I’ve always had a fondness for snakes. When I was young, I used to keep spare sheets of metal on the edges of the forest on our property in order to attract snakes to the metal’s warmth and cover. I’d flip the metal and grab the snakes to get a better look, usually resulting in them pooping on me or biting me or both.
Pennsylvania is home to few species of venomous snakes, so my game of snake catch and release wasn’t terribly dangerous. This game is not recommended in my new home of Costa Rica due to the large number of snakes that possess a bite that can send you to the hospital. Today’s featured snake, though perfectly willing to bite you, will not inject you with any venom. Let’s meet the boa.
The boa (Boa imperator) is also known as the boa constrictor, the Mesoamerican boa constrictor, or the Central American boa in English. In Spanish, I’ve seen boa común and béquer listed as common names in literature, but I’ve only ever heard people refer to them simply as boas. There are three other species of boas in Costa Rica, but Boa imperator has the largest range and is the most well-known in the country.
The variety of snakes in Costa Rica come in a marvelous array of colors and patterns. Boas aren’t outstanding colorwise, being almost entirely brown, but they do have an attractive pattern running down their backs. What is outstanding about the boa’s appearance is its size. Boas are both the largest and heaviest snakes in Costa Rica. To get a feel for their size, average snakes are around 6 to 8 feet long. That’s average! One of my snake books claims the longest one ever found was over 14 feet long, but there’s nothing to fear because they rarely exceed 9 feet.
Boas are habitat generalists, that is, they live in a wide range of different habitats. They can be found in humid jungles as well as the tropical dry forest of Guanacaste. They’re at home in untouched, pristine, mature forests, but they’re also at home in your house or chicken coop. Since they can live just about anywhere, they’re found through the entirety of the country with the only exception being the very highest altitudes.
Boas are ambush predators. They find a good spot near a body of water or burrow and wait for some future food item to wander by. The type of animal they’re interested in eating has everything to do with how big the particular boa is. Smaller, younger boas dine on smaller animals like small lizards, birds, and small mammals. Larger, more mature boas are able to take prey items as large as monkeys, tamanduas, and opossums, with very large snakes eating the likes of ocelots and juvenile white-tailed deer.
I’ve had several interactions with boas during my time in Costa Rica. I’ve seen several slithering their way through the underbrush while checking camera traps. Once I saw one squeezing the life out of a black spiny-tailed iguana. While working at a wildlife rehabilitation and release center, I once found a large boa with two baby duck sized bumps in its body in the baby duck enclosure rather than the ducks themselves. I also pulled one from a hole in an owl cage, an interaction that left such a mark on me that I wrote a Tico Times article about it.
Boas very infrequently grace me with their presence on my camera traps. I recorded them eating birds a few times, with the last flutters of the birds’ wings triggering the camera. In those occasions the boa was waiting patiently for unwary birds to drink from a dry season water puddle to strike.
I also recorded one once taking a drink from a hollow tree, but the snake didn’t trigger the camera, a coati that was forced to wait his turn to drink did the triggering. Some of the boas eating birds videos were on a hard drive that died, but I have clips of the boa and coati and a boa eating a squirrel cuckoo to share in the video below.
About the Author
Vincent Losasso, founder of Guanacaste Wildlife Monitoring, is a biologist who works with camera traps throughout Costa Rica. Learn more about his projects on facebook or instagram. You can also email him at: vincent@guanacastewildlifemonitoring.com
