title: Prey interception drives web invasion and spider size determines successful web takeover in nocturnal orb-web spiders.
abstract: A striking feature of web-building spiders is the use of silk to make webs, mainly for prey capture. However, building a web is energetically expensive and increases the risk of predation. To reduce such costs and still have access to abundant prey, some web-building spiders have evolved web invasion behaviour. In general, no consistent patterns of web invasion have emerged and the factors determining web invasion remain largely unexplored. Here we report web invasion among conspecifics in seven nocturnal species of orb-web spiders, and examined the factors determining the probability of webs that could be invaded and taken over by conspecifics. About 36% of webs were invaded by conspecifics, and 25% of invaded webs were taken over by the invaders. A web that was built higher and intercepted more prey was more likely to be invaded. Once a web was invaded, the smaller the size of the resident spider, the more likely its web would be taken over by the invader. This study suggests that web invasion, as a possible way of reducing costs, may be widespread in nocturnal orb-web spiders.
authors.affiliation: Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, Huazhong Agricultural University, Wuhan, Hubei 430070, China Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China.
authors.forename: Wenjin
authors.initials: W
authors.lastname: Gan
authors.affiliation: Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.
authors.forename: Shengjie
authors.initials: S
authors.lastname: Liu
authors.affiliation: Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Yang
authors.affiliation: Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, 1117543, Singapore dbslidq@nus.edu.sg ioir@mail.hzau.edu.cn.
authors.forename: Daiqin
authors.initials: D
authors.lastname: Li
authors.affiliation: Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, Huazhong Agricultural University, Wuhan, Hubei 430070, China dbslidq@nus.edu.sg ioir@mail.hzau.edu.cn.
authors.forename: Chaoliang
authors.initials: C
authors.lastname: Lei
keywords: Conspecific competition; Intruder; Nocturnal; Orb spiders; Prey abundance; Web invasion