Excerpts from Jim Conrad's
Naturalist Newsletter

Indigo Snake, DRYMARCHON CORAIS, juvenile in Yucatan, Mexico

from the September 5, 2010 Newsletter issued from Hacienda Chichen Resort beside Chichén Itzá Ruins, central Yucatán, MÉXICO

Alex of the grounds crew approached the hut warily carrying a white bucket and I figured he was bringing me a snake. It'd be a little one, though, because the fellows are afraid of snakes. But I like those little ones since usually they're the most interesting. I was right. It was a juvenile, and like so many species it was pale below but dark above, with no lines, bands or blotches. However, some distinctive-looking black facial markings on the head gave me hopes for naming it. The snake made no attempt to bite or get away as I reached into the bucket. You can see the little fellow above.

A shot showing more of the body, including the black tail that was minus a couple inches of its tip, below:

Indigo Snake, DRYMARCHON CORAIS, juvenile

Those black lines on the face and the black tail nicely matched pictures in Jonathan Campbell's Amphibians and Reptiles of Northern Guatemala, the Yucatán, and Belize. It's a juvenile Indigo Snake, DRYMARCHON CORAIS. The species' Spanish name is Arroyera de Cola Negra, or "Black-tailed Arroyo Snake," an arroyo being a small stream that's dry most of the time. With that black tail and lack of blueness, the Spanish name for our snake is more appropriate than its English name.

Back in the 70s my Zoology teacher back at the University of Kentucky, Dr. Roger Barbour, kept a big Indigo he'd collected in Florida in a large metal, swimming-pool-like container near his office, and I remember that amazingly easy-going snake as being a very dark blue. However, Campbell describes adult Indigos in our area as having the front half of their bodies pale brown to olive-tan, becoming darker further back, so that the tail and about the last fourth of the bodies are blackish.

The thing about Indigo Snakes is that they can grow very large. Occurring in Florida and Georgia, they're regarded as North America's longest snake, the record being 103.5 inches (262.8 cm, over 8.6 feet). In the Yucatan we have two species that grow longer than that, Boa Constrictors and Tiger Treesnakes.

Indigo Snakes eat frogs, lizards, other snakes, birds and mammals. They don't constrict their prey like Boas. They just rush and seize their prey, then swallow it alive. That's often the way you find an Indigo -- by its prey's distress calls as it disappears into the snake.

Alex's little Indigo had been found in the tourist area, so he couldn't be returned there. I laid him on the ground beneath my Zinnias. Within two seconds he'd slipped between the hut's foundation rocks, and I figure that that's a good place for him.

from the May 26, 2007 Newsletter issued from  from Sierra Gorda Biosphere Reserve, QUERÉTARO, MÉXICO

Above a cliff of outcropping limestone next to the lake I was hiking an overgrown cattle trail through scrub paying more attention to keeping my balance on the steep slope than anything. Then I saw it: Not a yard from my leg rose the front end of a massive, blue-gray snake between six and seven feet long, his head hooked forward and pointed at my right knee. My first thought was, "Well, I've been looking for you for a long time!"

For, it was an Indigo Snake, DRYMARCHON CORAIS, North America's longest snake, the record being 103.5 inches (262.8 cm, over 8.6 feet). In the US the species occurs in Florida and Georgia, with old records placing it in other states as well, but those populations appear to have been wiped out because of habitat destruction and intentional killing. As the species is understood now, it's distributed south to Brazil. There's talk about separating populations found west of the Mississippi River, which includes ours, into the species D. melanurus.

By the time I'd pulled off my backpack (I'd camped overnight in the area) and got my camera set up, the Indigo had slipped over the cliff. However, just a few feet away I found a shed skin, which I photographed next to my 12.5-inch long sandal for scale. You can see that imagebelow:


Back at the casita I looked up the Indigo in Jonathan Campbell's herp book which previously I used in the Yucatan. It said that Indigos in the southern US have "... a reputation for being docile and mild-mannered. This is not true of tropical indigos, which are easily irritated to the point of inflating the throat and vibrating the tail, and often delivering a powerful, although nonvenomous, bite." I got a twang in my right knee when I read that.

In the US, Indigos are listed in the US Federal Register as threatened.