The Journey Begins
By Niels van der Vegt, MSc Student, Geo-information Science and Biology, Wageningen University, The Netherlands
In June 2023, I stumbled upon an intriguing internship opportunity through my university: radio-tracking Critically Endangered Jamaican Rock Iguana hatchlings. After reaching out to Dr. Stesha Pasachnik at the International Iguana Foundation, I found myself in Kingston, Jamaica a year later, preparing to explore one of the oldest and most well-preserved natural areas in the Caribbean: the dry forests and limestone hills of Hellshire.
My strong interest in using technology to aid wildlife conservation efforts led me to this internship, which focuses on pushing the limits of tracking technology to help save this unique species. Instead of tracking adult iguanas, which can weigh over 2 kg, we’re following brand-new hatchlings that weigh only about 30 g. Since hatchlings are so small, we need to use traditional VHF radio-tracking technology, as their bodies cannot support the newer and much larger GPS tracking devices.
Our goal is to understand the hatchling’s survival during the critical early months after their emergence to the wild. The main threat to this species is invasive species, and conservation and management actions to protect them from this threat have been underway since the early 1990s. In 2021, the protected area was expanded, and this critical fieldwork will help determine the impact of the recent improvements. We will also gain important information on the iguanas’ movement patterns and habitat preferences.
Life in the Field
On the day I headed to the field for the first time, I woke up at 5 a.m., ready for the adventure ahead. I spent the previous two days acclimating to the heat and preparing with Dr. Pasachnik by shopping for two months of groceries. We also tested the radio-tracking equipment in a local park in Kingston, Jamaica. The journey to the field site requires an hour drive, followed by an hour boat ride, in sometimes very rough waters. Then we arrive at what is likely the cleanest—and in my opinion, the most beautiful—beach in Jamaica. But that’s not our destination—we still have to hike into the field site. Every bit of equipment and supplies must be carried to base camp on our backs, which is no easy task over the extreme terrain.
My next nine weeks would be spent in the rugged environment of Hellshire Hills, the only known location these iguanas inhabit in the wild. Here, resources are scarce; electricity, food, and water are precious, especially in this extremely dry region. Thankfully, I was in capable hands, living with four full-time rangers—Garnett, Jomo, Oneil, and Rojay—who would assist me on my radio-tracking adventure.
Before tracking the hatchling iguanas, we first needed to catch them. Fortunately, Stesha, with her decades of experience, pinpointed the emergence of the first hatchlings to the day, and the rangers had already constructed enclosures around the nesting sites to protect the hatchlings as they emerged. Each year the team encloses all known nesting sites so that all the hatchlings can be collected, processed, then sent to the Hope Zoo for headstarting, or tracked and released directly back to the wild.
Once captured, the hatchlings are transported to base camp for processing, which consists of weighing, measuring, sexing, and collecting a DNA sample. To do this we used pesola scales, a ruler, sexing probes, and vials to collect DNA. Those hatchlings selected for tracking then got a tiny 2g radio transmitter attached to the side of their tail. This delicate task requires precision; Stesha and I had to have very steady hands, and we could make no sudden movements while sweat was dripping from our heads and mosquitos and sand flies were attacking us. There is no indoor space at this camp. We sleep in tents, but everything else is open air and very primitive. We carefully glued the transmitters to the squirming hatchlings, and then released them back at their nest sites for subsequent tracking.
Challenges in the Field
The following day, it was time to begin hiking in the extremely challenging terrain. The conditions were even tougher than I had anticipated, and despite my experience in long-distance hiking and mountaineering, I was taken aback by the harshness of the landscape. Stesha had warned me that this would be the most difficult thing I had ever done, and I was up for the challenge. The limestone ground, once a coral reef, was riddled with sharp spikes created by rain erosion. A fall could prove very dangerous in such a remote location. Each hike became a balancing act to avoid injury, and my ankles were constantly fatigued from the uneven surface.
Even for a field season of two months, two pairs of hiking boots were required, as the sharp rocks destroy even the best boots. The rangers go through countless pairs in a year. In the sweltering heat, with temperatures above 30°C (85°F), I found myself drenched in sweat, as if I’d been rained upon. I often had to take a break to ring out my shirt. What can I say, I’m a large guy living in northern Sweden, a mere 400km from the Arctic circle—this was quite a change for me!
But despite these challenges, our morning hikes yielded plenty of rewards. We followed the beeps on the radio receiver, which grew louder and louder as we approached the tiny iguanas. We often had to clear paths with machetes to access areas where the signals were strongest. Then we would spend time pinpointing exactly where the hatchling was. What a sight to behold: finding the little iguanas hiding in a dead tree, peeking out to see what all the commotion was about. I would then collect a variety of data, including that the individual was alive and what the habitat was like in the area.
Appreciating the Little Things
During my nine weeks, I managed to spend three weekends in Kingston, providing a welcome respite from camp life. I relished the opportunity to restock fresh food supplies (there is of course no refrigeration at camp) and enjoy a much-needed shower. Limited rain means only water for drinking and no shower for three weeks at a time. Living in such a demanding environment shifted my priorities; I learned to appreciate the little comforts, like a well-placed tent mesh to keep out mosquitoes. The first five weeks were dry, and we relied on the rangers to transport supplemental water to camp on foot. When the rains finally came, they were fierce and invigorating, a moment of celebration shared with my team.
As my final weeks at camp approached, we continued to track the hatchlings. We noted the unfortunate loss of a few transmitters, likely due to predation or the harsh terrain. But we were happy to conclude that the majority of the hatchlings were alive and thriving at the end of the study. This was a dramatic increase from before the protected area improvement.
Before I knew it, my two months were up, and I found myself back in Mr. Facey’s car, driving to Kingston, reflecting on the fond memories of this experience. Not only did I gain valuable insights into the habitat and behavior of an endangered species; I also built confidence for future wildlife fieldwork. I learned what goes into making a field program happen, including all the equipment, large and small, that is needed to make things flow and to gather the vital data needed to direct conservation and management action. After enduring two months in Hellshire, I felt ready to tackle any fieldwork challenges that lay ahead.
Can You Contribute to Funding Iguana Conservation?
If you would like to help the International Iguana Foundation keep projects like this going, please consider donating to the Tools and Tech to Save Iguanas fundraising campaign. Did you know that the tiny VHF radios we use cost $200 USD each, and the receiver used to find the radios is $2,000 USD? Even the smallest donations add up to make a big difference!
