title: Assessing the Threat of Amphibian Chytrid Fungus in the Albertine Rift: Past, Present and Future.
abstract: Batrachochytrium dendrobatidis (Bd), the cause of chytridiomycosis, is a pathogenic fungus that is found worldwide and is a major contributor to amphibian declines and extinctions. We report results of a comprehensive effort to assess the distribution and threat of Bd in one of the Earth's most important biodiversity hotspots, the Albertine Rift in central Africa. In herpetological surveys conducted between 2010 and 2014, 1018 skin swabs from 17 amphibian genera in 39 sites across the Albertine Rift were tested for Bd by PCR. Overall, 19.5% of amphibians tested positive from all sites combined. Skin tissue samples from 163 amphibians were examined histologically; of these two had superficial epidermal intracorneal fungal colonization and lesions consistent with the disease chytridiomycosis. One amphibian was found dead during the surveys, and all others encountered appeared healthy. We found no evidence for Bd-induced mortality events, a finding consistent with other studies. To gain a historical perspective about Bd in the Albertine Rift, skin swabs from 232 museum-archived amphibians collected as voucher specimens from 1925-1994 were tested for Bd. Of these, one sample was positive; an Itombwe River frog (Phrynobatrachus asper) collected in 1950 in the Itombwe highlands. This finding represents the earliest record of Bd in the Democratic Republic of Congo. We modeled the distribution of Bd in the Albertine Rift using MaxEnt software, and trained our model for improved predictability. Our model predicts that Bd is currently widespread across the Albertine Rift, with moderate habitat suitability extending into the lowlands. Under climatic modeling scenarios our model predicts that optimal habitat suitability of Bd will decrease causing a major range contraction of the fungus by 2080. Our baseline data and modeling predictions are important for comparative studies, especially if significant changes in amphibian health status or climactic conditions are encountered in the future.
authors.affiliation: Wildlife Conservation Society, Bronx, NY, United States of America.
authors.forename: Tracie A
authors.initials: TA
authors.lastname: Seimon
authors.affiliation: Wildlife Conservation Society, Bronx, NY, United States of America.
authors.forename: Samuel
authors.initials: S
authors.lastname: Ayebare
authors.affiliation: Department of Environmental Sciences, Makerere University, Kampala, Uganda.
authors.forename: Robert
authors.initials: R
authors.lastname: Sekisambu
authors.affiliation: Wildlife Conservation Society, Bronx, NY, United States of America.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Muhindo
authors.affiliation: Wildlife Conservation Society, Bronx, NY, United States of America.
authors.forename: Guillain
authors.initials: G
authors.lastname: Mitamba
authors.affiliation: Department of Biological Sciences, University of Texas at El Paso, El Paso, TX, United States of America.
authors.forename: Eli
authors.initials: E
authors.lastname: Greenbaum
authors.affiliation: Tropical Biodiversity Section, MUSE, The Science Museum of Trento, Trento, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Menegon
authors.affiliation: Tropical Biodiversity Section, MUSE, The Science Museum of Trento, Trento, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Pupin
authors.affiliation: Wildlife Conservation Society, Bronx, NY, United States of America.
authors.forename: Denise
authors.initials: D
authors.lastname: McAloose
authors.affiliation: Wildlife Conservation Society, Bronx, NY, United States of America.
authors.forename: Alyssa
authors.initials: A
authors.lastname: Ammazzalorso
authors.affiliation: Department of African Biology, Royal Museum for Central Africa, Tervuren, Belgium.
authors.forename: Danny
authors.initials: D
authors.lastname: Meirte
authors.affiliation: Department of Environmental Sciences, Makerere University, Kampala, Uganda.
authors.forename: Wilbur
authors.initials: W
authors.lastname: Lukwago
authors.affiliation: Department of Environmental Sciences, Makerere University, Kampala, Uganda.
authors.forename: Mathias
authors.initials: M
authors.lastname: Behangana
authors.affiliation: Wildlife Conservation Society, Bronx, NY, United States of America.
authors.forename: Anton
authors.initials: A
authors.lastname: Seimon
authors.affiliation: Wildlife Conservation Society, Bronx, NY, United States of America.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Plumptre
mesh_terms: D000350:Africa, Central; D000663:Amphibians / Q000382:microbiology*; D000818:Animals; D044822:Biodiversity; D008411:Chytridiomycota / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity*; D004271:DNA, Fungal / Q000235:genetics / Q000302:isolation & purification; D003881:Dermatomycoses / Q000266:history / Q000382:microbiology / Q000662:veterinary; D017753:Ecosystem; D056727:Endangered Species / Q000266:history; D049673:History, 20th Century; D049674:History, 21st Century; D016133:Polymerase Chain Reaction; D012867:Skin / Q000382:microbiology / Q000473:pathology
chemical_list: D004271:DNA, Fungal