Galapagos land iguana

Last updated

Contents

Galápagos land iguana
Galapagos land iguana (4201792789).jpg
CITES Appendix II (CITES) [2]
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Iguania
Family: Iguanidae
Genus: Conolophus
Species:
C. subcristatus
Binomial name
Conolophus subcristatus
(Gray, 1831)

The Galápagos land iguana (Conolophus subcristatus) is a very large species of lizard in the family Iguanidae. It is one of three species of the genus Conolophus . It is endemic to the Galápagos Islands, in the dry lowlands of the islands of Fernandina, Isabela, Santa Cruz, North Seymour, Baltra, and South Plaza. [1] [3] [4]

Taxonomy

The land iguanas in the Galápagos vary in morphology and coloration among different populations. [5] In addition to the relatively widespread and well-known Galápagos land iguana (C. subcristatus), there are two other species of Conolophus: the Galápagos pink land iguana (C. marthae) from northern Isabela Island and the Santa Fe land iguana (C. pallidus) from Santa Fe Island. [5] [6] Based on mtDNA, land iguanas and marine iguanas diverged about 8–10 million years ago. [7] [8] Within the land iguana genus, the oldest split based on mtDNA, about 5.7 million years old, is between C. subcristatus and C. marthae. [8] [9] A more recent study that included both mtDNA and nuclear DNA indicates that the marine iguana split from the land iguana about 4.5 million years ago, and among the land iguanas C. subcristatus and C. marthae split from each other about 1.5 million years ago. [10] The differentiation between the last two species, C. subcristatus and C. pallidus, is less clear and it has been questioned whether they are separate species. [5] Based on mtDNA and cytochrome b, they fall into three monophyletic groups: C. subcristatus of western islands (Isabela and Fernandina), C. subcristatus of central islands (Santa Cruz, Baltra and South Plaza) and C. pallidus. Although the exact pattern is uncertain, it is possible that C. pallidus is closer to one of the C. subcristatus groups than the two C. subcristatus groups are to each other. [9]

Its specific name subcristatus is derived from the Latin words sub meaning "lesser" and cristatus meaning "crested", and refers to the low crest of spines along the animal's back, which is not as tall as in most iguanas.

Anatomy and morphology

Charles Darwin described the Galápagos land iguana as "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." [11] The Galápagos land iguana is one of the largest lizards in the world [12] growing to a length of 0.9 to 1.5 m (3–5 ft) with a body weight of up to 13 kg (29 lb), depending upon which island they are from. [13] [14] Being cold-blooded, they absorb heat from the sun by basking on volcanic rock, and at night sleep in burrows to conserve their body heat. [13] These iguanas also enjoy a symbiotic relationship with birds; the birds remove parasites and ticks, providing relief to the iguanas and food for the birds. [3] [15]

Diet and longevity

Feeding Galapagos land iguana feeding.JPG
Feeding
Feeding on fallen cactus pads Landiguana-southplaza-feeding.jpg
Feeding on fallen cactus pads

Land iguanas are primarily herbivorous; however, some individuals have shown that they are opportunistic carnivores supplementing their diet with insects, centipedes and carrion. [3] Because fresh water is scarce on its island habitats, the Galápagos land iguana obtains the majority of its moisture from the prickly-pear cactus, which makes up 80% of its diet. All parts of the plant are consumed, including the fruit, flowers, pads, and even spines. [3] [13] During the rainy season it will drink from available standing pools of water and feast on yellow flowers of the genus Portulaca . [13] [15]

The Galápagos land iguana has a 60 to 69 year lifespan. [3] [14]

Reproduction

Basking Conolophus subcristatus 01.jpg
Basking

Galápagos land iguanas become sexually mature anywhere between eight and fifteen years of age, depending on which island they are from. [3] Mating season also varies between islands, but soon after mating, the females migrate to sandy areas to nest, laying 2–20 eggs in a burrow about 50 cm (20 in) deep. [3] The eggs hatch anywhere from 90 to 125 days later. [3] [14]

On South Plaza Island, where the territories of marine iguanas and land iguanas overlap, the two sometimes interbreed, resulting in a hybrid iguana that shows a mixture of features from each species. [3] The most likely unions tend to be between male marine iguanas and female land iguanas. Despite their long separation time and their being two distinct species from different genera, the offspring are viable, although likely sterile. [3] [5]

Population

It is estimated that between 5,000 and 10,000 land iguanas are found in the Galápagos Islands. [3] These iguanas were so abundant on Santiago Island at one time that naturalist Charles Darwin remarked when it was called King James Island that "...when we were left at James, we could not for some time find a spot free from their burrows on which to pitch our single tent". [13] [16] In the years since then, entire populations (including all the animals on Santiago Island) have been wiped out by introduced feral animals such as pigs, rats, cats, and dogs. [3] [13]

Evolutionary history

Researchers theorize that Galápagos land iguanas and marine iguanas evolved from a common ancestor since arriving on the islands from South America, presumably by rafting. [17] [18] The marine iguana diverged from the land iguana some 8 million years ago, which is older than any of the extant Galápagos islands. [19] [7] It is therefore thought that the ancestral species inhabited parts of the volcanic archipelago that are now submerged. The two species remain mutually fertile in spite of being assigned to distinct genera, and they occasionally hybridize where their ranges overlap.

Recovery efforts

Male Galapagos Islands Land Iguana.JPG
Male
Yellow land iguana at the Charles Darwin Research Station Yellow Land Iguana at the Charles Darwin Research Station photo by Alvaro Sevilla Design.JPG
Yellow land iguana at the Charles Darwin Research Station
Galapagos land iguana on North Seymour Island. A Galapagos Land Iguana on the North Seymour Island in the Galapagos photo by Alvaro Sevilla Design.JPG
Galápagos land iguana on North Seymour Island.

Beginning in the early 1990s, the Galápagos land iguana has been the subject of an active reintroduction campaign on Baltra Island. These animals became extinct on Baltra by 1954, allegedly wiped out by soldiers stationed there who shot the iguanas for amusement. [3] [15] However, in the early 1930s, William Randolph Hearst had translocated a population of land iguanas from Baltra to North Seymour Island, a smaller island just a few hundred metres north of Baltra, because he could not understand why no iguanas were present there. Hearst's translocated iguanas survived and became the breeding stock for the Charles Darwin Research Station captive breeding program that has successfully reintroduced the species to Baltra and a number of other areas. [3] Visitors today frequently see iguanas on both the runway of the Baltra airport or while they cross the road.

Related Research Articles

<span class="mw-page-title-main">Galápagos Islands</span> Ecuadorean archipelago and protected area

The Galápagos Islands are an archipelago of volcanic islands in the Eastern Pacific, located around the Equator 900 km (560 mi) west of South America. They form the Galápagos Province of the Republic of Ecuador, with a population of slightly over 33,000 (2020). The province is divided into the cantons of San Cristóbal, Santa Cruz, and Isabela, the three most populated islands in the chain. The Galápagos are famous for their large number of endemic species, which were studied by Charles Darwin in the 1830s and inspired his theory of evolution by means of natural selection. All of these islands are protected as part of Ecuador's Galápagos National Park and Marine Reserve.

<i>Conolophus</i> Genus of lizards

The Galápagos land iguanas comprise the genus Conolophus of the Galápagos Islands (Ecuador). The number of species of this variable genus has always been disputed; the most current taxonomic surveys suggest that three species exist:

<span class="mw-page-title-main">Galapagos hawk</span> Species of bird

The Galápagos hawk is a large hawk endemic to most of the Galápagos Islands.

<span class="mw-page-title-main">Galápagos Islands xeric scrub</span>

The Galápagos Islands xeric scrub, also known as the Galápagos Islands scrubland mosaic, is a terrestrial deserts and xeric shrublands ecoregion that covers the Galápagos Islands. The Galápagos Islands are volcanic in origin, and remote from continents and other islands. The ecoregion is well known for its unique endemic species, including giant tortoises, birds, and marine iguanas, which evolved in isolation to adapt to islands' environments.

<span class="mw-page-title-main">Marine iguana</span> Species of marine reptile endemic to Galapagos Islands

The marine iguana, also known as the sea iguana, saltwater iguana, or Galápagos marine iguana, is a species of iguana found only on the Galápagos Islands (Ecuador). Unique among modern lizards, it is a marine reptile that has the ability to forage in the sea for algae, which makes up almost all of its diet. Marine iguanas are the only extant lizard that spends time in a marine environment. Large males are able to dive to find this food source, while females and smaller males feed during low tide in the intertidal zone. They mainly live in colonies on rocky shores where they bask after visiting the relatively cold water or intertidal zone, but can also be seen in marshes, mangrove swamps and beaches. Large males defend territories for a short period, but smaller males have other breeding strategies. After mating, the female digs a nest hole in the soil where she lays her eggs, leaving them to hatch on their own a few months later.

<span class="mw-page-title-main">Puerto Ayora</span> Town in Galápagos, Ecuador

Puerto Ayora is a town in central Galápagos, Ecuador. Located on the southern shore of Santa Cruz Island, it is the seat of Santa Cruz Canton. The town is named in honor of Isidro Ayora, an Ecuadorian president. The town is sometimes mistakenly referred to as Santa Cruz. Puerto Ayora is the most populous town in the Galápagos Islands, with a population of 12,696.

<span class="mw-page-title-main">Isabela Island (Galápagos)</span> Largest Island in the Galápagos Archipelago

Isabela Island is the largest of the Galápagos Islands, with an area of 4,586 km2 (1,771 sq mi) and a length of 100 km (62 mi). By itself, it is larger than all the other islands in the chain combined and it has a little under 2000 permanent inhabitants. The island straddles the equator.

<span class="mw-page-title-main">Santiago Island (Galápagos)</span> Volcanic Island in the Galápagos Archipelago

Santiago Island is one of the Galápagos Islands. The island, which consists of two overlapping volcanoes, has an area of 585 square kilometers (226 sq mi) and a maximum altitude of 907 meters (2,976 ft), atop the northwestern shield volcano. The volcano in the island's southeast erupted along a linear fissure and is much lower. The oldest lava flows on the island date back to 750,000 years ago.

<i>Grapsus grapsus</i> Species of crab

Grapsus grapsus is one of the most common crabs along the western coast of the Americas. It is known as the red rock crab, or, along with other crabs such as Percnon gibbesi, as the Sally Lightfoot crab.

<span class="mw-page-title-main">Baltra Island</span> Island in the Galápagos Archipelago

Baltra Island is a small island in the Galápagos Archipelago in Ecuador. It is a small flat island located near the center of the chain and includes Seymour Airport (GPS), originally established by the United States Air Force to help monitor and protect western access to the Panama Canal. Baltra is not part of the Galápagos National Park but some effort has been made to protect the local environment, including modernization of the airport and the reintroduction of the island's land iguanas.

The Galápagos Islands are located off the west coast of South America straddling the equator. The Galápagos are located at the confluence of several currents including the cold Humboldt Current traveling north from South America and the Panama Current traveling south from Central America make the islands cooler and provide the perfect environment for the unique mix of wildlife that inhabits the islands.

<span class="mw-page-title-main">North Seymour Island</span> Island in the Galápagos Archipelago

North Seymour Island is a small island near Baltra Island in the Galápagos Islands in Ecuador. It was formed by uplift of a submarine lava formation and is now covered with low, bushy vegetation. It has an area of 1.9 km2 (0.73 sq mi) and a maximum elevation of 28 meters (92 ft). There is no permanent population but a visitor trail has been established approximately 2 km (1.2 mi) in length for guided tours crossing the interior of the island and exploring the rocky coast.

<span class="mw-page-title-main">Galápagos National Park</span> National park in Ecuador

Galápagos National Park was established in 1959. It began operation in 1968, and it is Ecuador's first national park and a UNESCO World Heritage Site.

<span class="mw-page-title-main">Volcán Wolf</span> Highest mountain in the Galápagos Islands

Wolf Volcano, also known as Mount Whiton, is the highest peak in the Galápagos Islands. It is situated on Isabela Island and reaches 1,710 m (5,610 ft). It is a shield volcano with a characteristic upturned soup bowl shape.

<i>Conolophus pallidus</i> Species of lizard

Conolophus pallidus is a species of lizard in the family Iguanidae. It is one of three species in the genus Conolophus and is endemic to Santa Fe Island in the Galapagos.

<span class="mw-page-title-main">Hybrid iguana</span> Hybrid lizard

The hybrid iguana is a first-generation hybrid, the result of intergeneric breeding between a male marine iguana and a female Galapagos land iguana on South Plaza Island in the Galápagos Islands, where the territories of the two species overlap.

<i>Conolophus marthae</i> Species of reptile

Conolophus marthae, the Galápagos pink land iguana, is a species of lizard of the family Iguanidae. This critically endangered iguana is native only to the Wolf Volcano in northern Isabela Island of the Galápagos Islands (Ecuador). It has a pink body with some dark stripes, prompting some to call it the pink iguana or the Galápagos rosy iguana. The species was first discovered in 1986 and was identified as a separate species, distinct from the Galápagos land iguana, early in 2009. This species is the only example of ancient diversification in the genus Conolophus.

Howard L. Snell is an American ecologist and professor at the University of New Mexico. His research and conservation efforts have focused on the Galapagos land iguanas, which were in danger of extinction.

<i>Microlophus albemarlensis</i> Species of lizard

Microlophus albemarlensis, the Galápagos Lava lizard, also known as the Albemarle Lava lizard, is a species of Lava lizard. It is endemic to the Galápagos Islands, where it occurs on several islands in the western archipelago: the large islands Isabela, Santa Cruz, Fernandina, Santiago and Santa Fe, as well as several smaller islands: Seymour, Baltra, Plaza Sur, Daphne Major and Rábida. It is the most widespread of the Galápagos species of Microlophus, the others only occurring on single islands. Some authors however, consider populations on Santiago, Santa Cruz, and Santa Fe to be distinct species. The species is commonly attributed to the genus Microlophus but has been historically placed in the genus Tropidurus.

References

  1. 1 2 Kumar, K.; Gentile, G.; Grant, T.D. (2020). "Conolophus subcristatus". IUCN Red List of Threatened Species . 2020: e.T5240A3014082. doi: 10.2305/IUCN.UK.2020-2.RLTS.T5240A3014082.en . Retrieved 17 November 2021.
  2. ↑ "Appendices | CITES". cites.org. Retrieved 2022-01-14.
  3. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 "Land iguanas" (PDF). Charles Darwin Research Station Fact Sheet. Charles Darwin Foundation for the Galapagos Islands. 2006. Archived from the original (PDF) on 2007-06-06. Retrieved 2007-10-14.
  4. ↑ Swash, A.; R. Still (2000). Birds, Mammals & Reptiles of the Galápagos Islands . Yale University Press. pp.  118–119. ISBN   0-300-08864-7.
  5. 1 2 3 4 Rassmann, Kornelia; Markmann, Melanie; Trillmich, Fritz; Tautz, Diethard (2004), "Tracing the Evolution of the Galapagos Iguanas", Iguanas: Biology and Conservation, California: University of California Press, pp. 71–83, ISBN   978-0-520-23854-1
  6. ↑ Gentile, Gabriele; Anna Fabiani; Cruz Marquez; Howard L. Snell; Heidi M. Snell; Washington Tapia; Valerio Sbordonia (2009). "An overlooked pink species of land iguana in the Galapagos". Proceedings of the National Academy of Sciences of the United States of America. 106 (2). National Academy of Sciences of the United States of America: 507–11. doi: 10.1073/pnas.0806339106 . PMC   2626733 . PMID   19124773.
  7. 1 2 "Explaining the Divergence of the Marine Iguana Subspecies on Espa". amnh.org.
  8. 1 2 Black, Richard (5 January 2009). "Pink iguana rewrites family tree". BBC News. BBC. Retrieved 20 May 2017.
  9. 1 2 Gabriele Gentile; Anna Fabiani; Cruz Marquez; Howard L Snell; Heidi M Snell; Washington Tapia; Valerio Sbordoni (2009). "An overlooked pink species of land iguana in the Galápagos". Proceedings of the National Academy of Sciences of the United States of America. 106 (2). National Academy of Sciences of the United States of America: 507–511. doi: 10.1073/pnas.0806339106 . PMC   2626733 . PMID   19124773.
  10. ↑ MacLeod, A.; A. Rodríguez; M. Vences; P. Orozco-terWengel; C. García; F. Trillmich; G. Gentile; A. Caccone; G. Quezada; S. Steinfartz (2015). "Hybridization masks speciation in the evolutionary history of the Galápagos marine iguana". Proceedings of the Royal Society B. 282 (1809): 20150425. doi:10.1098/rspb.2015.0425. PMC   4590447 . PMID   26041359.
  11. ↑ Darwin, Charles (1989), The Voyage of the Beagle: Charles Darwin's Journal of Researches, New York: Penguin Classics, p. 401, ISBN   978-0-14-043268-8
  12. ↑ "The 10 Largest Lizards in The World". a-z-animals.com. 18 August 2021. Retrieved 12 February 2022.
  13. 1 2 3 4 5 6 Rogers, Barbara (1990), Galapagos, New York: Mallard Press, p. 144, ISBN   978-0-7924-5192-1
  14. 1 2 3 Rosenthal, Ellen (1997), "Days and nights of the iguana: in the Galapagos, a devoted pair work to save land iguanas", Animals
  15. 1 2 3 Kricher, John (2006), Galapagos: A Natural History, New Jersey: Princeton University Press, pp. 9, 51, 91, 200, ISBN   978-0-691-12633-3
  16. ↑ Darwin, Charles (1839), Narrative of the surveying voyages of His Majesty's Ships Adventure and Beagle between the years 1826 and 1836, describing their examination of the southern shores of South America, and the Beagle's circumnavigation of the globe. Journal and remarks., London: Henry Colburn, p. 488
  17. ↑ Rassmann, K.; Tautz, D.; Trillmich, F.; Gliddon, C. (1997). "The micro – evolution of the Galápagos marine iguana Amblyrhynchus cristatus assessed by nuclear and mitochondrial genetic analysis". Molecular Ecology. 6 (5): 437. doi:10.1046/j.1365-294X.1997.00209.x. S2CID   84822976.
  18. ↑ Marine Iguana. marinebio.org.
  19. ↑ Rassmann, Kornelia (1997). "Evolutionary age of the Galápagos iguanas predates the age of the present Galápagos Islands". Molecular Phylogenetics and Evolution. 7 (2): 158–172. doi:10.1006/mpev.1996.0386. PMID   9126557 . Retrieved 18 January 2023.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.