Mona ground iguana

Last updated

Mona ground iguana
Iguana sitting down looking to the left.jpg
CITES Appendix I (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: Cyclura
Species:
C. stejnegeri
Binomial name
Cyclura stejnegeri
Barbour & Noble, 1916
Synonyms

Cyclura cornuta stejnegeri(Barbour & Noble, 1916)

The Mona ground iguana (Cyclura stejnegeri) is a critically endangered species of rock iguana, endemic to Mona Island, Puerto Rico. It is one of the island nation's few large land animals, and it is the largest endemic terrestrial lizard in the country, and one of the biggest rock iguanas within the Antilles. It was previously considered a subspecies of the rhinoceros iguana (Cyclura cornuta).

Contents

Taxonomy

The Mona ground iguana belongs to the genus Cyclura . It was named by Thomas Barbour and Gladwyn Kingsley Noble as a species in 1916. [3] In 1937, Barbour considered it to be a subspecies of Cyclura cornuta, although he doubted it was particularly distinct. Research into scalation patterns in 1977 found little difference between this taxon and the nominate subspecies on Hispaniola, but markedly more differences in the subspecies onchiopsis, and thus found Barbour's 1937 taxonomic interpretation best approximated the obvious relatedness of these taxa. [4] Its specific name, stejnegeri honors Leonhard Hess Stejneger, who, when writing his Herpetology of Porto Rico in 1902, suspected the rhinoceros iguanas of Mona Island might be slightly different in scale count than those in Haiti, although he was unsure. [5]

In 1993 Robert Powell suggested that all three subspecies of the rhinoceros iguana could be seen as distinct species, if the word "species" was redefined to mean any population which was separated from another population. Although it does not appear to be distinct from the nominotypical subspecies morphologically, in a 1999 article, Powell again recommended recognizing this population as a different species, based on what he had said in 1993. [4] Some authorities have decided to follow Powell. [6] [7] Still, others consider it a regional variant of the parent species, C. cornuta.

Description

Mona ground iguana no.1.jpg

The Mona ground iguana is a large-bodied, heavy-headed lizard with strong legs and a vertically flattened tail, which is capable of reaching 1.22 m (4 ft 0 in) in length (from snout to tail). [5] A crest of pointed, horned scales extends from the nape of the neck to the tip of the tail. The color is a uniform gray to olive drab, with slight brown or blue colorations. Juveniles differ from adults in that they have gray transverse bands across their bodies. [8] These bands last until they are sexually mature at about three years of age.

Males possess bony, prominent tubercles on their snouts resembling horns, adipose pads in the form of a helmet on the occipital region of their heads, and large dewlaps. This subspecies, like other species of Cyclura, is sexually dimorphic; males are larger than females, and have more prominent dorsal crests, "horns" and femoral pores on their thighs, which are used to release pheromones. Thomas Wiewandt, who spent an extended period on Mona Island studying C. stejnegeri, suggested that the horns, along with lateral spines and prominent parietal bulges, function as protective armor against sharp rocks or as defensive tools to facilitate the escape of males from the grasp of one another. [9] [10] [11]

Habitat

Mona ground iguanas are diurnal and spend most of the day basking in the sun conserving energy. Mona ground iguanas are endemic to Mona Island; they are scattered through the entire island, though the southwest part of the island is only used during the nesting season. They live a considerable portion of their lives underground, and are usually found in talus slopes, caves and sinkhole depressions. The average depth underground that they can be found is 1.5 m (4 ft 11 in).

Reproduction

Mona ground iguana hatchling Mona ground iguana hatchling.jpg
Mona ground iguana hatchling

Although Mona ground iguanas use the whole island as their habitat, only 1% of the territory, located on the southwest coast, is suitable for nesting because it contains loose sand, and receives direct sunlight. The females bury their eggs in the sand, and the sunlight incubates the eggs. Males reach sexual maturity at a size of 28–31 cm (11–12 in) in length from snout to vent, usually in their third to fourth year, while females mature one year later at a size of 35–40 cm (14–16 in).

Nesting season begins in the second week of June. Usually, one female mates with more than one male in the two weeks the mating season lasts. Copulation may last from 15  sec to 2  mins and 15 sec. One month later, nesting begins. Females will dig a tunnel 0.91 m (3 ft) long located one to two feet underground, where they deposit from five to 19 eggs, with 12 being the average. They will guard their nests for several days, but provide no parental care for the hatchlings, which hatch three months later. Hatchlings measure, on average, 32 cm (13 in) and weigh 73.7 g (2.60 oz) and grow at a rate of 5.23 cm (2.06 in) per year. [12]

Diet

Mona ground iguanas, like most Cyclura species, are primarily herbivorous, consuming leaves, flowers, berries, and fruits from different plant species. [13] A study in 2000 by Dr Allison Alberts of the San Diego Zoo revealed that seeds passing through the digestive tracts of Cycluras germinate more rapidly than those that do not. [14] [15] These seeds in the fruits consumed by Cyclura have an adaptive advantage, by sprouting before the end of very short rainy seasons. [4] [15] The Mona ground iguana is also an important means of distributing these seeds to new areas (particularly since females migrate to nesting sites) and, as the largest native herbivores of their ecosystems, they are essential for maintaining the balance between climate and vegetation. [4] [15] Their diets are very rarely supplemented with insect larvae, crabs, slugs, dead birds, and fungi; individual animals do appear to be opportunistic carnivores. [4] [9] Fewer than a dozen animal species and 71 plant species are found in the Mona ground iguanas' diets. [9] Mona ground iguanas eat the caterpillar of sphingid moths. [4] These larvae feed on poisonous plants and are aposematically colored and avoided by other predators. [16]

Endangered status

Population numbers are estimated at 1,500 with lower densities than similar iguana-inhabited islands in the West Indies. Immature iguanas are scarce and represent only 5–10% of the population, revealing that the population is aging and in decline. [17]

Reasons for decline

The biggest threat to C. stejnegeri are invasive species; feral pigs pose the most serious threat, as they root up iguana nests, and like most Cyclura species, the Mona ground iguana nests communally and at high density. [13] [17] Introduced goats and pigs are a major competitor for food and overbrowsing by goats also leads to loss of protective cover from birds of prey such as the osprey and predation of juveniles by feral cats. [13] [17]

Recovery efforts

A headstarting program was put into place by the Puerto Rico Department of Natural and Environmental Resources, with cooperation from the IUCN Iguana Specialist Group, the US Fish and Wildlife Service, the Toledo Zoo, and the University of Puerto Rico in 1999, to aid in the recovery of the Mona ground iguana. [18] From within the safety of this program, the iguanas are reared until they are large enough to survive in the wild, and predators, such as pigs and feral cats, are no longer a threat. [15] The facility also carries out health screening prior to the release of specimens. [15] This health screening has been used to provide baselines of the normal physiologic values of the species, identifying potential future problems due to parasites, diseases, etc. which might threaten the population. [17]

See also

Related Research Articles

<span class="mw-page-title-main">Turks and Caicos rock iguana</span> Species of lizard

The Turks and Caicos rock iguana is a species of lizard endemic to the Turks and Caicos islands. This small iguana can reach 30 in (76 cm) and becomes mature at seven years and may live for twenty. A single clutch of up to nine eggs is laid each year, and these take three months to hatch. This iguana is mostly herbivorous, but supplements this by adding some animal matter to its diet.

<span class="mw-page-title-main">Blue iguana</span> Species of reptile

The blue iguana, also known as the Grand Cayman ground iguana, Grand Cayman blue iguana or Cayman Island rock iguana, is an endangered species of lizard which is endemic to the island of Grand Cayman. It was previously considered to be a subspecies of the Cuban iguana, Cyclura nubila, but in a 2004 article Frederic J. Burton reclassified it as a separate species because according to him the genetic differences discovered four years earlier between the different C. nubila populations warranted this interpretation. The blue iguana is one of the longest-living species of lizard.

<span class="mw-page-title-main">Jamaican iguana</span> Species of lizard

The Jamaican iguana, also known commonly as Colley's iguana, is a large species of lizard in the family Iguanidae. The species is endemic to Jamaica. It is critically endangered, even considered extinct between 1948 and 1990. Once found throughout Jamaica and on the offshore islets Great Goat Island and Little Goat Island, it is now confined to the forests of the Hellshire Hills.

<span class="mw-page-title-main">Rhinoceros iguana</span> Species of iguana endemic to the Caribbean

The rhinoceros iguana is an endangered species of iguana that is endemic to the Caribbean island of Hispaniola and its surrounding islands. A large lizard, they vary in length from 60 to 136 centimetres, and skin colours range from a steely grey to a dark green and even brown. Their name derives from the bony-plated pseudo-horn or outgrowth which resembles the horn of a rhinoceros on the iguana's snout. It is known to coexist with the Ricord's iguana ; the two species are the only taxa of rock iguana to do so.

<span class="mw-page-title-main">Northern Bahamian rock iguana</span> Species of lizard

The northern Bahamian rock iguana is a species of lizard of the genus Cyclura that is found on Andros Island and the Exuma islands in the Bahamas. Its status on the IUCN Red List is vulnerable, with a wild population of less than 5,000 animals.

<i>Cyclura nubila</i> Species of reptile

The Cuban rock iguana, also known as the Cuban ground iguana or Cuban iguana, is a species of lizard of the iguana family. It is the second largest of the West Indian rock iguanas, one of the most endangered groups of lizards. A herbivorous species with a thick tail and spiked jowls, it is one of the largest lizards in the Caribbean.

<i>Cyclura ricordii</i> Species of iguana endemic to Hispaniola

Cyclura ricordii, also known as Ricord's ground iguana or Ricord's rock iguana, is an endangered species of medium-sized rock iguana, a large herbivorous lizard. It is endemic to the island of Hispaniola. It is known to coexist with the nominate subspecies of the rhinoceros iguana ; the two species are the only taxa of rock iguana to do so. The natural habitats of its three subpopulations are hot, dry, wooded savanna on limestone with access to soil and sandy flats in southern Hispaniola. It is threatened by predation by introduced predators and habitat loss, due to overgrazing and charcoal manufacture.

<i>Cyclura rileyi nuchalis</i> Subspecies of lizard

The Acklins ground iguana, also commonly known as the Watling Island iguana, is an endangered subspecies of lizard of the genus Cyclura it is one of three subspecific forms of Cyclura rileyi in the family Iguanidae.

<i>Cyclura rileyi</i> Species of lizard

Cyclura rileyi, commonly known as the Bahamian rock iguana or the San Salvador rock iguana, is a critically endangered species of lizard in the family Iguanidae. The species is native to three island groups in the Bahamas, and is in decline due to habitat encroachment by human development and predation by feral dogs and cats. There are three subspecies: the Acklins ground iguana, the White Cay iguana, and the nominotypical subspecies.

The Andros Island iguana or Andros iguana is an endangered subspecies of Northern Bahamian rock iguana of the genus Cyclura that is found on Andros Island on the western edge of Grand Bahama. Its status is Endangered, with a wild population of 3,500 animals, and it can be found on the IUCN Red List.

Cyclura cornuta onchiopsis, the Navassa Island iguana, was a subspecies of rhinoceros iguana that was found on the Caribbean island of Navassa.

Cyclura carinata bartschi, commonly known as Bartsch's iguana or the Booby Cay iguana, is a subspecies of lizard in the family Iguanidae. The subspecies is endemic to a single cay, Booby Cay, in The Bahamas.

<i>Cyclura nubila caymanensis</i> Subspecies of lizard

Cyclura nubila caymanensis, the Lesser Caymans iguana, Cayman Brac iguana, Cayman Island brown iguana or Sister Isles iguana, is a critically endangered subspecies of the Cuban iguana. It is native to two islands to the south of Cuba: Cayman Brac and Little Cayman, which are also known as the Sister Isles due to their similar shapes and close proximity to each other. The population of this subspecies has been impacted by habitat encroachment by human development and is likely being destroyed due to predation by cats, the population on Cayman Brac has remained particularly small for decades.

<i>Cyclura cychlura inornata</i> Subspecies of lizard

Cyclura cychlura inornata, the Allen Cays rock iguana or Allen Cays iguana, is a subspecies of the northern Bahamian rock iguana that is found on Allen's Cay and adjacent islands in the Bahamas. Its status in the IUCN Red List is critically endangered. The population has been growing over the last century. Although it was considered extinct in 1916, there are as of 2018 at least 482 mature adult animals counted on two islands, Leaf Cay and U Cay, and a few hundred on at least five other nearby islands where they have recently spread to by unknown means, as well as many juveniles.

<i>Cyclura cychlura figginsi</i> Subspecies of lizard

Cyclura cychlura figginsi, known by the common name of guana and sometimes called the Exuma Island iguana in the international literature, is a subspecies of the northern rock iguana, C. cychlura, that is found on the Exuma island chain in the Bahamas with an estimated wild population of 1,300 animals in 2004, it has been listed on the IUCN Red List as critically endangered.

<i>Cyclura rileyi cristata</i> Subspecies of lizard

Cyclura rileyi cristata, the White Cay iguana or Sandy Cay rock iguana, is a critically endangered subspecies of lizard of the genus Cyclura native to a single cay in the Bahamas: White Cay located in the Southern Exumas.

<i>Cyclura</i> Genus of lizards

Cyclura is a genus of lizards in the family Iguanidae. Member species of this genus are commonly known as "cycluras" and only occur on islands in the West Indies. Rock iguanas have a high degree of endemism, with a single species or subspecies originating on an individual island.

<i>Cyclura pinguis</i> Species of reptile

Cyclura pinguis, the Anegada rock iguana, Anegada ground iguana or stout iguana, is a critically endangered species of lizard of the genus Cyclura belonging to the family Iguanidae. The species can be found exclusively in the islands of Anegada and Guana. Historically, it inhabited the islands of Puerto Rico and Saint Thomas; however, the animal's original range has been greatly diminished over prehistory.

<span class="mw-page-title-main">Isla Magueyes</span> Island with marine research in Puerto Rico

Isla Magueyes is a 7.2 hectares island 50 metres (160 ft) from the southwest coast of the island of Puerto Rico. It is encircled with mangrove and has an interior of dry scrub habitat, where it gets its name. It is named for the presence of many century plants or maguey. The surrounding shelf of the island is mostly coral reef. There are buildings on the western end of the island associated with the Department of Marine Sciences, University of Puerto Rico at Mayagüez. UPR- Mayagüez is an important center in the Atlantic region for the study of tropical marine science due to its location, facilities, and first-rate researchers. The research facilities includes the Puerto Rico Water Resources and Environmental Research Institute, the Caribbean Coral Reef Institute (CCRI), the Research and Development Center, the Agricultural Research Station and the Caribbean Atmospheric Research Center (ATMOSCarib).

<span class="mw-page-title-main">Mona and Monito Islands Nature Reserve</span> Two islands off western Puerto Rico

Mona and Monito Islands Nature Reserve consists of two islands, Mona and Monito, in the Mona Passage off western Puerto Rico in the Caribbean. Mona and Monito Islands Nature Reserve encompasses both land and marine area, and with an area of 38,893 acres it is the largest protected natural area in the Commonwealth of Puerto Rico. Much like the Galapagos Islands in the Pacific Ocean, the Mona and Monito Islands reserve represents a living laboratory for archaeological, biological, geological, oceanographical and wildlife management research.

References

  1. ↑ Garcia, M.A.; Figuerola, C.; Grant, T.D. (2020). "Cyclura stejnegeri". IUCN Red List of Threatened Species . 2020: e.T29605A2790768. doi: 10.2305/IUCN.UK.2020-2.RLTS.T29605A2790768.en . Retrieved 19 November 2021.
  2. ↑ "Appendices | CITES". cites.org. Retrieved 2022-01-14.
  3. ↑ Barbour, Thomas & Noble, G. Kingsley (1916). "A revision of the lizards of the genus Cyclura". Bulletin of the Museum of Comparative Zoology at Harvard College. 60 (4): 139–164.
  4. 1 2 3 4 5 6 Powell, Robert (1999), "Herpetology of Navassa Island, West Indies" (PDF), Caribbean Journal of Science, 35 (1–2): 1–13, archived from the original (PDF) on 20 July 2011, retrieved 2007-09-09
  5. 1 2 Stejneger, Leonhard (1902), The Herpetology of Porto Rico, New York: Rept. U.S. Nat. Mus, pp. 549–724
  6. ↑ "Cyclura stejnegeri Barbour and Noble, 1916", Integrated Taxonomic Information System, 2001, retrieved 2007-10-16
  7. ↑ "Cyclura stejnegeri". The Reptile Database. Retrieved 2021-07-07.
  8. ↑ Rivero, J.A. 1978. Los anfibios y reptiles de Puerto Rico. Universidad de Puerto Rico, Editorial Universitaria, Mayaguez, Puerto Rico. 152p. 49 plates. (in Spanish)
  9. 1 2 3 Wiewandt, Thomas A. (1977). Ecology, behavior, and management of the Mona Island ground iguana Cyclura stejnegeri (Ph.D.). Cornell University.
  10. ↑ De Vosjoli, Phillipe; Blair, David (1992), The Green Iguana Manual , Escondido, California: Advanced Vivarium Systems, ISBN   978-1-882770-18-2
  11. ↑ Martins, Emilia P.; Lacy, Kathryn (2004), "Behavior and Ecology of Rock Iguanas, I: Evidence for an Appeasement Display", Iguanas: Biology and Conservation, University of California Press, pp. 98–108, ISBN   978-0-520-23854-1
  12. ↑ Iverson, John; Smith, Geoffrey; Pieper, Lynne (2004), "Factors Affecting Long-Term Growth of the Allen Cays Rock Iguana in the Bahamas", Iguanas: Biology and Conservation, University of California Press, p. 176, ISBN   978-0-520-23854-1
  13. 1 2 3 Byrd, Dan; Byrd, Sylvia (1996), "The Rhinoceros Iguanas of Mona Island", Reptiles: Guide to Keeping Reptiles and Amphibians, 4 (1): 24–27
  14. ↑ Derr, Mark (2000-10-10), "In Caribbean, Endangered Iguanas Get Their Day", New York Times Science Section
  15. 1 2 3 4 5 Alberts, Allison; Lemm, Jeffrey; Grant, Tandora; Jackintell, Lori (2004), "Testing the Utility of Headstarting as a Conservation Strategy for West Indian Iguanas", Iguanas: Biology and Conservation, University of California Press, p. 210, ISBN   978-0-520-23854-1
  16. ↑ Powell, Robert (8 January 2000), "Horned Iguanas of the Caribbean", Reptile and Amphibian Hobbyist, 5 (12)
  17. 1 2 3 4 Knapp, Charles R.; Hudson, Richard (2004), "Translocation Strategies as a Conservation Tool for West Indian Iguanas", Iguanas: Biology and Conservation, University of California Press, pp. 199–204, ISBN   978-0-520-23854-1
  18. ↑ Perez-Buitrago, Nestor (2005), "Successful Release of Head Start Mona Island Iguanas" (PDF), Iguana Specialist Group Newsletter, 8 (1): 6, archived from the original (PDF) on 2007-08-12
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.