2019 Anegada Program Report
Conservation, applied research, and recovery of the Anegada iguana, Cyclura pinguis
Kelly Bradley Fort Worth Zoo
Overview and Objectives.
The Anegada Iguana conservation program is a long-term project centered on headstarting iguanas to combat high juvenile mortality due to the presence of feral cats. The program is entering its 22nd year with over 240 animals released back to the wild. Even though the National Parks Trust Virgin Islands (NPT VI) is still recovering from the devastating effects of the 2017 hurricanes, investigators proposed to build upon the progress made in previous years through several actions. First, a quantitative habitat assessment of the island Fallen Jerusalem (FJ) was initiated to determine the suitability for a future translocation of Anegada iguanas. The assessment included cameras traps and footprint tracking tunnels to determine what invasive species (cats, rats, mongoose, or green iguanas) are on FJ. Researchers (including botanists from the Royal Botanic Gardens, Kew, and J.R. O’Neal Botanic Gardens, BVI) surveyed the island’s flora to map the presence, abundance and distribution of iguana food plants.
Actions on Anegada included continuing investigations of iguana and flora interactions. Researchers (FWZ, KEW, and JRONBG) conducted ground surveys to identify new areas with the presence of rare plants. These areas will then be included in the camera-trapping grids in the hopes of detecting previously unknown populations of iguanas. Bradley also continued camera trapping program in the core iguana area to document the distribution and abundance of wild/repatriated iguanas and invasive species, and nesting activities.
Researchers continued to support the headstart program through searching for and protecting nests in July, collecting hatchlings in the fall, and releasing individuals from the headstart facility that are at least 20 cm in SVL. The program also hosted its annual education/outreach event, Iguana Fest, on Monday October 21st.
Outcomes and Impact
Two sessions of surveys have been completed on the island of Fallen Jerusalem with our partners from Kew and staff from JRONBG. Researchers have set up arrays of camera traps and footprint tracking tunnels to determine what invasive species (cats, rats, mongoose, or green iguanas) are on FJ. The group has also worked on mapping the presence of all reptile species on island. Researchers have recorded anoles, geckos, and skinks, but no Puerto Rican Racers (Borikenophis portoricensis) have been observed to date. Camera and tunnel trap data have been collected and analysis is ongoing, but to date the only invasive species recorded are rats. One last survey session will be completed in an upcoming late January trip.
In May 2019, researchers from KEW and JRONBG and FWZ completed several plant surveys on Anegada to ground truth potential areas that were previously highlighted with remote sensing. An eastern area was confirmed to be a high-quality patch of forest. Bradley set up a 27-camera grid in this area on 29 October 2019. The cameras will continue to take pictures until Bradley returns in February. The results from this survey may result in the identification of a previously unknown pocket of iguanas on Anegada.
The camera trapping effort continued to monitor wild and released iguanas and invasive mammal species on Anegada. Since May of 2019, cameras have sampled Low Cay, Windlass Bight, the Faulkner site, and Bones Bight. At the end of July, the project’s cameras were set up at all identified nests in the core iguana area.
Given the low numbers of hatchlings brought in the last two post-hurricane emergent seasons, it was vital to the program that as many nests as possible be identified. Bradley conducted nest surveys on Anegada from early July until the 10th of August. Ms. Jill Jolly an ISG and IIF board member accompanied Bradley for approximately three weeks to assist in the search for nests. Cooper’s Rock, Loblolly Bay, Jacks Bay, the core iguana area (north shore), and Middle Cay were surveyed for evidence of nesting. Eight possible nests were located, and at least four appeared to be good candidates for successful nests.
Unfortunately, no nests identified in July hatched. Currently it is unclear if this is a result of actual nest mortality, perhaps due to the continued drought on Anegada this summer or perhaps the nests hatched early this year before the flashing was put up. Several colleagues working with other Cyclura species reported that their nests hatched significantly earlier than usual in 2019. It is not uncommon for reptile eggs to develop faster at slightly higher temperatures. Fortunately, there were three camera traps set up on each nest to capture hatching behavior data. The SD memory cards from these cameras were collected on 28 October and the images are currently being processed. Despite the disappointing nesting results, 18 new hatchlings were brought into the facility this year. All individuals were captures from random sightings of newly emerged hatchlings.
In November 2019 a new emergency generator, TV video monitor, and project field car (2008 Honda Element) was delivered to Anegada. The vehicle was registered, insured, and had the undercarriage sprayed on Tortola to protect it from the salt air before being shipped to Anegada by a local cargo boat. The generator is the final piece of our hurricane preparedness kit. The TV monitor will be used to display a short conservation film centered on the Anegada iguana at the facility’s visitor’s center.
Iguana Fest 2019 took place on 21 October. The ecology games were set up in a new format. Instead of playing each game with all the children at once, each game was set up as an individual station. The participants could visit each station individually or in small groups to complete the activity. All participants were issued an official Iguana Fest Passport that was stamped each time an activity was completed; a filled-out passport was exchanged for a small iguana fest prize (drawstring backpack and silicone bracelet). We received great feedback on the addition of the passport. The children were very motivated to completely fill all the space available for stamps. There were more spaces than actual games, so the kids repeated all the activities several times to fill the book. This resulted in heavy repetition of our ecology/conservation message.
Twelve animals (6.6) were chosen to be released based on a facility inventory conducted in mid-October. Students from Claudia Creque Education Centre (grades 4-12) participated in the public release on October 23, 2019. All animals were released south of the road on the western portion of Bones Bight, bringing the total number of released animals up to 260.
Researchers will continue the Fallen Jerusalem surveys in February, focusing on the presence of invasive species, presence of native reptile species, and the presence of rare and/or iguana food plant species. On Anegada, the camera grid set up in October 2019, will be collected and a new grid will be set up in a second site located at the east end during the previous ground surveys in May of 2019.