As I trek over a craggy limestone terrain pitted with ankle-breaking holes, spiked bushes and wind-bent trees, I have to laugh. Indiana Jones (“I hate snakes!”) would be shaking in his boots right now for I am walking through the Boa Forest. “We call it that because this is a gathering place for boa constrictors on Aruba,” says my guide for the morning, Diego Marquez. He should know. Marquez is the biologist for Arikok National Park located on Aruba’s wild north coast where wind and wave rule the day.
“Even though this area is extremely arid, humidity hangs under the bushes and trees,” continues Marquez. “Much of it is produced from sea spray blown in by the trade winds. The boas thrive in this place. Let’s go find one.”
With snake hook in hand, we take off across this treacherous, trail-less moonscape of a land. Forget about the snakes. I’m just trying to avoid the barbs, needles and thorns that seemingly poke out from every plant I encounter. “Watch out for the thistles, too,” warns Marquez. “If you brush up against one of those, you will get a bad chemical burn.” And then there is the unforgiving terrain. Any misstep here and chances are good for a twisted ankle in the very least. I want to view this hauntingly beautiful place while walking, but that is out of the question. I only can focus on the next step and where to place my feet. After a tedious, five-minute walk, we stop in front of a huliba tree.
“Can you find the snake?” asks Diego, pointing to the tree.
Marquez points to the base of the trunk with his snake hook and I instantly see a 4-foot boa constrictor. “This one is head down in ambush mode waiting for a lizard. Welcome to the Boa Forest.”
I am a bit miffed. I stand no more than three feet away from the snake, and yet, was unable to find it. Their natural camouflage and color are a perfect fit for this brown and beige, arid island. Diego tells me that even trained rangers have a difficult time spotting these phantom reptiles. “If a ranger finds one snake an hour, that’s about average.”
That holds true for our ramble through the Boa Forest today. We walk another fifty minutes and don’t see another snake. Finally, we stop next to a divi divi tree for water and talk. I learn that the boas are not restricted to the park, but are found all over Aruba—from residents’ back yards to tourists’ hotel rooms, from car interiors to the island’s Parliament. Experts estimate that there are 5000 boas on the loose. The first recorded snake in the wild was in 1999, believed to have been someone’s pet. In 2008, over 800 were captured.
“We have started a Boa Task Force to control the population,” explains Marquez. “We conduct annual hunts, train citizens in how to identify and catch boas, and offer a 10 florin bounty for each one returned live to the island’s veterinary center.”
About this time, I look over the biologist’s shoulder. I instinctively leap backwards, nearly falling into a limestone hole. “Damn, Diego. There’s a boa right behind you!” Sure enough, a six-foot long snake is curled around a branch with the upper third of his body paralleling the lines of the tree.
“People think that the boas go out and grab prey,” says Marquez as he calmly seizes the snake by the head, “but actually they lie in waiting to ambush. They tend to locate themselves where a good food source will pass by. After striking, they squeeze the animal dead and then eat it. This boa here was obviously waiting for a bird to perch. One third of their diet is from wild birds.”
That’s a big problem for Aruba’s natural world according to Greg Peterson, president of the Aruba Birdlife Conservation Foundation. He and Marquez did some data crunching with what they consider conservative numbers and estimate that over 17,000 birds are devoured each year by boas. One bird hit hard is the Shoko, a subspecies of the burrowing owl found only
on Aruba. Peterson recently dissected a killed boa one day and found four shokos, an entire family, in the belly of the snake. World-renowned avian biologist, Adrian Del Nevo, pegs Aruba’s Shoko population at around 200 pairs. The owl-eating boa that Peterson dissected, therefore, ate 1% of the population at one ‘sitting’. Aruba has a Minister of Environment but no department dedicated to handling a bio-invasion like this. That is a bit like having a steering wheel but no car. Until a Department of Environment with trained staff is established, the island’s wild birds will continue to be impacted by boa constrictors. Hopefully, change will come soon.
If it does, part of the credit will need to be given to Greg Peterson. He has spent countless hours in the field photographing boas and their attacks on wild birds. The power of his stunning photos is making people take notice.
Marquez returns the boa to the tree branch precisely where I first spotted it for the Boa Forest is an area of scientific study. Herpetologists like Andrew Odum from the Toledo Zoological Society are now conducting long-term research on the species to see if and how it is affecting the cascabel, Aruba’s endangered rattlesnake found nowhere else in the world. Odum has been coming to Aruba for 25 years to study the rare rattler. He first heard of wild boas on the island in the 1980s, at least ten years before the first official sighting.
We head out of the Boa Forest and back to the jeep. Diego leaves me with these parting thoughts about the boa invasion. “We need daily patrols in high density areas, places like roois (arroyos) in the city. They are perfect places for the snakes since they hold plenty of water and birds. But until the government of Aruba gets that in place, we can’t effectively control the boa.”