Chuckwalla
Encyclopedia
Chuckwallas are large lizard
s found primarily in arid regions of the southwestern United States
and northern Mexico
. Some are found on coastal islands. There are five species of chuckwallas, all within the genus
Sauromalus; they are part of the iguanid family
, Iguanidae
.
name, Sauromalus, is a combination of two Ancient Greek
words:σαῦρος (sauros) meaning "lizard". and ομαλυς (omalus) meaning "flat". The common name chuckwalla derives from the Shoshone
word "tcaxxwal" or Cahuilla
"caxwal", transcribed by Spaniards
as "chacahuala".
(Sauromalus ater) measures 40 cm in length whereas insular species such as the giant chuckwalla of San Esteban Island
(Sauromalus varius) can measure as much as 76 cm in total length.
They are sexually dimorphic
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 and possess well-developed femoral pore
s located on the inner sides of their thighs; these pores produce secretions believed to play a role in marking territory
.
s of the Sonoran
and Mojave Desert
s. The common chuckwalla (Sauromalus ater
) is the species with the greatest range, found from southern California
east to southern Nevada
and Utah
, western Arizona
and south to Baja California
and northwestern Mexico. The peninsular chuckwalla
(Sauromalus australis) is found on the eastern portion of the southern half of the Baja California peninsula
.
The other species are island-dwelling and therefore have much more restricted distributions. The Angel Island chuckwalla
(Sauromalus hispidus) is found on Isla Ángel de la Guarda
and surrounding islands off the coast of the Baja California peninsula. Two rare and endangered species
are the Montserrat chuckwalla
(Sauromalus slevini) found on Islas Carmen, Coronados and Montserrat in the southern Gulf of California
and the San Esteban chuckwalla
or painted chuckwalla (Sauromalus varius) found on San Esteban Island
, Lobos and Pelicanos.
Chuckwallas prefer lava flows and rocky areas. These areas are typically vegetated by creosote bush
and other such drought-tolerant scrub. The lizards may be found at elevations of up to 4,500 feet (1,370 m).
Primarily herbivorous
, chuckwallas feed on leaves, fruit and flowers of annual
s and perennial plant
s; insect
s represent a supplementary prey. The lizards are said to prefer yellow flowers, such as those of the brittlebush (Encelia farinosa).
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 communication
).
Chuckwallas are diurnal
animals and as they are ectotherm
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, Juveniles emerge first, then adults, as tempatures reach around 90 °F. Chuckwallas hibernate
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.
species of chuckwalla an important food item. It is believed they translocated the lizards to most of the islands in Bahia de los Angeles
for use as a food source in times of need.
Lizard
Lizards are a widespread group of squamate reptiles, with nearly 3800 species, ranging across all continents except Antarctica as well as most oceanic island chains...
s found primarily in arid regions of the southwestern United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
and northern Mexico
Mexico
The 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 chuckwallas, all within the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Sauromalus; they are part of the iguanid family
Family (biology)
In 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. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
, Iguanidae
Iguanidae
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 et...
.
Taxonomy and etymology
The genericGenera
Genera 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 Greek
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being 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 Shoshone
Shoshone
The Shoshone or Shoshoni are a Native American tribe in the United States with three large divisions: the Northern, the Western and the Eastern....
word "tcaxxwal" or Cahuilla
Cahuilla
The Cahuilla, Iviatim in their own language, are Indians with a common culture whose ancestors inhabited inland areas of southern California 2,000 years ago. Their original territory included an area of about . The traditional Cahuilla territory was near the geographic center of Southern California...
"caxwal", transcribed by Spaniards
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
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 chuckwallaSauromalus ater
The 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 Island
San Esteban Island
San 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 dimorphic
Sexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
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 and possess well-developed femoral pore
Femoral pore
Femoral pores are a part of a holocrine secretory gland found on the inside of the thighs of certain lizards and amphisbaenians which releases pheromones to attract mates or mark territory. In certain species only the male has these pores and in other species, both sexes have them, with the males...
s located on the inner sides of their thighs; these pores produce secretions believed to play a role in marking territory
Territory (animal)
In ethology 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 biomeBiome
Biomes are climatically and geographically defined as similar climatic conditions on the Earth, such as communities of plants, animals, and soil organisms, and are often referred to as ecosystems. Some parts of the earth have more or less the same kind of abiotic and biotic factors spread over a...
s of the Sonoran
Sonoran Desert
The 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. It is one of the largest and hottest...
and Mojave Desert
Mojave Desert
The Mojave 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. The common chuckwalla (Sauromalus ater
Sauromalus ater
The 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...
) is the species with the greatest range, found from southern California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
east to southern Nevada
Nevada
Nevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...
and Utah
Utah
Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...
, western Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
and south to Baja California
Baja California
Baja California officially Estado Libre y Soberano de Baja California is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is both the northernmost and westernmost state of Mexico. Before becoming a state in 1953, the area was known as the North...
and northwestern Mexico. The peninsular chuckwalla
Peninsular Chuckwalla
The peninsular chuckwalla is a lizard belonging to the family Iguanidae. It is in the same genus as the other chuckwalla species. S...
(Sauromalus australis) is found on the eastern portion of the southern half of the Baja California peninsula
Baja California Peninsula
The Baja California peninsula , is a peninsula in northwestern Mexico. Its land mass separates the Pacific Ocean from the Gulf of California. The Peninsula extends from Mexicali, Baja California in the north to Cabo San Lucas, Baja California Sur in the south.The total area of the Baja California...
.
The other species are island-dwelling and therefore have much more restricted distributions. The Angel Island chuckwalla
Angel Island Chuckwalla
The 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) is found on Isla Ángel de la Guarda
Isla Ángel de la Guarda
Isla Ángel de la Guarda, also called Archangel Island, and called Xazl Iimt east of Bahía de los Ángeles, and separated from the Baja California Peninsula by the Canal de Ballenas . It is the second largest of the eleven Midriff Islands or Islas Grandes. It is part of the state of Baja California,...
and surrounding islands off the coast of the Baja California peninsula. Two rare and endangered species
Endangered species
An 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...
are the Montserrat chuckwalla
Sauromalus slevini
The 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 California
Gulf of California
The Gulf of California is a body of water that separates the Baja California Peninsula from the Mexican mainland...
and the San Esteban chuckwalla
San Esteban Chuckwalla
The 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 Island
San Esteban Island
San 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.
Creosote bush
Larrea tridentata is known as Creosote bush as a plant, chaparral as a medicinal herb, and as "gobernadora" in Mexico, Spanish for "governess," due to its ability for inhibiting the growth of nearby plants to have more water. In Sonora, it is more commonly called "hediondilla." It is a flowering...
and other such drought-tolerant scrub. The lizards may be found at elevations of up to 4,500 feet (1,370 m).
Primarily herbivorous
Herbivore
Herbivores are organisms that are anatomically and physiologically adapted to eat plant-based foods. Herbivory is a form of consumption in which an organism principally eats autotrophs such as plants, algae and photosynthesizing bacteria. More generally, organisms that feed on autotrophs in...
, chuckwallas feed on leaves, fruit and flowers of annual
Annual plant
An 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 plant
Perennial plant
A perennial plant or simply perennial is a plant that lives for more than two years. The term is often used to differentiate a plant from shorter lived annuals and biennials. The term is sometimes misused by commercial gardeners or horticulturalists to describe only herbaceous perennials...
s; insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
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 will wedge itself into a tight rock crevice and inflate its lungs 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 communication
Animal communication
Animal 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, is sometimes called Zoosemiotics has played an important part in the...
).
Chuckwallas are diurnal
Diurnal animal
Diurnality is a plant or animal behavior characterized by activity during the day and sleeping at night.-In animals:Animals that are not diurnal might be nocturnal or crepuscular . Many animal species are diurnal, including many mammals, insects, reptiles and birds...
animals and as they are ectotherm
Ectotherm
An ectotherm, from the Greek εκτός "outside" and θερμός "hot", 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, Juveniles emerge first, then adults, as tempatures reach around 90 °F. Chuckwallas hibernate
Hibernation
Hibernation is a state of inactivity and metabolic depression in animals, characterized by lower body temperature, slower breathing, and lower metabolic rate. Hibernating animals conserve food, especially during winter when food supplies are limited, 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’ac (Seri) considered the Angel IslandIsla Ángel de la Guarda
Isla Ángel de la Guarda, also called Archangel Island, and called Xazl Iimt east of Bahía de los Ángeles, and separated from the Baja California Peninsula by the Canal de Ballenas . It is the second largest of the eleven Midriff Islands or Islas Grandes. It is part of the state of Baja California,...
species of chuckwalla an important food item. It is believed they translocated the lizards to most of the islands in Bahia de los Angeles
Bahía de los Ángeles
' is a coastal bay on the Sea of Cortez, located along the eastern shore of the Baja California Peninsula in the state of Baja California, Mexico...
for use as a food source in times of need.