Chuckwallas are

lizard Lizard is the common name used for all Squamata, squamate reptiles other than snakes (and to a lesser extent amphisbaenians), encompassing over 7,000 species, ranging across all continents except Antarctica, as well as most Island#Oceanic isla ...

s found primarily in arid regions of the southwestern United States and northern Mexico. Some are found on coastal islands. The five species of chuckwallas are all placed within the

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

''Sauromalus''; they are part of the iguanid

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Iguanidae The Iguanidae is a family of lizards composed of the iguanas, chuckwallas, and their prehistoric relatives, including the widespread green iguana. Taxonomy Iguanidae is thought to be the sister group to the Crotaphytidae, collared lizards (fam ...

Taxonomy and etymology

The generic name, ''Sauromalus'', is said to be a combination of two

ancient Greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...

words: ''sauros'' meaning "lizard" and ''homalos'' (ὁμαλός) meaning "flat". The common name "chuckwalla" derives from the

Shoshone The Shoshone or Shoshoni ( or ), also known by the endonym Newe, are an Native Americans in the United States, Indigenous people of the United States with four large cultural/linguistic divisions: * Eastern Shoshone: Wyoming * Northern Shoshon ...

word ''tcaxxwal'' or Cahuilla ''čaxwal'', transcribed by

Spaniards Spaniards, or Spanish people, are a Romance-speaking ethnic group native to the Iberian Peninsula, primarily associated with the modern nation-state of Spain. Genetically and ethnolinguistically, Spaniards belong to the broader Southern a ...

as ''chacahuala''.

Extant species

Description

Chuckwallas are stocky, wide-bodied lizards with flattened midsections and prominent bellies. Their tails are thick, tapering to a blunt tip. Loose folds of skin characterize the neck and sides of their bodies, which are covered in small, coarsely granular scales. The common chuckwalla (''Sauromalus ater'') measures long, whereas insular species such as the

San Esteban chuckwalla The San Esteban chuckwalla (''Sauromalus varius''), also known as the piebald chuckwalla or pinto chuckwalla, is a species of chuckwalla belonging to the family Iguanidae endemic to San Esteban Island in the Gulf of California. It is the largest ...

of San Esteban Island (''Sauromalus varius'') can measure as long as They are

sexually dimorphic Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...

, with males having reddish-pink to orange, yellow, or light gray bodies and black heads, shoulders, and limbs; females and juveniles have bodies with scattered spots or contrasting bands of light and dark in shades of gray or yellow. Males are generally larger than females and possess well-developed femoral pores located on the inner sides of their thighs; these pores produce secretions believed to play a role in marking

territory A territory is an area of land, sea, or space, belonging or connected to a particular country, person, or animal. In international politics, a territory is usually a geographic area which has not been granted the powers of self-government, ...

Range, habitat, and diet

The genus ''Sauromalus'' has a wide distribution in

biome A biome () is a distinct geographical region with specific climate, vegetation, and animal life. It consists of a biological community that has formed in response to its physical environment and regional climate. In 1935, Tansley added the ...

s of the Sonoran and

Mojave Desert The Mojave Desert (; ; ) is a desert in the rain shadow of the southern Sierra Nevada mountains and Transverse Ranges in the Southwestern United States. Named for the Indigenous peoples of the Americas, indigenous Mohave people, it is located pr ...

s. The common chuckwalla ('' S. ater'') is the species with the greatest range, found from southern

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

east to southern

Nevada Nevada ( ; ) is a landlocked state in the Western United States. It borders Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the seventh-most extensive, th ...

and

Utah Utah is a landlocked state in the Mountain states, Mountain West subregion of the Western United States. It is one of the Four Corners states, sharing a border with Arizona, Colorado, and New Mexico. It also borders Wyoming to the northea ...

and western

Arizona Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the nort ...

, and south to

Baja California Baja California, officially the Free and Sovereign State of Baja California, is a state in Mexico. It is the northwesternmost of the 32 federal entities of Mexico. Before becoming a state in 1952, the area was known as the North Territory of B ...

and northwestern Mexico. The peninsular chuckwalla (''S. australis'') is found on the eastern portion of the southern half of the Baja California Peninsula. The other species are island-dwelling, so have much more restricted distributions. The

Angel Island chuckwalla The Angel Island chuckwalla (''Sauromalus hispidus''), also known as the spiny chuckwalla, is a species of chuckwalla lizard belonging to the family Iguanidae endemic to Isla Ángel de la Guarda (Guardian Angel Island) in the Gulf of California. T ...

(''S. hispidus'') is found on

Isla Ángel de la Guarda Isla Ángel de la Guarda, (Guardian Angel Island) also called Archangel Island, is a large uninhabited island in the Gulf of California (Sea of Cortez) east of Bahía de los Ángeles in northwestern Mexico, separated from the Baja Peninsula, Baja ...

and surrounding islands off the coast of the Baja California Peninsula. Two rare and

endangered species An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...

are the Montserrat chuckwalla (''S. slevini'') found on Islas Carmen, Coronados, and Montserrat in the southern

Gulf of California The Gulf of California (), also known as the Sea of Cortés (''Mar de Cortés'') or Sea of Cortez, or less commonly as the Vermilion Sea (''Mar Vermejo''), is a marginal sea of the Pacific Ocean that separates the Baja California peninsula from ...

and the San Esteban chuckwalla or painted chuckwalla (''S. varius'') found on San Esteban Island, Lobos, and Pelicanos. Chuckwallas prefer

lava flow Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a Natural satellite, moon onto its surface. Lava may be erupted at a volcano or through a Fissure vent, fractu ...

s and rocky areas typically vegetated by creosote bush and other such drought-tolerant scrub. The lizards may be found at elevations up to 4,500 ft (1,370 m). Primarily

herbivorous A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat n ...

, chuckwallas feed on leaves, fruit, and flowers of annuals and

perennial plant In horticulture, the term perennial (''wikt:per-#Prefix, per-'' + ''wikt:-ennial#Suffix, -ennial'', "through the year") is used to differentiate a plant from shorter-lived annual plant, annuals and biennial plant, biennials. It has thus been d ...

insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...

s represent a supplementary prey. The lizards are said to prefer yellow flowers, such as those of the brittlebush (''Encelia farinosa'').

Behavior and reproduction

Harmless to humans, these lizards are known to run from potential threats. When disturbed, a chuckwalla wedges itself into a tight rock crevice and inflates its lungs to entrench itself.Stebbins, Robert C., (2003) ''A Field Guide to Western Reptiles and Amphibians'', 3rd Edition. Houghton Mifflin Company, Males are seasonally and conditionally territorial; an abundance of resources tends to create a hierarchy based on size, with one large male dominating the area's smaller males. Chuckwallas use a combination of color and physical displays, namely "push-ups", head-hobbing, and gaping of the mouth, to

communicate Communication is commonly defined as the transmission of information. Its precise definition is disputed and there are disagreements about whether unintentional or failed transmissions are included and whether communication not only transmit ...

and defend their territory. Chuckwallas are diurnal animals and as they are

ectotherm An ectotherm (), more commonly referred to as a "cold-blooded animal", is an animal in which internal physiological sources of heat, such as blood, are of relatively small or of quite negligible importance in controlling body temperature.Dav ...

ic, spend much of their mornings and winter days basking. These lizards are well adapted to desert conditions; they are active at temperatures up to . Chuckwallas hibernate during cooler months and emerge in February. Juveniles emerge first, then adults, as temperatures reach around . Mating occurs from April to July, with five to 16 eggs laid between June and August. The eggs hatch in late September. Chuckwallas may live for 25 years or more. File:Male Chuckwalla.JPG, Large male chuckwalla, picture taken in the White Tank Mountains near Surprise, AZ File:Chuckwalla.jpg, Adult chuckwalla of the Sonoran Desert File:Juvenile Chuckwalla.jpg, Juvenile chuckwalla of the Sonoran Desert File:Chuckwalla(landers ca).jpg, Adult chuckwalla of the Mojave Desert File:Basking Chuckwalla.jpg, Large male common chuckwalla in Joshua Tree National Park File:Chuckwalla Sneezing.jpg, A chuckwalla sneezing salt in Anza-Borrego Desert State Park File:Chuckwalla baby.jpg, Baby Chuckwalla, Titus Canyon, Death Valley National Park

Human use

The

Seri people The Seri or ''Comcaac'' people are an Indigenous group of the Mexican state of Sonora. The majority reside on the Seri communal property (), in the towns of Punta Chueca () and El Desemboque () on the mainland coast of the Gulf of California ...

considered the Angel Island species of chuckwalla an important food item.Richard Felger and Mary B. Moser (1985) ''People of the desert and sea: ethnobotany of the Seri Indians'' Tucson: University of Arizona Press. They are believed to have translocated the lizards to most of the islands in Bahia de los Angeles for use as a food source in times of need.

References

External links

*ARKive
images and movies of the San Esteban Island chuckwalla ''(Sauromalus varius)''
{{Authority control Reptile genera Lizards of North America Reptiles of Mexico Fauna of the Colorado Desert Reptiles of the United States Taxa named by Auguste Duméril