Using high-powered flashlights and headlamps to light the way, researchers manoeuvred around mud puddles, bushes and mossy slopes while looking straight up at the trees in Sage Mountain National Park.
That night, they hoped to catch a glimpse of an all-white underbelly woven among the leaves that would be the tell-tale sign of their target: the Virgin Islands tree boa.
This wasn’t simply a nature hike for wildlife lovers: It was fieldwork key to the growth of a programme meant to preserve the species. Though the reptile proved elusive that evening, the week-long search provided invaluable information for researchers hoping to discover more about the little-known snake.
Experts from United States-based zoos and universities were guided by Eco Adventures BVI founder Mervin Hastings on their research trip to the VI early this month, and in total they were able to find 22 live boas and two deceased specimens on Tortola.
The VI tree boa was first added to the US federal endangered species list in 1979, and the US-based Center for Biological Diversity states that it is “highly imperilled” because of severe habitat destruction and fragmentation in the sub-tropical dry forests of this territory, Puerto Rico, and the USVI.
However, it is not uncommon to find the reptile in the forests of those territories.
The research effort began as part of a US-based programme to protect the boa, according to Dustin Smith, curator of reptiles and amphibians at the North Carolina Zoo.
Researchers have now turned their attention to Tortola, and Mr. Smith said they hope to learn more about the species’ genetics and distribution.
The Virgin Islands Boa Recovery Programme stemmed from a meeting among professionals around 2017 in St. Thomas, when the North Carolina Zoo began collaborating with the US Fish and Wildlife Service, Mr. Smith said.
“They saw the need to kind of reinvigorate a programme that once existed and was successful with the Virgin Islands tree boa, because where it occurs in St. Thomas and Puerto Rico its populations are in decline, and some of them are in significant decline,” he said.
Similar efforts have proved effective in bolstering the Puerto Rican crested toad, he said.
Mr. Hastings attended the 2017 meeting virtually and advocated for research in this territory, where little formal research has been conducted, but Mr. Smith said other areas took priority during the programme’s formation.
Now that monitoring programmes have been set up in the USVI and Puerto Rico, attention is shifting to this territory and other small islands.
“Some of these islands [where the boas reportedly live] have never been surveyed or they haven’t been surveyed in five or 10 years,” he said. “That’s why we’re really interested in learning more about those kinds of underrepresented populations — or understudied populations.”
The research team that recently visited the VI included Diane Barber, curator of ectotherms at Fort Worth Zoo; Dr. R. Graham Reynolds, associate professor at the University of North Carolina Asheville; and Justin Elden, curator of herpetology at St. Louis Zoo.
Dr. Reynolds is a leading expert on the VI tree boa: He conducted genetic work on early population samples in the USVI and PR, and he wrote the scientific paper leading to the classification of the VI tree boa as a specific species — not merely a subspecies of the threatened Mona Island boa.
After spending the first day of their trip surveying sites to explore, the team set out for their first official excursion on Jan. 30.
What they found
The surveys were conducted at night because the species is nocturnal, and Mr. Smith said the experts explored areas throughout Tortola based on the snake’s favoured types of habitat and history of sightings.
“On the first night, we found nine snakes,” he said. “When we went out to dinner on the first night, we didn’t talk a lot about expectations, but I think we all agreed that you hope for the best and plan for the worst. We hope to find a lot of animals, but when we go in, we know — for example, I spent two days in the USVI about two months ago, and I got skunked both nights. … For those of us that have been doing fieldwork for a long time, you know that you never know. But we went in there really hoping that we would find quite a few boas and that we would find a few of these really big ones that we kept hearing about.”
They found success on subsequent nights as well.
On the Feb. 2 hike, the last of the trip, researchers searched around the park entrance and along the hill leading to it, then tried their luck just east of Enis Adams Primary School. They found examples of the boas’ prey like lizards, frogs and insects, as well as a racer snake. However, they didn’t find a live boa. Nevertheless, the hike sparked discussion of the snake’s habitat preferences based on elevation, prey availability, and other factors that they said could be revealed through further observation.
Mr. Smith also had the opportunity to demonstrate to volunteers how to take measurements and tissue samples from a deceased snake apparently struck by a vehicle.
Mr. Hastings had put out a call on social media for VI residents to report sightings of the boa, living or otherwise, so the research team could investigate, and a few residents called them in.
All this data contributes to learning more about the boa’s habitat patterns and more.
Only so much can be learned in a week, though, and Mr. Smith shared the team’s plans to keep the ball rolling with the help of the community. One idea is to launch a Facebook page where residents can report sightings of the boa throughout the year, sharing photos and location data to be confirmed by experts.
In the absence of extensive scientific publications about the snake, he noted, informal social media reports of sightings can be very useful.
In response to Mr. Hastings’ Facebook post, one resident called in about a live snake and was able to get the experts’ assistance in reviving the lethargic reptile with food and water.
Mr. Smith said he hopes to return to the VI in the future to further explore Tortola and search the sister islands. More broadly, the team aims to continue educating the public on the importance of “underappreciated wildlife” like the tree boas to the ecosystem.
As a long-time studier of reptiles, Mr. Smith said people have no reason to fear the VI tree boa considering it is nonvenomous and easy to handle.
He added that none of the boas he’s handled with this recovery project have bitten him, even when being injected with tiny tracking devices called PIT tags on previous excursions.
“People are often scared of things because they don’t understand them, but there’s nothing to be scared of with this boa — that’s the truth,” he said.
The VI can already take particular pride in one fact of the history of the boa: The first documented example of the species was found in this territory. The sample is housed at the Harvard Museum of Comparative Zoology. Mr. Smith added that the territory can also likely claim to have the biggest population in the world. However, he said, more research is needed. One of the team’s main research goals now is to work with the VI residents who are interested in carrying forward the work year-round, according to Mr. Smith.
“Everybody we talked to seems to be really, really excited to know that there’s some attention being paid to the species in Tortola, because that hasn’t really happened in a long time,” he said.
Team members shared their hope that such research will make a difference in how people view the VI’s wildlife.
“It’s just good to have these endemic animals finally being researched in the BVI, as we have one the healthiest populations between Puerto Rico and the USVI,” Mr. Hastings said. “I’m hoping that this research brings more information and awareness to residents to their importance, as most of the animals encountered are killed.”