title: Dramatic Declines of Montane Frogs in a Central African Biodiversity Hotspot.
abstract: Amphibian populations are vanishing worldwide. Declines and extinctions of many populations have been attributed to chytridiomycosis, a disease induced by the pathogenic fungus Batrachochytrium dendrobatidis (Bd). In Africa, however, changes in amphibian assemblages were typically attributed to habitat change. We conducted a retrospective study utilizing field surveys from 2004-2012 of the anuran faunas on two mountains in western Cameroon, a hotspot of African amphibian diversity. The number of species detected was negatively influenced by year, habitat degradation, and elevation, and we detected a decline of certain species. Because another study in this region revealed an emergence of Bd in 2008, we screened additional recent field-collected samples and also pre-decline preserved museum specimens for the presence of Bd supporting emergence before 2008. When comparing the years before and after Bd detection, we found significantly diminished frog species richness and abundance on both mountains after Bd emergence. Our analyses suggest that this may be the first disease-driven community-level decline in anuran biodiversity in Central Africa. The disappearance of several species known to tolerate habitat degradation, and a trend of stronger declines at higher elevations, are consistent with Bd-induced declines in other regions. Not all species decreased; populations of some species remained constant, and others increased after the emergence of Bd. This variation might be explained by species-specific differences in infection probability. Increased habitat protection and Bd-mitigation strategies are needed for sustaining diverse amphibian communities such as those on Mt. Manengouba, which contains nearly half of Cameroon's frog diversity.
authors.affiliation: Museum für Naturkunde Berlin, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstraße 43, 10115 Berlin, Germany.
authors.forename: Mareike
authors.initials: M
authors.lastname: Hirschfeld
authors.affiliation: Department of Herpetology, California Academy of Sciences, San Francisco, California 94118, United States of America.
authors.forename: David C
authors.initials: DC
authors.lastname: Blackburn
authors.affiliation: Conservation Research & Action for Amphibians of Cameroon, Royal Zoological Society of Scotland, Edinburgh Zoo, Edinburgh, United Kingdom.
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Doherty-Bone
authors.affiliation: Cameroon Herpetology-Conservation Biology Foundation (CAMHERP-CBF), PO Box 8218, Yaoundé, Cameroon.
authors.forename: LeGrand Nono
authors.initials: LN
authors.lastname: Gonwouo
authors.affiliation: Department of Herpetology, California Academy of Sciences, San Francisco, California 94118, United States of America.
authors.forename: Sonia
authors.initials: S
authors.lastname: Ghose
authors.affiliation: Museum für Naturkunde Berlin, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstraße 43, 10115 Berlin, Germany.
authors.forename: Mark-Oliver
authors.initials: MO
authors.lastname: Rödel
mesh_terms: D000349:Africa; D000818:Animals; D001001:Anura / Q000254:growth & development* / Q000382:microbiology*; D044822:Biodiversity; D002163:Cameroon; D008411:Chytridiomycota; D017753:Ecosystem; D009144:Museums; D009181:Mycoses / Q000382:microbiology; D012189:Retrospective Studies; D013045:Species Specificity; D013048:Specimen Handling