caa a22 4500 465782965 CHVBK 20180323112000.0 cr unu---uuuuu 170327e19900801xx s 000 0 eng 10.1007/BF00168449 doi (NATIONALLICENCE)springer-10.1007/BF00168449 Trade-offs in foraging success and predation risk with spatial position in colonial spiders [Elektronische Daten] [Linda Rayor, George Uetz] Summary: Colonial web-building spiders respond to trade-offs between selective forces relative to spatial position within colonies and thus provide support for the selfish herd theory. The size distribution of spiders within colonies of Metepeira incrassata, a colonial orb-weaver (Araneae: Araneidae) from tropical Mexico is nonrandom; larger (mature) spiders and females guarding eggsacs are more prevalent in the center, whereas more small (immature) spiders are found on the periphery. Experimental field studies with spiders of selected size classes show that larger spiders actively and aggressively seek protected positions in the center of the colony webbing, even though prey availability and capture rates are significantly higher on the periphery. Attacks by predatory wasps, other spiders, and hummingbirds are more frequent on the periphery than in the core of the colony. Reproductive females on the periphery are at greater risk because they are captured more often than smaller spiders, and if their egg sacs consequently remain unguarded, chances of cocoon parasitism are increased. As a result, spiders in the core of the colony have greater reproductive success, producing more egg sacs with greater hatching frequency. Colonial spiders thus appear to be making a trade-off between foraging and protection from predation and show a spatial organization predicted by the selfish herd theory. The influence of such trade-offs on individual fitness and the structure of colonies is discussed. Springer-Verlag, 1990 Rayor Linda Department of Biological Sciences, University of Cincinnati, 45221-0006, Cincinnati, OH, USA aut Uetz George Department of Biological Sciences, University of Cincinnati, 45221-0006, Cincinnati, OH, USA aut Behavioral Ecology and Sociobiology Springer-Verlag 27/2(1990-08-01), 77-85 0340-5443 27:2<77 1990 27 265 https://doi.org/10.1007/BF00168449 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00168449 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Rayor Linda Department of Biological Sciences, University of Cincinnati, 45221-0006, Cincinnati, OH, USA aut NATIONALLICENCE 700 1- Uetz George Department of Biological Sciences, University of Cincinnati, 45221-0006, Cincinnati, OH, USA aut NATIONALLICENCE 773 0- Behavioral Ecology and Sociobiology Springer-Verlag 27/2(1990-08-01), 77-85 0340-5443 27:2<77 1990 27 265 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer