The Amphibians and Reptiles of the Estación Biológica Jatun Sacha in the Lowland Rainforest of Amazonian Ecuador: A 20-Year Record

Abstract

The amphibian and reptile fauna within a small area in a lowland rainforest fragment reserve in Amazonian Ecuador was intensively surveyed over an initial 2- year period via removal sampling (1986-88), coinciding with the construction of a road through the area and a subsequent surge of increased forest conversion and fragmentation in surrounding areas. A time-constrained transect sampling technique was employed to facilitate later, post-fragmentation visual-encounter monitoring to gather long-term data on species richness and composition (on a chronologically coarse scale). Between 1998 and 2005, an approximately equivalent quantity of sampling effort was accumulated in the same small area to compare with data from 1986-88, in an attempt to evaluate the efficacy of this reserve in conserving the herpetofaunal community documented more than 10 years earlier. Based on a total of 6,722 individual records obtained over 1,117 effort-hours of sampling divided into two primary and five secondary sampling periods, herpetofaunal species richness was among the highest yet reported from a single locality in Amazonia, with 84 amphibian and 82 reptile species recorded from 1986 through 2007. A complete species list is provided, with commentary on noteworthy records. Of 73 amphibian and 46 reptile species recorded in 1986-88 sampling, 68 amphibians (93%) and 40 reptiles (87%) were recorded again in sampling from 1998 through 2007; 11 amphibian and 33 reptile species not recorded in 1986-88 were added from 1998 to 2007. Pairwise comparisons of species composition among all sampling periods using a similarity index revealed a . 50% similarity for both taxonomic groups across all periods; similarity of the two primary periods (1986-88 vs. 1998-2005) was 0.90 for amphibians and 0.70 for reptiles. The present study provides another single-site reference point for the mega-diverse herpetofauna of the upper Amazon basin, but is distinct in offering long-term data on species persistence; results from the 20-year span of sampling suggest that this small reserve has, since 1986, successfully conserved this fauna. These results concur with previous long-term studies from the central Amazon basin in suggesting that relatively small reserves and other forest remnants with sufficient habitat diversity may substantially contribute to the continued survival of species-rich Amazon rainforest herpetofaunal communities amidst widespread regional deforestation.