Mojave Desert

The Mojave Desert is the hottest, driest desert in North America. The topography is typical of the Basin and Range Province, where mountain ranges run North-South separated by broad, relatively flat, arid valleys. So arid, in fact, that while by definition deserts receive less than 12" of rain on average per year, the Mojave sees only 5".

  Such little precipitation leads to extreme fluctuations in daily and seasonal temperatures. On any given year, temperatures range from well below freezing in the winter to over 120°F in the summer. This unique environment has shaped the evolution of organisms and allowed distinctive species to flourish. Consequently, the hydrological characteristics and botanical inhabitants are used to distinguish the Mojave from adjacent regions.

Ecoregions of the Southwest

Ecoregions of the Southwest are delineated based on hydrological characteristics and botantical inhabitants.

  The most thorough study to characterize the Mojave Desert was conducted by the United States Geological Survey (Brussard et al, 1999). It is from this study that we adopt the defined range of the Mojave Desert for the purposes of this book. Although the maps in this book delineate the Mojave with a definite line, there is a relatively broad transition zone at the boundary that has a mixture of characteristics from the Mojave Desert and the adjacent region. Additionally, the higher elevations within the Mojave, beginning where desert shrubs transition to junipers, are better described as pockets of the Great Basin within the Mojave Desert.

Places

There are many parks and protected areas within the Mojave Desert that are easy to access and are excellent for viewing reptiles and amphibians. In all of these areas, the herps are protected, which means they cannot be collected, handled, or harassed. Some areas have nominal entrance fees that contribute to local management and conservation. This is important because these places often have many user groups, which stresses the native ecosystems.


Lake Mead National Recreation Area

  The Lake Mead National Recreation Area (LMNRA) spans the Mojave region of the Colorado River. Whether accessed by car or boat, the area has vast expanses of classic desert scrub landscapes that host many of the amphibians and reptiles in this book. Not only are there great habitats for terrestrial species, but the area also includes the Colorado River, the Virgin River, Lake Mead, and a number of warm springs within its boundaries where species such as Texas spiny softshells (Apalone spinifera emoryi), relict leopard frogs (Lithobates onca), and Arizona toads (Anaxyrus microscaphus) can be found.


Valley of Fire State Park

  Valley of Fire State Park lies in the northeast portion of the Mojave adjacent to the north end of the LMNRA – and each is accessible from the other. The park is named for the striking colors of beautiful sand and sandstone formations found within its boundaries. Many reptile species adapt to such areas by closely matching their coloration and patterns to their habitats. Southern desert horned lizards (Phrynosoma platyrhinos calidiarum) and Southwestern speckled rattlesnakes (Crotalus mitchellii pyrrhus) often have striking patterns of yellows, oranges, and reds, as the name of the park suggests. Due to the high traffic by tourists, many of the animals here are tolerant of humans. For instance, common chuckwallas (Sauromalus ater) allow people to get quite close for photo opportunities, while elsewhere in the Mojave one would be lucky to come within 50 yards of an animal before it dashes into a crevice.


Red Rock Canyon National Conservation Area

  The Red Rock Canyon National Conservation Area lies on the western outskirts of Las Vegas. This area is much more diverse in elevation and habitats than Valley of Fire, which allows for a great diversity of herps. The paved scenic loop has several parking lots and trailheads that make access easy. As the name implies, this area also has colorful sandstone formations that have had the same effect as seen in the Valley of Fire on some of the herp species. Red Rock Canyon is another place where many of the animals have grown accustomed to humans. The diversity of habitats includes ephemeral sources of water and a handful of permanent, spring-fed wetlands, so there is an abundance of amphibians associated with these features. Pine Creek, for example, is full of Baja California treefrogs (Pseudacris hypochondriaca). Also, ponds and “tanks” found throughout the area host healthy populations of red-spotted toads (Anaxyrus punctatus).


Death Valley National Park

Josh Parker - Author of the Reptiles and Amphibians of the Mojave Desert.

Numerous badlands are found in Death Valley National Park.

  Death Valley National Park lies at the northern extent of the Mojave Desert and includes many rugged canyons and mountains, some of which host relatively endemic species like the Panamint rattlesnake (Crotalus stephensi) and the Panamint alligator lizard (Elgaria panamintina). While there are some areas that are inhospitable, even for Mojave-adapted species, there are others that host a rich variety of herps, and can easily be found on drives or hikes in areas such as the Grapevine Mountains or the Panamint Range and Valley. Most areas can be easily accessed by well-developed paved and dirt roads.


Mojave National Preserve

  The Mojave National Preserve lies to the southwest of Las Vegas, just across the state border in California. The preserve straddles the border of the Mojave, which means there is a transition from Mojave habitats into Sonoran habitats. As a preserve, it is less developed, but there are plenty of established campgrounds. The whole area is mainly a vast expanse of classic desert scrub. There are some areas of middle elevation characterized by Joshua trees and pinyon-juniper woodlands. Among many other lizard species, Southwestern speckled rattlesnakes (Crotalus mitchellii pyrrhus), red racers (Coluber flagellum piceus), and common chuckwallas (Sauromalus ater) seem to be always nearby. Also within the boundaries of the Mojave National Preserve are the Kelso Dunes and Cinder Cone Lava Beds, which are unique habitats that make for some great herping. The Kelso Dunes host a healthy population of Mohave fringe-toed lizards (Uma scoparia), and several of the species found in the Cinder Cone Lava Beds have dark pigmentation, which matches the black substrate.


Joshua Tree National Park

  At the southern extent of the Mojave Desert is Joshua Tree National Park. There is a gradient of habitats in this park associated with elevation variations. This allows for a great diversity of herps. Hiking through the Cholla Cactus Garden, the Hidden Valley, and Lost Palms Oasis Trail, among others, will yield quite different landscapes as well as herp species. While there is no shortage of Joshua trees and other Yucca sp., visitors should curb the impulse to dig through the fallen trees and branches to find desert night lizards (Xantusia vigilis). Everything in the park is protected by National Park laws.


Public Lands – Responsible Use

  The majority of the Mojave Desert is on public lands that often require permits issued by state wildlife agencies to handle herps. Always familiarize yourself with and obey local, state, and federal wildlife use and handling regulations. Although it is never appropriate to harass an animal, brief periods of capture and gentle handling for closer examination do not usually cause any lasting harm.

Public Land in the Mojave

Although often difficult to access, public lands provide some great herping in the Mojave.

  These lands may be more difficult to access without a four-wheel drive or high-clearance vehicle to navigate the countless dirt roads and trails that lead far from the signs of tourists, or anyone else for that matter. Always observe local land use regulations and stay on designated routes.

  While there are seemingly countless areas to explore, described below are some of the best for herping:

  When driving on Interstate 15 between Las Vegas and San Bernadino, nearly any exit will lead into prime Mojave scrublands – great herping on the flatlands.

  The old mining roads off the major roadways north of Las Vegas lead to some very rugged and herp-rich mountains with beautiful geology and landscapes. This is an excellent location for finding collared lizards (Crotaphytus bicinctores) and the best place to find Great Basin rattlesnakes (Crotalus oreganus lutosus).

  The mountains and valleys between the Spring Mountains and Death Valley are also gorgeous and excellent places for herping. The Panamint rattlesnake (Crotalus stephensi), for example, can be found in places such as the Pahrump and Chicago Valleys and the Resting Spring and Nopah Ranges.

  The Virgin River, much of which runs through public lands before it enters the LMNRA, is a relatively small river and a tributary of the Colorado. Its slow-flowing waters and backwaters form riparian areas that are home to many of the amphibian species of the Mojave. Additionally, many “fringe” species of the Mojave are associated with the Virgin River and its adjacent habitats.

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