REVERSING TROPICAL AMPHIBIAN DECLINES
with Steven Whitfield PhD, Dr. Steven Whitfield is a wildlife biologist and Conservation and Research Specialist at Zoo Miami
Beginning the 1980s, many populations of amphibians began disappearing around the world - as an infectious fungal disease suddenly appeared. This mysterious and potentially lethal skin infection (known as chytridiomycosis), emerged in North and South America and Australia, and caused mass mortality events and rapid population declines for amphibians. Amphibians that were formerly common disappeared entirely, and in some cases biologists reported finding huge numbers of dead or dying amphibians in habitats that looked otherwise healthy. Hundreds of species of amphibians was feared extinct after these declines.
In many cases, this emerging fungal disease my be interacting with other environmental issues - climate change, pollution, or even other wildlife diseases. Zoo Miami’s Dr. Steven Whitfield conducts field research in the rainforests of Costa Rica to understand how disease interacts with climate, with environmental contamination, and with viral diseases. Understanding these combinations of environmental problems (“multiple stressors”) is critical for designing conservation measures. Check out this video to learn how Dr. Whitfield uses “frog robots" to understand how frogs respond to warming temperatures from climate change, and you can watch a video here to learn about amphibian declines in Costa Rica.
However, recent survey efforts have identified “relict populations” that have survived declines – generally, these relict populations represent the last known individuals from their species. It currently remains unclear how these relict populations to survive when all other individuals of their species have been lost – these relict populations are “enigmatic survival” from enigmatic amphibian declines. What we do understand is that these species are surviving with infections of the lethal fungus, and that they may receive protection from bacteria on their skin that kill the fungus. Zoo Miami staff work in collaboration with biologists at the University of Costa Rica and universities across the US to help monitor these sensitive amphibian populations, to try to understand how these relict populations survived extinction, and how to protect these critically endangered amphibians from extinction.
Mendelson, J.R.III, S.M. Whitfield, M.J. Sredl. 2019. A recovery engine model for amphibian conservation in the context of disease. Biological Conservation 236:188-191. DOI: 10.1016/j.biocon.2019.05.025
Scheele, B.C., F. Pasmans, L. Berger, L. Skerratt, A. Martel, W. Beukema, A.A. Acevedo, P.A. Burrowes, T. Carvalho, A. Catenazzi, I. De La Riva, M.C. Fisher, S.V. Flechas, C.N. Foster, P. Frías-Álvarez, T.W.J. Garner, B. Gratwicke, J. M. Guayasamin, M. Hirschfeld, J.E. Kolby, T. A. Kosch, E. La Marca, D.B. Lindenmayer, K.R. Lips, A.V. Longo, R. Maneyro, C.A. McDonald, J. Mendelson III, P. Palacios-Rodriguez, G. Parra-Olea, C.L. Richards-Zawacki, M. Rödel, S.M. Rovito, C. Soto-Azat, L.F. Toledo, J. Voyles, C. Weldon, S.M. Whitfield, M. Wilkinson, K.R. Zamudio, S. Canessa. 2019. The aftermath of an amphibian fungal panzootic reveals unprecedented loss of biodiversity. Science 363:1459-1463. DOI: 10.1126/science.aav0379
Kueneman, J. M.C. Bletz , V.J. McKenzie , G. C. Becker , M. Joseph , J.G. Abarca , H.M. Archer, L. Arellano , A. Bataille , M. H. Becker, L. K. Belden , A. Crottini, R. Geffers , C.F. Haddad, R.N. Harris , W.M. Holden , M.C. Hughey , B. Waldman, M. Jarek, J. Kerby, J. Kielgast, A. Kurabayashi , A.V. Longo, A. Loudon, D. Medina , J.J. Nuñez , B.R.G. Perl , A.A. Pinto-Tomás , F.C.E. Rabemananjara, E.A Rebollar, A. Rodríguez, L.A. Rollins-Smith, R. Stevenson, C.C. Tebbe , G. Vargas Asensio , J.B. Walke , S.M. Whitfield, K.R. Zamudio, I. Zúñiga Chaves, D.C. Woodhams, M. Vences. 2019. Community richness of amphibian skin bacteria correlats with bioclimate at the global scale. Nature Ecology and Evolution. DOI: 10.1038/s41559-019-0798-1
Abarca, J.G., G. V Vargas-Asensio, Ibrahim Zúñiga-Chaves, S. M. Whitfield, D.C. Woodhams, J.L. Kerby, V. J. McKenzie, C. Murillo-Cruz, A. Pinto-Tomás. 2018. Assessment of Bacterial Communities Associated with the Skin of Costa Rican Amphibians at La Selva Biological Station. Frontiers in Microbiology. DOI: 10.3389/fmicb.2018.02001
Nowakowski, A.J., J.I. Watling, M. Thompson, G. Brusch, A. Catenazzi, S.M. Whitfield, D. Kurz, A Suarez-Mayorga, A. Aponte-Gutierrez, M.A. Donnelly, B.D. Todd. 2018. Thermal biology mediates responses of amphibians and reptiles to habitat modification. Ecology Letters. DOI: 10.1111/ele.12901
Gomez-Hoyos, D.A., S. Escobar-Lasso, R. Seisdedos-de-Vergara, J.G. Abarca, J. Schipper, S.M. Whitfield, G. Alvarado, J.F. Gonzalez-Maya. 2018. Phytotelmata selection by anurans and implications for their conservation at Las Tablas Protected Zone, Costa Rica. Alytes 34:1-11.
Whitfield, S.M., G. Alvarado, J. Abarca, H. Zumbado, M. Wainwright, J.L. Kerby. 2017. Differential patterns of infection by Batrachochytrium dendrobatidis in relict amphibian populations following severe disease-associated declines. Diseases of Aquatic Organisms 126:33-41. DOI: 10.3354/dao03154.
Bickford, D.P., R. Alford, M.L. Crump, S. M. Whitfield, N. Karraker, and M. A. Donnelly. 2017. Impacts of Climate Change on Amphibian Biodiversity. Reference Module in Earth Systems and Environmental Sciences. DOI: 10.1016/B978-0-12-409548-9.10022-3
Madison, J.D., E.A. Berg, J. Abarca Alvarado, S.M. Whitfield, O. Gorbatenko, A. Pinto, J.L. Kerby. 2017. Characterization of Batrachochytrium dendrobatidis-inhibiting bacteria from amphibian populations in Costa Rica. Frontiers in Microbiology 8:290 DOI: 10.3389/fmicb.2017.00290
Nowakowski, A., J. Watling, S.M. Whitfield, B. Todd, D. Kurz, M.A. Donnelly. 2017. Tropical amphibians in shifting thermal landscapes under land use and climate change. Conservation Biology 31(1):96-105. DOI: 10.1111/cobi.12769
Whitfield, S.M., K R. Lips, M.A. Donnelly. 2016. Amphibian decline and conservation in Central America. Copeia 104(2):351–379. DOI: 10.1643/CH-15-300
Alza, C., M.A. Donnelly, S.M. Whitfield. Additive effects of mean temperature, temperature variability, and chlorothalonil to Red-Eyed Treefrog (Agalychnis callidryas) larvae. Environmental Toxicology and Chemistry. DOI: 10.1002/etc.3484
Brusch, G, E. N. Taylor, S.M. Whitfield. Turn up the heat: Thermal tolerances of lizards in La Selva, Costa Rica. Oecologia 180(2):325-334. DOI: 10.1007/s00442-015-3467-3
Nowakowski, A.J., S.M. Whitfield, E.A. Eskew, M.E. Thompson, J.P. Rose, B.L. Caraballo, J.L. Kerby, M.A. Donnelly, B.D. Todd. 2016. Infection risk decreases with increasing mismatch in host and pathogen environmental tolerances. Ecology Letters 19:1051-1061. DOI: 10.1111/ele.12641