Top Predators as Conservation Tools: Ecological Rationale, Assumptions, and Efficacy

Abstract

We review the ecological rationale behind the potential compatibility between top predators and biodiversity conservation, and examine their effectiveness as surrogate species. Evidence suggests that top predators promote species richness or are spatio-temporally associated with it for six causative or noncausative reasons: resource facilitation, trophic cascades, dependence on ecosystem productivity, sensitivity to dysfunctions, selection of heterogeneous sites and links to multiple ecosystem components. Therefore, predator-centered conservation may deliver certain biodiversity goals. To this aim, predators have been employed in conservation as keystone, umbrella, sentinel, flagship, and indicator species. However, quantitative tests of their surrogate-efficacy have been astonishingly few. Evidence suggests they may function as structuring agents and biodiversity indicators in some ecosystems but not others, and that they perform poorly as umbrella species; more consensus exists for their efficacy as sentinel and flagship species. Conservation biologists need to use apex predators more cautiously, as part of wider, context-dependent mixed strategies.

Biogeography and conservation in Southeast Asia: how 2.7 million years of repeated environmental fluctuations affect today’s patterns and the future of the remaining refugial-phase biodiversity

“…Large carnivores, for example, are especially vulnerable in fragmented landscapes and their extirpation can lead to increased numbers of small carnivores (mesopredator release) and, in turn, to the decline of their prey (birds and other small vertebrates) (Crooks and Soulé 1999). The biogeography and ecology of large carnivores therefore merits our attention (Sergio et al 2008).…”

Selection and Implementation of a Flagship Fleet in a Locally Undervalued Region of High Endemicity

“…Following Barua et al (2011) we did not specifically seek an umbrella, sentinel, or keystone species. However, as Sergio et al (2006Sergio et al ( , 2008 suggest, flagship species may receive more support from biologically oriented conservationists if they have important ecological functions or interactions with other species. Ecological importance can make the flagship a broadly fundable object of research, increasing its exposure to professionals, funders, and the public.…”

More buck for less bang: Reconciling competing wildlife management interests in agricultural food webs

“…A range of other socio-ecological factors must also be considered before top-predators are managed positively (Treves and Karanth 2003;Sergio et al 2008;Fleming et al 2012a). Ultimately, the best outcome for managing top-predators in food webs that include livestock production should seek to retain the ecological functions of top-predators while enhancing livestock production.…”