Exotic snake species from Africa, Southeast Asia and elsewhere are making homes for themselves in Hong Kong, after being abandoned by pet owners or escaping from food shops, according to conservation officials.
Hong Kong is home to at least 52 indigenous snake species, or one-fourth of China's total. But thriving international pet trades and irresponsible pet owners have in recent years introduced new and exotic species to the list.
Calabar pythons, originally from Africa, and the striped-tailed rat snake from Southeast Asia and mainland China are among the exotic species occasionally spotted by a dedicated ecological survey team from the Agriculture, Fisheries and Conservation Department.
"They are usually abandoned by their owners and released in the wild. But that might not be in their best interests," said Fung Tze-ho, a member of the survey team, which was formed in 2002.
Fung said these exotic species inevitably compete for food with native snakes. The stripe-tailed rat snake, for one, has already bred locally and established a population here, the team has learned.
Also discovered living in Hong Kong is the red-headed rat snake, originally from mainland China, which is sometimes sold at snake meat or soup shops. Its release into the city may have even been intentional, officials said.
The snakes encountered in Hong Kong's wild areas are still the native ones, like the bamboo snake, Chinese cobra, red-necked keelback, many-banded krait and common rat snake.
While country parks provide good shelter for most snakes, other favourite habitats - such as agriculture fields - are gradually being replaced by development, Fung said.
But gauging how this is affecting their population is no easy task, he said. Many snakes live in habitats inaccessible to people, while others are too shy to come out of hiding in the daytime.
They are most commonly seen in fringe areas between green belts and villages, Fung said. "Beneath rubbish bins and inside or near drainage [channels] are common places where snakes are found. Some can be found sunbathing on paved concrete surfaces," he said.
Many people have misperceptions about snakes as evil and aggressive, and sometimes overreact, beating snakes whenever they see them, he said.
"We have seen some snakes driven over on the road as they were sunbathing, while others have their heads crushed flat by overreacting humans," said Fung. "In fact, many snakes are quite afraid of people, and they don't challenge humans unless they are provoked or guarding their nests," he said.
Fung advises hikers to be patient when they encounter snakes, which normally slither away when they see people.
"If they stay where they are, they are probably guarding something, so it is better to take a different route," he said.