Paraje Tres Cerros is comprised of three outcrops that rise above the Corrientes plains and constitute true rocky “islands”. Until this project, the herpetofauna of the site were unknown. The primary objectives of this project were to survey the herpetofauna and use the results as a tool for educating the regional population and contributing to the effort to create a nature reserve at the site. A three-day census was conducted each month for a year, with one day each census dedicated to each of the three outcrops and their surroundings. A direct observation, unrestricted search of amphibians and reptiles was conducted in natural refuge areas (rocks and trunks) and under cardboard. Pit traps and auditory monitoring were also employed. Outreach occurred through three presentations at regional schools and one interactive workshop and display at the Paraje Tres Cerros interpretive center. These efforts were supplemented with radio and print interviews, informational pamphlets, and informal conversations with local residents and property owners at every opportunity.
Fifty species of herpetofauna were identified: 24 amphibians and 26 reptiles (18 snakes, 5 lizards, 2 worm lizards and 1 caiman). This represents 40% of amphibian species and 26% of reptile species known to inhabit Corrientes Province. A highlight was the discovery of two lizards species new to science and endemic to the outcrops: one species of Phyllodactylidae (Homonota taragui) described during the study period, and one species of Teidae (Cnemidophorus sp. nov.) in the process of being classified. On the outcrops themselves, 20 species were identified, four of which were exclusive to this type of habitat. Areas of mixed grass and rock had the highest species richness (17). At the base of the outcrops and in surrounding meadowland, 45 species were identified, 30 of which were exclusive to this type of habitat. Areas with highest species richness included dikes and pastures (17 each), followed by ponds (15) and forest patches (14). Of the species identified, four are nationally recognized as vulnerable, while the rest are not considered threatened. Of the four vulnerable species, three were found on the outcrops, two exclusively so; meanwhile, two of the four vulnerable species were found at the base of outcrops and surrounding meadowland, one exclusively so.
Overall, the research aspect of the project illustrated the great importance of the area for regional biodiversity. The outreach activities revealed a deep lack of knowledge about local amphibians and reptiles, and some sense of suspicion regarding the establishment of a nature reserve at Paraje Tres Cerros. Future work will require a focus on outreach and education, working with local land owners in particular to develop a sense of value to the outcrops as protected areas. ($5,565)