Catching Coquis

Updated: Aug 5, 2020

By Carolina May, Virginia-Rose Seagal, and Rosanise Odell

In September, TRACE began a new experimental component with collaborators Dr. Tanya Matlaga and Dr. Patricia Burrowes focused on investigating the effects of warming on Puerto Rico’s favorite amphibian: the common coqui (Eleutherodactylus coqui). Coqui frogs are found all over the island in great abundance, filling the night with their characteristic “kho-kee” call and serving as symbol of life in Puerto Rican culture. Since September, the TRACE team has been accompanying Dr. Tanya Matlaga on coqui surveys twice a month, exploring the field of herpetology, and collecting a growing set of new data to understand the impacts of warming.

We begin our surveys just after dark, splitting into teams of two and conducting 15 minute searches in each plot. Coquis are collected inside the plots as well as in the vegetation along the outside, placed in sample bags and labeled with the exact capture location. Most surveys yield around 40-50 captured coquis, which are taken back to the lab for measurements and marking.

Once inside the lab, individuals are measured, weighed, sexed, and sorted into groups of marked and unmarked individuals. Unmarked individuals are marked with colorful elastomer injections in the limbs in unique combinations that make them identifiable when captured again. Marking individuals allows us to track movement in/out of the plot as well as between plots, recapture rates, and changes in growth and survival over time. After measurements and marking are complete, the coquis are released back into the plots in the exact locations they were captured from.

Coqui surveys have been a fun opportunity to learn more about sampling methods, amphibian research, and El Yunque ecosystems. While most of our work with TRACE centers around plants, soils, and biogeochemistry, this experiment brings an element of wildlife into the mix! Since coquis are such a ubiquitous part of the forest, it has been exciting to include them in our research. And, of course, spending time with these adorable amphibians is always a highlight!