Just as Central Oregonians crane their necks skyward in the name of birding, local herpetologists sift through rock fields and waterways to spy cold-blooded critters. Herpetology, whose Greek root word means “to creep,” is the study of reptiles and amphibians. Looking for these alternately scaly and clammy scamps is a fun way to spice up any hike or camping trip.

Jeff Jensen, a herpetologist and the owner of The Reptile Zone on Bend’s east side, couldn’t agree more. On a recent day at his shop, which features about 60 species, Jensen, 60, was busy filling customers’ orders for live crickets and roaches — reptile and amphibian food. Two 13-foot Burmese pythons roamed the floor while volunteers cleaned their tanks. Throughout the whirl of activity, Jensen rattled off the information for the following guide to several native reptiles — and one ubiquitous invasive frog.

Gopher snake & Northern Pacific rattlesnake

A top priority for Jensen is distinguishing between gopher snakes and Northern Pacific rattlesnakes, which are often confused for each other. Both snakes are tan to light brown in color and feature a pattern of black blotches — called “saddles” — that run along their spines. They both grow 3 to 4 feet in length. Adding to the confusion is the gopher snake’s tendency, when agitated, to coil while hissing loudly and shaking its tail. If the gopher snake is in leaf litter, the tail thrashing will make a rustling sound, conflating its similarity to a rattler. This mimicry is not an accident — the gopher snake wants you think it’s more threatening than it is.

“Gopher snakes are usually heard before they’re seen,” Jensen said.

You can tell the mostly harmless gopher snake from the Northern Pacific rattlesnake by noticing a few characteristics. First, the gopher snake is slimmer, particularly in the neck area, which, in a Northern Pacific rattlesnake, is swollen by venom-producing glands. Northern Pacific rattlesnakes also have a diamond-shaped head, while gopher snakes’ are narrower.

The Northern Pacific rattlesnake’s rattle is comprised of shed skin, which is contained in “buttons.” A rattlesnake is born with a single button, which multiplies and increases in size as the snake grows. It’s a popular myth that you can tell a rattlesnake’s age by the number of its buttons, but buttons are fragile and can fall off.

“I had a rattlesnake with 12 buttons, and it was only 2 years old,” Jensen said.

As with any animal that can be dangerous when threatened, these snakes should be given plenty of space.. While Jensen doesn’t recommend wrangling a Northern Pacific rattlesnake for fun, he doesn’t see a problem with gently picking a tranquil gopher snake by its tail and placing your hand or a stick under its belly. If a gopher snake bites you, clean the wound with hand sanitizer or, if available, soap and water, Jensen said. If a Northern Pacific rattlesnake sinks its fangs into you, however, you have a much larger problem. Compress the wound. Do not cut the wound and do not suck the blood out. Get to the emergency room as soon as possible.

Sighting spots: Both snake species are found throughout Central Oregon’s High Desert, primarily in the early morning and evening. During peak heat, you probably won’t find them because they’re hiding under rocks. While cold-blooded reptiles need the sun’s warmth, they can’t handle too much, Jensen said.

Predators/prey: These snakes primarily prey on smaller rodents, such as field mice, gophers and pack rats. They will also nab a bird if available. While birds of prey have been known to swoop on these snakes, their primary predators are “stupid people,” Jensen said. “We’re nature’s worst enemy.” Many landowners will mistake the gopher snake for the Northern Pacific rattler and kill it. To safely remove either snake from your yard, Jensen recommends picking it up with a large stick and placing it in a bucket, which you should seal with a perforated lid. Release it several miles away and you’ll never see it again, he said.

Western skink

This striking reptile has a very slender body and head. Fully grown, the western skink measures approximately 9 inches long, although its tail makes up two-thirds of its length. It’s brown with black veins that run from the head toward the tail. They’re born with trademark bright blue tails, and their iridescence wanes as the lizards age.

When threatened, the western skink will shed its tail through a process called caudal autotomy. The tail’s nerve endings make it continue to jump and wriggle for a few minutes. It’s a process common in many other lizard species.

“The whole design of it is to dissuade predators from attacking the lizard and make them go after the tail,” Jensen said. “The lizard can break its tail off at the halfway point, and it’s peachy keen.”

If the tail separates too close to where it meets the body, however, the lizard may die. Otherwise, the skink, over the course of several months, “will have a pretty good stub growing,” Jensen said, depending on food intake.

Sighting spots: Western skinks are primarily found in moist places, such as under rocks and logs, in a variety of habitats that include grasslands, chaparral and near desert creeks and rivers.

Predators/prey: Almost anything that is carnivorous likes to eat western skinks. Predators include birds of prey, raccoons, coyotes and garter snakes. In turn, the western skink will eat almost anything that crawls on the ground, including flies, ants, wasps, crickets, ticks and fleas. They’re incredibly beneficial garden lizards, Jensen said. To attract skinks and other lizards to your garden with the purpose of combating insects, build a stone wall to give the skinks suitable places to hide. Western skinks are harmless to humans. “Their bite is like a pinch,” Jensen said.

Western fence lizard, aka ‘blue belly lizard’

The western fence lizard is very similar in appearance to the sagebrush lizard, which is tan with golden-to-light-brown saddles, and the aptly-named side-blotch lizard, which varies in color with lighter yellow in its side. These lizards range in length from 7 to 8 inches. You can discern the western fence by its grayish body and its bluish/turquoise splotches on its back. There is more blue coloring on males’ throats than females’. All three species feature a blue underside and are colloquially yet incorrectly called “blue bellies.” They also lose their tails when threatened.

Sighting spots: The western fence lizard lives in a huge range of habitats, from desert canyons to grasslands and thicker forests. However, you won’t find them at higher elevations around the Cascade lakes, for example. Like all reptiles and amphibians, lizards must bask in the sun to raise their body temperature to sufficiently digest food and have energy they need to hunt. Some of the best places to find a lizard is under a rock in the morning, when it is cold and slow-moving. After basking for an hour or so, however, the lizard is so sprightly “you’ll have a little rocket in your hands,” Jensen said. “They won’t sit still for nothing. They book.”

Predators/prey: The same animals prey on both the western fence lizard and its blue-bellied compatriots.

Bullfrog

Made famous by Mark Twain, these bullfrogs are not native to Central Oregon, but Jensen includes them in this list for their invasive ubiquity. Six inches long, they’re muted olive green in color, and are distinctive in appearance, with a high haunch and very long rear legs that stick up past their backbones. Males emit a loud croak during mating season. When he was a teen, Jensen entered a bullfrog in a jumping contest. It covered 10 feet in three jumps but didn’t even place among the top five bullfrogs.

“There were guys jumping frogs 15, 20 feet in three jumps,” Jensen said. Less cute is the bullfrog’s voracious and invasive appetite, which encroaches on the same buggy food sources that the natives — Oregon spotted frog and western toad — depend on.

Predators/prey: Bullfrogs are sometimes preyed on by raptors, but its main threat is human encroachment.

In the South, their legs are considered delicacies. The bullfrog eats insects, small mammals, birds and even native frogs.

“If it moves, it eats it,” Jensen said.

Sighting spots: In bodies of water and marshland.

— Reporter: 541-617-7816, pmadsen@bendbulletin.com

The nonvenomous gopher snake is slimmer, particularly in the neck area, which, in a Northern Pacific rattlesnake, is swollen by venom-producing glands. Northern Pacific rattlesnakes also have a diamond-shaped head, while gopher snakes’ are narrower.