Snakes

Snake Research with Northern Arizona University

At Montezuma Castle, Montezuma Well, and Tuzigoot National Monuments, rattlesnakes have been the subject of a long-term research project conducted by Dr. Erika Nowak of Northern Arizona University. By capturing, releasing, and tracking individual snakes for almost three decades, Dr. Nowak's study has furthered our understanding of these secretive and amazing creatures.

From 1994-2016, over 222 individual rattlesnakes have been captured between all three sites, a process that continues today. Rangers are trained to capture the snakes and place them in a secure bucket until an expert herpetologist, such as Jim Starkey, can come by and process the rattlesnake. He weighs it, measures the length, identifies the sex, and inserts a PIT-tag for future tracking of the snake. After all the data is collected, the rattlesnake is released as close as possible to where it was found, unharmed.

A valuable component of the southwestern environment, rattlesnakes play a vital role in controlling rodent populations. Healthy predator populations keeps the entire ecosystem in check. The NPS collaboration with Dr. Nowak not only better informs rangers on the complex ecosystems of the southwest, but helps visitors develop a meaningful relationship with these misunderstood creatures.

If you find a rattlesnake on park trails, note the location and report the sighting to a ranger as soon as possible. DO NOT APPROACH THE SNAKE. Rangers are trained to capture and relocate rattlesnakes in a way that is safe for them and the public.

Snake Species

Venomous Snakes

Rattlesnakes belong to the pit-viper family, which also includes snakes such as cottonmouths, moccasins, and copperheads. They have a heat sensing pit located behind each nostril that can detect differences in temperature, sometimes that are only a fraction of a degree apart. The heat given off by an animal is detected by the snake helping it to determine predator from prey.

Their rattle is made up of a protein called keratin, the same protein that your hair and fingernails are made of. A new segment is added each time a rattlesnake sheds, approximately two to four times a year. Due to this, and the fact that segments of the rattle can break off, you can't tell a snake's age by counting the rattle segments. Rattlesnakes are also ovoviviparous, which means females grow eggs inside themselves over a period of several months, eventually giving live birth to her young.

In most situations, if you give the snake space to escape it will do so, they fear humans and are not looking to strike if they don't have to. However, if you accidentally get too close and are bitten, it is extremely dangerous and can be lethal if it is not treated immediately.

IF YOU ARE BITTEN BY A RATTLESNAKE, CALL 9-1-1 or ARIZONA POISON CONTROL IMMEDIATELY (800) 222-1222

Western Diamondback Rattlesnake (Crotalus atrox)

Our most common rattlesnake in the park, the Western Diamondback thrives in flat coastal plains all the way up to steep rocky canyons and hillsides. They are social during mating season, and can often be seen on our trails in early spring and fall. Their prey consists of anything they can wrap their head around, as they are not picky eaters. The average length is 4-6 feet, and they can live up to 25 years. This species is classified as Least Concern on the IUCN Red List of Threatened Species.

Black-tailed Rattlesnake (Crotalus molossus)

This medium sized species can reach up to 42 inches in length and live up to 20 years. They range in color from yellows and olive greens to browns and blacks. Their most distinguishing feature is their black tail below the rattle. The Black-tailed Rattlesnake is found in the southwestern United States, Gulf of California, and Mexico. Their primary food source is small mammals, lizards, and birds. This species is classified as Least Concern on the IUCN Red List of Threatened Species.

Mojave Rattlesnake (Crotalus scutulatus)

The Mojave Rattlesnake is highly venomous and is considered one of the worlds most potent pit-vipers. Although they often look almost identical to the Western Diamondback, a key difference is that the Mojave's black stripes are much narrower than the Diamondback's and do not wrap completely around their tail. See if you can notice it in the picture on the left! They are usually not seen near Tuzigoot; however, there was one documented at park in 2020. Mojaves are primarily found in high deserts or lower mountain slopes and hunt small mammals and reptiles. This species is classified as Least Concern on the IUCN Red List of Threatened Species.

Arizona Black Rattlesnake (Crotalus cerberus)

Although not normally seen in the Verde Valley, if you plan to hike in neighboring Flagstaff or Mogollon Rim, be on the lookout (and up!) for this acrobatic snake. They grow up to an average length of 3 feet with a color pattern that consists of a dark gray, brownish-black, or a reddish-brown color. Arizona Black Rattlesnakes undergo morphological color relatively quickly, juveniles are born shades of white and tan that darkens with age. This ability is shared with chameleons, lizards, and some other snake species. Their primary prey is reptiles, birds, eggs, and small mammals.

Non-venomous Snakes

Of the 38 non-venomous snake species in Arizona, about 14 of them can be found in and around the Verde Valley. These snakes often have bright colors and/or striking patterns along their spine. Because they lack the ability to envenommate their prey, they are often quite quick and use the element of surprise in order to ambush their meals. A common trait is biting prey to use as leverage and then wrapping their body around the animal in order to slowly suffocate them before chowing down. Knowing how to identify the difference between venomous and non-venomous snakes will help hikers make smart decisions on trails, while taking advantage of unique learning opportunities.

California Kingsnake (Lampropeltis californiae)

Although there are multiple subspecies of Kingsnakes in Arizona, you are most likely to see the California Kingsnake while hiking around the Verde Valley. Kingsnakes are medium-sized, nonvenomous snakes that kill by constriction. They grow to be 40-80 inches oin length and have a varied diet. Kingsnakes are known to eat other snakes, but also prey upon rodents, lizards, small turtles and birds. Interestingly, the Kingsnake has a high tolerance to rattlesnake venom, protecting it from larger snake predators.

Gopher Snake (Pituophis melanoleucus)

Gopher Snakes may seem intimidating due to their large size, but do not pose any real threat to humans. Reaching anywhere from 4-9 feet in length, their coloration ranges from dark brown, reddish, to a tan and cream color. They have mastered the art of imitation and can trick those with an untrained eye into believing that they are a rattlesnake. They pound their tails against the ground and some even making hissing sounds that sound eerily similar to a rattlesnake rattling. Hence the name, they mostly prey on rodents, but will also eat birds and eggs as well.
Bull snakes are a subspecies of Gopher Snakes, they have similar characteristics and can also be found throughout the Verde Valley.

Mexican Gartersnake (Thamnophis eques)

A very special member of the Verde Valley's riparian ecosystem, the Mexican Gartersnake is an endangered and protected species in Arizona. They love to nest along the Verde River and average about 44 inches in length. Mexican Gartersnakes forage for frogs, toads, tadpoles, fish, and other invertebrates. This species used to be common across river basins throughout Arizona, but now only exist in a handful of streams draining the Mogollon Rim and areas of southeast Arizona. The common practices of underground pumping and water diversion throughout the state has rapidly decreased the available ecosystem left for these snakes. Efforts to protect the species is ongoing, and U.S. Fish and Wildlife Service has designated over 20,000 acres across Arizona and New Mexico as critical habitat for them.

Striped Whipsnake (Masticophis taeniatus)

These small, harmless snakes grow to be 30-72 inches long and occupy much of the Western United States. You can identify them with quite easily with their dark bodies and light yellow stipes going along the underside of their body. They take shelter in trees, shrubs, old rodent burrows, or rock outcrops, which depends on the habitat they are found in. Whipsnakes are active in the day, fast-moving, and highly alert. When threatened, these snakes normally flee into shrubs, burrows, or rocks. Young Whipsnakes eat mostly lizards, but adults expand their diet to include small mammals and birds, insects and even other snakes.

Western Patch-nosed Snake (Salvadora hexalepis)

This slender, speedy snake averages in length from 20-40 inches. Its body is normally peach-colored with dark black and gray stripes going parallel down its sides. They are mostly found in the Southwestern United States and are harmless to humans. Western Patch-nosed eat mostly lizards, along with small mammals, nestling birds, reptile eggs, and amphibians. Females lay 4-10 eggs during spring and summer, which hatch in early fall.

Snake Safety

While rattlesnakes can be dangerous, it is possible to have an enriching encounter with this iconic symbol of the desert. Here are some tips to make your next sighting memorable for all the right reasons.

• Treat the snake with respect. Do not throw rocks or poke it with a stick.
• Give it some space. About six feet is the minimum for safety.
• If a snake wants to retreat, do not chase it.
• If you hear a rattle but do not see the snake, do not back up. Try to stand still and locate the snake before you decide where to move next. Move in the opposite direction of the snake so it does not view you as a threat, before trying to identify or observe the species.
• Always photograph and observe rattlesnakes from a safe distance, at least 6 feet away.

As a general rule in the desert, remember to never put your hands or feet anywhere your eyes have not been first.

If you are ever bitten by a snake, do not attempt to treat yourself. Many folk remedies do more damage than good. Call 911 and go to the hospital immediately.