Giant and Phantom Frogs in the Atlantic Forest: Historical distribution and conservation implications

Abstract

Amphibian populations are declining at unprecedented rates across the globe. Some declines occur in a short timeframe and are promptly detected, others are happening in a much slower pace, making them more difficult to detect. One approach that could revel these hidden declines is through analyses of individual historical records. Here, based on an extensive review including literature records, specimens deposited in scientific collections, and experts’ personal communication, we reviewed all available spatiotemporal records of our three taxa of interest, Ceratophrys aurita, Megaelosia spp., and Phantasmarana spp., with predominant distribution in the Brazilian Atlantic Forest, a region with known amphibian population declines and extinctions. We found a sampling decline for Phantasmarana spp. in the decade of 1970, followed by concomitant declines for C. aurita and Megaelosia spp. during the 1980s. We found that these taxa were not resampled for more than 50 years in 50 % of the sites with historical records. Recent records for C. aurita are restricted to less than 30 % of its historical sites of occurrence. After the suggested declines, since 1990 all three taxa showed a certain level of sampling recovery, as it has been documented for populations of other anuran species in the Atlantic Forest. Our study reinforces the importance of species-focused exhaustive reviews to detect population fluctuation over time, one of the top priorities in animal conservation.