Re-introduction of the Antiguan racer to offshore islands of Antigua, West Indies

Summary

The Antiguan racer (Alsophis antiguae), Critically Endangered and rediscovered on the mongoose-free 8-hectare Great Bird Island in 1989 with just 50 remaining individuals, half bearing rat-bite injuries, was the subject of a reintroduction program launched in 1999 by a coalition including Fauna & Flora International, the Environmental Awareness Group and Durrell Wildlife Conservation Trust, following rat eradication on Great Bird that more than doubled the founder population within two years. Between 1995 and 2008, invasive black rats and, where present, small Asian mongooses were eradicated from 12 of Antigua's roughly 30 offshore islands, with extensive public education overcoming widespread negative attitudes toward snakes and securing permission to release even on privately owned islands. Wild-caught adult and subadult racers, limited to no more than 10% of the closely monitored Great Bird source population annually, were tagged, tissue-sampled and boat-transported within 24 hours to release sites: Rabbit Island in 1999, Green Island in 2002, and York Island in 2008. Young racers were observed within two to three years at every release site, confirming successful breeding, and periodic mark-recapture censuses recorded the total population exceeding 500 adults and subadults by 2010, a tenfold increase since the project began. Major difficulties included overcoming entrenched fear of snakes, signs of inbreeding in the historically isolated source population, and persistent threats from rats and invasive fire ants amid growing tourist visitation. The project rates itself Highly Successful, citing successful breeding colonies on all three reintroduction islands and a tenfold global population increase.