ST. CROIX — The red-tailed boa constrictor is here to stay, and more than 80,000 of the non-native, invasive predators were estimated to be on St. Croix in 2018.
The popular pet snake that grows to at least 10 feet was first reported on the West End 12 years ago. It reproduced so quickly and is so elusive and non-territorial it can’t be hunted or eradicated.
The presence of these nonvenomous snakes that live up to 30 years, however, can be managed with the community’s help by calling wildlife officials when they are spotted, or by humanely killing them with a blow to the brain.
Since 2012, more than 1,000 boas have been caught and killed on St. Croix, the only island in the territory where DPNR has confirmed they exist.
The boa is always on the move. It eats any animal in its way from mice to small deer when it’s not curled up napping under some sort of shelter or inside something, posing a threat to the ecosystem with a noticeable decline in birds already observed.
William Coles, chief of Environmental Education for the Division of Fish and Wildlife within the Virgin Islands Department of Planning and Natural Resources, said there are not as many birds on the northwest of St. Croix with the introduction of the boa. As the snake population expands, he said the island could lose more birds.
“They’re eating all of our native and non-native animals,” he said.
Coles pointed out boas also eat bats, one of the primary pollinators of fruit trees. He stressed the importance of catching and killing the snakes.
“If we don’t remove them from the population, then we’ll lose everything that we have here.”
There is an opportunity with roots already embedded in the community to take advantage of the exotic snakeskin resource by tanning it into leather that could be sold to crafters or used to make items to sell. Boas are also being eaten. DPNR, however, warns against consuming the snakes because it can’t be known whether they swallowed a mouse or rat that ate poison.
Boa constrictors are generally harmless to humans, but there have been documented deaths of people strangled by them. Coles warned against people holding a boa by wrapping the snake around their neck.
“Do not put yourself into a situation that you could lose your life because you’re playing with an animal that can’t be trained,” he said. “They can habituate, but they’re not trainable.”
Comments in social media posts displaying photos and videos of caught boas have shown a concern in the community about the presence of these large snakes. There’s consensus that they don’t belong on island, eat everything, and need to be killed.
DPNR can be called to catch boas found in homes or yards, but it’s simply not possible for the agency to proactively hunt them since they like to hide in the bush. DPNR prioritizes management of boas found in areas important to the ecosystem, but the agency can’t do anything to remove them if the snakes aren’t reported.
“In ecologically important areas — our wetlands, our nesting sea turtle beaches, our farms — we have small animals that might be impacted by the snakes,” Nicole Angeli, director of DPNR’s Division of Fish and Wildlife, said. “These are the spaces where it’s important to manage these snakes, and so those are the areas that we’re focusing on.”
The Virgin Islands Department of Agriculture has received reports about boas from farmers.
“We’ve had a problem with snakes eating chickens,” Agriculture Commissioner Louis Petersen Jr. said.
There are no known native predators on island like eagles, jaguars, or crocodiles to naturally reduce the boa population, but the snakes are being caught and humanely euthanized by humans.
Wildlife control operators:
“In 2015, DPNR already knew that red-tail boas would never be eradicated, and so what we are trying to do now is put tools in place that allow the community to feel comfortable living alongside this invasive species, and one of those tools is having this list of wildlife control operators,” Angeli said.
DPNR has teamed up with more than 45 residents, including licensed vermin-control businesses, who have become certified through the department as wildlife control operators or removal agents to educate the community about boas in addition to removing them, or other nuisance animals when they are sighted. The dead snakes are turned into the Division of Fish and Wildlife for a proper necropsy, or animal autopsy.
Juan Bermudez, a certified wildlife control operator, is featured in the Division of Fish and Wildlife’s first issue of its magazine, Go Wild, Go Fish VI, that was published last July. The article on Bermudez includes a photo of him with a dead red-tailed boa strung up from a tree. The article indicates he had caught more than 100 of the invasive reptiles and turned in at least 70 of them to DFW after spotting them near his home in the rainforest.
In addition to DPNR staff and wildlife control operators and removal agents, Coles catches boas in his spare time when he’s not on the job or teaching archery for DPNR on the weekends.
“I don’t mind doing that,” he said. “It gives me a sense of purpose with the community that I live in.”
Coles records the location each snake was caught and performs a necropsy. He works with the St. Croix Snakes Facebook group to post the information, including photos and videos of him and others catching snakes.
“I try to make sure that all the information that I get is posted, and I try to do it monthly,” Coles said, noting he has processed more than 1,000 boas caught by himself and others since they were first reported on St. Croix in 2012.
Bounty program:
Wildlife control operators can become certified after paying a $25 educational fee and $25 annual permit fee. They receive a $50 bounty for dead snakes turned into DFW that are less than 4 feet long and $100 for snakes longer than 4 feet.
The bounty program was initially funded with a $10,000 appropriation that was expended in less than 11 months, Angeli said. She said DPNR has funding available to pay more bounties owed, but the agency is still determining the legal path to do so since the law didn’t specify how to pay the bounties if the appropriated funds were expended.
“We know who those folks are,” Angeli said, adding that DPNR will pay them their bounties. “We need to determine the legal pathway to do it.”
Angeli said the law that established the bounty program, Act No. 8450 (Bill No. 34-0023), needs to be amended so DPNR can pay the bounties owed.
The legislation established the Invasive Species Eradication Community Program Fund consisting of all sums appropriated from time to time by the Legislature and all administrative fees and permit fees collected from bounty program applicants.
Senator Kenneth Gittens, who sponsored the bill that established the bounty program along with Senator Franklin Johnson, said his office has been consulting with DPNR and Angeli to include additional language in Act No. 8450 to replenish the fund. He said an amendment to the law would allow for fees collected from recreational fishing licenses, fines collected for importation of snakes into the territory, federal and local grants, gifts, donations, bequests of money, and any funds appropriated by the Legislature from time to time to be placed in the fund.
“Obviously funding is an issue there and we need to replenish the invasive species fund,” Gittens said.
Snake study:
Angeli and Coles were among the authors of a study published April 30, 2019 that was the first to investigate the release of non-native constricting snakes on St. Croix.
After using spatial and genetic analyses to determine the range and origin of boas on St. Croix, the authors of the study concluded the snakes came from a single founding female, originating in the pet trade.
“They all came from one mother; all of them,” Angeli said. “And we estimated, based on the genetic size of the population and the genes as well as a demographic study using mathematics, that in 2018 there were over 80,000 boas on St. Croix, so that’s a big number. That’s almost as many nearly six years ago as the number of persons in the whole Virgin Islands.”
Despite the large estimation of boas living on island, Angeli said people don’t see them every day.
“They are cryptic species; they don’t want to see you either,” she said. “They are here and they’re here to stay, and we’ve known that for a long time.”
The genetic analyses revealed that the mother had to have been in the pet trade because she was from Yucatan, Mexico and she was one of the most important genetic strains in the pet trade, Angeli said.
“There are genetic signatures for these animals in the pet trade, and she had one of those genetic signatures, so we know that she was a pet that was released at some point,” Angeli said. “Maybe she had stored sperm for a long time. Maybe she had belonged to a breeder at the time, someone who wasn’t sanctioned to breed.”
Although the study indicated the range of boas on St. Croix spans from the far west to Salt River Bay, Coles said the range is 90% on the West End. He said the boas, however, have been artificially moved east by climbing into car engines and hitching rides. He said he has responded to calls to retrieve snakes found in engine compartments, adding that he knows of 200 boas that were accidentally transported by vehicles. He said the snakes were also moved farther east to Kingshill when hurricane debris from the 2017 storms was picked up by heavy equipment and placed in the field across from the Kingshill Cemetery.
Coles disagrees with the theory that all the snakes on St. Croix came from a single mother, even though his name is on the study. He said he has tried to have his name removed from the paper several times but has not been successful. His theory is that former Hovensa workers released their pet boas on the West End before they left island after the refinery closed in 2012.
“I can’t document it, but there were a group of people who worked at Hovensa, and maybe some Hovensa suppliers, who had snakes here and were breeding them for color,” he said, adding he has seen many different colors of boas on St. Croix that are not part of the U.S. pet trade.
Coles said samples taken during the 2019 study were only collected from five snakes that were caught in the same place at the same time, so they all had the same genetics. Angeli disagrees.
“That’s incorrect because if you read the paper, you see that there are far more than five samples,” she said.
If the origin of the snakes on St. Croix were the pet trade with multiple releases over time by multiple owners, genetic sequences would likely match a multitude of boa constrictor populations common to the pet trade as in the Puerto Rico invasion or the populations in Cozumel, according to the study. Because all the St. Croix individuals that are from different localities across many months shared an identical mitochondrial haplotype, the study found they are likely the result of a single introduction event, from a single source population, perhaps even from a single founding female.
Angeli stands by the theory all the boas came from the same mother.
“That is what the data implicates,” she said.
Coles also disagrees there were an estimated 80,000 boas on St. Croix in 2018, suggesting he would have caught hundreds of them during that year if the estimation was accurate.
“In 2018, I only caught 40 snakes,” he said.
Angeli pointed out the detectability of snakes in the wild ranges from 1% to 15%. If 100 snakes were caught in a year, she said 1% detectability would indicate there were 100,000 of them in the same area the others were caught. She stands by the estimation that 80,000 snakes were on St. Croix in 2018.
“That is what the accepted population modeling implicates,” she said.
Snake industry:
Coles, who said bounties don’t work because there’s no way to continuously fund such programs, sees the emerging snake industry as a way to manage the boas instead of offering bounties because residents would be incentivized to catch them for their valuable skins.
“There’s already things beginning to happen, sort of outside of my sphere, but I want to encourage that because the more we can do things to make it economically viable, we can manage this problem and it won’t cost us, it won’t cost the government, it won’t cost the people,” Coles said.
Matt and Carmen Corradino, owners of Mount Victory Camp Eco Lodge in the rainforest, have been tanning hides for two decades and tanning snakeskins for the past five years. They even teach the primitive skill as part of their annual, weeklong Tropical Skills course. They held a special two-hour course specifically on snakeskin tanning last Saturday that will conclude with the final segment tomorrow, providing participants with all the skills they need to get started.
“We’re making stuff out of sustainable products,” Matt Corradino said. “That’s why we incorporated the snakes.”
Carmen Corradino, who said she has noticed a “significant drop” in the common ground dove population from a meadow she frequently drives past, supports creating a local snake industry.
“I see a lot of opportunities for people between just tanning the skins and selling the raw leather and making products out of the leather like bags and shoes and clothing to sell to tourists and locals,” she said. “There’s so much opportunity.”
The Corradinos have used tanned snakeskin to weave a basket, accent a deerskin backpack with snakeskin stripes and straps, and place on the back of a handmade bow. They incorporated rawhide snakeskin that was not tanned into a handcrafted arrow quiver. A former student who participated in their tanning course used calabash and rawhide snakeskin to make a drum. Carmen Corradino said crafters on island who incorporate snakeskin into their merchandise could earn a viable income.
“I definitely think that someone could make this their livelihood,” she said, noting she has heard tourists talk about the lack of locally-made crafts available on island. “There is a demand for it.”
Angeli said DPNR encourages the non-consumptive use of boas, noting that making wallets and earrings are a great use of snakeskin.
“What I would encourage folks to do is really think about how they can live a full life knowing that red-tail boas are going to coexist alongside them,” she said. “If they want to use the skins of red-tail boas, we encourage that.”
Although DPNR staff, Coles and certified wildlife control operators are available to catch snakes that get reported, Angeli said a lot of residents are catching the snakes themselves. She said the best way to humanely kill them is by putting something behind their heads and smashing their brains with a hammer or large rock.
“It is very inhumane to chop off the head of a snake,” she said. “Its nerve endings are still alive, and it will feel that pain.”
Angeli said DPNR is asking residents to learn about boas. Although the bounty program won’t result in the eradication of the snakes, she said it will help educate residents about them.
“What bounties do is incentivize education,” she said. “The more folks that know about how to control invasive species, the more support we’ll get from the public in helping us control species in our ecologically sensitive areas, and in educating the public, educating our mothers, educating our grandmothers, educating our uncles in what to do when they see a snake.”
If a boa constrictor is spotted, individuals are urged keep track of the location and call 911 or DPNR’s Division of Fish and Wildlife between 8 a.m. to 5 p.m. Monday to Friday at 340-773-1082. Wildlife control operators or removal agents based on St. Croix, as well as Coles can also be contacted to remove boas or any other nuisance animal from a home or property. For assistance in removing red-tailed boas, individuals can call Bermudez at 340-473-7165, Coles at 340-643-6262, Eric Thompson at 340-474-7345, or Xperts Exterminating at 340-473-2370.
