Possible control of introduced giant African land snails (Achatina spp.) by the reintroduced endemic skink Leiolopisma telfairii, Ile aux Aigrettes, Mauritius

The giant African land snail (Achatina fulica) is one of the world’s worst invasive species, out‐competing endemic snails, consuming native vegetation and potentially altering nutrient cycles. Attempts to eradicate the snail from islands have only been successful with incipient populations. We present correlative evidence that native island predators may act as an effective control agent for the snail. In 2000 a population of between 37,300 and 45,100 African land snails was estimated on the 26ha nature reserve island of Ile aux Aigrette, Mauritius. Between 2006 and 2007, 260 endemic Telfair’s skink Leiolopisma telfairii were reintroduced to the reserve. Snail population surveys in 2008 and 2009 showed that the introduced snail population had declined to 5,569 (± 3,630) and 6,871 (±5,379), respectively. Previous studies showed that the introduced snails were selective over other invertebrate prey items. We suggest that predation by the endemic skink has been an important causal factor behind the snail population decline.