The Snake that Is Both Venomous and Poisonous

Hong Kong is home to 52 native snake species, consisting of 46 land-dwelling types and 6 sea snakes. From the king cobra, the longest venomous snake in the world, to the Burmese python, the third largest, the region hosts some of the planet's most iconic snakes. Yet, anyone hiking through Hong Kong's forests might stumble upon one of the most unique, though often overlooked, species.

Snakes are usually classified into three broad categories: venomous snakes that hunt by injecting venom into their prey (cobras and vipers, for instance); constrictors that suffocate prey within their coils (pythons and boas, for instance); and a third category that neither envenomate nor constrict (garter snakes and grass snakes, for instance).

However, out of roughly 3,900 snake species worldwide, a select 20 to 30 are actually poisonous. Remarkably, these rare species are both venomous and poisonous, meaning they can deliver a lethal toxin through a bite or cause poisoning if consumed by a predator. As it happens, Hong Kong is home to one of these rare snakes: the red-necked keelback.

Paradoxically, while the number of snake species that are both venomous and poisonous is exceptionally small, the red-necked keelback remains one of the most widely distributed and frequently encountered snakes throughout Hong Kong.