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.

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 meaning "shimmering". This is in reference to Gray's description of "a play of colors effect from the body scales".

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.

Distribution and habitat

200px|thumb|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. 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. 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.

Biology

thumb|left|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 when fully grown, with the tail accounting for more than half this length.

The Solomon Islands skink has a long, slender body, strong, short legs, and a triangular shaped head with small round eyes. The skink has a strong crushing jaw but the teeth are small and used for eating plant material. Male Solomon Islands skinks tend to have a broader head and a more slender body shape than female skinks. This includes the somewhat toxic (due to high concentrations of calcium oxalate) Epipremnum pinnatum (cf. E. aureum) plant, which the lizard eats without ill effect. Juvenile skinks often eat feces from adults in order to acquire the essential microflora to digest their food. 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.

Reproduction

The Solomon Islands skink is one of the few species of reptile that lives in a communal group known as a circulus. The newborn skink is of a large size compared to its mother; the northern Solomon Islands skinks are approximately in length and weigh , whereas the common Solomon Islands skinks are and when they are born. 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.

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.

Footnotes

References

Further reading

  • Boulenger GA (1887). Catalogue of the Lizards in the British Museum (Natural History). Second Edition. Volume III. ... Scincidæ ... London: Trustees of the British Museum (Natural History). (Taylor and Francis, printers). xii + 575 pp. + Plates I-XL. (Corucia zebrata, p. 142).
  • Goin CJ, Goin OB, Zug GR (1978). Introduction to Herpetology, Third Edition. San Francisco: W.H. Freeman and Company. xi + 378 pp. . (Corucia zebrata, p. 301).
  • Parker F (1983). "The prehensile-tailed skink (Corucia zebrata) on Bougainville Island, Papua New Guinea". pp. 435–440. In: Rhodin AGJ, Miyata K (editors) (1983). Advances in Herpetology and Evolutionary Biology: Essays in Honor of Ernest E. Williams. Cambridge, Massachusetts: Harvard University Press. xix + 725 pp. .
  • Honolulu Zoo Species Profile
  • Santa Barbara Zoo Species Profile
  • ISIS Abstract