Charles Hood - Sea Turtles to Sidewinders: A Guide to the Most Fascinating Reptiles and Amphibians of the West

CHARLES HOOD, ERIN WESTEEN, and JOS GABRIEL MARTNEZ-FONSECA

Timber Press | Portland, Oregon

This is a book that will help you appreciate and celebrate the amazing diversity of reptiles and amphibians of western North America. Using this book, you will be able to identify the things you see and know where to look for more interesting animals.

Horned lizards look like tanks; one defense is squirting blood from their eyes.

We use the Continental Divide as our eastern boundary; this is the watershed that follows the mountains and splits runoff into two directions. West of the Continental Divide, water flows into the Pacific, and on the east, the Atlantic, with the self-contained Great Basin (which drains into itself) in the middle. We use Canada and Mexico as the north and south boundaries. That means we are interested in species that occur in Arizona, California, Nevada, Oregon, Utah, and Washington, plus the western parts of Montana, Wyoming, Colorado, and New Mexico.

Herpetologists are professional scientists who study reptiles and amphibians, and the animals they specialize in are collectively known as herps. Non-professionals who like these animals are called herpers, and when they set out to look for wild frogs and turtles and snakes and lizards, they are going herping. Some herpers have permits to capture wild animals; this book is about the watch, dont touch side of herpingwe encourage you to identify as many species as you can but urge you to leave all the herps you come across alone.

This books eastern range border is the Continental Divide, where rain and snow split into separate flows. On one side, water drains to the Pacific, and on the other, into the Atlantic.

The formal term herpetology (from the Greek, crawling on the ground) has been around since the 1820s. To go more deeply into this subject, see the helpful resources in the appendix, and please contact any of the authors if you want to know more about how to enter the exciting field of herpetology.

By reptiles, we mean a large group that includes turtles, lizards, and snakes. Reptiles breathe air, lay eggs, have scales, and are cold-blooded (ectothermic), which means they use external sources like sunlight or warm rocks to maintain suitable body temperatures. This group also contains the worm lizards, the tuatara of New Zealand (which looks a lot like a lizard but isnt), and the crocodilians. Crocodilians are more closely related to birds than they are to other reptiles. This may seem counter-intuitive, but birds and crocodiles (and their relatives) have a lot in common, including the type of parental care they give to their offspring. In this book we wont focus on these other animals because they dont occur naturally in western North America, although sometimes a pet caiman or crocodile turns up in a marsh.

Crocodilians like this baby spectacled caiman are more closely related to birds than to lizards and snakes.

Many people consider reptiles to be slimy, but they are not. Reptiles are scaly, not slimy.

For technical reasons, on paper all living birds are also reptiles; to avoid confusion, we will use the laypersons definition of reptile and exclude birds.

Lets take a tour of the primary reptile categories.

Animals in this group are easily recognizable by the fact that they carry their houses around with them in the form of the shell, or carapace. The turtles shell is a special adaptation derived from their ribs. That means that turtles dont have ribs within their shell, as one might imaginethe shell is their ribs. And since the shell is rigid, that means turtles dont breathe the way other animals do, by expanding and contracting muscles attached to the ribcage. Though turtles are primarily aquatic, they must come up to the surface to breathe, and they do so via special mechanisms, including moving their necks and limbs to expand their lungs. Some turtles can actually breathe through their buttsokay, not really their butts, but their cloaca, the organ through which all herps excrete waste and reproduce. This is mostly needed during hibernation, to ensure that oxygen from the water can be absorbed by the blood.

The nesting behavior of some turtles, especially sea turtles, is dramatic, with many females laying eggs in the same location. Some turtles have what is known as temperature-dependent sex determination. Basically, if the temperature goes over a certain threshold, all the eggs will develop as one sex (usually females at high temperatures, but not always). As climate change worsens, turtles are especially at risk. If all the eggs develop as one sex, mating opportunities will decrease, potentially leading to serious population declines. For more about this, see .

What is the difference between a tortoise and a turtle? Just as all squares are rectangles, all tortoises are turtles. Tortoises are special turtles that live on land all the time, instead of spending all or part of their time in water. Some of the best-known turtles are the giant tortoises of Galapagos, which can live to be 188 years old (and perhaps more than that).

Both lizards and snakes belong to a group of animals known as lepidosaurs; some key characteristics of this group include shedding their skin, losing their tails (most species), and males having paired copulatory organs (hemipenes). Tail dropping is generally considered an adaptation to distract predators. Imagine you are chasing a tasty-looking lizard and suddenly its tail pops off and starts wriggling around in front of you. While you are distracted, the lizard makes a dashing escape. The tail will grow back in a few weeks. Some other cool defensive adaptations in lizards include cryptic color (spiny lizards, 161), intense bursts of sprinting speed (sand lizards, 144), spurting blood from their eyes (horned lizards, 149), and mouths full of venom (Gila monster, 111).

Lizards can be small (a few inches long in some geckos and chameleons) or massive (10-foot Komodo dragon). Some are cryptic; others are brightly colored. Many are excellent climbers (anoles); others are adept swimmers (marine iguanas). With so many species, lizards encompass nearly every imaginable niche. Luckily, we have lots of lizard species in the American West, and we will discuss them in depth in the species accounts. Most are out in daytime, and many can be found in all the places people like to go, from trails in the Grand Canyon to backyards to rest stops along I-10. If we were giving out awards for the most fun, accessible reptile group, lizards would get first prize.