Exotic invaders gain foraging benefits by shoaling with native fish

• Published in: Royal Society Open Science
• Main Authors: Camacho Cervantes, Morelia, Macias Garcia, Constantino De Jesus, Ojanguren, Alfredo Fernandez, Magurran, Anne
• Other Authors: European Research Council, University of St Andrews. School of Biology, University of St Andrews. Scottish Oceans Institute, University of St Andrews. Marine Alliance for Science & Technology Scotland, University of St Andrews. Institute of Behavioural and Neural Sciences, University of St Andrews. St Andrews Sustainability Institute, University of St Andrews. Fish Behaviour and Biodiversity Research Group, University of St Andrews. Centre for Research into Ecological & Environmental Modelling, University of St Andrews. Centre for Biological Diversity
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2015
• Subjects: Allee effects; Sociability; Goodeids; Interspecific interactions; Invasion success; QH301 Biology; Ecology; QH301; Cortés; Antarc*; Antarctica
• Online Access: http://hdl.handle.net/10023/6098; https://doi.org/10.1098/rsos.140101; http://rsos.royalsocietypublishing.org/content/1/3/140101

We thank the University of St Andrews School of Biology Research Committee for funding. M.C.-C. thanks Topo Cortés and Bati Loch for fieldwork assistance. A.E.M. acknowledges the ERC (project BioTIME 250189) and the Royal Society. Freshwater habitats are under increasing threat due to invasions of exotic fish. These invasions typically begin with the introduction of small numbers of individuals unfamiliar with the new habitat. One way in which the invaders might overcome this disadvantage is by associating with native taxa occupying a similar ecological niche. Here we used guppies (Poecilia reticulata) from a feral population in Mexico to test the prediction that exotic shoaling fish can associate with heterospecifics, and that they improve their foraging efficiency by doing so. Guppies have invaded the Mexican High Plateau and are implicated in the declines of many native topminnow (Goodeinae) species. We show that heterospecific associations between guppies and topminnows can deliver the same foraging benefits as conspecific shoals, and that variation in foraging gains is linked to differences in association tendency. These results uncover a mechanism enabling founding individuals to survive during the most vulnerable phase of an invasion and help explain why guppies have established viable populations in many parts of Mexico as well in every continent except Antarctica. Publisher PDF Peer reviewed