The
Chuckwalla (less commonly
chuckawalla) is a large
lizardLizards are a very large and widespread group of squamate reptiles, with nearly 5,000 species, ranging across all continents except Antarctica as well as most oceanic island chains...
found primarily in arid regions of the southwestern
United StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
and northern
MexicoThe United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
. Some are found on coastal islands. There are five species of chuckwalla, all within the
genusIn biology, a genus is a taxonomic unit used in the classification of living and fossil organisms. The term comes from Latin genus "descent, family, type, gender" , cognate with – genos, "race, stock, kin" ..In addition, genus is a taxonomic rank in the hierarchy In biology, a genus (plural:...
Sauromalus; they are part of the iguanid
familyIn biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus...
,
IguanidaeThe Iguanidae is a family of lizards, composed of iguanas and related species.-Classification of iguanidae:Two different classification schemes have been used to define the structure of this family. These are the "traditional" classification and the classification presented by Frost et al. .Frost...
.
Taxonomy and etymology
The
genericGenera is a commercial operating system and development environment for Lisp machines developed by Symbolics. It is essentially a fork of an earlier operating system originating on the MIT AI Lab's Lisp machines which Symbolics had used in common with LMI and Texas Instruments...
name, Sauromalus
, is a combination of two Ancient GreekAncient Greek is the historical stage in the development of the Greek language spanning across the Archaic , Classical , and Hellenistic periods of ancient Greece and the ancient world. It is predated in the 2nd millennium BC by Mycenaean Greek...
words:σαῦρος (sauros) meaning "lizard". and ομαλυς (omalus) meaning "flat". The common name chuckwalla derives from the
ShoshoneThe Shoshone are a Native American tribe in the United States with three large divisions: the Northern, the Western and the Eastern. The Shoshone were sometimes called the Snake by early White trappers, travelers, and settlers....
word "tcaxxwal" or
CahuillaThe Cahuilla are a tribe of Native Americans that have inhabited the U.S. state of California for more than 2,000 years, originally covering an area of about 2,400 square miles . The traditional Cahuilla territory was near the geographic center of Southern California...
"caxwal", transcribed by
SpaniardsSpain , officially the Kingdom of Spain , is a country located in southwestern Europe on the Iberian Peninsula.
[The Spanish constitution does not establish any official denomination of the country, even though España , Estado español and Nación española are used interchangeably...]
as "chacahuala".
Physical description
Chuckwallas are a stocky wide-bodied lizard with a flattened midsection and prominent belly. Their tails are thick, tapering to a blunt tip. Loose folds of skin characterize the neck and sides of the body, which is covered in small, coarsely granular scales. The
common chuckwallaThe Common Chuckwalla is a species of lizard in the family Iguanidae. It inhabits the Sonoran and Mojave Deserts of the southwestern United States and northwestern Mexico...
(Sauromalus ater
) measures 40 cm in length whereas insular species such as the giant chuckwalla of San Esteban IslandSan Esteban Island is a small island in the Gulf of California, Mexico, located to the southwest of Tiburón Island. It is part of the Municipality of Hermosillo in Sonora, and has a land area of 39.773 km² , the 15th-largest island in Mexico. It is located in the Sea of Cortés...
(Sauromalus varius) can measure as much as 76 cm in total length.
They are
sexually dimorphicSexual dimorphism is the systematic difference in form between individuals of different sex in the same species. Examples include colour , size, and the presence or absence of parts of the body used in courtship displays or fights, such as ornamental feathers, horns, antlers or tusks.-Examples:In...
with males having reddish-pink to orange, yellow or light gray bodies and black heads, shoulders and limbs; females and the immature have bodies with scattered spots or contrasting bands of light and dark in shades of gray or yellow. Males are generally larger than females.
Males also possess well-developed femoral
porePore may refer to:In animal biology and microbiology:* Sweat pore, an anatomical structure of the skin of humans used for secretion of sweat...
s located on the inner sides of their thighs; these pores produce secretions believed to play a role in marking
territoryIn ethology, sociobiology and behavioral ecology, the term territory refers to any sociographical area that an animal of a particular species consistently defends against conspecifics...
.
Range, habitat and diet
The genus Sauromalus
has a wide distribution in desertA desert is a landscape or region that receives almost no precipitation. Deserts are defined as areas with an average annual precipitation of less than per year, or as areas where more water is lost by evapotranspiration than falls as precipitation. In the Köppen climate classification system,...
biomeBiome are climatically and geographically defined areas of ecologically similar climatic conditions such as communities of plants, animals, and soil organisms, and are often referred to as ecosystems...
s. This is especially true of the common chuckwalla (Sauromalus aterThe Common Chuckwalla is a species of lizard in the family Iguanidae. It inhabits the Sonoran and Mojave Deserts of the southwestern United States and northwestern Mexico...
), found from southern CaliforniaCalifornia is the most populous state in the United States, and the third largest by area. California is the second most populous sub-national entity in the Americas, behind only São Paulo, Brazil...
east to southern NevadaNevada is a state located in the western region of the United States. The capital is Carson City and the largest city is Las Vegas. The state's nickname is Silver State, due to the large number of silver deposits that were discovered and mined there...
and UtahUtah is a western state of the United States. It was the 45th state admitted to the Union, on January 4, 1896. Approximately 80 percent of Utah's 2,736,424 people live along the Wasatch Front, centering around Salt Lake City. In contrast, vast expanses of the state are nearly uninhabited, making...
, western ArizonaThe State of Arizona is a state located in the southwestern region of the United States. The capital and largest city is Phoenix. The second largest city is Tucson, followed in size by the four Phoenix metropolitan area cities of Mesa, Glendale, Chandler, and Scottsdale.Arizona was the 48th and...
and south to Baja CaliforniaBaja California is both the northernmost and westernmost state of Mexico. Before becoming a state in 1953, the area was known as the North Territory of Baja California. It has an area of , or 3.57% of the land mass of Mexico and comprises the northern half of the Baja California peninsula, north...
and northwestern Mexico.
The other species are island-dwelling and therefore have much more restricted distributions: Two rare and endangered speciesAn endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters. Also it could mean that due to deforestation there may be a lack of food and/or water...
are the Montserrat chuckwallaThe Monserrat Chuckwalla, is a species of chuckwalla belonging to the Iguanidae family native to three small islands in the Sea of Cortes.-Taxonomy and etymology:...
(Sauromalus slevini
) found on Islas Carmen, Coronados and Montserrat in the southern Gulf of CaliforniaThe Gulf of California is a body of water that separates the Baja California Peninsula from the Mexican mainland...
and the San Esteban chuckwallaThe San Esteban chuckwalla is a species of chuckwalla belonging to the Iguanidae family endemic to San Esteban Island in the Sea of Cortés...
or Painted chuckwalla (Sauromalus varius
) found on San Esteban IslandSan Esteban Island is a small island in the Gulf of California, Mexico, located to the southwest of Tiburón Island. It is part of the Municipality of Hermosillo in Sonora, and has a land area of 39.773 km² , the 15th-largest island in Mexico. It is located in the Sea of Cortés...
, Lobos and Pelicanos.
The Angel Island chuckwallaThe Angel Island Chuckwalla is a species of chuckwalla belonging to the Iguanidae family endemic to Isla Ángel de la Guarda in the Sea of Cortés...
(Sauromalus hispidus
) and peninsular chuckwallaThe Peninsular Chuckwalla is a lizard belonging to the Iguanidae family. It is in the same genus as the other Chuckwalla species. S. australis inhabits southeastern Baja California and eastern Baja California Sur in Mexico....
(Sauromalus australis
) are found on Isla Ángel de la GuardaIsla Ángel de la Guarda, also called Archangel Island, and called Xazl Iimt Isla Ángel de la Guarda, also called Archangel Island, and called Xazl Iimt Isla Ángel de la Guarda, also called Archangel Island, and called Xazl Iimt ( 'homes of the pumas' in the Seri language, is a large island in...
and surrounding islands off the coast of the Baja California peninsulaThe Baja California peninsula is a peninsula in western Mexico. It extends some 1250 km from Mexicali, Baja California, in the north to Cabo San Lucas, Baja California Sur, in the south, separating the Pacific Ocean from the Gulf of California...
.
Chuckwallas prefer lava flows and rocky areas, and many more such as those found in the SonoranThe Sonoran Desert is a North American desert which straddles part of the United States-Mexico border and covers large parts of the U.S. states of Arizona and California and the northwest Mexican states of Sonora, Baja California, and Baja California Sur...
and Mojave DesertThe Mojave Desert , , locally referred to as the High Desert, occupies a significant portion of southeastern California and smaller parts of central California, southern Nevada, southwestern Utah and northwestern Arizona, in the United States...
s. These areas are typically vegetated by creosote bushLarrea tridentata, known as creosote bush , is a flowering plant in the family Zygophyllaceae...
and other such drought-tolerant scrub. The lizards may be found at elevations of up to 4,500 feet (1,370 m).
Primarily herbivorousA herbivore is an animal that is adapted to eat plants and not meat.Herbivory is a form of predation in which an organism consumes principally autotrophs such as plants, algae and photosynthesizing bacteria....
, chuckwallas feed on leaves, fruit and flowers of annualAn annual plant is a plant that usually germinates, flowers, and dies in a year or season. True annuals will only live longer than a year if they are prevented from setting seed...
s and perennial plantA perennial plant or perennial is a plant that lives for more than two years. When used by gardeners or horticulturalists, this term applies specifically to perennial herbaceous plants...
s; insectInsects are arthropods, having a hard exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae. They are the most diverse group of animals on the planet and include more than a million species that are already described. Insects represent more than half of all...
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, the chuckwalla will wedge itself into a tight rock crevice, gulp air, and inflate its body in order to entrench itself.
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 colour and physical displays, namely "push ups", head-hobbing, and gaping of the mouth to communicate and defend their territory (see animal communicationAnimal communication is any behavior on the part of one animal that has an effect on the current or future behaviour of another animal. The study of animal communication, sometimes called spencerology has played an important part in the methodology of ethology, sociobiology, and the study of animal...
).
Chuckwallas are diurnalDiurnality is an animal behavior characterized by being active during the day and sleeping at night. Animals that are not diurnal might be nocturnal or crepuscular . Many animal species are diurnal, including many mammals, insects and birds...
animals and as they are ectothermEctothermic, from the Greek ectos, "outside" and therme, "heat," refers to organisms that control body temperature through external means. As a result, organisms are dependent on environmental heat sources and have relatively low metabolic rates. For example, many reptiles regulate their body...
ic, spend much of their mornings and winter days basking. These lizards are well adapted to desert conditions; they are active at temperatures of up to 102°F (39°C). Chuckwallas hibernateHibernation is a state of inactivity and metabolic depression in animals, characterized by lower body temperature, slower breathing, and lower metabolic rate. Hibernating animals conserve energy, especially during winter when food is short, tapping energy reserves, body fat, at a slow rate...
during cooler months and emerge in February.
Mating occurs from April to July, with 5-16 eggs laid between June and August. The eggs hatch in late September. Chuckwallas may live for 25 years or more.
Human use
The Comca’acThe Seris 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...
(Seri) considered the Angel Island species of chuckwalla an important food item. It is believed they translocated the lizards to most of the islands in Bahia de los AngelesThe ' is a bay located along the east side of the Baja California Peninsula, in the state of Baja California, in northwest Mexico. The bay faces the Sea of Cortez, and has a desert climate. It has many islands off the coast, and is famous for its fabulous fishing...
for use as a food source in times of need.
External links