Building the DR frog knowledge base

by Jeff Dawson - March 1, 2017

Over the last year or so Durrell have been working with local partners in the Dominican Republic, Grupo Jaragua and the National Museum of Natural History, to increase our knowledge of some of the countries threatened amphibian fauna.

The Dominican Republic (DR) comprises the eastern part of the island of Hispaniola, neighbouring Haiti to the west. Of the 66 species found on Hispaniola, 59 are threatened with extinction primarily from habitat loss and fragmentation.  One of the most important and threatened sites is the Sierra de Bahoruco, in the southwest. Home to 16 species, of which 13 are globally threatened species and  11 endemic to the Bahoruco; the native forest habitat is highly fragmented due to agriculture and the remaining forest threatened by illegal cutting primarily for charcoal.

Forest edge habitat in the Sierra de Bahoruco. Photo: Cristian Marte

Whilst the rough distribution of species is known little is known about individual species habitat associations, population size and the impact of habitat loss and fragmentation on them. These are important factors to understand if effective conservation management is to be implemented for both amphibians in general and specific species and for populations to be effectively monitored.

With funding from Mohammed bin Zayed Species Conservation Fund and Stiftung Artenshutz, six week long rapid surveys have been carried out to build this knowledge. Utilising visual encounter and acoustic transect surveys alongside the use of static acoustic recorders, the team led by Cristian Marte of the National Museum surveyed agricultural, forest edge and native forest habitats at each site.

Establishing transect for survey in an agricultural plantation. Photo: Cristian Marte

The transect surveys have recorded 10 species including four Critically Endangered, one Vulnerable and two introduced species – none of the globally threatened species were recorded in agricultural habitat. Preliminary results also indicate that forested habitats have significantly higher species diversity and densities of frogs. Whilst this may be the common belief surveying agricultural and anthropogenic habitats is important to prove and demonstrate the impact forest loss is having on amphibian assemblages. These preliminary findings were recently presented by Crisitan at the Caribbean Biodiversity Congress in Santo Domingo, DR and generated a lot of interest amongst participants

A Critically Endangered species recorded during the surveys Eleutherodactylus leoncei. Photo: Cristian Marte

In addition to increasing our knowledge on the countries amphibian fauna, this work is also important in developing the amphibian conservation capacity of the DR, as whilst there are a number of biologists few are engaged in amphibian work. For that reason it is great that alongside technicians from Grupo Jaragua, three Dominican students have been involved in the project, learning more about the countries amphibian fauna and how to survey them. Crisitian

More survey work is needed however to further elucidate findings and then use them to inform conservation action and measures. Further surveys are also important as the results so far are likely to have been impacted by the severe droughts experienced across the Caribbean in 2015, the worst in nearly 100 years, so may not have provided a full and accurate picture. We are looking to continue this work into 2017 and beyond to really get a good baseline against which populations can be monitored and the impact of future conservation actions be measured.