Growing up in Costa Rica, I was always interested in snakes. Finding the bones of a tiny garden snake and then a group of baby coral snakes in my back yard generated more curiosity than fear, and being able to hold a baby boa constrictor that my friend had found in his yard was an amazing experience.

Since then, I have read about Burmese pythons invading Florida and looked for opportunities to photograph snakes at every opportunity. Last summer, in Kerala, I was lucky enough to find a green vine snake while hiking, but what I’d really like to find is a boa constrictor, perhaps due to my childhood experiences, or because the species is often held in captivity as pets or zoo attractions and I want to find one free in the wild.

This morning I went on a trail hike with Harvey, and we saw a group of howler monkeys, several birds, and a couple variegated squirrels. But it was towards the end of our excursion that we found a creature worth seeing that wasn’t warm-blooded. As we walked on a dirt road between two rows of tall trees, something large rustled loudly in front of us. On the back of the blur twisting through the grass on the side of the road, I thought I saw markings I recognized. Maybe this was a young boa constrictor! I quickly cut left while pulling out my camera and approached the still-moving snake. It was already climbing a tree, and I managed to take a few shots once it was up in the branches. I could easily see that it was yellow mixed with a much darker color, maybe green or black, but it was quickly clear that what we were looking at wasn’t a boa constrictor, since the yellow was so bright and its head wasn’t arrow-shaped. When we got back to the lodge, Harvey and I carefully reviewed the few pictures and attempted to identify the snake with a few guidebooks. Based on the colors, size, and where we found it, we decided it was a tiger rat snake. Despite our fortune at seeing such a large snake in the first place, I couldn’t help wishing it had been a boa.

Better luck next time.

But my search for the boa constrictor is far from over. Every time I hike I peer into the undergrowth or crane my neck to scour nearby branches. Perhaps I will have more chances at night, since the species hunts nocturnally. I plan on going on a few night walks to find the elusive strangler.

Some details on the tiger rat snake: This black and yellow species eats small mammals, frogs, and birds. It lives in trees or open areas at environmental edges, which is where we found it: at the edge of a dirt road not far from the mangroves and right next to a plot of trees planted by MR guests. When it sensed us, it slid through the grass and up a tree, giving evidence for the guidebook referring to the species as an “astonishingly agile climber,” as well as the Mexican common name voladora, or flyer. According to Twan Leenders, the Dutch herpetologist responsible for “A Guide to Amphibians and Reptiles of Costa Rica,” the tiger rat snake, or Spilotes pullatus, can occasionally “stand their ground when approached closely and employ an impressive threat display. The neck and the front of the body are compressed and sometimes lifted off the ground; the tail tip is rattled simultaneously, creating an audible buzz.” Although this behavior would have presented an awesome photograph opportunity, I’m glad the one we found didn’t feel threatened enough to defend itself aggressively.