Data from: Bourgeois behaviour and freeloading in the colonial orb-web spider Parawixia bistriata (Araneae, Araneidae)

Spiders of the tropical American colonial orb weaver Parawixia bistriata form a communal bivouac in daytime. At sunset, they leave the bivouac and construct individual, defended webs within a large, communally built scaffolding of permanent, thick silk lines between trees and bushes. Once spiders started building a web, they repelled other spiders walking on nearby scaffolding with a “bounce” behavior. In nearly all cases (93%), this resulted in the intruder leaving without a fight, akin to the “bourgeois strategy,” in which residents win and intruders retreat without escalated contests. However, a few spiders (6.5%) did not build a web due to lack of available space. Webless spiders were less likely to leave when bounced (only 42% left) and instead attempted to “freeload,” awaiting the capture of prey items in nearby webs. Our simple model shows that webless spiders should change their strategy from bourgeois to freeloading satellite as potential web sites become increasingly occupied.

热带美洲群居圆网蛛（colonial orb weaver）双纹副络新妇（Parawixia bistriata）会在日间形成集体栖息的巢幕。日落时分，它们离开该巢幕，在树木与灌丛间由永久性粗丝线搭建的大型公共支架结构内，各自构筑带有防御功能的蛛网。一旦某只蜘蛛开始构筑蛛网，便会通过“弹跳”行为驱赶在邻近支架上活动的其他蜘蛛。在近93%的案例中，这种行为会使入侵者不战而退，这类似于“资产阶级策略（bourgeois strategy）”——即领地所有者获胜，入侵者无需升级冲突便会撤退。然而，约6.5%的蜘蛛因可利用的筑巢位点不足而无法构筑蛛网。未结网的蜘蛛在遭遇弹跳驱赶时，仅42%会选择离开，远低于结网蜘蛛的逃逸比例；它们反而会尝试“搭便取食（freeload）”，即等候邻近蛛网捕获的猎物。我们构建的简易模型表明，随着潜在筑巢位点逐渐被占据，未结网蜘蛛的策略应从资产阶级策略转变为搭便车的卫星型策略。