The island of Madagascar, an ancient chunk of the Indian subcontinent that somehow ended up very close to Africa’s eastern shores, has always been a magnet for biologists. And not surprisingly so: the place is bursting with ancient and endemic lineages, and in some groups of organisms 100% of their species can be found nowhere else. Lemurs usually get the most attention, but other animal groups are equally deserving gasps of wonder, and none more so than the mind-blowing Leaf tailed geckos (Uroplatus.)
When I first held the Giant Leaf tailed gecko (U. fimbriatus) in my hand after catching it in the rainforest of northern Madagascar, it felt as if I were holding a living, breathing beanie baby. It was the size of small puppy, and its skin was velvet-soft and warm. The gecko’s hands grasped my fingers the way a newborn holds its parent’s finger – softly but firmly at the same time. Having this animal sit in my hand was one of the most pleasant tactile experiences of my life.
Of course, Leaf tailed geckos are not sweet, fuzzy toys – like all geckos, they are efficient killing machines, predators capable of catching and swallowing remarkably large prey. The smiley face of the gecko hides incredibly sharp teeth, and lots of them. Leaf tailed geckos have the highest number of teeth of any amniote (which includes most of terrestrial vertebrates) – their lower jaw can have 97-148, while the upper between 112 and 169. That’s, potentially, 317 teeth! To put it in perspective, other geckos have between 100-180 teeth, while our puny human jaws carry only 32 teeth.
Why so many? Nobody knows for sure, because virtually nothing is known about their feeding behavior in the wild. In captivity they will eat almost anything that moves, but in their native habitat, the wet and humid forests of Madagascar, they may be targeting frogs, which are a remarkably species-rich and abundant group in that part of the world. A huge number of small, sharp teeth is likely to help hold such slippery prey. A higher than usual number of teeth may also be very useful in capturing moths, whose scale-covered bodies are as difficult to grasp as those of wet amphibians.
About 20 species of Leaf tailed geckos are known, including several newly discovered species that await their formal description. Alas, many of these animals are already on the brink of extinction, and some may already be gone. Over 90% of the natural forest habitat of Madagascar has been destroyed, and with it countless species, including several Leaf tailed geckos. Illegal pet trade in these lizards is contributing to the decline but, interestingly, it also contributes to the discovery of the previously unknown species: the largest species of Leaf tailed geckos (U. giganteus), was first collected by amateur herpetologists and its photos appeared in pet trade literature 5 years before the official description, prompting a more scientific interest in this species.