Galápagos Land-Iguana

Reptiles of Ecuador | Sauria | Iguanidae | Conolophus subcristatus

Spanish common name: Iguana terrestre de Galápagos.

Recognition: ♂♂ 107 cm ♀♀ 91.8 cm. Conolophus subcristatus is one of four species of iguanas in the Galápagos Islands. It is generally the only land-dwelling iguana wherever it occurs. On Wolf Volcano on northern Isabela Island, it coexists with the distinctively colored Pink Iguana (C. marthae). In coastal areas of some islands, the territory of the Galápagos Land-Iguana approaches the habitat of the Marine Iguana (Amblyrhynchus cristatus), a reptile that has a blunt snout, a laterally flattened tail adapted to swimming, and a distinct, usually blackish, background color.

"Like their brothers the sea-kind, they are ugly animals, of a yellowish orange beneath, and of a brownish red colour above: from their low facial angle they have a singularly stupid appearance."

Charles Darwin, 1835.1

Natural history: Extremely common to extremely rare depending on the locality. Conolophus subcristatus is a diurnal iguana that inhabits dry shrublands, dry grasslands, deciduous forests, and volcanic rock areas if there is vegetation nearby.2,3 Galápagos Land-Iguanas are terrestrial to semiarboreal (individuals climb to shrubs and trees to feed and sleep). They feed mostly on, and obtain water from,1 cacti, grasses, and the leaves of trees. Their diet also includes berries, seeds, crabs, crickets, grasshoppers, carrion, and their own shed skin.4 Individuals of Conolophus subcristatus are most active between 8:00–10:00 and 15:00–18:00.4 When they are not active, they retreat into burrows, under thick vegetation, or in crevices in the lava rocks.5

"The individuals, and they are the greater number, which inhabit the lower country, can scarcely taste a drop of water throughout the year; but they consume much of the succulent cactus, the branches of which are occasionally broken off by the wind."

Charles Darwin, 1835.1

Galápagos Land-Iguanas, especially juveniles, are preyed upon by introduced predators such as pigs, dogs, cats, and rats, as well as by native predators such as hawks and snakes (Pseudalsophis dorsalis and P. occidentalis).6–9 When threatened, individuals of Conolophus subcristatus run into burrows, vegetation, and crevices. They may also open their mouths aggressively if cornered.4 Adult females compete fiercely over nesting sites and are capable of traveling for up to 40 km to arrive at suitable nesting grounds.6 They dig holes in sandy soil2 and lay 8–22 eggs6 that take nearly four months to hatch.10

Adult males defend their territories by bobbing their heads or fighting with intruders.4 The Galápagos Land-Iguana is known to hybridize with the Marine Iguana (Amblyrhynchus cristatus) on Plaza Sur Island.11 Members of Conolophus subcristatus are estimated to live up to 70 years.9

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Conservation: Vulnerable.12 We consider Conolophus subcristatus to be properly listed in this category given that the entire population is estimated to be composed of less than 10,000 mature individuals,7 many subpopulations are either extinct (Santiago and Rábida islands)10 or nearly extinct (most of Santa Cruz and southern Isabela Island),7 and the species faces the threat of invasive predators.10

Special thanks to Shannon DeVaney and Kathryn Tosney, our two official protectors of the Galápagos Land-Iguana, for symbolically adopting this species and helping bring the Reptiles of Galápagos project to life.

Distribution: Conolophus subcristatus is endemic to an estimated 5,401 km2 area in Galápagos, Ecuador. Galápagos Land-Iguanas occur on Baltra, Isabela, Fernandina, Seymour Norte, Plaza Sur, and Santa Cruz islands. The species has been re-introduced to Santiago Island and extirpated from Rábida Island.

Distribution of Conolophus subcristatus Distribution of Conolophus subcristatus in Santa Cruz Island

Etymology: The generic name Conolophus, which comes from the Greek words konos (meaning “cone”) and lophos (meaning “crest”),13 refers to the cone-like scales that compose the dorsal crest of the Galápagos Land-Iguana. The specific epithet subcristatus, which comes from the Latin words sub (meaning “less than”), crista (meaning “ridge”), and the suffix -atus (meaning “provided with”),13 refers to the comparatively small dorsal crest of this species.

See it in the wild: The easiest places to see Galápagos Land-Iguanas are Plaza Sur and Seymour Norte islands. At these tourism sites, individuals of Conolophus subcristatus can be seen year-round with ~100% certainty.

FAQ

Can I own a Galápagos Land-Iguana? Not legally. Galápagos Land-Iguanas are the natural heritage of Ecuador and are protected by this country's constitution. They are a Vulnerable species and listed under Appendix II of the Convention on International Trade in Endangered Species (CITES). However, this has not stopped people from trying to keep iguanas as pets. In 2012, Ecuadorian authorities confiscated four land iguanas from the luggage of a German tourist. In 2015, two iguanas were confiscated from the backpack of a Mexican citizen. However, not all attempts to smuggle iguanas out of Galápagos have been unsuccessful. There are live individuals of Conolophus subcristatus in private collections in Europe.

What do Galápagos Land-Iguanas eat? Galápagos Land-Iguanas are mainly vegetarians. They feed mostly on cacti, grass, and the leaves of trees. They may also ingest berries, seeds, crabs, crickets, grasshoppers, carrion, and their own shed skin.4

How do female Galápagos Land-Iguanas differ from the males? Female Galápagos Land-Iguanas are smaller than the males, have narrower heads, smaller dorsal crests, and more slender tails.

Authors: Alejandro ArteagaaAffiliation: Biodiversity Field Lab, Khamai Foundation, Quito, Ecuador. and Juan M GuayasaminbAffiliation: Laboratorio de Biología Evolutiva, Universidad San Francisco de Quito (USFQ), Quito, Ecuador.,cAffiliation: Galapagos Science Center, Galápagos, Ecuador.,dAffiliation: Centro de Investigación de la Biodiversidad y Cambio Climático, Universidad Tecnológica Indoamérica, Quito, Ecuador.

Academic reviewer. Miguel Vences.

Photographers: Jose VieiraaAffiliation: Tropical Herping (TH), Quito, Ecuador.,eAffiliation: ExSitu, Quito, Ecuador. and Alejandro ArteagaaAffiliation: Tropical Herping (TH), Quito, Ecuador.

How to cite? Arteaga A, Guayasamin JM (2020) Conolophus subcristatus. In: Arteaga A, Bustamante L, Vieira J, Guayasamin JM (Eds) Reptiles of Ecuador: Life in the middle of the world. Available from: www.reptilesofecuador.com

Literature cited:

  1. Darwin CR (1845) Journal of researches into the natural history and geology of the countries visited during the voyage of H.M.S. Beagle round the world, under the command of Capt. Fitz-Roy, R.N. John Murray, London, 519 pp.
  2. Carpenter CC (1966) The marine iguana of the Galápagos Islands, its behavior and physiology. Proceedings of the California Academy of Sciences 34: 329–376.
  3. Gentile G, Márquez C, Snell HL, Tapia W, Izurieta A (2016) Conservation of a new flagship species: the Galápagos pink land iguana (Conolophus marthae Gentile and Snell, 2009). In: Angelici FM (Ed) Problematic wildlife. Springer, New York, 315–336.
  4. Carpenter CC (1969) Behavioral and ecological notes on the Galápagos land iguanas. Herpetologica 25: 155–164.
  5. Van Denburgh J, Slevin JR (1913) Expedition of the California Academy of Sciences to the Galápagos Islands, 1905-1906. IX. The Galapagoan lizards of the genus Tropidurus with notes on iguanas of the genera Conolophus and Amblyrhynchus. Proceedings of the California Academy of Sciences 2: 132–202.
  6. Werner DI (1983) Reproduction in the iguana Conolophus subcristatus on Fernandina Island, Galápagos: clutch size and migration costs. The American Naturalist 121: 757–775.
  7. Márquez CM, Muñoz EA, Gentile G, Tapia WH, Zabala FJ, Naranjo SA, Llerena AJ (2010) Estado poblacional de las iguanas terrestres (Conolophus subcristatus, C. pallidus, y C. marthae: Squamata, Iguanidae), Islas Galápagos. Boletín Técnico, Serie Zoológica 6: 25–43.
  8. Werner DI (1980) Galápagos land iguana (Conolophus): natural history and conservation survey. In: Eberhardt U (Ed) Annual reports. Charles Darwin Research Station, Puerto Ayora, 142-145.
  9. Washington Tapia, unpublished data.
  10. Snell HL, Snell HM, Tracy CR (1984) Variation among populations of Galápagos land iguanas (Conolophus): contrasts of phylogeny and ecology. Biological Journal of the Linnean Society 21: 185–207.
  11. Rassmann K, Trillmich F, Tautz D (1997) Hybridization between the Galápagos land and marine iguana (Conolophus subcristatus and Amblyrhynchus cristatus) on Plaza Sur. Journal of Zoology 242: 729–739.
  12. World Conservation Monitoring Centre (1996) Conolophus subcristatus. The IUCN red list of threatened species. Available from: www.iucnredlist.org
  13. Brown RW (1956) Composition of scientific words. Smithsonian Books, Washington, 882 pp.