Animal Loop Trail

Desert Tortoise Research Natural Area Virtual Field Trip

Animal Loop Trail

POST #1 Gopher snake, Pituophis melanoleucus
The Desert Tortoise Research Natural Area is home to many species of reptile including several snakes such as this attractively marked Great Basin gopher snake, Pituophis melanoleucus deserticola.Snakes are an important and vital component of the desert ecosystem. Gopher snakes are nonvenomous and feed mainly on kangaroo rats and pocket mice.
POST #2 Sidewinder, Crotalus cerastes
The sidewinder, Crotalus cerastes, is the most frequently encountered rattlesnake at the Desert Tortoise Research Natural Area. It is a small snake of 6 to 30 inches in length.The sandy coloring makes it difficult to see as it frequently coils in a saucer-shaped depression in the soil. Watch carefully for this well camouflaged snake and for its distinctive tracks in washes.As it side winds over soft sand the sidewinder leaves this distinctive pattern of “J” shaped marks
POST #3 Leopard lizard, Gambelia wislizenii
There are many lizards found at the Desert Tortoise Research Natural Area.At the top of the lizard food chain is the spectacular long-nosed leopard lizard, Gambelia wislizenii. The leopard lizard can occasionally be seen chasing down and eating the smaller zebra-tailed lizards which seem to be a favored prey.The orange blotches are most pronounced on gravid females, like this one.
POST #4 Zebra-tailed lizard
The slender-bodied, zebra-tailed lizard, Calisaurus draconoides draconoides, is frequently seen darting across open patches of desert pavement. Built for speed, this small lizard runs with its tail pointing forward over its body. The distinct striped tail may act to deflect the attention of predators away from the body. Like many other lizard species, the zebra-tailed has a fragile joint in the tail which facilitates loss of the tail should a predator seize it. The lizard can regenerate its tail later.
POST #5 Side-blotched lizard, Uta stansburiana
The small side-blotched lizard, Uta stansburianais a common lizard of the arid west.Side-blotched lizards at the Desert Tortoise Research Natural Area are a pretty light-phase color morph. The back of the male is often speckled with pale blue dots like the handsome individual shown here. The females are less colorful and lack the blue speckling.
POST #6 Horned lizard, Phrynosoma platyrhinos
The desert horned lizard, Phrynosoma platyrhinos calidiarum, is often encountered on trails especially in the early morning and afternoon. Despite their distinctive appearance when viewed at close-hand, desert horned lizards are a cryptic species whose coloration provides superb camouflage against the desert floor. Although they eat a variety of invertebrates and even some vegetation they have a predilection for harvester ants, of which the DTRNA boasts 3 species.
POST #7 Ant rings

Recently established
harvester ant colony.

Harvester ants collect and eat the seeds of desert plants. They dispose of the seed cases and husks in a mound encircling the colony entrance. Seeds that were missed and disposed of in this “house cleaning” may germinate the following season to form a 1 to 2 feet diameter “ant ring”.

An “ant ring” of
grasses and forbs.

POST #8 Tarantula, Aphonopelma
The DTRNA is home to several fascinating arachnids such as the turret building wolf spider and the larger tarantula seen here. Male tarantulas especially are most visibly active during the fall. The tarantula may look formidable but the greatest danger from being bitten by this species is infection caused by bacteria in the saliva, rather than its extremely weak venom.
POST #9 Desert mammal signs
Most desert mammals are nocturnal and rarely seen by casual visitors. However, signs of their presence can be seen all around the Desert Tortoise Research Natural Area.Concealed within the base of a creosote bush is this nest of a desert woodrat (Neotoma lepida lepida). Woodrats (or “pack rats” as they are commonly known) build elaborate nests of a variety of materials such as sticks, twigs, stones, animal dung, and other items that they collect. Woodrats often share their residence with lizards.The soil underneath creosote bushes is often pockmarked with animal burrows of different sizes. Generally, the larger holes are occupied by antelope ground squirrels, Mohave ground squirrels, and Merriam kangaroo rats. The smaller holes are made by such species as the long-tailed pocket mouse, little pocket mouse, and grasshopper mouse. Lizards too, may excavate burrows in the shelter of shrubs.Rodent burrow complexes are also often found in and around the abandoned burrows of kit fox and other predators.
POST #10 Mohave ground squirrel
Like the desert tortoise, the Mohave ground squirrel, Spermophilus mohavensis, is listed as threatened under California’s Endangered Species Act.The Mohave ground squirrel is vegetarian with a fondness for fiddleneck (Amsinckia tessellata) and other annuals.For more information visit the Mojave Ground Squirrel page.
POST #11 Kangaroo rat, Dipodomys spp.
Kangaroo rats of the genus Dipodomys are a common feature of the southwestern deserts. Two species occur at the Desert Tortoise Research Natural Area: Merriam’s kangaroo rat, Dipodomys merriami and the Panamint kangaroo rat, D. panamintinus.These rodents are superbly adapted to desert life. They are largely granivorous (seed eating) in diet, and have remarkable fur-lined cheek pouches which they use to carry food back to their burrows.
POST #12 Black-tailed hare
The black-tailed hare, Lepus californicus deserticola, is commonly called a jackrabbit and is the most frequently observed desert mammal. With camouflage provided by gray coloring and the habit of staying still or “frozen”, a hare can remain unseen by predators. The hare is food for kit foxes, coyotes, eagles and other predators.How does this non-burrowing animal keep cool in the hot desert? Behavior patterns such as being active at night and spending the daytime under rocks and bushes help to decrease loss of body water. But it has another cooling mechanism: its magnificent ears radiate heat when environmental conditions are right. Jackrabbits have other complex physiological processes which enable them to tolerate high temperatures. Unlike the kangaroo rats, they cannot survive entirely on dried food, but require some moist food or free water.
POST #13 Major mammalian predators

Coyote
Canis latrans

American badger
Taxidea taxus

Kit fox
Vulpes macrotis

POST #14 Burrowing owl, Speotyto cunicularia
Despite their name, burrowing owls (Speotyto (Athene) cunicularia) don’t dig their own burrows but prefer to adopt vacant tortoise burrows, or kit fox or ground squirrel dens. Unlike most other owls, these small birds are often active during daylight.The owls nest underground, and during the breeding season small family groups may be seen close to their burrows.The burrowing owl population is decreasing and the species is listed as a Species of Special Concern by California Department of Fish and Game.

Photo credits: Kristin H. Berry, Robert D. Berry, Nathan W. Cohen, Michael J. Connor,
Ralph Crane, Susan Moore, Mary H. Shepherd, Beverly Steveson, Laura Stockton

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