The Silver Boa

Scientists identified 20 of the snakes during two expeditions to the Caribbean. Photograph: Graham Reynolds/PA. A new species of boa constrictor has been discovered on a remote island in the Bahamas. Scientists identified 20 of the metre-long snakes during two expeditions to the Caribbean islands, the second made in October last year.

One of the creatures made a dramatic appearance by slithering on to the head of the expedition leader as he slept. The silver boa, Chilabothrus argentum, is so named because of its distinctive metallic colour and the fact that the first specimen found was climbing a silver palm tree. 

The US team led by Dr Graham Reynolds, from Harvard University, confirmed the snake was a previously unknown species after conducting a genetic analysis of tissue samples. Commenting on the find, boa constrictor expert Robert Henderson, from the Milwaukee Museum of Natural History, said: “Worldwide, new species of frogs and lizards are being discovered and described with some regularity. New species of snakes, however, are much rarer.

“Graham Reynolds and his co-authors have not only discovered and described a new species of snake, but even more remarkable, a new species of boa. That’s rare, exciting, and newsworthy. “The beautiful Bahamian silver boa, already possibly critically endangered, reminds us that important discoveries are still waiting to be made.”

A report from Harvard University described how, during the first expedition, one of the snakes introduced itself to Dr Reynolds while he and his colleagues were sleeping on a beach. “As Dr Reynolds slept, a boa crawled down from the forest, across the beach, and directly onto his head,” the report revealed.

“This caused him to awake with a start, and upon realising what had happened, he awoke the others.” Captured silver boas were electronically tagged by the scientists before being freed back into their forest home. 

The creature is said to be critically endangered according to the International Union for Conservation of Nature’s “Red List” criteria, and threatened by feral cats that roam the island. A paper describing the silver boa is published in the journal Breviora.

Like other constricting snakes, the boa wraps its body around prey and causes death by suffocation. The staple diet of boas in the Bahamas consists of frogs, birds and rats. The silver boa was discovered on Conception Island Bank, which comprises uninhabited Conception Island and its satellite islets.