As you roam through the woods at dusk, a speck springs swiftly – eek! Take it easy! It's a greeting from the Hong Kong Tree Gecko (Hemiphyllodactylus hongkongensis), a gecko with a body length of just 8cm that hides neither deadly jaws nor killer claws. Even if Hong Kong Tree Gecko never makes its enemies flinch like a crunching crocodile, it is definitely top-notch for its endemism to Hong Kong, proven just a year ago.
Among the eight locally recorded species of geckos, the Hong Kong Tree Gecko, as its name suggests, is the only species found exclusively in Hong Kong. The first finding of Hong Kong Tree Gecko could date back to the 1990s. Yet, the discovery was not validated owing to inadequate data of the genome map. Taking reference from the predecessors’ effort, local scientists started collecting specimens and studying the gecko intensively in 2016. Two years later, the Hong Kong Tree Gecko was confirmed as being endemic to Hong Kong by virtue of the official declaration in an international academic journal in 2018.
Thus far, Hong Kong Tree Geckos could only be seen in southern Hong Kong. There are voices for preserving their extraordinary habitats, such as including them in Sites of Special Scientific Interest or country park.
Using Claws and Tail to the Full
With no more than 8cm total length, the petite Hong Kong Tree Gecko preys on even smaller insects, like ants. Meanwhile, being mid-low level in the food chain, Hong Kong Tree Gecko may fall prey to snakes and frogs. Hence, its protective colouration provides excellent camouflage in order to veil itself in the nocturnal hours.
Like other gecko species, there are millions of setae attached on the toe pads of Hong Kong Tree Gecko. On the tip of each seta are spoon-shaped spatulae, these “toothbrushes” help them to crawl on any vertical surface in any direction with ease. Also, Hong Kong Tree Gecko could entwine its tail in twigs. No wonder you could see them scurrying agilely in the woods.
On the other hand, Hong Kong Tree Gecko has different structures of fingers and toes than other gecko species. The divided lamellae on the fingertips and toe tips of Hong Kong Tree Gecko notably resemble leaf-vein patterns. Another distinctive characteristic focuses on the clawless thumbs, which definitely makes Hemiphyllodactylus one of a kind!