Snakes in Costa Rica: Meet the Black-tailed Cribo

Last night, while dining with American friends vacationing in Guanacaste, I was asked a common question: “You’re the wildlife guy.” What snakes should we worry about? » Costa Rica is home to 141 species of snakes, and it’s common for several of these species to invade your home, slip into your suitcase, or bite your unsuspecting children.

My answer came from my own experience: “Chances are you won’t see any snakes during your week-long beach vacation. » Of course, how often one encounters snakes depends on the type of habitat in which you are vacationing. Here on Guanacaste Beach, I spend more time than most people wandering through the forest and interactions with snakes are pleasant and rare. When I encounter one, it is quite often the black-tailed cribo.

The black-tailed cribo (Drymarchon melanurus) is also known as the Central American indigo snake. In Spanish Tico, it is called the Sabanera real. These snakes are among the largest in Costa Rica, reaching a length of over nine feet. Most of their body is a pale yellowish/brown tan that darkens at the tip of the tail. The characteristics that make them easier to identify in the field, besides their length, are the black lines on the sides of the head and neck.

They range from Mexico to South America. In Costa Rica, their population is mainly concentrated in the dry forests of Guanacaste, but scattered sightings have been made in other parts of the country. In dry forests, they are most often found near water sources.

These large, fast, non-venomous snakes have an extremely varied diet. This seems like an “I eat what fits in my mouth” situation. They are known to eat fish, eels, frogs, lizards, birds, bird eggs, small mammals including bats, and even juvenile turtles. What really stands out about their diet is that it includes many other snakes. A quick search of the scientific literature on black-tailed cribos brought up a series of articles that might all share the same title: “Hey, I saw this snake eat another species of snake.” Snake highlights on the menu include other black-tailed cribos, boas, and several venomous species like the Central American rattlesnake, Central American jumping viper, and terciopelo.

As I mentioned before, black-tailed cribos are one of the snake species I see most frequently in Guanacaste. Sometimes I see their large bodies sliding down dirt roads as I drive to camera sites and sometimes I pass them as I make my way through the forest to reach a camera trap. Usually, I walk along a stream in a wooded area, we pass each other, I say “nice!” A snake!” and the snake goes in the opposite direction.

Videos of camera trap snakes are an infrequent treat, but black-tailed cribos tend to trigger cameras more than most, probably for two reasons. First, I like to place my cameras near the Guanacaste water sources and that’s where they like to hunt. And second, the movement of their large bodies is enough to trigger the cameras’ motion sensor. Take a look at some of my favorite blacktail cribo camera trap clips 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: [email protected]