Conservation: Reflecting on the Antiguan Racer's remarkable resilience

By Shanna Challenger, Offshore Islands Conservation Programme Coordinator, Environmental Awareness Group

It’s not easy to get people to fall in love with snakes. For many of us, our first introduction to snakes was in the Bible, where they are portrayed as loathsome creatures known for their crafty and dishonest ways. With this fear interwoven into the fabric of our culture, how can one then convince people to transform this innate fear into unconditional love?

Awareness Group (EAG) and our partners were tasked with to save the world’s rarest snake from extinction. We’ve all heard the saying, “Christopher Colombus sailed the ocean blue in 1492.” But while this tale is true, in addition to sailors and artists, he brought rats too. These unwanted stowaways were transported to the West Indies in early travellers’ ships, where they soon adapted to their new homes and began wreaking havoc on native wildlife. The rats quickly became public enemy number one as they decimated the ‘cash crop’ of the times – sugar cane fields. Desperate for a solution to their problems, cane growers introduced Indian mongooses to counteract the growing plague of rats. This initially worked well, but the life histories of these species were incompatible, given that mongooses are primarily diurnal (active in the day) while rats are nocturnal (active at night). Soon the mongooses moved on to eating what was most readily available – the native wildlife.

Compounding the impact of these harmful invasive alien species (IAS) was the boom in agriculture, which led to widespread deforestation across Antigua & Barbuda. The combined effects of the invasive mammalian predators and habitat loss proved to be too much to bear, leading to the extinction of several native species, including the burrowing owl, the Antiguan parrot and the Antiguan curly-tail lizard. However, one species was able to withstand these impacts and serve as the inspiration for this very article. The Antiguan racer (Alsophis antiguae) is a harmless lizard-eating snake that was almost driven to the brink of extinction due to decades of relentless hunting by the rats and mongooses.

Once dubbed the world’s rarest snake, the Antiguan racer was erroneously declared extinct in 1936 as its population had significantly declined and was extirpated from mainland Antigua & Barbuda. It wasn’t until the early 1990s that a group of determined local volunteers found an Antiguan racer on Great Bird Island – a tiny offshore island with an area totalling only 8.4 hectares. There were no mongooses on this island which meant the racers could survive there, but the huge population of rats was causing severe problems for the species.

A rapid assessment by researchers in 1995 revealed that a mere 50 individuals remained on the planet, with more than 50 percent of the snakes observed with tail injuries from rat bites. Thus began the quest to save this special snake from imminent extinction as the Antiguan Racer Conservation Project (ARCP). With an overwhelming feeling of national responsibility and an uncertain future for the racers, a small group of EAG and local forestry staff sought technical expertise from international organisations: Fauna & Flora International (FFI), the Durrell Wildlife Conservation Trust, Island Resources Foundation and Black Hills University to eradicate rats from Great Bird Island. Using best practices for rat eradication in tropical islands, the eradication consisted of deploying stations with a waxy anticoagulant rodenticide bait across the island - the eradication lasted seven days and was the first such project in the Caribbean.

With the rats removed, the snake population remarkably rebounded, more than doubling within 18 months. Unexpected but welcome benefits were also observed as populations of lizards and breeding seabirds increased simultaneously. But, after the initial boom in numbers, the ARCP team noticed a decline in the racer’s population. In the absence of the rats and constrained by the size of the island, the snakes had reached their carrying capacity and were now being restricted by the number of prey species (lizards) and the availability of space for burrowing sites. The entire global population being restricted to one island was also cause for concern as one major event could wipe the population off the planet. The need became crystal clear – it was time for reintroduction. The only way to truly secure a long-term future for this critically endangered species was to increase its numbers as quickly as possible by expanding the population’s range.

Antigua Racer Snake

Fortunately, Antigua & Barbuda has over 50 offshore islands and cays that the racers likely inhabited in the past. Before offshore islands could be identified as potential candidates for reintroduction, eradicating invasive mammalian predators was a crucial prerequisite. These eradications needed to be conducted not only on these core islands but also on other neighbouring islands, which posed a significant reinvasion risk if the IAS used them as stepping-stones. Thanks to the successful eradications and reintroductions, today the Antiguan racer can now be found on four different islands, with a population of over 1,200 individuals. The wealth of animals and plants that the offshore islands support is not only nationally significant but notable on a regional and global scale. As biodiversity hubs, they are a safe haven for threatened species such as the near-threatened (NT) Antiguan ground lizard and the endangered green sea turtle and support breeding populations of nine species of seabirds, including brown noddies and bridled terns.

The tale of the racer is far from over, but its survival depends not just on the EAG but on you and me. We all have a role to play in keeping Antigua & Barbuda’s offshore islands invasive species-free and ensuring this species is around for generations to come.

Locally, these islands are located within the largest marine reserve in Antigua & Barbuda, known as the North-East Marine Management Area (NEMMA). Internationally, these islands are classified as a Key Biodiversity Area (KBA) and an Important Bird and Biodiversity Area (IBA). These designations safeguard the most critical sites for nature on our planet and show how genuinely invaluable these islands are. Recognising the tangible benefits to wildlife populations and their associated habitats, the project shifted from a species approach to an ecosystem approach and expanded its scope as the Offshore Islands Conservation Programme (OICP). This award-winning programme is a collaborative partnership between the EAG, Fisheries Division, Department of Environment (DOE), Ministry of Tourism and Investment, Forestry Unit, National Parks Authority, and FFI. This partnership is working towards the vision of “adaptively managed, flourishing offshore island ecosystems where wildlife thrives, people are meaningfully engaged, and sustainable use is valued and practised for the benefit of all.” Between 1995 and 2021, 16 offshore islands have been cleared of rats (and, where present, mongooses and goats), creating over 100 hectares of safe habitat for local and migratory wildlife to recover and a clean, healthy space for locals and visitors to enjoy.

The OICP’s core pillars are island restoration, capacitybuilding, environmental education and scientific research, and it has worked relentlessly to demonstrate the offshore islands’ ecological and economic value. The programme continues to conduct eradications, most recently in 2021 with the eradication of Green and Smith Islands and building local capacity with over 50 percent of the team being Antiguan. Post-eradication, these volunteers have become Invasive Species monitors and visit the offshore islands every five weeks to conduct biosecurity monitoring checks to detect any signs of reinvasion by invasive mammals. The EAG recently launched “Into the Wild with the EAG” - a virtual field-trip journey into Antigua & Barbuda’s exceptional ecosystems. The three-part video series (available on the Environmental Awareness Group’s YouTube) seeks to teach children about the value of their environment, with a specific focus on the species and ecosystems within the NEMMA. Accompanying the videos are Student Activity Booklets and Teachers’ Resource Guides, which were carefully curated to complement the primary school curriculum. The narrator of the booklet is none other than Acer the Antiguan Racer, who takes the students on this educational journey – further destigmatising the fear of snakes. To date, over 1,200 Grade Four students and 78 teachers from across Antigua & Barbuda have been recipients.

The tale of the racer is far from over, but its survival depends not just on the EAG but on you and me. We all have a role to play in keeping Antigua & Barbuda’s offshore islands invasive species-free and ensuring this species is around for generations to come. Within the last year, the OICP’s conservation efforts have been supported by the Global Environment Fund (GEF), the US Fish & Wildlife Service Neotropical Migratory Bird Conservation Act and the Sandals Foundation. However, these sources of funding are finite, and the work of the OICP is ever-expanding. The EAG is currently in pursuit of funding to conduct a rapid population survey of the Antiguan racer across its entire range, which will be instrumental in developing a Conservation Action Plan that focuses on this keystone species.

If you are interested in donating to local conservation efforts or joining/ volunteering with the EAG, find us on all social media @EAGAntigua.