The initial reaction to herps is often Eek! or Eew! But take a different perspective, and these creatures are beautiful, fascinating, colorful and unconventional. There are the snakes, limbless animals that glide through the world on their bellies; the lizards, which leave their tails twitching beneath the paw of a predator, the turtles, who live encased in an armored shell; and the amphibians, their life cycle a microcosm of evolution. Born as fish (figuratively speaking), they lose their gills and fins to complete life on land equipped with legs and lungs. Amphibians include frogs, toads and salamanders; reptiles include lizards, snakes and turtles. All together, they’re herptiles!

Herptiles are found throughout Colorado from the plains to the alpine tundra, though 80% of Colorado herptiles are not found above 8000 feet. They live in a variety of habitats-rocky canyons, mountain ponds, eastern grasslands, wooded waterways. A few hardy species live above timberline. The western boreal toad may live as high as 11,860 feet, the tiger salamander at 12,000 feet.

Look under a log on a moist forest floor and you may well find a tiger salamander, its face bearing a perpetual smile. Colorado’s only salamander, the tiger is patterned with black and orange. Its immature form, which lives in the water, is often called a “waterdog.” Salamanders resemble lizards, but they have soft, moist, scale-less skin and lack claws on their feet. We all know amphibians go through metamorphosis, from the aquatic larval stage (tadpole, pollywog, etc.) to terrestrial adult. But tiger salamanders sometimes throw a wrench in the works, becoming sexually mature and reproducing without metamorphosing! This phenomenon is called neoteny. The failure of some individuals to lose their gills and leave the water may be a response to local environmental conditions, because their young often will metamorphose.

Perhaps nothing identifies frogs and toads so much as their voices. During breeding season, male frogs and toads set up territories and sing to attract mates. Inflating the vocal sac beneath their chins they expel the air with a variety of croaks, chirps and ribbits.

What’s the difference between a frog and a toad? Frogs are generally more “svelte”, with slimmer bodies and smooth skin. Compared to frogs, toads are sumo wrestlers, with warty skin, chunky bodies and sluggish movements. Frogs usually live in or near water while toads are generally creatures of drier habitats.

Both reptiles and amphibians are cold-blooded (what biologist call ectothermic) meaning their body temperature varies with the environment. When the temperature drops, so does herptile activity. That’s why snakes and lizards spend time basking in the sun. But they can’t tolerate too much heat, so they are most active in morning and late afternoon. Snakes become more nocturnal as the days get hotter, so by mid-summer, evening and night are the best times to see them. Unable to stay warm enough to remain active, herps hibernate in winter.

Many Colorado reptiles are quite handsome and colorful. Male six-lined racerunners have bright green necks and shoulders, with blue bellies. The collared lizard is green with two black neck collars and yellow stripes on its neck and back. The longnose leopard lizard has large brown spots speckling its back, with matching bars down the tail. The milk snake is beautifully marked with rings of black, white and red; the garter snake with sleek cream or yellow lines running from head to tail. The painted turtle has a handsome, dark green or black shell with yellow and red markings. Even the lumbering box turtle carries a shell intricately painted with geometric designs in yellow.

If you think lizards don’t have much of a personal life, guess again. Just like birds, they engage in courtship and compete for mates. Male eastern fence lizards have bright blue patches on their bellies and chins, which they display at other males by flattening their sides and raising their heads as if doing pushups. Some males develop red or orange lips and throat during the mating season. The colors function to attract females or challenge other males. A confrontation between males may escalate from bobbing to actual fighting in which the combatants circle, bite, roll over together or try to flip each other belly-up. The loser runs away.

Have you ever heard of a snake playing dead? The western hognose snake is accomplished at this trick. Also called “puff adder” because of its skill at bluff, it hisses and strikes if threatened, though it seldom bites. If these maneuvers don’t work, the hognose suddenly rolls belly-up, lolls out its tongue and plays dead. Flip it over and the snake will promptly flip again on its back—“I’m dead, darn it, leave me a lone!” seems to be the message.

Only two poisonous snakes live in Colorado—the western rattlesnake and the massasauga (that’s pronounced maw-saw-gwa). [Note: As of 2007, the prairie rattlesnake—formerly classified as a sub-species of the western rattlesnake—is considered a separate species.] Both belong to the family Viperidae, hence the name viper, meaning a venomous snake. The latter is a small, nonaggressive rattlesnake, usually less than 24 inches long. The western rattlesnake, which can reach lengths of 48 inches, is found throughout Colorado. It has two subspecies—the prairie rattlesnake, which lives through most of eastern and southern Colorado, and the midget-faded rattlesnake, a resident of west central Colorado. The rattle of these vipers is a part pf western folklore and a warning to be heeded. Contrary to popular thought, you can tell the age of a rattlesnake by the number of rattles. A new rattle is added each time the snake sheds its skin (two to four times a year) but the rattles frequently break off. Biologist are concerned that rattlesnakes may be declining due to agricultural development, reduction of prairie dogs (which provide food and burrows), and killing by humans-for sport, protection and out of fear. Recently the Colorado Wildlife Commission added restrictions to the regulations for killing or capturing prairie rattlesnakes. Both the midget-faded rattlesnake and the massasauga are nongame species and are protected from being killed (except in self-defense) or captured.

Now that you know more about them, the next time you meet a herp, think of them not as creepie-crawlies but as the colorful, wonderfully diverse creatures of Colorado’s Underworld.

Next: Snakes are Good

(The information contained in this issue of Colorado's Wildlife Company was accurate at the time of original publication. Situations and circumstances described, staff positions, contact information, and dates of some events may have changed in the interim. Present knowledge and understanding of biological and behavioral facts and information may also be different, now, than presented here.)