title: Quantitative evidence for the effects of multiple drivers on continental-scale amphibian declines.
abstract: Since amphibian declines were first proposed as a global phenomenon over a quarter century ago, the conservation community has made little progress in halting or reversing these trends. The early search for a "smoking gun" was replaced with the expectation that declines are caused by multiple drivers. While field observations and experiments have identified factors leading to increased local extinction risk, evidence for effects of these drivers is lacking at large spatial scales. Here, we use observations of 389 time-series of 83 species and complexes from 61 study areas across North America to test the effects of 4 of the major hypothesized drivers of declines. While we find that local amphibian populations are being lost from metapopulations at an average rate of 3.79% per year, these declines are not related to any particular threat at the continental scale; likewise the effect of each stressor is variable at regional scales. This result - that exposure to threats varies spatially, and populations vary in their response - provides little generality in the development of conservation strategies. Greater emphasis on local solutions to this globally shared phenomenon is needed.
authors.affiliation: U.S. Geological Survey Patuxent Wildlife Research Center, SO Conte Anadromous Fish Lab, 1 Migratory Way, Turners Falls, MA 01376, United States of America.
authors.forename: Evan H Campbell
authors.initials: EH
authors.lastname: Grant
authors.affiliation: Department of Ecosystem Science and Management, Pennsylvania State University, University Park, PA, 16802, United States of America.
authors.forename: David A W
authors.initials: DA
authors.lastname: Miller
authors.affiliation: Department of Evolutionary Biology and Environmental Studies, University of Zurich, Switzerland.|KARCH, 2000 Neuchatel, Switzerland.
authors.forename: Benedikt R
authors.initials: BR
authors.lastname: Schmidt
authors.affiliation: U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, Corvallis, OR, 97331, United States of America.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Adams
authors.affiliation: Department of Ecosystem Science and Management, Pennsylvania State University, University Park, PA, 16802, United States of America.
authors.forename: Staci M
authors.initials: SM
authors.lastname: Amburgey
authors.affiliation: Department of Ecosystem Science and Management, Pennsylvania State University, University Park, PA, 16802, United States of America.|U.S. Geological Survey Patuxent Wildlife Research Center, Laurel, MD, 20708, United States of America.
authors.forename: Thierry
authors.initials: T
authors.lastname: Chambert
authors.affiliation: Department of Evolutionary Biology and Environmental Studies, University of Zurich, Switzerland.
authors.forename: Sam S
authors.initials: SS
authors.lastname: Cruickshank
authors.affiliation: U.S. Geological Survey, Western Ecological Research Center, San Diego, CA, 92101 United States of America.
authors.forename: Robert N
authors.initials: RN
authors.lastname: Fisher
authors.affiliation: Redpath Museum, McGill University, Montreal, Quebec, Canada.
authors.forename: David M
authors.initials: DM
authors.lastname: Green
authors.affiliation: U.S. Geological Survey, Northern Rocky Mountain Science Center, Aldo Leopold Wilderness Research Institute, Missoula, MT, 59801 United States of America.
authors.forename: Blake R
authors.initials: BR
authors.lastname: Hossack
authors.affiliation: University of Colorado, Boulder, Ecology and Evolutionary Biology Department, Boulder, CO, 80309 United States of America.
authors.forename: Pieter T J
authors.initials: PT
authors.lastname: Johnson
authors.affiliation: University of Colorado, Boulder, Ecology and Evolutionary Biology Department, Boulder, CO, 80309 United States of America.
authors.forename: Maxwell B
authors.initials: MB
authors.lastname: Joseph
authors.affiliation: University of Connecticut, Department of Natural Resources and the Environment, Storrs, CT, 06269 United States of America.
authors.forename: Tracy A G
authors.initials: TA
authors.lastname: Rittenhouse
authors.affiliation: School of Environment and Forest Sciences, University of Washington, Seattle, WA, 98195 United States of America.
authors.forename: Maureen E
authors.initials: ME
authors.lastname: Ryan
authors.affiliation: U.S. Geological Survey, Wetland and Aquatic Research Center, Lafayette, LA, 70506 United States of America.
authors.forename: J Hardin
authors.initials: JH
authors.lastname: Waddle
authors.affiliation: U.S. Geological Survey, Wetland and Aquatic Research Center, Gainesville, FL, 32653 United States of America.
authors.forename: Susan C
authors.initials: SC
authors.lastname: Walls
authors.affiliation: Colorado State University, Department of Fish, Wildlife and Conservation Biology, Fort Collins, CO, 80523 United States of America.
authors.forename: Larissa L
authors.initials: LL
authors.lastname: Bailey
authors.affiliation: U.S. Geological Survey, Western Ecological Research Center, Point Reyes Station, CA, 94956 United States of America.
authors.forename: Gary M
authors.initials: GM
authors.lastname: Fellers
authors.affiliation: Department of Fish and Wildlife Conservation, Virginia Tech, Blacksburg, VA, 24061 United States of America.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Gorman
authors.affiliation: Greater Yellowstone Network Program, National Park Service, Bozeman, MT, 59715 United States of America.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Ray
authors.affiliation: U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, Boise, ID, 83702 United States of America.
authors.forename: David S
authors.initials: DS
authors.lastname: Pilliod
authors.affiliation: Department of Forestry, University of Kentucky, Lexington, KY, 40506 United States of America.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Price
authors.affiliation: Southern Research Station, Forest Service, U.S. Department of Agriculture, Nacogdoches, TX, 75961 United States of America.
authors.forename: Daniel
authors.initials: D
authors.lastname: Saenz
authors.affiliation: U.S. Geological Survey, Upper Midwest Environmental Sciences Center, La Crosse, WI 54603, United States of America.
authors.forename: Walt
authors.initials: W
authors.lastname: Sadinski
authors.affiliation: U.S. Geological Survey, Fort Collins Science Center, Fort Collins, CO, 80526, United States of America.
authors.forename: Erin
authors.initials: E
authors.lastname: Muths
mesh_terms: D000663:Amphibians / Q000145:classification / Q000502:physiology*; D000818:Animals; D057231:Climate Change; D003247:Conservation of Natural Resources / Q000379:methods*; D017753:Ecosystem; D056727:Endangered Species; D005060:Europe; D053476:Extinction, Biological; D005843:Geography; D008954:Models, Biological; D009656:North America; D011156:Population Density; D011157:Population Dynamics; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors