Nature's Dead Leaves and Pez Dispensers: Genus Uroplatus (Flat-tailed geckos)

by Petra Spiess

There are few reptile genera that can boast more bizarre-looking species than the genus Uroplatus (Flat-tailed geckos). The largest member, Uroplatus fimbiratus, opens its mouth so wide during its threat display, it looks like it has a flip-top head, invoking images of childhood pez dispensers. One of the smaller members, Uroplatus phantasticus, has a morphology that so closely resembles a dead leaf, its tail even has irregular patches missing from the margin to simulate decay. The entire genus is endemic to Madagascar and contains a total of 9 species including Uroplatus fimbriatus, U. phantasticus, U. ebenaui, U. lineatus, U. sikorae, U. henkeli U. alluaudi, U. guentheri and the recently described U. malahelo. As this genus is generally found only in primary, undisturbed Madagascar forests, it is quite possible that more species will be discovered as more research efforts are directed at cataloguing Madagascar's native reptiles. Unfortunately, these magnificent geckos, and many other Malagasy natives, are plagued by extensive habitat disturbance as the primary forests are cut down to make way for agriculture and livestock. It is estimated that if deforestation continues at its present rate, only small patches of primary forest will remain in Madagascar by the year 2020 (Glaw and Vences, 1994). Many members of this genus have been reproduced in captivity, but not in enough numbers to supply the demand of the pet trade, so many Uroplatus species are still exported. With the strong threat of population decline through habitat loss, herpetoculturists should be encouraged to set-up and maintain viable colonies of this genus to relieve some of the collection pressure off of wild populations.

 

A Gallery of Bizarre Species

Uroplatus fimbiratus is the largest species in the genus, and one of the largest geckos in the world, with a snout-to-vent length (SVL) of 140-190 mm (5.6-7.6 in). The body, especially the head and the semi-prehensile tail, are extremely flattened. Huge, yellow-brown or beige eyes with vertical pupils bulge from the head. The ground color is usually a mottled brown or blackish brown with occasional irregular patches of yellow or yellow-green. The patches of yellow interspersed with the mottled brown shades mimic a lichenous tree truck almost exactly. Fimbriatus spends almost the entire day sleeping, head down, on the trunks of trees. A fringed flap of skin that hangs off of the bottom jaw helps the gecko to break up its body outline while in this position. The primary defense of fimbiratus, and of all of the species in this genus, is extremely cryptic camouflage. Uroplatus blend perfectly with the background and move very little during the daytime, making it difficult for predators to notice them. Fimbiratus , if disturbed, does have a rather impressive threat display. An agitated fimbiratus will push itself up from its resting spot on all four limbs, and gape its prodigious mouth widely to display its bright red tongue. This threat display is certainly effective against the Malagasy people, as they regard this species with great trepidation and avoid disturbing it.

Uroplatus henkeli has a SVL of 120-160 mm (4.8-5.6 in) and is very similar to fimbriatus. The sexes in this species have different coloration, the males being yellowish-brown and the females more greyish. Henkeli have wide mottling, giving them in some cases, a "calico" appearance. Both sexes have pinkish-brown or beige eyes with red spots (Glaw and Vences, 1994). Both fimbriatus and henkeli are capable of noticeable color changing (generally from light to dark or vice versa). When threatened, henkeli will gape as fimbiratus does, but if grasped will also let out a loud distress call.

Uroplatus phantasticus and U. ebenaui are very similar, both have a morphology that resemble dead, decaying leaves. Both species have a ground color of brown, grey, tan or orange and their skin has a pattern that closely imitates leaf veins. The average SVL of each species is 57 mm (2.28 in) for phantasticus and 56-66 mm (2.2-2.6 in) for ebenaui (Glaw and Vences, 1994). The tail of phantasticus is longer and more elaborate in detail, often having areas from the margin missing that give the tail the overall appearance of a decaying or insect eaten leaf Ebenaui has a short, sometimes arrowhead-shaped tail. Both of these species have extremely cryptic morphology and coloration, against the forest floor, they are virtually invisible. Both species spend the day at the base of tree trunks, and subsequently lack the dermal flaps on the body and tail that helps the larger species to break up their body outline. Ebenaui and phantasticus do however, posses a spine-like dermal flap on each eye, behind the head, down the spine, and on the limbs (Henkel and Schmidt, 1995).

Uroplatus sikorae is medium sized, with a SVL of 86-123 mm (3.4-4.9 ). This species is similar to other members of the genes in color, it is bark colored and patterned. Sikorae often has irregular patches of green that resemble the moss found on the trunks of trees where its spends the majority of the day. Uroplatus guntheri is smaller than sikorae, with a SVL of 72-79 mm (3-3.1 in), and is grey or yellowish brown in color. This species also has a vertebral stripe running from the base of the head to the tip of the tail. An interesting flight behavior has been noted in this species. When threatened, guntheri will roll into a ball, drop to the ground, and speed off into the underbrush. U. alluadi is very similar in appearance to guntheri, but is reported to be rare (Glaw and Vences, 1994). The recently described U. malahelo (Nussbaum and Raxworthey, 1994) is similar to both U. alluadi and U. guntheri in size and coloration. U. lineatus is a beautiful and delicate gecko, with striking pattern and coloration. It is the third largest in the genus. Lineatus has very few dermal flaps, giving it a rather "smooth" appearance. The ground color is yellowish-brown with many longitudinal stripes of varying brown and yellow shades. There is a dermal spine above each eye that make this species appear as if it has eyelashes. Of the 9 species, lineatus is the most divergent from the "look" of the genus. This is attributed to the fact that lineatus is reported to live in bamboo forests, a niche no other Uroplatus species share.

The most commonly kept and bred species of the genus are U. fimbriatus, U. henkeli, U. phantasticus, U. ebenaui, and U. guntheri. Captive bred specimens of the above species can be purchased from breeders, and are vastly superior to imported wild animals in every respect. Imported animals are stressed from shipping and are invariably loaded with parasites. Uroplatus are not currently protected by CITES or listed as threatened, but if current deforestation trend continue, this genus will most likely be so in the future.

Captive Care

Captive care is similar for the entire genus, with a few modifications for species size or temperature preferences. All species come from areas with very high annual rainfall, so the captive enclosure should have very high (75-100%) humidity most of the time. Temperatures can range from 77-84 degrees F (25-29 degrees C) for U. fimbiratus, U. henkeli and U. sikorae. U. phantasticus, U. ebenaui, and U. guntheri prefer lower temperatures, with a range of 66-78 degrees F (19-26 degrees C). Enclosures housing Uroplatus should include live plants and climbing branches. With species that spend the majority of the day on tree trunks, it is useful to include vertical slabs of cork bark. The geckos will often choose to sleep on these objects (although they blend so well it can make them difficult to spot in the enclosure). The larger species, U. fimbriatus and U. henkeli need a rather large enclosure, with minimum dimensions of 2 x 4 x 3 ft (60 x 120 x 90 cm) for a pair. The smaller species may be kept in enclosures with minimum dimensions of 2 x 3 x 2 ft (60 x 90 x 60 cm). All enclosures should be cross-ventilated. Suitable substrates for Uroplatus housing are bark chips (not cedar) and peat moss. A mixture of peat moss and bark is both aesthetically pleasing and easy to spot clean. Dry substrates such as newspaper or wood shavings should not be used to house Uroplatus because all of the species lay their eggs on the floor of the enclosure. Full-specturm lighting that emits UVB should be included in the enclosure. There is anecdotal evidence that irradiation with UVB improves the breeding performance of Uroplatus, most notably fimbriatus, and it will benefit any plants in the enclosure. A naturalistic photoperiod should be provided.

All species are insectivorous and readily accept domestic crickets, mealworms, roaches, wax worms, moths, and grasshoppers. The larger species will accept baby domestic mice from feeding tongs. Uroplatus are exclusively nocturnal, so it is recommended that prey items be offered in the evening hours. A feeding dish may be used, but Uroplatus feed with such gusto that they can damage their snouts on hard dishes. One author solved this problem by using one pint, plastic deli cups with a thin sponge at the bottom cut to fit (Burger, 1993). When leaf-tailed geckos spot a prey item, they focus on it, raise and wave their tail, and then launch themselves towards the food in a cat-like leap. All prey items should be coated with a high quality calcium supplement. To ensure that each specimen is receiving enough calcium, some breeders give a calcium/ fruit baby food mixture through a dropper by restraining the animal and placing drops on its snout. This method works well, especially if food items are broadcast into the enclosure and have time to remove some of their calcium coating.

Breeding

Uroplatus breed from spring to summer in the wild, with eggs being deposited on the forest floor in late summer (Russel, 1996). In captivity, clutch size ranges from 2 to 4 eggs, with several clutches during the year possible. The developing eggs can be viewed through the skin of females when egg-laying is imminent. Some breeders house the sexes separately, only introducing them for short periods for copulation. Other breeders house pairs or trios together the entire year. Both methods have produced successful results. All species will lay their eggs on, or close to, the floor of the enclosure. The eggs should be artificially incubated at 78 degrees F (25.5 degrees C) in vermiculite (1:1 ratio vermiculite to water by weight). The incubation period varies by species from 60 to 90 days. Hatchlings should be housed in the same manner as the adults.

Conclusion

The bizarre and fascinating appearance of the genus Uroplatus makes these geckos unique in any collection. The habitat that is necessary for the existence of these geckos is rapidly disappearing. Captive breeding of this genus can help conservation efforts by relieving some of the exportation pressure. Hopefully, conservation efforts to protect the primary forests of Madagascar will be successful, so that the genus Uroplatus can astonish and captivate generations of herpers to come.

 

Literature Cited

Burger, R. M. 1993. "Leaftailed geckos: some notes on the maintenance and reproduction of Uroplatus henkeli (Bohme & Ibish). Dactylus. 1(4):11-16.

Glaw, F and M. Vences. 1994. A Fieldguide to the Amphibians and Reptiles of Madagascar. 2nd ed. Germany: Moos Druck, Leverkusen

Henkel, F. W. and W. Schmidt. 1995. Geckoes. Krieger Publishing Company. Malabar, Fl.

Nussbaum, R. A. and C. J. Raxworthy. 1994. Herpetologica. 50:319-325

Russell, M. 1996. "Natural history and captive care of leaf-tailed geckos with emphasis on Uroplatus fimbiratus". Vivarium. 7(5):6-9.



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