By Shanna Challenger, Offshore Islands Conservation Programme Coordinator, EAG
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? That’s exactly what the Environmental 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 Columbus 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 known as Public Enemy #1 as they decimated the “cash crop” of the times – sugarcane 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 as 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 easily available – the native wildlife.
Compounding the impacts of these harmful invasive alien species (IAS) was the boom in agriculture which led to widespread deforestation across Antigua and 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 Antigua Curly-Tail Lizard. But 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 which 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 it was extirpated from mainland Antigua and 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 serious 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 Antiguan Racer Conservation Project (ARCP), an initiative to save this special snake from imminent extinction.
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. 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, constrained by the size of the island, the snakes had reached their carrying capacity and were now being restricted by the amount of prey species (lizards) and 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. Fortunately, Antigua and Barbuda has over 50 offshore islands and cays which the racers likely inhabited in the past. Before the racer could be reintroduced to candidate offshore islands, eradication of invasive mammalian predators needed to be conducted both on these core islands and on neighbouring islands which posed a significant re-invasion risk if the IAS used them as stepping-stones. Thanks to the successful eradications and reintroductions, the Antiguan Racer can now be found on four different islands and had a population of over 1,200 individuals as of 2016.
The tale of the racer is far from over, but its survival depends on not just the EAG, but you and me. We all have a role to play in keeping Antigua and Barbuda’s offshore islands invasive species-free and ensuring this species is around for generations to come.
Within the last year, the OICP’s conservations 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 has received funding to conduct a census of the Antiguan Racer across its entire range as part of the Antiguan Racer Conservation Action Plan. The census will run from July to September 2023.
If you are interested in donating to local conservation efforts, or joining/volunteering with the EAG, simply email us at [email protected] or call +1(268) 462-6236. Find us on all social media @EAGAntigua.
