That Reptile Blog – Reptile, Amphibian and Exotic Pet Care and Information

The 1,200+ skink species form the largest lizard family, Scincidae, and among them we find quite a number of unusual animals. Yet the prehensile-tailed skink manages to distinguish itself as unique in not one, but many ways.Largely unknown in the pet trade until the late 1980’s, these arboreal skinks became widely available when logging in the Solomon Islands brought their formerly inaccessible treetop homes crashing to the ground, and left the lizards in reach of collectors. I and others noticed right away that they were quite different than anything we had run across previously.

A Highly Social Lizard
The limited field studies suggest, and our captive observations support, that prehensile-tailed skinks live in hierarchal colonies (a reptilian social group is known as a circulus) and exhibit a variety of highly-developed social behaviors. Group members seem to recognize one another by scent, and mark their territories with waxy secretions. Although often found in pairs, up to 10 individuals have been collected from a single tree hollow, but the functioning of these groups is not understood.

A Placenta and a Giant Offspring
Females, which average 24 inches in length, have a true placenta. They produce 1, rarely 2, huge (to 13 inches) offspring after an amazingly long gestation period of 6 – 8 months. Esteemed veterinarian and herpetologist Dr. Kevin Wright has likened this feat to that of a woman giving birth to a 6 year old child!

Complex Parental Care
The young stay close to their mothers for some time and the females become very aggressive towards people and other skinks after giving birth. Although we do not as yet understand the interactions between adults and young, it is quite clear that those reared in isolation exhibit, if you will, “anti-social” behavior (they are noticeably more aggressive than other skinks, to the point of charging people opening the door of their cages).

Coprophagy (eating of feces) is common, and some believe that this provides the young with important intestinal flora. Breeding occurs year round in the wild and captivity. The young begin feeding at about 10 days of age, and reach sexual maturity in 10 months to 1 year.

Much More to Learn
All told, a strange and fascinating beast. Although captive longevities approach 25 years, we have yet to scratch the surface when it come to understanding prehensile-tailed skink social interactions.

The American Association of Zookeepers has posted an informative article on this species’ fascinating social structure at:
http://www.aazk.org/forum/viewtopic.php?pid=1320

Introduction
The family Scincidae, the skinks, contains over 1,200 species – more than any other family of lizards.  Skinks range throughout the Eastern and Western Hemispheres, reaching their greatest diversity in Southeast Asia, Australia and Africa.  Among its members we find some of our most common pet reptiles and least-known lizards.  The following information is meant to introduce you to their wonderful diversity of forms and lifestyles.

The Unusual Giant
The group’s largest member, the Prehensile-Tailed Skink, Corucia zebrata, reaches 28 inches in length and is unique in a number of ways – it is entirely arboreal, has a prehensile tail, is limited in range to the Solomon and surrounding islands, feeds on leaves, gives birth to 1 (rarely 2) large offspring after a gestation period of 8-9 months, and seems to have a complex social structure that includes parental care of the young.

Lifestyle and Diet
Typical skinks are elongated in form with small legs and shiny scales.  Most are secretive and, although often diurnal (active by day), spend a good deal of time below rocks, logs or leaf litter.  Legs are absent or reduced in many species, including the various African and Middle Eastern “Sandfish” (Shenops and other genera) which seem to swim as they wriggle through shifting sand dunes.  Most skinks are insectivorous, but many also take fruit, carrion and small mammals, birds, reptiles and amphibians.  Several consume vegetation exclusively.

Skink Reproduction
Almost half of the known species bear live young, and a number of these have evolved a primitive placenta.  Many oviparous (egg-laying) skinks guard their eggs, and there is evidence that females may move the egg clutch in response to disturbances.

A Few That Break the Mold
Quite a few skink species depart from the group’s typical body plan and lifestyle.  New Guinea’s Fojia Skink, Fojia bumui, for example, has plate-like scales down the center of the back and granular scales along the sides.  It clings to vertical rock surfaces along streams, dives after small invertebrates that swim by, and climbs into bushes to sleep on large, sturdy leaves.  The genus Egernia contains at least 23 species that live in extended family groups and exhibit complex social behavior.  There are also aquatic, arboreal and fossorial skinks, some of which have scale-covered, sightless eyes.

Carl Kauffeld and New York City’s Lizards
While growing up in NYC, I was pleased to learn that New York State is home to 2 skink species – the Five-Lined Skink, Eumeces fasciatus and the Coal Skink, E. anthracinus. They are, in fact, the state’s only native lizards – Staten Island’s Eastern Fence Lizards were introduced there by none other than the Staten Island Zoo’s famed reptile man, Carl Kauffeld (to provide a source of food for lizard-eating snakes) and the Italian Wall Lizard of the Bronx, Queens and Nassau County is a pet trade escapee (I have observed free-living Wall Lizards for some time now…more on them to come).

Further background information on skinks, with links to individual species, is available at:
http://www.tigr.org/reptiles/families/Scincidae.html