Historical amphibian declines and extinctions in Brazil linked to chytridiomycosis

Abstract

The recent increase in emerging fungal diseases is causing unprecedented threats to biodiversity. The origin of spread of the frog-killing fungus () is a matter of continued debate. To date, the historical amphibian declines in Brazil could not be attributed to chytridiomycosis; the high diversity of hosts coupled with the presence of several lineages predating the reported declines raised the hypothesis that a hypervirulent genotype spread from Brazil to other continents causing the recent global amphibian crisis. We tested for a spatio-temporal overlap between and areas of historical amphibian population declines and extinctions in Brazil. A spatio-temporal convergence between and declines would support the hypothesis that Brazilian amphibians were not adapted to prior to the reported declines, thus weakening the hypothesis that Brazil was the global origin of emergence. Alternatively, a lack of spatio-temporal association between and frog declines would indicate an evolution of host resistance in Brazilian frogs predating 's global emergence further supporting Brazil as the potential origin of the panzootic. Here, we-screened over 30 000 museum-preserved tadpoles collected in Brazil between 1930 and 2015 and overlaid spatio-temporal data with areas of historical amphibian declines. We detected an increase in the proportion of-infected tadpoles during the peak of amphibian declines (1979-1987). We also found that clusters of -positive samples spatio-temporally overlapped with most records of amphibian declines in Brazil's Atlantic Forest. Our findings indicate that Brazil is post epizootic for chytridiomycosis and provide another piece to the puzzle to explain the origin of globally.

Floodplains provide important amphibian habitat despite multiple ecological threats

“…, Carvalho et al. ). For the Pacific Northwest, however, our study provides additional support to long‐standing evidence that if a bullfrog effect exists, it is minor when contrasted to effects by exotic fishes (Hayes and Jennings ) or habitat (Adams et al.…”

The acoustic repertoire of the Atlantic Forest Rocket Frog and its consequences for taxonomy and conservation (Allobates, Aromobatidae)

“…Targeting these populations in future studies are critical, as if the different populations are considered distinct species, the occurrence range of A. olfersioides will be restricted to the state of Rio de Janeiro, where declines and local extinctions were reported (Weygoldt 1989, Verdade 2010, Carvalho et al 2017). In such case, A. olfersioides conservation status (today considered as “Least Concern”) would change to “Vulnerable”, and A. capixaba , and A. alagoanus would be considered as “Data Deficient”, as currently is classified in the Brazilian list of Threatened Species (MMA 2014).…”

“…Méndez-Cárdenas et al 2008, Forti et al 2016, Köhler et al 2017). That is especially relevant for the populations considered presently as they are already categorized as threatened (MMA 2014), population declines have been reported (Weygoldt 1989, Verdade 2010, Carvalho et al 2017), and the Atlantic Forest itself is one of the biodiversity hotspots in the world (Myers et al 2000). …”

“…Therefore, a comparative analysis of the acoustic communication among different populations would enlighten the group taxonomy. In spite of this, populations of the Atlantic Forest Allobates are showing evidence of decline in the states of Rio de Janeiro and Espírito Santo (Weygoldt 1989, Verdade 2010, Carvalho et al 2017), and hence, multiple acoustic recordings are scarce.…”

Prevalence and genetic diversity of Batrachochytrium dendrobatidis in Central African island and continental amphibian communities

“…Riparian species with aquatic larvae (aquatic index = 2.5) have high infection intensities in field surveys in Kenya (Kielgast et al., ) and Gabon (Jongsma et al., ) indicating that species with these life histories are highly susceptible to Bd infections. Although no studies to date have linked African amphibian declines to chytridiomycosis and individuals with high Bd loads appear asymptomatic (Jongsma et al., ; Kielgast et al., ), studies in Central American, South American, and Australian amphibian communities demonstrate that species with aquatic larvae are more likely to decline (Carvalho, Becker, & Toledo, ; Hero & Morrison, ; Lips et al., ), and those that are tolerant may spread Bd between aquatic and terrestrial habitats (Brem & Lips, ). Our results indicate that there is potential for these same disease dynamics to operate in Central African amphibian communities.…”