A regular Source column, Undercurrents explores issues, ideas and events developing beneath the surface in the Virgin Islands community.
There’s a new resident in the Crucian countryside and a local wildlife authority is not happy about it.
The red tail boa, a subspecies of boa constrictor usually found in Central and South America, seems to be making itself very comfortable on the western end of St. Croix.
“I’m catching all these snakes,” said Dr. William Coles, chief of wildlife for the Division of Fish and Wildlife at the Department of Planning and Natural Resources on St. Croix. “And that’s a little bit disconcerting.”
Coles said he’s been with the division for 15 years and that, up until recently, he had caught just one red tail boa. According to a news story, that took place in 2008. But in the last two to three years, he said, he has caught 12 more.
Coles said that early this month, he caught two snakes in one week. All of them were sighted west of the Carlton area.
It’s not clear how the reptiles got to St. Croix, but Coles has a theory. He believes they or their immediate ancestors were brought in as exotic pets by someone who worked for HOVENSA and that when the refinery closed in 2012, sending many workers back to the mainland, the snakes’ owner or owners left them behind.
As a pet, the red tail boa is especially popular with reptilian fans because of its pretty coloration and its relatively docile nature. Its skin is decorated with a pattern of geometric shapes that tend to be brownish black for much of the body but turn to a red hue near the tail.
An adult typically grows to 10 feet long and weighs up to 50 pounds, according to various Internet sites. Coles said the snake can grow to as long as 16 feet, though the largest he has caught so far was about six and a half feet long.
Despite its size, the red tail boa is generally not harmful to humans. It can bite but it is not venomous. It is nocturnal, hunting at night and hiding out during the day. It feeds on small mammals such as rats or mongoose as well as on birds. Like other constrictors, it kills its prey by wrapping itself around the unlucky animal and squeezing it to death. But it isn’t greedy. It may go as long as a month between meals.
The problem is that the red tail boa is not native to the Virgin Islands. It has no predator here to keep it in check. A female can lay 62 eggs at a time. If they all survive, that’s a lot of snakes. And they have a life span that tops out at about 30 years.
The red tail boa climbs trees, making it safe from predators who can’t climb trees and particularly dangerous to native tropical birds. In the fragile, closed environment of an island, there’s the potential for a major disruption in the ecological balance.
Many of the snakes Coles has caught had issues such as disease or injury, and the territorial veterinarian euthanized them. But currently, he has four red tail boas in cages.
“The problem is that nobody wants them,” he said. “We can’t give them away … We’ve talked to zoos in the States” but they already have plenty of them.
Local authorities don’t even know where the snakes originated, so they can’t just send them “home.” Coles said all four surviving boas have slightly different coloration, indicating they come from different regions. One may be from Brazil, another from Columbia. Without genetic analysis, there’s no way to discern origin with any accuracy.
And even if their origins could be determined, officials would be reluctant to release them for fear that the animals could be infected and would introduce a new disease to their old habitat.
“Our hands are tied,” Coles said.
