title: Vultures acquire information on carcass location from scavenging eagles.
abstract: Vultures are recognized as the scroungers of the natural world, owing to their ecological role as obligate scavengers. While it is well known that vultures use intraspecific social information as they forage, the possibility of inter-guild social information transfer and the resulting multi-species social dilemmas has not been explored. Here, we use data on arrival times at carcasses to show that such social information transfer occurs, with raptors acting as producers of information and vultures acting as scroungers of information. We develop a game-theoretic model to show that competitive asymmetry, whereby vultures dominate raptors at carcasses, predicts this evolutionary outcome. We support this theoretical prediction using empirical data from competitive interactions at carcasses. Finally, we use an individual-based model to show that these producer-scrounger dynamics lead to vultures being vulnerable to declines in raptor populations. Our results show that social information transfer can lead to important non-trophic interactions among species and highlight important potential links among social evolution, community ecology and conservation biology. With vulture populations suffering global declines, our study underscores the importance of ecosystem-based management for these endangered keystone species.
authors.affiliation: Department of Zoology, School of Natural Sciences, Trinity College Dublin, Dublin 2, Republic of Ireland Centre for Biodiversity Research, Trinity College Dublin, Dublin 2, Republic of Ireland kanead@tcd.ie.
authors.forename: Adam
authors.identifier: http://orcid.org/0000-0002-2830-5338
authors.initials: A
authors.lastname: Kane
authors.affiliation: Department of Zoology, School of Natural Sciences, Trinity College Dublin, Dublin 2, Republic of Ireland Centre for Biodiversity Research, Trinity College Dublin, Dublin 2, Republic of Ireland.
authors.forename: Andrew L
authors.identifier: http://orcid.org/0000-0001-7334-0434
authors.initials: AL
authors.lastname: Jackson
authors.affiliation: The Peregrine Fund, 5668 West Flying Hawk Lane, Boise, ID 83709, USA National Museums of Kenya, Ornithology Section, PO Box 40658, Nairobi 00100, Kenya.
authors.forename: Darcy L
authors.initials: DL
authors.lastname: Ogada
authors.affiliation: All Out Africa Research Unit, Department of Biological Sciences, University of Swaziland, Private Bag 4, Kwaluseni, Swaziland.
authors.forename: Ara
authors.initials: A
authors.lastname: Monadjem
authors.affiliation: Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JT, UK Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JT, UK.
authors.forename: Luke
authors.identifier: http://orcid.org/0000-0002-1928-6235
authors.initials: L
authors.lastname: McNally
mesh_terms: D000818:Animals; D003247:Conservation of Natural Resources; D020307:Eagles / Q000502:physiology*; D046093:Falconiformes / Q000502:physiology*; D005247:Feeding Behavior; D005716:Game Theory; D007630:Kenya; D008954:Models, Biological
keywords: inter-guild interactions; producer–scrounger game; scavengers; social information; vultures