Articles on this page are available in 1 other language: Spanish (10) (learn more)

Overview

Brief Summary

Biology

This diurnal lizard emerges in the morning and basks in the sun to raise its body temperature before foraging for food (8). Chuckwallas are primarily herbivorous, feeding on a variety of fruit, leaves, buds, succulent stems and flowers (8), with some species supplementing their diet with the occasional insect (7). When danger is sensed, chuckwallas display a unique defensive strategy of evading a potential predator. The threatened animal scurries into a rock crevice wherein it firmly lodges itself by inflating its lungs, thereby making removal by a predator almost impossible (5) (8). Relatively little is known about the reproductive biology of the San Esteban Island chuckwalla. Chuckwallas generally lay a clutch of between 5 and 16 eggs in June to perhaps August, although some females may not lay eggs every year (7).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Wildscreen

Source: ARKive

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Description

This plump lizard can grow up to 60 centimetres, making it by far the largest of the chuckwallas (Sauromalus), and similar in size to its large iguana relatives (4) (5). This is a prime example of 'insular gigantism', the tendency of small mainland animals to increase in size once established on an island due to fewer natural predators (2) (4). The chuckwalla's grainy, sand-coloured skin is splotched with shadowy grey blotches over the entire body, providing almost perfect camouflage against potential predators in its rocky habitat. Sadly, this lizard's large size, rather small head, loose, gathered folds of skin, and long, thick, blunt tail means that it has sometimes been mistaken for the poisonous gila monster, and persecuted as such (6).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Wildscreen

Source: ARKive

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Distribution

Continent: Middle-America
Distribution: Mexico (Gulf of California: San Esteban, Roca Lobos, Pelicano)
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Peter Uetz

Source: The Reptile Database

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Historic Range:
Mexico

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Range

Found only on the small islands of San Esteban, Roca Lobos and Pelicanos in the Gulf of California (4).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Wildscreen

Source: ARKive

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Physical Description

Type Information

Holotype for Sauromalus varius
Catalog Number: USNM 64441
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Preparation: Ethanol
Year Collected: 1911
Locality: San Esteban Island, Gulf of California, Isla San Esteban, Sonora, Mexico
Vessel: U.S.S. "Albatross"
  • Holotype: Dickerson, M. C. 1919. Bull. Amer. Mus. Nat. Hist. 41 (10): 464.
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles

Source: National Museum of Natural History Collections

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Paratype for Sauromalus varius
Catalog Number: USNM 64570
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Preparation: Ethanol
Year Collected: 1911
Locality: San Esteban Island (= Isla San Esteban), Isla San Esteban, Sonora, Mexico
Vessel: U.S.S. "Albatross"
  • Paratype: Dickerson, M. C. 1919. Bull. Amer. Mus. Nat. Hist. 41 (10): 464.
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles

Source: National Museum of Natural History Collections

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Paratype for Sauromalus varius
Catalog Number: USNM 64569
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Preparation: Ethanol
Year Collected: 1911
Locality: San Esteban Island (= Isla San Esteban), Isla San Esteban, Sonora, Mexico
Vessel: U.S.S. "Albatross"
  • Paratype: Dickerson, M. C. 1919. Bull. Amer. Mus. Nat. Hist. 41 (10): 464.
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles

Source: National Museum of Natural History Collections

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Paratype for Sauromalus varius
Catalog Number: USNM 64568
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Preparation: Ethanol
Year Collected: 1911
Locality: San Esteban Island (= Isla San Esteban), Isla San Esteban, Sonora, Mexico
Vessel: U.S.S. "Albatross"
  • Paratype: Dickerson, M. C. 1919. Bull. Amer. Mus. Nat. Hist. 41 (10): 464.
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles

Source: National Museum of Natural History Collections

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Paratype for Sauromalus varius
Catalog Number: USNM 64567
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Preparation: Ethanol
Year Collected: 1911
Locality: San Esteban Island (= Isla San Esteban), Isla San Esteban, Sonora, Mexico
Vessel: U.S.S. "Albatross"
  • Paratype: Dickerson, M. C. 1919. Bull. Amer. Mus. Nat. Hist. 41 (10): 464.
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles

Source: National Museum of Natural History Collections

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Paratype for Sauromalus varius
Catalog Number: USNM 64566
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Preparation: Ethanol
Year Collected: 1911
Locality: San Esteban Island (= Isla San Esteban), Isla San Esteban, Sonora, Mexico
Vessel: U.S.S. "Albatross"
  • Paratype: Dickerson, M. C. 1919. Bull. Amer. Mus. Nat. Hist. 41 (10): 464.
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles

Source: National Museum of Natural History Collections

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Paratype for Sauromalus varius
Catalog Number: USNM 64565
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Preparation: Ethanol
Year Collected: 1911
Locality: San Esteban Island (= Isla San Esteban), Isla San Esteban, Sonora, Mexico
Vessel: U.S.S. "Albatross"
  • Paratype: Dickerson, M. C. 1919. Bull. Amer. Mus. Nat. Hist. 41 (10): 464.
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles

Source: National Museum of Natural History Collections

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Paratype for Sauromalus varius
Catalog Number: USNM 64564
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Preparation: Ethanol
Year Collected: 1911
Locality: San Esteban Island (= Isla San Esteban), Isla San Esteban, Sonora, Mexico
Vessel: U.S.S. "Albatross"
  • Paratype: Dickerson, M. C. 1919. Bull. Amer. Mus. Nat. Hist. 41 (10): 464.
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles

Source: National Museum of Natural History Collections

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Paratype for Sauromalus varius
Catalog Number: USNM 64563
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Preparation: Ethanol
Year Collected: 1911
Locality: San Esteban Island (= Isla San Esteban), Isla San Esteban, Sonora, Mexico
Vessel: U.S.S. "Albatross"
  • Paratype: Dickerson, M. C. 1919. Bull. Amer. Mus. Nat. Hist. 41 (10): 464.
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles

Source: National Museum of Natural History Collections

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Paratype for Sauromalus varius
Catalog Number: USNM 64562
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Preparation: Ethanol
Year Collected: 1911
Locality: San Esteban Island (= Isla San Esteban), Isla San Esteban, Sonora, Mexico
Vessel: U.S.S. "Albatross"
  • Paratype: Dickerson, M. C. 1919. Bull. Amer. Mus. Nat. Hist. 41 (10): 464.
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles

Source: National Museum of Natural History Collections

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Paratype for Sauromalus varius
Catalog Number: USNM 64561
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Preparation: Ethanol
Year Collected: 1911
Locality: San Esteban Island (= Isla San Esteban), Isla San Esteban, Sonora, Mexico
Vessel: U.S.S. "Albatross"
  • Paratype: Dickerson, M. C. 1919. Bull. Amer. Mus. Nat. Hist. 41 (10): 464.
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles

Source: National Museum of Natural History Collections

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Paratype for Sauromalus varius
Catalog Number: USNM 64560
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Preparation: Ethanol
Year Collected: 1911
Locality: San Esteban Island (= Isla San Esteban), Isla San Esteban, Sonora, Mexico
Vessel: U.S.S. "Albatross"
  • Paratype: Dickerson, M. C. 1919. Bull. Amer. Mus. Nat. Hist. 41 (10): 464.
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles

Source: National Museum of Natural History Collections

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Paratype for Sauromalus varius
Catalog Number: USNM 64571
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Preparation: Ethanol
Year Collected: 1911
Locality: San Esteban Island (= Isla San Esteban), Isla San Esteban, Sonora, Mexico
Vessel: U.S.S. "Albatross"
  • Paratype: Dickerson, M. C. 1919. Bull. Amer. Mus. Nat. Hist. 41 (10): 464.
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles

Source: National Museum of Natural History Collections

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Ecology

Habitat

Chuckwallas occupy open flats, rocky outcrops, dry canyons and washes, often being found near large rocks and boulders (7) (8).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Wildscreen

Source: ARKive

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Life History and Behavior

Life Expectancy

Lifespan, longevity, and ageing

Maximum longevity: 11.3 years (captivity)
Creative Commons Attribution 3.0 (CC BY 3.0)

© Joao Pedro de Magalhaes

Source: AnAge

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Conservation

Conservation Status

Current Listing Status Summary

Status: Endangered
Date Listed: 03/20/1980
Lead Region: Foreign (Region 10) 
Where Listed: Entire


Population detail:

Population location: Entire
Listing status: E

For most current information and documents related to the conservation status and management of Sauromalus varius , see its USFWS Species Profile

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Status

This species is yet to be classified by the IUCN, but is listed on Appendix I of CITES (3).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Wildscreen

Source: ARKive

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Threats

The precise threats to the San Esteban Island chuckwalla are unknown, although historically it has been widely captured for the burgeoning United States pet trade (6).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Wildscreen

Source: ARKive

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Management

Conservation

Chuckwallas have been maintained in captivity at the Arizona-Sonora Desert Museum (ASDM) since 1977 (9), where there have been ongoing studies of the species' behaviour and reproductive biology within the large breeding colony held there (10). The San Esteban Island chuckwalla is listed on Appendix I of CITES, banning all international trade in the species (3).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Wildscreen

Source: ARKive

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Wikipedia

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 Iguanidae family endemic to San Esteban Island in the Sea of Cortés. It is the largest of the five species of chuckwallas and the most endangered.

Taxonomy and etymology[edit]

The generic name, Sauromalus, is a combination of two Ancient Greek words:σαῦρος (sauros) meaning "lizard". and ομαλυς (omalus) meaning "flat".[2] Its specific name varius is Latin for "speckled," in reference to the chuckwalla's mottled coloration.[3][4] It was first described by American herpetologist Mary C. Dickerson in 1919.[5]

The common name chuckwalla derives from the Shoshone word "tcaxxwal" or Cahuilla "caxwal", transcribed by Spaniards as "chacahuala". The Seri people named originally the island for this species: Coftécöl lifa or the Peninsula of the Giant Chuckwalla.[6]

Distribution and habitat[edit]

The San Esteban chuckwalla is endemic to San Esteban Island in the Sea of Cortés.[3] While it is abundant on this small island, it occurs naturally nowhere else and is protected under the Endangered Species Act. At one time the Seri translocated populations of this lizard to other islands in the Sea of Cortés as a food item, however, none of these populations have survived beyond the original population found on San Esteban.[6]

Behavior and reproduction[edit]

Harmless to humans, these large lizards are known to run from potential threats.[7] When disturbed, the chuckwalla will wedge itself into a tight rock crevice, gulp air, and inflate its body in order to entrench itself.[7]

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.[7] 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).[7]

Chuckwallas are diurnal animals and as they are ectothermic, spend much of their mornings and winter days basking in the sun.[7] These lizards are well adapted to desert conditions; they are active at temperatures of up to 102°F (39°C).[7]

Mating occurs from April to July, with 5–16 eggs laid between June and August. The eggs hatch in late September.[7] San Esteban chuckwallas may live for 25 years or more.

Diet[edit]

Chuckwallas prefer dwelling in lava flows and rocky areas with nooks and crannies available for a retreat when threatened. These areas are typically vegetated by creosote bush and cholla cacti which form the staple of their diet as the chuckwalla is primarily herbivorous. Chuckwallas also feed on leaves, fruit and flowers of annuals, perennial plants, and even weeds; insects represent a supplementary prey if eaten at all.

Description[edit]

Sauromalus varius at St Louis Zoo.

The San Esteban chuckwalla is the largest species of chuckwalla reaching 61 centimetres (24 in) in body length, 76 centimetres (30 in) overall length and weighing up to 1.4 kilograms (3.1 lb).[3] It is considered a textbook example of island gigantism as it is 3 to 4 times the size of its mainland counterparts.[3] Their skin is gray with tan to yellow patches over their entire bodies, and their faces are gray to black. Females are duller in appearance with less patches. Their colorations provide almost perfect camouflage against some of their predators.

Human contact[edit]

The Seri considered this species of chuckwalla an important food item due to its large size.[8] The tribe of Seri who once inhabited San Esteban Island referred to themselves as Coftécöl Comcáac, "People of the Giant Chuckwalla" and named the island for this species.[6]

The San Esteban chuckwalla is an endangered species due to hunting from the Seri and the introduction of feral animals such as rats and mice which prey upon the chuckwalla's eggs and feral dogs and cats which prey upon the lizards.[6] Due to these factors and overcollection from the pet trade, the species was declared an Appendix I animal under CITES.

There is an in situ chuckwalla captive breeding program in Punta Chueca, a Seri village on the Mexican mainland.[6] A successful ex situ program has also been in place at the Arizona-Sonora Desert Museum since 1977. The species is present in private collections and is often crossbred with the smaller Angel Island chuckwalla.

References[edit]

  1. ^ "Sauromalus varius". Integrated Taxonomic Information System. Retrieved 26 September 2008. 
  2. ^ Schwenkmeyer, Dick. "Sauromalus ater Common Chuckwalla". Field Guide. San Diego Natural History Museum. Retrieved 17 September 2008. 
  3. ^ a b c d Case, T. J. (1982). "Ecology and evolution of insular gigantic chuckwallas, Sauromalus hispidus and Sauromalus varius". Iguanas of the World (Park Ridge, New Jersey: Noyes Publications). pp. 184–212. ISBN 0-8155-0917-0. 
  4. ^ Hollingsworth, Bradford D. (2004). "The Evolution of Iguanas an Overview and a Checklist of Species". Iguanas: Biology and Conservation (University of California Press). pp. 43–44. ISBN 978-0-520-23854-1. 
  5. ^ Dickerson, M. C. (1919). Diagnoses of twenty-three new species and a new genus of lizards from Lower California. Bulletin of the American Museum of Natural History. 41 (10): 461–477
  6. ^ a b c d e Nabhan, Gary (2003). Singing the Turtles to Sea: The Comcáac (Seri) Art and Science of Reptiles. University of California Press. p. 350. ISBN 0-520-21731-4. 
  7. ^ a b c d e f g Stebbins, Robert C.,(2003) A Field Guide to Western Reptiles and Amphibians, 3rd Edition. Houghton Mifflin Company, ISBN 0-395-98272-3
  8. ^ Richard Felger and Mary B. Moser (1985) People of the desert and sea: ethnobotany of the Seri Indians Tucson: University of Arizona Press.
Creative Commons Attribution Share Alike 3.0 (CC BY-SA 3.0)

Source: Wikipedia

Unreviewed

Article rating from 0 people

Default rating: 2.5 of 5

Disclaimer

EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.

To request an improvement, please leave a comment on the page. Thank you!