Sauromalus ater

Common chuckwalla [1]
Conservation status
Least Concern  (IUCN 3.1) [2]
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Squamata
Suborder:	Iguania
Family:	Iguanidae
Genus:	Sauromalus
Species:	S. ater
Binomial name
Sauromalus ater Dumeril, 1856
Approximate range of S. ater
Synonyms
Sauromalus obesus (Baird, 1859)

Sauromalus ater, also known as the common chuckwalla or northern chuckwalla, is a species of lizard in the family Iguanidae. ^{[2] [3]} It inhabits the Sonoran and Mojave Deserts of the Southwestern United States and northwestern Mexico. Its range extends from eastern California, Utah, and Nevada south to Baja California and Sonora. ^[4]

Taxonomy

The common name "chuckwalla" (or chuckawalla) is derived from the Shoshone word tcaxxwal, or caxwal, the form used by the Cahuilla of southeastern California. ^[5]

Its generic name, Sauromalus, is said to be a combination of two ancient Greek words: sauros meaning "lizard" and omalus meaning "flat". ^[6] The proper ancient Greek word for "flat" is however homalos (ὁμαλός) or homalēs (ὁμαλής). ^[7] Its specific name is ater, Latin for "black" or "dark"

The United States populations of the species were previously known as Sauromalus obesus; although that name is no longer officially recognized, it is still very common in the literature and it remains in many standard natural history references for North America. In 1998, Bradford D. Hollingsworth examined variations in Sauromalus and concluded that only five species should be recognized. He regarded S. obesus as conspecific with S. ater, and he used S. ater, which has priority, as the specific name of the combined taxon. ^[8] Based primarily on the extensive use of the name S. obesus, a petition to give that name precedence over that of S. ater was submitted to the ICZN. ^[8] However, this reasoning was dubious and the priority of S. ater was maintained. ^[8] In 2004, ICZN ruled that the name Sauromalus ater was first described by zoologist Auguste Duméril in 1856, thus had precedence over the name Sauromalus obesus which was not named until 1858 by Baird. ^[8]

Subspecies

Five subspecies are recognized: ^[3]

• Sauromalus ater ater Duméril, 1856
• Sauromalus ater shawi Cliff, 1958
• Sauromalus ater multiforaminatus (Tanner & Avery, 1964)
• Sauromalus ater townsendi Dickerson, 1919
• Sauromalus ater tumidus Shaw, 1945

Description

The common chuckwalla is a large, flat-bodied lizard with a large, rounded belly, and a wide-based, blunt-tipped tail. ^[5] Reaching a total length of 20 in and a weight of 0.9 kg (2.0 lb). ^[9] Small scales cover its body, with larger scales protecting the ear openings. ^[5] The coloration of these lizards varies by location and between juveniles and adults, as well as between males and females. ^[5] In adult males, the head, shoulder, and pelvic regions are black, while the midbody is light tan speckled with brown. ^[5] Adult females are brownish in color with a scattering of dark red spots. Young chuckwallas have four or five broad bands across their bodies, and three or four on the tail which are lost in adulthood by males, but retained somewhat by females. ^[5]

Common chuckwalla Sauromalus ater at Bristol Zoo, England

Behavior

Harmless to humans, these lizards are known to run from potential threats. ^[9] When disturbed, the chuckwalla enters crevices between rocks and inflates its lungs using a gular pump. ^[10] Lung inflation distends its body and wedges the lizard tightly in place. ^[9]

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. ^[9] Chuckwallas use a combination of color and physical displays, namely "push ups", head-hobbing, and gaping of the mouth to communicate and defend their territory. ^[9]

Chuckwallas are diurnal animals, and as they are ectothermic, spend much of their mornings and cooler days basking. ^[9] These lizards are well adapted to desert conditions; they are active at temperatures up to 102 °F (39 °C). ^[9] Chuckwallas brumate during cooler months and emerge in February. ^[9]

Mating occurs from April to July, with five to 16 eggs laid between June and August. The eggs hatch in late September. ^[9]

Diet

Primarily herbivorous, the chuckwalla eats creosote bush flowers, leaves, fruit, and occasionally insects. ^[9]

Gallery

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References

1. "Sauromalus ater". Integrated Taxonomic Information System . Retrieved 15 September 2008.
2. Hammerson, G.A. (2007). "Sauromalus ater". IUCN Red List of Threatened Species . 2007: e.T64054A12740491. doi: 10.2305/IUCN.UK.2007.RLTS.T64054A12740491.en . Retrieved 1 March 2024.
3. Sauromalus ater at the Reptarium.cz Reptile Database. Accessed 1 March 2024.
4. Grismer, L. Lee (2002). Amphibians and Reptiles of Baja California, Including its Pacific Islands, and the Islands in the Sea of Cortés. University of California Press. p. 130. ISBN   978-0-520-22417-9.
5. Schwenkmeyer, Dick. "Sauromalus ater Common Chuckwalla". Field Guide. San Diego Natural History Museum. Retrieved 17 September 2008.
6. Avise, John C. (2015). Sketches of Nature: A Geneticist's Look at the Biological World During a Golden Era of Molecular Ecology. Elsevier Science. p. 142. ISBN   978-0-12-801960-3.
7. Liddell, H.G. & Scott, R. (1940). A Greek-English Lexicon. revised and augmented throughout by Sir Henry Stuart Jones. with the assistance of. Roderick McKenzie. Oxford: Clarendon Press.
8. Hollingsworth, Bradford D. (2004). "The Evolution of Iguanas: an Overview and a Checklist of Species". In Alberts, Allison (ed.). Iguanas: Biology and Conservation. University of California Press. p. 42. doi:10.1525/california/9780520238541.003.0003. ISBN   978-0-520-23854-1.
9. Stebbins, Robert C.,(2003) A Field Guide to Western Reptiles and Amphibians, 3rd Edition. Houghton Mifflin Company, ISBN   0-395-98272-3
10. Deban, Stephen M.; O'Reilly, James C.; Theimer, Tad (1994). "Mechanism of defensive inflation in the chuckwalla, Sauromalus obesus". Journal of Experimental Zoology. 270 (5): 451–459. doi:10.1002/jez.1402700506.

External links

• Taxonomic controversy