Into the Field and Under the Water: Tracking Hatchling Hicatees
by Jonathan Dubon, BFREE
My name is Jonathan Dubon and I am the Wildlife Fellow at the Belize Foundation for Research and Environmental Education (BFREE), a biological field station and private reserve in the foothills of the Maya Mountains in southern Belize. Here, I work at the Hicatee Conservation and Research Center (HCRC) which is a captive breeding and research facility for the critically endangered Central American River Turtle (Dermatemys mawii), known in Belize as Hicatee. Since June 2020, I have been part of a two-year work training program sponsored by the Turtle Survival Alliance and BFREE.
As part of my training, I had the opportunity to work with Wesley Smith, a Master‚Äôs student from Missouri State University (MSU). Wes is a student in Dr. Day Ligon‚Äôs Turtle Ecology Lab at MSU. His Master‚Äôs project was to radio track two-month-old captive-born Hicatee from the Hicatee Conservation and Research Center. Taking part in this study was really special to me because I took care of these turtles since they were just eggs. I found and collected these eggs from their nests at the HCRC ponds and incubated them until they hatched.
These hatchlings were released in June 2021 in a lagoon in north central Belize. They were equipped with VHF radio transmitters, which allowed us to actively track them and conduct our study. Wes‚Äô research goal is to find out valuable information such as habitat preference, mortality/survival rates, and monitoring movement patterns and growth over time. We recorded variables such as obstructions in the water (vines, hanging/fallen branches, immersive vegetation, etc.), canopy cover, and also water depth and visibility. We surveyed during the day and at night. We used a spherical densiometer to measure canopy cover, a Secchi disc to measure visibility, and a rangefinder (when possible) to measure the distance to shore. We also recorded GPS points wherever we found these turtles. We were not able to record habitat data during the night for obvious reasons, but we found as many turtles as we could and left flag markers that we would come back to during the day to catch up on our study.
We found that hatchlings often congregate at fallen branches and vines with a lot of obstructions. They sometimes hang out just under the surface of the water, but situated deep in these brush piles. There was only one situation where we saw a hatchling in open water and this was only because we were trying to catch them for morphometric data (during the night) and scared it out of its brush. The main challenges we faced during our study were that there are some canals in which our boat could not enter because of fallen trees, some turtles being situated deep in their brush pile, and a curfew from the COVID-19 pandemic. Overall, the study was a very fun and educational experience for me since I learned what habitats Hicatee prefer in the wild and observed their behavior‚Äîthough I would like to learn more about how deep they actually dive and what they eat.
During the study I also found a wild Hicatee nest of eggs! Unfortunately, the eggs were no longer alive and we speculated that they were submerged underwater for too long.* Regardless, it shows signs that the adults present are reproductive. Wes and I also found a wild Hicatee hatchling! We were unable to capture it, but we know it was not one of ours is because all of our turtles have transmitters attached to their shells and are also notched.
In closing, I just want to thank the rest of the team from the Missouri State University Turtle Ecology Lab who worked on the project as well: Cora Dyslin, Anthony Grate, and Nix Coppock‚Äîand to their advisors Day Ligon and Denise Thompson. I also want to thank Turtle Survival Alliance for helping to make this fellowship program possible.
* Hicatee reproduction has evolved so that their eggs undergo a natural diapause when inundated with water. Diapause is a temporary arrest in embryonic development. When floodwaters reside, the embryo resumes development.