Desert iguana
Encyclopedia
The desert iguana is one of the most common lizard
s of the Sonoran
and Mojave desert
s of the southwestern United States
and northwestern Mexico
. They also occur on several Gulf of California
islands.
and Charles Frédéric Girard
, in 1853 as Crotaphytus dorsalis it was reclassified two years later as Dipsosaurus dorsalis by Edward Hallowell. The generic
name comes from a combination of two Greek
words meaning "thirsty lizard": "Dipsa" (δίψα) for "thirsty", and "sauros" (σαῦρος) for "lizard". The specific name, "dorsalis", comes from the Latin
word dorsum meaning "back", in reference to a row of enlarged keeled scales
on the middle of the lizard's back which form a crest that extends almost to the tip of its tail. Dipsosaurus is a monotypic
genus with D. dorsalis being its only recognized species.
that become slightly larger as you move down the back. The reticulated pattern gives way to brown spots near the back legs, turning into stripes along the tail. The tail is usually around 1½ times longer than the body from snout to vent. The belly is pale. During the breeding season, the sides become pinkish in both sexes.
is largely contained within the range of the creosote bush, mainly dry, sandy desert scrubland
below 3300 ft (1,005.8 m). It can also be found in rocky streambeds up to 3300 ft. In the southern portion of its range this lizard lives in areas of arid subtropical scrub and tropical deciduous forest
.
These lizards can withstand high temperatures and are out and about after other lizards have retreated into their burrows. They burrow extensively, and will often climb into shrubs for shelter and defense. Their burrows are usually constructed in the mounds of sand that accumulate around the bases of bushes like the creosote. They also often use ready-made burrows of kit fox
es and desert tortoise
s.
s is laid each year, with each clutch having 3-8 eggs. The hatchlings emerge around September.
Desert iguanas are primarily herbivorous
, eating buds, fruit
s and leaves of many annual
and perennial plant
s. They are especially attracted to the yellow flower
s of the creosote bush. They have also been reported to eat insect
s, feces
(mammal
and lizard) and carrion
.
Predators of these iguanas and their eggs are birds of prey
, fox
es, rat
s, Long-tailed Weasel
s, some snake
s, and humans.
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 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 of the southwestern United States
Southwestern United States
The Southwestern United States is a region defined in different ways by different sources. Broad definitions include nearly a quarter of the United States, including Arizona, California, Colorado, Nevada, New Mexico, Oklahoma, Texas and Utah...
and northwestern 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...
. They also occur on several 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...
islands.
Taxonomy
The species was first described in the Catalog of North American Reptiles, by Spencer Fullerton BairdSpencer Fullerton Baird
Spencer Fullerton Baird was an American ornithologist, ichthyologist and herpetologist. Starting in 1850 he was assistant-secretary and later secretary of the Smithsonian Institution in Washington, D.C...
and Charles Frédéric Girard
Charles Frédéric Girard
Charles Frédéric Girard was a French biologist specializing in ichthyology and herpetology.Born in Mulhouse, France, he studied at the College of Neuchâtel, Switzerland as a student of Louis Agassiz. In 1847, he accompanied Agassiz as his assistant to Harvard...
, in 1853 as Crotaphytus dorsalis it was reclassified two years later as Dipsosaurus dorsalis by Edward Hallowell. The generic
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...
name comes from a combination of two Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
words meaning "thirsty lizard": "Dipsa" (δίψα) for "thirsty", and "sauros" (σαῦρος) for "lizard". The specific name, "dorsalis", comes from the Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
word dorsum meaning "back", in reference to a row of enlarged keeled scales
Keeled scales
Keeled scales refer to reptile scales that, rather than being smooth, have a ridge down the center that may or may not extend to the tip of the scale, making them rough to the touch...
on the middle of the lizard's back which form a crest that extends almost to the tip of its tail. Dipsosaurus is a monotypic
Monotypic
In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...
genus with D. dorsalis being its only recognized species.
Description
The desert iguana is a blunt, medium-sized lizard which grows to 16 in (40.6 cm) including the tail. They are pale gray-tan to cream in color with a light brown reticulated pattern on their backs and sides. Down the center of the back is a row of slightly-enlarged, keeled dorsal scalesDorsal scales
In snakes, the dorsal scales are the longitudinal series of plates that encircle the body, but do not include the ventral scales.When counting dorsal scales, numbers are often given for three points along the body, for example 19:21:17...
that become slightly larger as you move down the back. The reticulated pattern gives way to brown spots near the back legs, turning into stripes along the tail. The tail is usually around 1½ times longer than the body from snout to vent. The belly is pale. During the breeding season, the sides become pinkish in both sexes.
Habitat
Their preferred habitatHabitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
is largely contained within the range of the creosote bush, mainly dry, sandy desert scrubland
Deserts and xeric shrublands
Deserts and xeric shrublands is a biome characterized by, relating to, or requiring only a small amount of moisture.-Definition and occurrence:...
below 3300 ft (1,005.8 m). It can also be found in rocky streambeds up to 3300 ft. In the southern portion of its range this lizard lives in areas of arid subtropical scrub and tropical deciduous forest
Tropical and subtropical dry broadleaf forests
The tropical and subtropical dry broadleaf forest biome, also known as tropical dry forest, is located at tropical and subtropical latitudes. Though these forests occur in climates that are warm year-round, and may receive several hundred centimeters of rain per year, they have long dry seasons...
.
These lizards can withstand high temperatures and are out and about after other lizards have retreated into their burrows. They burrow extensively, and will often climb into shrubs for shelter and defense. Their burrows are usually constructed in the mounds of sand that accumulate around the bases of bushes like the creosote. They also often use ready-made burrows of kit fox
Kit Fox
The kit fox is a fox species of North America. Its range is primarily in the southwestern United States and northern and central Mexico. Some mammalogists classify it as conspecific with the swift fox, V. velox, but molecular systematics imply that the two species are distinct.-Range:The...
es and desert tortoise
Desert Tortoise
The desert tortoise is a species of tortoise native to the Mojave desert and Sonoran desert of the southwestern United States and northwestern Mexico. They can be located in western Arizona, southeastern California, southern Nevada, and southwestern Utah. The species name agassizii is in honor of...
s.
Diet and reproduction
Mating takes place in the early spring. It is believed that only one clutch of eggEgg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
s is laid each year, with each clutch having 3-8 eggs. The hatchlings emerge around September.
Desert iguanas are 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...
, eating buds, fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
s and leaves of many 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...
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. They are especially attracted to the yellow flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s of the creosote bush. They have also been reported to eat 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, feces
Feces
Feces, faeces, or fæces is a waste product from an animal's digestive tract expelled through the anus or cloaca during defecation.-Etymology:...
(mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
and lizard) and carrion
Carrion
Carrion refers to the carcass of a dead animal. Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters include vultures, hawks, eagles, hyenas, Virginia Opossum, Tasmanian Devils, coyotes, Komodo dragons, and burying beetles...
.
Predators of these iguanas and their eggs are birds of prey
Bird of prey
Birds of prey are birds that hunt for food primarily on the wing, using their keen senses, especially vision. They are defined as birds that primarily hunt vertebrates, including other birds. Their talons and beaks tend to be relatively large, powerful and adapted for tearing and/or piercing flesh....
, fox
Fox
Fox is a common name for many species of omnivorous mammals belonging to the Canidae family. Foxes are small to medium-sized canids , characterized by possessing a long narrow snout, and a bushy tail .Members of about 37 species are referred to as foxes, of which only 12 species actually belong to...
es, rat
Rat
Rats are various medium-sized, long-tailed rodents of the superfamily Muroidea. "True rats" are members of the genus Rattus, the most important of which to humans are the black rat, Rattus rattus, and the brown rat, Rattus norvegicus...
s, Long-tailed Weasel
Long-tailed Weasel
The long-tailed weasel , also known as the bridled weasel or big stoat is a species of mustelid distributed from southern Canada throughout all the United States and Mexico, southward through all of Central America and into northern South America.-Evolution:The long-tailed weasel is the product of...
s, some snake
Snake
Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...
s, and humans.