Highly Endangered Round Island Boa Captive Population Doubles at Durrell02/04/2008 13:10:05
February 2008. The Durrell Wildlife Conservation Trust is hailing a breakthrough in the husbandry of the Round Island boa, one of the world’s rarest snakes.
Once found throughout Mauritius and the surrounding islands, the Round Island boa (Casarea dussumieri) is today restricted to Round Island off the Mauritian coast. The world’s only captive population is at Durrell’s Jersey headquarters where animal managers have recently made breakthroughs in increasing egg production and increasing the survival rates of young.
The Trust began keeping the species in the 1980’s, but the animals proved highly difficult to manage due to their specialized diet, and it has not been until recent years that advances in the snake’s husbandry have been made, leading the Jersey population to double from10 to 20 in five years.
Alasdair McMillan, a senior keeper at Durrell who works with the species, said: ‘Working with this unique species is a real challenge. They are very shy, easily stressed, and a specialist lizard feeder.’
Diet of Geckos and Lizards
The snakes’ preferred food is geckos and lizards, and some specimens refuse to eat anything else. But since the 1990’s staff at Durrell learned that the animals could be encouraged to eat mice if chick thigh meat was first used to scent them.
Mr McMillan added: ‘The boas are extremely shy and not aggressive at all, but are incredibly beautiful. We are delighted that the progress made in husbandry over the last 30 years has led to a doubling of the population here in Jersey.’
The Round Island boa is unique among all vertebrates in that it has a split top jaw which scientists believe may help it get a better grip on its lizard prey when hunting. It also changes colour throughout the day – remaining slate-grey throughout the morning, then becoming ghost grey throughout the evening; making it only one of a handful of the 2,700 species of snake able to alter their natural colour. It’s close cousin, the Round Island burrowing boa has not been seen since 1996 and is believed to be extinct.
Durrell and its partner organisations have carried out an extensive restoration of the snakes’ native habitat of Round Island – removing invasive species like goats and rabbits, and allowing the native flora and fauna to recover.