title: The discovery-dominance trade-off is the exception, rather than the rule.
abstract: 1. Interspecific trade-offs are thought to facilitate coexistence between species at small spatial scales. The discovery-dominance trade-off, analogous to a competition-colonisation trade-off, is considered an important structuring mechanism in ant ecology. A trade-off between species' ability to discover food resources and to dominate them may explain how so many species apparently dependent on similar resources can coexist. 2. The discovery-dominance trade-off is thought to be broken by invasive species in enemy-free space or territorial species whose activity is fuelled by domination of carbohydrate resources. It may also be mediated by factors such as temperature and habitat structure. 3. We investigate the generality and form of the discovery-dominance relationship in an experiment using habitats of contrasting complexity across three continents. In addition, to assess how widespread the discovery-dominance trade-off is, we conducted a systematic review combining all empirical studies (published and from our experiment). 4. From our own fieldwork and meta-analyses of available studies, we find surprisingly little empirical support for the trade-off, with results indicating that mean effect sizes were either not significantly different from 0 or significantly positive. The trade-off was only detected in studies with parasitoids present. Additionally, experimental data from simple and complex habitats within each continent suggest that simple habitats may facilitate both food resource discovery and dominance. 5. We conclude that the discovery-dominance trade-off is the exception, rather than the rule. Instead, these abilities were commonly correlated. Real food resources provide many axes along which partitioning may occur, and discovery-dominance trade-offs are not a prerequisite for coexistence.
authors.affiliation: Environmental Change Institute, School of Geography & the Environment, University of Oxford, South Parks Road, Oxford OX1 3QY, UK. kate.parr@ouce.ox.ac.uk
authors.forename: Catherine L
authors.initials: CL
authors.lastname: Parr
authors.forename: Heloise
authors.initials: H
authors.lastname: Gibb
mesh_terms: D000818:Animals; D001000:Ants / Q000145:classification / Q000469:parasitology / Q000502:physiology*; D001315:Australia; D004175:Diptera / Q000502:physiology; D017753:Ecosystem; D005060:Europe; D005247:Feeding Behavior; D020387:Food Chain; D013019:South Africa; D013045:Species Specificity