Genetic Analysis of Dermatemys mawii

BFREE’s second Hicatee (Central American River Turtle) Health Assessment of 2022 took place on July 5 and 6. These dates were much earlier than normal because there was an opportunity to conduct a much-needed genetics study. Dr. Natalia Gallego Garcia traveled from Colombia to collect the samples that will be used for genetic analysis. With the help of Luke Pearson and Isabelle Paquet-Durand, she was able to collect 44 samples from the 46 adult captive turtles in residence at the Hicatee Conservation and Research Center (HCRC). Collected samples will be stored at BFREE until export permits are received. The study is critical to the on-going work at the HCRC and for the Hicatee program in Belize.

Improving Captive Management

Using this genetics study, Natalia will implement a paternity analysis. Data collected will be used to assign all the clutches hatched at the HCRC to a mother (dame) and to potential fathers (sires). We will also gain an understanding of the reproductive output of the species by determining which captive adults are reproducing and how often. Results will be used to improve captive management protocols.

Supplementing Wild Populations

Further, the study will help us determine the genetic composition of wild populations and understand how to supplement those populations with captive animals if necessary. Dr. Gallego-Garcia will conduct a population genetics analysis that includes wild samples in Belize as well as Mexico and Guatemala.

In addition to the genetics study, morphometric data was collected on all adults as well as the majority of juveniles. Dr. Isabelle and her assistant performed ultrasounds on all adult females and identified follicles already forming in many of the turtles.

Finally, because a survey team from Turtle Survival Alliance’s North American Freshwater Turtle Research Group (NAFTRG) was onsite, Natalia was able to collect samples from a subset of those turtles as well.

Hicatee Health Assessment participants

UCLA Shaffer Lab – Natalia Gallego-Garcia; TSA- NAFTRG turtle survey team members – Eric Munscher, Collin McAvinchey, Becca Cozad, Tabitha Hootman, Arron Tuggle, Georgia Knaus, Maddie Morrison, Nichole Salvatico, Luke Pearson, and Stephen Ross; TSA and BFREE Board Member – Tim Gregory; Belize Wildlife and Referral Clinic – Isabelle Paquet Durand; BFREE – Tom Pop, Jonathan Dubon, Barney Hall, Jacob Marlin and Heather Barrett

Natalia Gallego García received her Ph.D in 2019 at Universidad de los Andes. For her dissertation, she used landscape genomics to determine mechanisms affecting the functional connectivity in two endangered and endemic turtles in Colombia. She conducts work through UCLA’s Shaffer Lab as a postdoc, working on a range wide landscape genomic analysis of the red-footed tortoise across South America, with a particular emphasis on Colombian population differentiation.

Saying goodbye to 55 Hicatee turtles

No, more like saying see you later!

By Jonathan Dubon

Watching your children grow up and eventually moving on may be hard for some, but it is something that takes place by nature. Although I am not talking about real children, it still feels the same when I release Hicatee turtles that I have helped to take care of over the past 2 years. The Hicatee Conservation and Research Center (HCRC) is a multi-pronged conservation effort for Hicatee, with one of the tasks being head-start rewilding.

On April 1st, I along with HCRC Manager, Tom Pop, loaded 55 juveniles and hatchlings from the HCRC at BFREE, to be taken to a creek in north central Belize – roughly 4-hours’ drive. Upon our arrival, we met with the Feste Films crew and locals from the nearby community to conduct our releases. There was a turnout of around 15 community members, including adults and children. Feste Films documented our release as a part of their upcoming four-part series ‘Belize Uncovered’ to be available online later this year. The well-known local chef, Sean Kuylen, and International Journalist, Gelareh Darabi, were the interviewers for the film and so participated in all the day’s activities.

Community participation

Before the actual release of the turtles, we gathered and talked about why we are releasing turtles and how important they are to the environment and to the culture. I asked the children “why do you think releasing juvenile Hicatee turtles is important?” I got responses such as: “because they are getting scarce”, “it is better for the wild environment” and the one that stood out the most to me was “because they are critically endangered”. We visited this village in August of 2020 and did a much smaller release, and many of the children who attended then, also attended this time around. To know that information shared a couple years ago is reiterated and remembered means that we are on the right track.

I also mentioned to the community that we are not just releasing turtles to say we do, but we are releasing them to be a part of a long-term studying and monitoring project since this is an active study site for us. All our turtles that were released have unique identification codes, which are placed by scute notching and inserting PIT tags (a microchip inserted under the skin of the turtles). This will allow us to accurately collect data for each turtle and monitor their growth rate, age and so forth.

When it was time to place the turtles in the water, we let every child who attended release a turtle. Hopefully, this will spark a love and passion in them for protecting this species. We only released 10 of the 55 at the creek’s bank where everyone was gathered. After which, Tom and I got into 2 canoes and went up stream to release the remaining 45.

Reflecting on the day

Tom was asked, “How do you feel to release these turtles? Are you sad that you are saying goodbye?” He replied, “I am happy and excited to release these turtles. Even though they have been under my watch and care since being hatched, and I have tried my best to raise these turtles, there is no better caretaker than mother nature herself. I believe with the help of the community and everyone else, we can help them to grow and reproduce on their own. Then we can say we have successfully reintroduced Hicatee turtles into the wild.”

Overall, it was a wonderful and amazing experience that not many can say they have gotten the chance to be involved in. When we were driving off, the mood of everyone was so cheerful and bright, not because we were leaving, but because we accomplished something so important and unique. I look forward to more releases in the future and spreading information with people who may not know.

Agami Heron Study

Since 2016, I have served on the Agami Heron Working Group. This is a group of scientists and conservationists from throughout Central and South America working together to better understand a very secretive and therefore under-documented bird. My role is to ensure that we collect and submit annual nesting data on a small colony of Agami herons. Because the lagoon acts as nesting habitat for Boat-billed herons and Anhinga, we include them in our observation data.

In order to minimize disturbance of the colony, we make infrequent, short visits to the lagoon. Our goal is to determine if nesting has begun for the Agamis. The Boat-billed herons and Anhingas generally nest earlier in the year – March through May. Around the time that they finish their season, individual Agami herons begin to arrive and appear to investigate the area but do not stay.

In late June or early July, pairs of Agamis arrive and begin rebuilding their nests. They use the same nest trees and often the same nests as the Boat-billed herons. They do not appear to use the Anhinga nests which are usually situated higher in the nest tree.

Data Collection

The instructions for documenting the Agami nesting habits are straight-forward, but the timing of their nesting always has made the process a bit tricky. Our data collection begins when the birds are on the nest; however, we can’t visit too frequently. So, it is sometimes difficult to identify the most accurate start date. When we observe the birds on the nest, we document the date, number of nests, number of birds, and other habitat data and then quickly and quietly depart. We return ten days later to do another count.

When eggs begin to hatch and hatchlings grow, we continue to our count: focusing on number of eggs and number of hatchlings. We also look for evidence of parental care, possible predation, and growth stages. At the end of each successful year of data collection, reports are submitted to the Working Group for review.

About the Agami Heron Working Group

The Agami Heron Working Group established an action plan for the conservation of the Agami Heron in 2015. The plan can be accessed in EnglishFrench or Spanish. The Group will continue to provide an information exchange and coordination point for those interested in research and conservation of the species. 

Testing sugar content in cacao

Cacao staff at BFREE are learning to harvest cacao pods when they are the sweetest. Last month, Elmer Tzalam and Mark Canti harvested cacao pods to test sugar content at different stages of ripeness. They carefully opened each pod one at a time. Then they scraped out several beans and place them in a mesh bag. They squeezed a few drops of juice from the bag onto a tool called a refractometer. Finally, they held the refractometer to their eye and looked into the direction of a bright light source. As a result, they received a reading of “degrees brix” which is the sugar content of an aqueous solution. 

One degree Brix is 1 gram of sucrose in 100 grams of solution and represents the strength of the solution as percentage by mass. Brix Refractometers are built to measure the sucrose content of a sample through refraction. These meters are capable of incredibly quick and accurate results and are used often in the food and beverage industries. 

The wild, heirloom criollo cacao at BFREE has never been grown in a farm setting. Therefore, the data we collect is new information to the cacao industry and is part of our efforts to characterize this ancient heirloom fine flavor variety. By using tools like the refractometer, we will begin to better understand the most desirable moment to harvest a pod.

Additional info about how Brix refractometers work

Traditional refractometers are handheld analogue instruments. They are held up to the light, so that it shines through the sample. The light is then directed through a prism and lenses onto a measurement scale. A shadow will be case on the measurement scale at the angle where total internal reflection occurs. Observing this shadow through the eyepiece gives the brix reading.

A special thanks to Skyler and Austin from the visiting ARRC group for their enthusiastic participation in this process.

Students and faculty from Kutztown University visit BFREE to initiate research projects focused on the endangered Yucatán black howler monkey

Drs. Chris Habeck and Matt Stone and four Kutztown University students majoring in Environmental Science (Corinne Ruggeiro and Nicole Prantow) and Biology (Stefan Grove and Sherry Jimenez) visited BFREE during January 2022 to explore the calling behaviors, movement patterns, and functional role that the endangered Yucatan black howler monkey plays in the neotropical forests of Belize. Here is their story.

By Dr. Chris Habeck

Monkeying around with climate change: howler monkeys and carbon sequestration in the tropical biome 

We are witnessing dramatic shifts in global climate brought on by human population growth and technological advancement. Deforestation and the use of fossil fuels is causing global temperatures to rise, more extreme weather events, and severe pressures on the natural resources needed for the maintenance of biodiversity. Carbon is at the heart of these problems. When fossil fuels are burned and land is cleared through deforestation, the concentration of a potent greenhouse gas, carbon dioxide (CO2), increases in the atmosphere. Greenhouse gases are not inherently bad. In fact, they allow life to exist on this planet by regulating global temperatures within physiological requirements. However, the abrupt increase in atmospheric CO2 over the past several decades is alarming in that species and ecosystems are struggling – often unsuccessfully – to cope with the rapid environmental changes. Scientists are currently on the hunt for strategies to mitigate the impacts of climate change. Obviously, a reduction in fossil fuel use and land clearing are options to slow the increase of atmospheric CO2, but we also need to prioritize the removal of excess CO2 that is already in the atmosphere to minimize the current impacts of climate change. One way to achieve this goal is to maximize the ability of natural systems to sequester carbon from the atmosphere for long-term storage. Protecting tropical forests may be an important part of this process.

Tropical forests represent the largest biological pool of carbon on Earth. Unlike temperate and boreal systems that hold most of their carbon in the soil, most of the carbon in tropical forests is locked up in living biomass, primarily trees. Trees sequester carbon via photosynthesis and store much of it as wood for structural support as they reach to the upper canopy in search of sunlight. In their quest for solar energy, some trees store more carbon than others because of differences in wood density. Wood density is a measure of wood mass per unit volume, often expressed as g/cm3. Trees with high wood density values store more carbon. For instance, trumpet trees (Cecropia peltata) and inga trees (Inga pezizifera) have wood densities of 0.3 g/cm3 and 0.61 g/cm3, respectively. As such, forests dominated by inga trees would store twice as much carbon than forests dominated by trumpet trees. But which processes promote tree communities with high wood density how might we leverage those processes to maximize the carbon sequestering capability of tropical forests in general?

We think the Yucatàn black howler monkey (Alouatta pigra) has an important role in this process of carbon sequestration. Howler monkeys consume many fruits found in the upper canopy of tropical forests. The fruits of trees consumed primarily by howlers tend to have large seeds and large-seeded tree species tend to have relatively higher wood density than smaller-seeded tree species. As such, we think the selective feeding behavior of howler monkeys could enhance the carbon sequestering capacity of tropical forests. Put another way, if we allow this endangered primate to go extinct, we not only lose an iconic species, but also the functional benefits of their presence.

In January 2022, we traveled to BFREE to initiate a long-term research project with the goal of understanding if and how howler monkeys influence carbon sequestration. With the expert help of Ranger Sipriano Canti, we located several howler monkey troops and documented the identity and size of tree species under tree canopies where they were feeding and in random locations away from their activity centers. By measuring the girth (diameter at breast height) of the trees and referencing a wood density database, we used allometric models to estimate the carbon stored as wood. Preliminary results suggest that carbon storage under monkey activity centers is twice that of random areas of the forests, supporting the idea that howler monkeys provide a key functional benefit at BFREE. Our plan is to continue to document the influence of howler monkeys at BFREE to more fully understand how they contribute to the enhancement of biodiversity and ecosystem function.

Working at BFREE is exciting, not only because of the important research questions that can be explored, but also because faculty and students can immerse themselves in the biological and cultural diversity of Belize. We appreciate the kindness of all the BFREE staff and their openness in sharing their knowledge with us. The support we’ve received from everyone is amazing and has contributed to our desire to plan and execute long-term research projects at BFREE and continue to run our winter study abroad program. Also, BFREE is beautiful. The diversity of animal sightings is astounding, from jaguar tracks and scat to flocks of scarlet macaws and night walks with sightings of kinkajou, snakes, frogs, and insects – this place inspires. The work that BFREE does to protect this special place and their role in promoting biodiversity research and education is a benefit to us, our students, and society at large.

BFREE Wildlife & Conservation Status Directory

BFREE Program Manager, Tyler Sanville, used data created by visiting and resident biologists to develop a complete list of the known organisms with the exception of snails, insects, and butterflies documented to date in the BFREE Reserve, along with their IUCN Status and Population Trend.

Known species found on the BFREE Privately Protected Area include six endangered (EN), seven vulnerable (VU), and twenty-one nearly threatened (NT) species of wildlife.BFREE’s Wildlife & Conservation Status Directory includes 95 mammal species, 324 bird species, 71 reptile species, 27 amphibian species, and 27 fish species. This list is based on the most up-to-date information available and is by no means complete. You can view the entire list of the nearly 550 species found at BFREE below. 

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.

Documenting Dermatemys mawii courtship, breeding, and nesting

by Thomas Pop and Jonathan Dubon

Last year, HCRC Manager, Thomas Pop, and Wildlife Fellow, Jonathan Dubon, separately witnessed two amazing events during their daily work at the Hicatee Conservation and Research Center. Tom observed captive Dermatemys mawii (Hicatee turtle) exhibiting courtship behavior and mating and later Jonathan recorded a female Hicatee laying eggs. Both events were firsts for the staff of the HCRC. Tom and Jonathan describe their individual sightings below.

Tom’s Account of D. mawii mating:  

During the 3-4th week of October 2021, I observed the following events:

Searching: I noticed that several males were following a single female and thought it might have been to initiate a courtship ritual. I saw the males searching both in the mornings and in the evenings on some days. This caught my attention because Hicatee rarely come to the surface of the water and generally only poke their nostrils out to breathe. I did not see any females searching for a male partner to mate with, but we cannot discard this idea as we do not have enough evidence.

Pre-copulation: Several activities were noted before copulation during this time. I saw that the males would try to get behind the female as if they were trying to pick up on a scent or hormone. The male turtles would then try to bite the female’s tail, as well as her marginal scutes and face. Males were observed shaking their heads from side to side while in front of the female, thereafter, trying to bite the female’s face. Again, I witnessed these activities sometimes in the mornings and evenings. There has not been any evidence of individuals being territorial or aggressive towards each other at the HCRC, including male to male, until this recent observation. The only aggression noticed was between dominant males and a female that may have been ready to mate.

Copulation: I noticed that one of the male turtles would try to jump onto the female turtle when they were a little deeper in the water and hook on. The female would then walk into the shallow water around the edge, so the male’s carapace was out of the water a bit.  I used this time to take some photos and videos. I also noticed that before mating, the male would try to drag the female a little deeper into the water as opposed to the shallow edge. Being that this activity happened around the edge of the pond, the turtles made the water very murky by disturbing the dirt present. During this time, I only observed the mating twice. I also noticed that the female involved in the copulation did not seem to want to go deeper in the water. She somewhat preferred to stay around the edge of the pond and seemed stressed.

Jonathan’s account of D. mawii laying eggs:

On December 22nd, 2021, around 7:30 am, I opened the gate to the HCRC and checked around the breeding ponds for nests that might have been deposited overnight. I was stopped in my tracks when I noticed a female Hicatee on land, digging a nest hole with her hind legs. I stood still and remained quiet so as not scare the turtle. She also remained still, and after about a minute or two, she continued to clear out the nest hole. I carefully snuck up behind her and took out my phone to document the occasion. 

At first, I was stooping down but my knees started to ache, so I sat down. After a little while, I laid down a few feet behind her so that I could get some great angles of the event. She continued to remove dirt from the nest hole for 15-20 more minutes. She then laid the first of a total six (6) eggs at around 8:05 am. I noticed that she would place one of her hind legs in the hole when she was laying, to hold and gently lower the egg into the hole. After placing the egg down, she would use her hind legs, switching between the two, to move the egg around and gently set it in place. She repeated these actions in the same way for all six eggs. By 8:30 am, approximately 25 minutes later, she was finished laying. 

After setting the final egg in place, she then began to pull dirt with her hind legs from around the hole to cover it. It took her around seven minutes to cover the nest with dirt while slightly compacting it. After covering up the nest, she slowly turned around and made her way back into the water, at the 8:37 am mark. 

To my surprise, she did not seem bothered by my presence. I do know that some sea turtles allow you to observe and even touch them while they are laying eggs, but I was not sure if Hicatee turtles would do the same. I did not want to risk scaring her, so I played it safe and tried to remain invisible and quiet throughout the activity. 

Why these observations are important:

BFREE Executive Director, Jacob Marlin, was very impressed by the incredible observation and documentation skills of Tom and Jonathan. He stated, “The documentation of courtship, breeding and nesting demonstrates one of the many benefits of developing the HCRC. This species has very secretive habits and barely comes out of the water, even to nest. These events have never been documented in the wild and without the Hicatee Conservation and Research Center and its dedicated staff, this incredible behavior would likely continue to elude science.”

Watch a short video of the events described by Tom and Jonathan at the HCRC.

About the Hicatee Conservation and Research Center:

BFREE is home to the Hicatee Conservation and Research Center (HCRC), a captive breeding facility for the Central American River Turtle, Dermatemys mawii, locally known in Belize as the Hicatee. The Hicatee is classified as Critically Endangered by the IUCN Red List and is listed in the report, “Turtles in Trouble:  The World’s 25 Most Endangered Tortoises and Freshwater Turtles – 2018,” by the Turtle Conservation Coalition. The HCRC was established along with the support of the Turtle Survival Alliance in 2011. Over the last ten years, the team has grown to include several additional partners working together to study reproductive biology, nesting ecology, and the feasibility of breeding Hicatee in captivity. To learn more about BFREE’s work in protecting the Hicatee, visit www.bfreebz.org/research/#hicatee

Photography and Videos by Thomas Pop and Jonathan Dubon. Video compilation by Jonathan Dubon.

Introducing #CantiCam

Puma or Mountain Lion caught on BFREE Camera Traps 2021

This July, BFREE launched a new wildlife monitoring program with Panthera Wildlife Cameras. These cameras are designed to endure the wet, humid rainforest conditions and are perfect for the BFREE Privately Protected Area. Protected Areas Manager and Head Park Ranger, Sipriano Canti, is tasked with managing the project. Canti states “With this monitoring program, we are playing an important role in identifying the wildlife that utilize the property. Not only for their homes but as a pass through to the neighboring protected areas.”

Sipriano Canti, BFREE Head Ranger, checking a wildlife camera in the young cacao agroforest

Executive Director, Jacob Marlin, has identified three goals for the project. 1. Several cameras will be situated in the cacao agroforest and will look at the species utilizing the area and their abundance over time; 2. Monitor and observe the species found throughout different parts of the reserve; and 3. Contribute to a regional jaguar monitoring research program.

Fun with Social Media

The wildlife cameras are also giving us a great opportunity to share with our audience the many cool things that move around the property on a daily (and nightly) basis. Look out for regular updates under these themes and more! #TapirTuesday #WildcatWednesday #FurryFriday #CantiCam