Determining sex ratios on captive-born Hicatee

The March bi-annual health assessment for Dermatemys mawii began on Saturday, March 5, and will wrap up on Tuesday, March 8, 2022. This is the first health assessment since March 2020 that we’ve been able to invite participants from abroad.

The Hicatee Conservation and Research Center has experienced successful breeding of our captive population of turtles since 2014. Since then, hundreds of turtles have been hatched at the facility. However, because there is little research on the species to date, we have not been able to distinguish male hatchlings from female hatchlings. To ensure a successful re-wilding program, we must verify the ratio of males to females. And, if the ratios are not correct, then we will use that information to modify our incubation methods. This health assessment is dedicated to determining our sex ratios at the HCRC.

Research shows that if a turtle’s eggs incubate below 81.86 Fahrenheit, the turtle hatchlings will be male. If the eggs incubate above 87.8° Fahrenheit, however, the hatchlings will be female. Temperatures that fluctuate between the two extremes will produce a mix of male and female baby turtles.

Turtle biologist, Dave Rostal, and Veterinarians, Elliott Jacobson and Isabelle Paquet-Durand are performing endoscopies to determine the sex of our hatchlings. Simultaneously, Bryan Windmiller and Emilie Wilder from Zoo New England are taking morphometric photos of each turtle to see if their plastron shape can help determine the sex of the turtles.

We are also collecting typical growth data on a subset of turtles as well as reviewing their overall health and performing ultrasounds on adult females.

Participants: Zoo New England Staff: Bryan Windmiller and Emilie Wilder; Visiting Veterinarian: Elliott Jacobson, Professor Emeritus, University of Florida, Visiting Biologist: Dave Rostal, Southern Georgia University, Local Veterinarian: Isabelle Paquet-Durand, Visiting Volunteers: Doris Dimmitt, Rod Dimmit, Emily Gregory, Tim Gregory, and Alexi Dart-Padover, BFREE staff: Thomas Pop, Jonathan Dubon, Mark Canti, Elmer Tzalam, Jacob Marlin, and Heather Barrett. BFREE Team Hicatee chef: Edwardo Pop.

Thanks to Zoo New England for their support of this health assessment as well as for their ongoing support for the program.