Excerpts from Jim Conrad's
Naturalist Newsletter

Boa Constrictor, BOA CONSTRICTOR

from the June 6, 2010 Newsletter issued from Hacienda Chichen Resort beside Chichén Itzá Ruins, central Yucatán, MÉXICO

Tuesday morning my friend Alex came running toward the hut yelling my name and I figured he and his pals on the grounds crew had run into a snake, and such was the case. "It's a big one, Jim, over a meter," he said. When I got to the snake spot and saw how many people were standing around wide-eyed with their mouths open I knew it'd be a good one.

It was a Boa Constrictor, BOA CONSTRICTOR, not a particularly large one, only five or six feet but big enough to terrorize the Maya who are as hysterical and ill informed about snakes as they knowledgeable and artful in the use of medicinal plants. Despite the snake's absolute harmlessness to humans, the critter had to be relocated from the tourist area, so I approached for a capture. After a few feeble strikes at my hand, clearly all bluff, I grabbed him behind the neck, he opened his mouth and hissed in a way that sent his audience jumping back, he coiled his thick body around my arm (he's a constrictor, so he does that very well), and you can see what that looked like at the top of this page.

Jonathan Campbell in his Amphibians and Reptiles of Northern Guatemala, the Yucatán, and Belize says that most boas he's come across in South America tend to be rather mild mannered and easily handled but "many Central American boas are easily aroused and aggressive when first encountered. They hiss loudly, mouth partly opened, and readily strike at any intruder." Campbell also says that the largest boas he's seen in Guatemala were a little over 8 feet long (2.5 m), though he's seen a collected and preserved one 10.5 feet long (3.2 m), and of course every village has someone with stories of one thick as a Mahogany tree and an eater of cattle.

Boa Constrictor, BOA CONSTRICTOR, head

Above you can see that one distinctive feature of a Boa Constrictor is that its head scales are much smaller than on most other snakes. You may remember our recent picture of a snake head where I labeled the various scale types -- it's still at http://www.backyardnature.net/pix/snakscal.jpg.

Our boa's head scale pattern is nothing like what's in the picture. That's because a boa's head scales aren't really scales at all, but rather intricately folded skin that helps the snake tightly grip surfaces and aid in locomotion. Boas do have true scales on their bellies, the ventral scales.

Notice the narrow, vertical pupil (like a cat's eye). Northerners used to thinking in terms of venomous pit vipers (rattlesnakes, cottonmouths, copperheads) having vertical pupils find this a bit unsettling, but in this case it doesn't mean anything. The above head picture also shows what appears to be a spurlike scale projecting from the lower lip. If anyone knows what that is drop me a line.

I carried the non-struggling boa about a kilometer into the forest, to a clearing where they'd planted fruit trees. Most of the trees had died because of a heavy infestation of root-eating "Tuzas," or pocket gophers. You can see the boa moments after his release, on his way to eat pocket gophers, I hope, below:

Boa Constrictor, BOA CONSTRICTOR