title: Secondary extinctions of biodiversity.
abstract: Extinctions beget further extinctions when species lose obligate mutualists, predators, prey, or hosts. Here, we develop a conceptual model of species and community attributes affecting secondary extinction likelihood, incorporating mechanisms that buffer organisms against partner loss. Specialized interactors, including 'cryptic specialists' with diverse but nonredundant partner assemblages, incur elevated risk. Risk is also higher for species that cannot either evolve new traits following partner loss or obtain novel partners in communities reorganizing under changing environmental conditions. Partner loss occurs alongside other anthropogenic impacts; multiple stressors can circumvent ecological buffers, enhancing secondary extinction risk. Stressors can also offset each other, reducing secondary extinction risk, a hitherto unappreciated phenomenon. This synthesis suggests improved conservation planning tactics and critical directions for research on secondary extinctions.
authors.affiliation: Department of Botany, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada; Department of Zoology, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada; Biodiversity Research Centre, University of British Columbia, Vancouver BC, V6T 1Z4, Canada. Electronic address: brodie@biodiversity.ubc.ca.
authors.forename: Jedediah F
authors.initials: JF
authors.lastname: Brodie
authors.affiliation: Conservation Education and Science Department, Arizona-Sonora Desert Museum, Tucson, AZ 85743, USA.
authors.forename: Clare E
authors.initials: CE
authors.lastname: Aslan
authors.affiliation: Department of Ecology and Evolutionary Biology, Rice University, Houston, TX 77005, USA.
authors.forename: Haldre S
authors.initials: HS
authors.lastname: Rogers
authors.affiliation: Archipelago Consulting, Portland, ME 04112, USA.
authors.forename: Kent H
authors.initials: KH
authors.lastname: Redford
authors.affiliation: Division of Biological Sciences, University of Montana, Missoula, MT 59803, USA.
authors.forename: John L
authors.initials: JL
authors.lastname: Maron
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721, USA.
authors.forename: Judith L
authors.initials: JL
authors.lastname: Bronstein
authors.affiliation: The Nature Conservancy, Bozeman, MT 59715, USA.
authors.forename: Craig R
authors.initials: CR
authors.lastname: Groves
mesh_terms: D000818:Animals; D044822:Biodiversity; D005075:Biological Evolution; D003247:Conservation of Natural Resources; D053476:Extinction, Biological; D008954:Models, Biological; D012307:Risk Factors
keywords: co-extinction; conservation planning; extinction debt; functional redundancy; mutualism; resilience; species interactions; trophic cascade