The common water monitor (Varanus salvator).

Sightings of these large lizards were first officially recorded in Hong Kong between 1961 and 1963 — in Sha Tau Kok, Fanling, Stonecutters Island and Cha Kwu Ling — according to University of Hong Kong’s School of Biological Sciences. But they once believe extinct.

Now sightings are more common, in reservoirs and around water, but these are probably escapees from the thriving illegal wildlife pet trade, or released animals.

These lizards can get very large and difficult to look after, as this is the world’s second-largest lizard after the Komodo dragon. An adult can grow to 1.5 metres to 2 metres in length, although there is a record of one monitor in Sri Lanka growing as long as 3.21 metres. Yikes.

Here one forages underwater.

Many conservationists - myself included - welcome these breeding populations back into the wilds of Hong kong, as they play an important part in our ecology, both as predator and carrion eater.