Solomon Islands skink

Last updated

Solomon Islands skink
Corucia zebrata (2).jpg
CITES Appendix II (CITES) [2]
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Family: Scincidae
Genus: Corucia
Gray, 1855
Species:
C. zebrata
Binomial name
Corucia zebrata
Gray, 1855 [3]

The Solomon Islands skink (Corucia zebrata), also known as prehensile-tailed skink, monkey-tailed skink, giant skink, zebra skink, and monkey skink, is an arboreal species of skink endemic to the Solomon Islands archipelago. It is the largest known extant species of skink.

Contents

The Solomon Islands skink is completely herbivorous, eating many different fruits and vegetables including the pothos plant. It is one of the few species of reptile known to function within a social group or circulus. Both male and female specimens are known to be territorial and often hostile towards members not a part of their family group.

Corucia is a monotypic genus, containing a single species. However, in 1997 it was determined that there are two subspecies of the Solomon Islands skink: the common monkey-tailed skink (Corucia zebrata zebrata) and the northern monkey-tailed skink (Corucia zebrata alfredschmidti). Among other variances, the northern skink is smaller and has darker eyes with a black sclera.

Extensive logging is a serious threat to the survival of this species. Consumption for food by indigenous Solomon Islanders and excessive pet trade exports have affected wild populations. Export of this species from the Solomon Islands is now restricted and the animal is protected under CITES appendix II.

Taxonomy and etymology

The Solomon Islands skink was first described by John Edward Gray in 1855 as Corucia zebrata. The generic name Corucia derives from the Latin word coruscus meaning "shimmering". This is in reference to Gray's description of "a play of colors effect from the body scales". [3] Its specific name zebrata is a Latinized form of the word zebra, in reference to the animal's zebra-like stripes. Some of its common names (prehensile-tailed skink, monkey-tailed skink, monkey skink) refer to its fully prehensile tail which the species uses as a fifth limb for climbing. [4]

Although appearances of Solomon Island skinks vary from island to island, only one subspecies, from the western islands of the Solomons Archipelago, was described by Dr. Gunther Köhler in 1996 as C. z. alfredschmidti, the trinomial name of which is in honor of German amateur herpetologist Alfred A. Schmidt. [5] [6]

The closest living relatives of C. zebrata are the blue-tongued skinks of the genus Tiliqua and skinks of the genus Egernia of Australia, New Guinea, and Indonesia, all of which are also assigned to the subfamily Lygosominae . [7] [8]

Distribution and habitat

Map of the Solomon Islands archipelago LocationSolomonIslands.png
Map of the Solomon Islands archipelago

The Solomon Islands skink is native to Papua New Guinea, and the Solomon Islands archipelago, a group of islands in the south-west Pacific Ocean. [9] [10] The common subspecies (C. z. zebrata) is found on the islands of Choiseul, New Georgia, Santa Isabel, Guadalcanal, Nggela, Malaita, Makira, Ugi and Owaraha. The northern subspecies (C. z. alfredschmidti) is known from the islands of Bougainville and Buka and the Shortland Islands. Bougainville and Buka are geographically part of the Solomons Archipelago, though politically part of Papua New Guinea. [11] Both subspecies of the Solomon Islands skink are strictly arboreal, usually inhabiting the upper canopy of forested areas throughout its range. The adults commonly establish a territory within the canopy of one tree. [12] It commonly occurs in the strangler fig tree (Ficus sp.), provided the epiphytic growth of its several food plants are present. It occurs in trees in semi-cleared areas and cultivated food gardens, again provided its food plants occur there. [13]

Biology

Solomon Islands skink at the St Louis Zoo Corucia zebrata.jpg
Solomon Islands skink at the St Louis Zoo

The Solomon Islands skink is the world's largest species of extant skink; adults can reach a total length (including tail) of 32 inches (81 cm) when fully grown, with the tail accounting for more than half this length. [14]

The Solomon Islands skink has a long, slender body, strong, short legs, and a triangular shaped head with small round eyes. [11] The skink has a strong crushing jaw but the teeth are small and used for eating plant material. [11] Its prehensile tail helps it maneuver from branch to branch with ease and gives the skink its more common names: monkey-tailed skink, prehensile-tailed skink, or monkey skink. [4] Male Solomon Islands skinks tend to have a broader head and a more slender body shape than do female skinks. [15] Males have a V-shaped pattern of scales just aft of the cloacal opening, which is not present in female skinks. [15]

The scales of Solomon Islands skinks are a dark green but are often speckled with light brown or black. [4] The scales on the underside vary from light yellow to different shades of green. [4] The toes on all four legs have thick, curved nails used for climbing and gripping tree limbs. [4]

As a crepuscular animal, it is most active during the dusk and dawn hours, feeding primarily at dusk. it also is active and eats during the hours of dawn, though to a lesser extent. It has quite good eyesight and relies upon it to identify threats, as well as potential food. It relies heavily on its sense of smell and uses it to identify its territory and other members of its group, called a circulus. Like snakes, the skink "smells" by flicking its tongue to gather scents and when the tongue is retracted, it touches it to the opening of a Jacobson's organ at the roof of its mouth. [15]

Subspecies

The common Solomon Islands skink (C. z. zebrata) has a white sclera with its eyes while the northern Solomon Islands skink (C. z. alfredschmidti) has a black sclera. The iris of the northern Solomon Islands skink is a mix of green and yellow whereas the iris of the common Solomon Islands skink can vary from several different shades of green to orange to a dark black. According to Dr. Gunther Köhler, who described the northern subspecies, this subspecies possesses "larger dorsal and ventral scales" and has "seven instead of usually five parietal scales". [5]

The northern Solomon Islands skink is the shorter of the two subspecies with males averaging 24 inches (61 cm) and females averaging 22 inches (56 cm) in total length. The common Solomon Islands skinks are slightly longer with the males averaging 28 inches (71 cm) and the females averaging 24 inches (61 cm) in total length. The common Solomon Islands skink, at 850 grams (1.87 lb), weighs more than the northern Solomon Islands skink, which weighs closer to 500 grams (1.1 lb). [5]

Diet

Solomon Islands skinks are herbivores, feeding on the leaves, flowers, fruit, and growing shoots of several different species of plants. [16] [17] This includes the somewhat toxic (due to high concentrations of calcium oxalate) Epipremnum pinnatum (cf. E. aureum) plant, [18] [note 1] which the lizard eats without ill effect. [19] [note 2] Juvenile skinks often eat feces from adults in order to acquire the essential microflora to digest their food. [9] Newborn skinks have been observed consuming their placental sac after birth and will not feed on other food for the first two days. [20] A study done in 2000 showed that this species still exhibits a feed response based on chemical cues from insects. It is believed that this is an ancestral trait that these skinks have retained, though it is not used in the wild. [21]

Reproduction

The Solomon Islands skink is one of the few species of reptile that lives in a communal group known as a circulus. [15] The Solomon Islands skink reproduces by viviparous matrotrophy: [note 3] the female provides a placenta for its young, which are born after a gestation period of six to eight months; this is a rare trait among reptiles. [22] The newborn skink is of a large size compared to its mother; the northern Solomon Islands skinks are approximately 29 centimetres (11 in) in length and weigh 80 grams (0.18 lb), whereas the common Solomon Islands skinks are 30 centimetres (12 in) and 175 grams (0.386 lb) when they are born. [5] This reduced size disparity led the former curator of reptiles at the Philadelphia Zoo, Dr. Kevin Wright, to compare it to "a human mother giving birth to a six year–old". [9] Almost all births are single babies, but occasionally twins will be born. [9] At least one instance of triplets has occurred according to herpetologist Bert Langerwerf. [11]

The newborn skink will stay within its circulus for six to twelve months during which time it will be protected by not only its parents but other unrelated adult skinks within the group. [10] Around one year of age, sometimes earlier, the juvenile will move off to form a new family group. [9] Individuals have been documented to stay within the group for several births without being expelled, however. [15] Females exhibit fierce protective behavior around the time of birth; this protectiveness of young is a rare occurrence in reptiles but is shorter in duration when compared to the protective behavior exhibited by a typical mammal. [9]

Conservation

Threats

Extensive logging is a serious ongoing threat to the survival of this species, as is consumption for food by native people, and export demand for the pet trade. [9] Because of the large numbers of lizards that were being exported for the pet trade, the small region to which the skink is native, and its low reproductive rate, in 1992 Corucia zebrata was listed as a CITES Appendix II animal, which allows limits to be placed on the number of animals in commercial trade between countries. [22] [23]

Since there is no regulation on the rapid deforestation occurring in the Solomon Islands, limited export to recognized institutions may be needed to aid this species in genetic diversity for its survival via ex situ breeding programs. According to herpetologists who study the Solomon Islands skink, such as Dr. David Kirkpatrick and Dr. Kevin Wright, captive breeding alone is not practical as a sole method of species survival due to the limited number of offspring and long gestation periods. [9] [22]

In captivity

Solomon Islands skink at the Buffalo Zoo Corucia zebrata - Buffalo Zoo.jpg
Solomon Islands skink at the Buffalo Zoo

The Solomon Islands skink is represented in both public and private collections. The Philadelphia Zoo has bred this species of skink over multiple generations for the past 40 years. The keeping of the Solomon Islands skink in captivity is not without its challenges: as it is a large arboreal tropical animal. It requires a large arboreal enclosure, with a constant temperature between 75–80 degrees Fahrenheit (24–27 degrees Celsius), with heat being provided from above as well as below, allowing the skink to bask in the heat from above as it would during dusk, while providing a radiant heat from below to aid digestion. The dynamics of the skink's circulus means that not all groups do well when new animals are introduced. Despite successful breeding programs, its somewhat unusual nature of single births and slow growth has made these programs challenging. [9] [22]

Biologist Michael Balsai of Temple University has noted a significant number of breedings between skinks from different islands has resulted in non-productive unions. Balsai's theory is that there are enough differences between animals from different islands that pairing of lizards from different locales will be unproductive, further frustrating many captive breeding attempts. [24]

Footnotes

  1. ↑ University of Nebraska (2006) "Plants which contain oxalate salts produce mucous membrane irritation and pain and/or swelling of mouth, lips, tongue, esophagus and stomach."
  2. ↑ Satter (2007) "note that it tends to turn their feces reddish in color".
  3. ↑ "Matrotrophy is the nourishment of embryos by resources provided between fertilization and parturition."

Related Research Articles

<span class="mw-page-title-main">Skink</span> Family of reptiles

Skinks are lizards belonging to the family Scincidae, a family in the infraorder Scincomorpha. With more than 1,500 described species across 100 different taxonomic genera, the family Scincidae is one of the most diverse families of lizards. Skinks are characterized by their smaller legs in comparison to typical lizards and are found in different habitats except arctic and subarctic regions.

<i>Egernia</i> Genus of lizards

Egernia is a genus of skinks that occurs in Australia. These skinks are ecologically diverse omnivores that inhabit a wide range of habitats. However, in the loose delimitation the genus is not monophyletic but an evolutionary grade, as has long been suspected due to its lack of characteristic apomorphies.

<span class="mw-page-title-main">Southern alligator lizard</span> Species of lizard

The southern alligator lizard is a common species of lizard in the family Anguidae. The species is native to the Pacific coast of North America. It ranges from Baja California to the state of Washington and lives in a variety of habitats including grasslands, chaparral, forests, and even urban areas. In dry climates, it is likely to be found in moist areas or near streams. There are five recognized subspecies.

<span class="mw-page-title-main">Prehensile tail</span> Tail of an animal that has adapted to be able to grasp or hold objects

A prehensile tail is the tail of an animal that has adapted to grasp or hold objects. Fully prehensile tails can be used to hold and manipulate objects, and in particular to aid arboreal creatures in finding and eating food in the trees. If the tail cannot be used for this it is considered only partially prehensile; such tails are often used to anchor an animal's body to dangle from a branch, or as an aid for climbing. The term prehensile means "able to grasp".

<i>Plestiodon egregius</i> Species of reptile

Plestiodon egregius, the mole skink, is a species of small lizard endemic to the Southeastern United States.

<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">Gladys Porter Zoo</span> Zoo in Brownsville, Texas, United States

Gladys Porter Zoo is a zoological and botanical park located in Brownsville, Texas, United States. The zoo officially opened on September 3, 1971, and currently averages over 424,000 visitors annually. Situated on 31 acres (13 ha), the zoo houses about 400 animal species and over 250 tropical and neo-tropical species and subspecies. It is the first zoo to have successfully bred the endangered Jentink's duiker. It is also the birthplace of Harambe, the gorilla.

<i>Tiliqua rugosa</i> Species of lizard

Tiliqua rugosa, most commonly known as the shingleback skink or bobtail lizard, is a short-tailed, slow-moving species of blue-tongued skink endemic to Australia. It is commonly known as the shingleback or sleepy lizard. Three of its four recognised subspecies are found in Western Australia, where the bobtail name is most frequently used. The fourth subspecies, T. rugosa asper, is the only one native to eastern Australia, where it goes by the common name of the eastern shingleback.

<i>Bothriechis schlegelii</i> Species of reptile

Bothriechis schlegelii, known commonly as the eyelash viper, is a species of venomous pit viper in the family Viperidae. The species is native to Central and South America. Small and arboreal, this species is characterized by a wide array of color variations, as well as the superciliary scales above the eyes. It is the most common of the green palm-pitvipers, and is often present in zoological exhibits. The specific name schlegelii honors Hermann Schlegel, who was a German ornithologist and herpetologist. For other common names see below. No subspecies are currently recognized as being valid.

<span class="mw-page-title-main">Black tree monitor</span> Species of reptile

The black tree monitor or Beccari's monitor is a species of lizard in the family Varanidae. The species is a relatively small member of the family, growing to about 90–120 cm (35–47 in) in total length. V. beccarii is endemic to the Aru Islands off New Guinea, living in an arboreal habitat. The skin color of adults is completely black, to which one common name refers.

<i>Plestiodon</i> Genus of lizards

Plestiodon is a genus of lizards in the family Scincidae (skinks). The genus contains many species formerly classified under the genus Eumeces, except those now placed in Mesoscincus. They are secretive, agile animals with a cylindrical body covered with smooth, shiny scales. They are distributed from East Asia to throughout North America from southern Canada south to Mexico, including oceanic islands such as Bermuda.

<span class="mw-page-title-main">Emerald tree monitor</span> Species of lizard

The emerald tree monitor or green tree monitor, is a small to medium-sized arboreal monitor lizard. It is known for its unusual coloration, which consists of shades from green to turquoise, topped with dark, transversedorsal banding. This coloration helps camouflage it in its arboreal habitat. Its color also makes the emerald tree monitor highly prized in both the pet trade and zoos alike.

<span class="mw-page-title-main">Spiny-tailed monitor</span> Species of lizard

The spiny-tailed monitor, also known as the Australian spiny-tailed monitor, the ridge-tailed monitor the Ackie dwarf monitor, and colloquially simply ackie monitor, is an Australian species of lizard belonging to the genus of monitor lizards (Varanus).

A circulus is a rarely occurring reptilian social group where there is interaction and personal exchange between individuals. Members will often protect and defend young, even if not of direct genetic linkage. Circulus is a Latin based term; one definition of the word is "a social gathering or circle company". Most reptiles are indifferent socially to each other as adults or to offspring.

<span class="mw-page-title-main">Solomon Archipelago</span> A marine ecoregion of the Pacific Ocean

The Solomon Archipelago is a terrestrial ecoregion and marine ecoregion in the Pacific Ocean. It includes the tropical ocean waters surrounding most of the Solomon Islands archipelago, and includes Bougainville Island and Buka Island of Papua New Guinea and their surrounding waters.

<span class="mw-page-title-main">Black-headed monitor</span> Species of lizard

The black-headed monitor or black-tailed monitor is a relatively small species of monitor lizards native to Australia. It is occasionally also called the mournful monitor, freckled monitor or the racehorse monitor, a name it shares with the Gould's monitor due to their exceptional speed. It is placed in the subgenus Odatria.

Richard Sternfeld was a German-Jewish herpetologist, who was responsible for describing over forty species of amphibians and reptiles, particularly from Germany's African and Pacific colonies.

<span class="mw-page-title-main">Cape Verde giant skink</span> Extinct species of lizard

The Cape Verde giant skink, also called Bibron's skink, Cocteau's skink, and lagarto in Cape Verdean Portuguese, is a recently extinct species of large lizard (skink) that was endemic to some of the Barlavento Islands of Cape Verde before disappearing in the 20th century.

<i>Varanus storri</i> Species of lizard

Storr's monitor is a species of monitor lizard in the family Varanidae. The species is endemic to Australia.

<span class="mw-page-title-main">Stokes's skink</span> Species of lizard

Egernia stokesii is a gregarious species of lizard of the Scincidae family. This diurnal species is endemic to Australia, and is also known as the Gidgee skink, spiny-tailed skink, Stokes's skink and Stokes's egernia. The species forms stable, long-term social aggregations, much like the social groups seen in mammalian and avian species. This characteristic is rarely found in the Squamata order, but is widespread within the Australian subfamily of Egerniinae skinks. Populations of E. stokesii are widely distributed, but fragmented, and occur in semi-arid environments. There are three recognised subspecies. The conservation status for the species is listed as least concern, however, one subspecies is listed as endangered.

References

  1. ↑ Hagen, I.J.; Harlow, P.; Allison, A. [in French]; Hamilton, A.; Tallowin, O. (2021). "Corucia zebrata". IUCN Red List of Threatened Species . 2021: e.T196593A2463961. Retrieved 29 January 2022.
  2. ↑ "Appendices | CITES". cites.org. Retrieved 2022-01-14.
  3. 1 2 Gray, J.E. (1856). "New Genus of Fish-scaled Lizards (Scissosaræ), from New Guinea". Annals and Magazine of Natural History, Second Series18: 345–346. (Corucia, new genus, p. 346; Corucia zebrata, new species, p. 346).
  4. 1 2 3 4 5 Netherton, John; Badger, David P. (2002). Lizards: A Natural History of Some Uncommon Creatures, Extraordinary Chameleons, Iguanas, Geckos, and More . Stillwater, MN: Voyageur Press. p.  137. ISBN   0-7603-2579-0.
  5. 1 2 3 4 Köhler, Gunther [in French] (1997). "Eine neue Unterart des Wickelschwanzskinkes Corucia zebrata von Bougainville, Papua-Neuguinea". Salamandra. 33 (1): 61–68. (in German).
  6. ↑ Alfred A. Schmidt – unser „Gründungsvater"!
  7. ↑ Reeder, Tod W. (2003). "A phylogeny of the Australian Sphenomorphus group (Scincidae: Squamata) and the phylogenetic placement of the crocodile skinks (Tribolonotus): Bayesian approaches to assessing congruence and obtaining confidence in maximum likelihood inferred relationships". Molecular Phylogenetics and Evolution. Department of Biology, San Diego State University. 27 (3): 384–397. doi:10.1016/S1055-7903(02)00448-7. PMID   12742744.
  8. ↑ Cogger, Harold; Zweifel, Richard (1992). Reptiles & Amphibians . Sydney: Weldon Owen. ISBN   0-8317-2786-1.
  9. 1 2 3 4 5 6 7 8 9 Wright, Kevin M. (2007). "Captivating Giants". Reptiles Magazine. 15 (12): 54–68.
  10. 1 2 Wright, Kevin M. (1996). "The Solomon Island Skink". Reptile & Amphibian Magazine. 3 (2): 10–19.
  11. 1 2 3 4 Langerwerf, Bert. "Monkey tailed skinks". Archived from the original on 2007-10-09. Retrieved 2007-10-16.
  12. ↑ Hagen, Ingerid J., and C. Michael Bull. “Home Ranges in the Trees: Radiotelemetry of the Prehensile Tailed Skink, Corucia Zebrata.” Journal of Herpetology, vol. 45, no. 1, 2011, pp. 36–39. JSTOR, JSTOR   41415241.
  13. ↑ McCoy, Michael (2006). Reptiles of the Solomon Islands. Australia: Pensoft Publishing. p. 212. ISBN   954-642-275-4.
  14. ↑ de Vosjoli, Philippe (1993). The General Care and Maintenance of Prehensile-tailed Skinks. Lakeside, CA: Advanced Vivarium Systems. ISBN   1-882770-24-2.
  15. 1 2 3 4 5 Satter, Celeste M. (2007). "Corucia zebrata". Southwestern Herpetologists Society Journal. California: SWHS: 5–6.
  16. ↑ Wright, Kevin M.; Sandra Skeba (1992). "Hematology and Plasma Chemistries of Captive Prehensile-Tailed Skinks (Corucia zebrata)". Journal of Zoo and Wildlife Medicine. American Association of Zoo Veterinarians. 23 (4): 429–432. JSTOR   20460296.
  17. ↑ Hazard, Lisa C. (2004). Sodium and Potassium Secretion by Iguana Salt Glands. University of California Press. pp. 84–85. ISBN   978-0-520-23854-1.{{cite book}}: |work= ignored (help)
  18. ↑ "Toxicity of Common Houseplants". University of Nebraska. 2006. Retrieved 3 October 2008.
  19. ↑ Sprackland, Robert George (1992). Giant Lizards. Neptune, New Jersey: T.F.H. Publications. pp. 113–114. ISBN   0-86622-634-6.
  20. ↑ Coborn, John (1996). Prehensile-Tailed Skinks. T.F.H. Publications. p. 64. ISBN   0-7938-0279-2.
  21. ↑ Cooper, W.E., Jr. (2000), Food chemical discriminations by an herbivorous lizard, Corucia zebrata–. J. Exp. Zool., 286: 372-378. https://doi.org/10.1002/(SICI)1097-010X(20000301)286:4<372::AID-JEZ5>3.0.CO;2-Q
  22. 1 2 3 4 Kirkpatrick, David T. (1996). "Observations on Mating Behavior of the Solomon Island Skink". Reptile & Amphibian Magazine. 7 (5): 24–31.
  23. ↑ "Corucia zebrata". CITES . Retrieved 2008-10-02.
  24. ↑ Balsai, Michael J. (1995). "Husbandry and Breeding of the Solomon Islands Prehensile-tailed Skink, Corucia zebrata". The Vivarium. 7 (1): 4–11.

Further reading

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.