The Mojave fringe-toed lizard (''Uma scoparia'') is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of medium-sized, white or grayish, black-spotted diurnal

lizard Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia alt ...

in the family

Phrynosomatidae The Phrynosomatidae are a diverse family of lizards, sometimes classified as a subfamily (Phrynosomatinae), found from Panama to the extreme south of Canada. Many members of the group are adapted to life in hot, sandy deserts, although the spiny ...

. It is adapted to arid climates and is most commonly found in sand dunes within the

Mojave Desert The Mojave Desert ( ; mov, Hayikwiir Mat'aar; es, Desierto de Mojave) is a desert in the rain shadow of the Sierra Nevada mountains in the Southwestern United States. It is named for the indigenous Mojave people. It is located primarily in ...

Fringe-toed lizard Fringe-toed lizards are lizards of the genus ''Uma'' in the family Phrynosomatidae, native to deserts of North America. They are adapted for life in sandy deserts with fringe-like scales on their hind toes hence their common name. Description ...

s are characterized by their fringed scales on their hind toes which make locomotion in loose sand possible.

Description

The Mojave fringe-toed lizard is a flat-bodied lizard with smooth skin. The color of its skin resembles the environment it inhabits, ranging from a tannish white to a grayish white, and likely contains small black spots along its back. On its underside, there are up to three crescent-shaped throat markings which are characteristic of the Mojave fringe-toed lizard. Also characteristic of this species are the dark bands on its tail and dark blotches on the sides of its belly. During breeding season, the dark spots on its belly-sides turn pink, and its underside turns pale-yellow. The length of this lizard's tail matches the length of its body, with the whole organism reaching lengths of around 7 inches long. The males are protective of their territory, as they walk the perimeter of their of their home and exhibit assertion displays. These displays are associated with reproduction rather than resource protection. Females are not seen to protect their territory, but rather exhibit territoriality over a specific site.

Life cycle

The adult form typically hibernates from November to February by burying itself around a foot below the sand. Juveniles hibernate much closer to the surface, but some don't hibernate at all and are active throughout the whole year. During March and April, this species of lizard is active for fewer hours in comparison to its close ''Uma'' relatives due to the cooler temperature of the Mojave desert. The Mojave fringe-toed lizard reaches sexual maturity during its second year, and its mating season is around late spring. The amount of rainfall influences the breeding capacity of the lizard, and females typically lay 1-5 eggs per mating season with an average of 2-3 eggs, hatching in September. There is no seasonal migration in this species. The lizards likely bury their eggs in the sand similar to other lizard species. More young are produced after wet winters, likely due to the abundance of spring annual plants and insects.

Diet

The lizard primarily feeds on

invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...

s which live near the surface such as ants, beetles, scorpions,

hemiptera Hemiptera (; ) is an order (biology), order of insects, commonly called true bugs, comprising over 80,000 species within groups such as the cicadas, aphids, planthoppers, leafhoppers, Reduviidae, assassin bugs, Cimex, bed bugs, and shield bugs. ...

ns, spiders,

antlion The antlions are a group of about 2,000 species of insect in the neuropteran family Myrmeleontidae. They are known for the predatory habits of their larvae, which mostly dig pits to trap passing ants or other prey. In North America, the larvae ...

larvae, and grasshoppers. They are also seen to eat plant matter such as seeds, leaves, flowers, and grasses. As annual plants become less common during the summer months, their diet shifts from primarily herbivorous to insectivorous. Occasionally, they have been observed to eat smaller lizards of different species as well as smaller conspecifics. During mating season, there are differences of behavior in regards to eating. Males have been observed to eat plants and insects during the morning only, while females and juveniles have been observed to eat these at all points in the day.

Geographic range

The Mojave fringe-toed lizard's range extends from

Inyo County Inyo County () is a county in the eastern central part of the U.S. state of California, located between the Sierra Nevada and the state of Nevada. In the 2020 census, the population was 19,016. The county seat is Independence. Inyo County is o ...

Los Angeles County Los Angeles County, officially the County of Los Angeles, and sometimes abbreviated as L.A. County, is the most populous county in the United States and in the U.S. state of California, with 9,861,224 residents estimated as of 2022. It is the ...

Riverside County Riverside County is a county located in the southern portion of the U.S. state of California. As of the 2020 census, the population was 2,418,185, making it the fourth-most populous county in California and the 10th-most populous in the Unit ...

, and

San Bernardino County San Bernardino County (), officially the County of San Bernardino, is a county located in the southern portion of the U.S. state of California, and is located within the Inland Empire area. As of the 2020 U.S. Census, the population was 2,181, ...

in California to western Arizona in

La Paz County La Paz County is the 15th county in the U.S. state of Arizona, located in the western part of the state. As of the 2020 census, its population was 16,557, making it the second-least populous county in Arizona. The county seat is Parker. Th ...

. Most are restricted to areas which have fine sand, dry lake beds, desert washes, and hillsides. The elevational range of their habitat is from sea level up to 3000 ft.

Threats

The Mojave fringe-toed lizard has a number of predators in its environment, consisting of roadrunners, badgers, loggerhead shrikes, coyotes, and various snakes. As these lizards are camouflaged within their surroundings or hidden beneath the surface, many have been killed due to off-roading recreational vehicles. These vehicles also damage the shrubbery which act as a source of food and protection for the lizards. Off-roading has tripled in dune areas since 1999, leading to increased lizard casualties and the decline of their population. Habitat loss can also be attributed to increased toxins from military operations, urban development, air pollution, and global warming.

References

External links

CaliforniaHerps.com page for Mojave fringe-toed lizard.
Includes detailed description and photos.

Close-up image of fringed toes.

Discusses basis and recent history of efforts to protect the lizard. {{Taxonbar, from=Q3016470 Uma Reptiles of the United States Fauna of the Mojave Desert Fauna of Riverside County, California Natural history of Los Angeles County, California Natural history of San Bernardino County, California Reptiles described in 1894 Taxa named by Edward Drinker Cope