south in Dry and Humid Chaco in Argentina, with the latter being the most derived. Species distribution modelling for each ecotype suggests that suitable habitat for each ecotype started to overlap at some point during the Last Glacial Maximum (21 ky BP). These results suggest that P. bistriata expanded from northern Cerrado south to the Gran Chaco, being able to colonize mesic habitats at a later stage when individuals reached southern territories in the Chaco. This evidence is opposite to the idea that GPC facilitated P. bistriata colonization from mesic to harsher environments. However, plasticity in group prey capture could have been important to allow individuals to establish in mesic habitats by reducing the cost of group capture when under high resource levels.

在社交动物中，捕获团体猎物可以促进资源匮乏的新地区的定殖。Parawixia bistriata是一种殖民蜘蛛，栖息于南美的季节性干燥森林和中性生境中。个体捕获猎物是一个整体，它允许个体通过合并无法被单独捕获的大型猎物来扩大其觅食利基。对虾表现出两种行为生态型，即“干”（塑料）生态型和“湿”（固定）生态型，“干”（塑料）生态型改变了个体根据食物资源捕获猎物的趋势，“湿”（固定）生态型仅通过捕食者的大小进行调节。猎物，但不是猎物的可用性。通过使用植物学和物种分布建模技术重建物种的范围扩展，我们间接检查了群体猎物的捕获是否可以帮助P. bistriata在资源贫乏的栖息地定居。基于细胞色素c氧化酶亚基I的基因谱系，我们发现巴西北部塞拉多（Cerrado）北部的种群较老，而阿根廷Dry and Humid Chaco的更南端则是最近的种群，后者是最衍生的。每种生态型的物种分布模型表明，每种生态型的适宜生境在上一次冰期最大值（21 ky BP）期间开始重叠。这些结果表明，P。bistriata从北部的Cerrado南部扩展至Gran Chaco，当个体到达Chaco的南部领土时，便能够在后期阶段定居于中生的栖息地。这一证据与GPC促进了P. bistriata的想法相反。从中生到恶劣环境的殖民化。但是，在高资源水平下，通过减少集体捕捞的成本，团体猎物的可塑性可能对允许个人在内陆栖息地中建立很重要。