One venomous snake to be watchful of is the Fer-de-Lance. This snake is brown and gray with lighter colored lines crisscrossing its back. It has a triangular-shaped head and yellow underbelly. According to Manbir Online it is one of the most feared snakes in Central and South America (see Ref. 1). It is difficult to detect because it's coloring and coiled resting position camouflages it so well. At night it wakes to search for prey.
The Bushmaster is another venomous snake to be aware of. It's coloring can vary from light gray (almost pink) to very light brown with dark brown, diamond shapes appearing on it's back. The Bushmaster can grow up to 10 feet long, although most grow to approximately 6 feet. The Bushmaster's bite can be fatal (see Ref. 2).
The Tropical Rattlesnake is light brown with dark brown diamond shapes down the back. Two brown stripes mark each side of it's neck. The head is diamond-shaped. The Tropical Rattlesnake has a rattle, which it will use as a warning signal if you get too close. Be watchful in dry, low-lying places, rock ledges or thick grass (see Ref. 3). These tend to be favorite resting places for this snake.
"A Field Guide to Reptiles & Amphibians of Eastern & Central North America (Peterson Field Guide Series)" by Roger Conant and Joseph T. Collins contains information about snakes.
