Hunting for snakes and their secrets

Snakehunters have been scouring swamps for water snakes that could help researchers discover why some species left the land for the sea

By Lea Wee

WHEN the sun went down and the evening calm settled over the swamps, the 'snakehunters' would spring into action.

In what became a frequent occurence throughout last month, groups of volunteers would meet at Sungei Buloh Nature Reserve and Pasir Ris Park just after dusk.

In the moonlight, they would wade through the muddy mangrove waters where, equipped with just their bare hands, torchlights and plastic bags, they would try to catch the nocturnal water snakes belonging to a group called the Homalopsinae.

Back in the laboratory at the Raffles Museum of Biodiversity Research, National University of Singapore, visiting professors Harold Voris and Daryl Karns would 'tag' the snakes and do the necessary measurements before releasing them back into the waters in which they were found.

Researchers inserted microchips into some of the snakes so they could 'radio-track' their movements in the mangroves. This is the first time this has been done for water snake research in South-east Asia.

The two professors from the American Field Museum of Natural History in Chicago are here on a two-month visit hosted by Professor Peter Ng of the Raffles Museum.

Said Prof Voris: 'During our stay here, we hope to find out how many species of Homalopsinae snake there are in Singapore, and how their populations are doing.'

Prof Ng said this information would help the Raffles Museum and conservation agencies here to conserve the snakes, as well as the mangrove habitats in which they live.

More than 30 species of the Homalopsinae have been found in various parts of South-east Asia. Unlike water snakes found in other parts of the world that inhabit mainly freshwater areas, many Asian water snakes spend most of their time in salt water.

Prof Voris hoped his research would ultimately shed light on why some organisms 'decided' to give up life on land and go back to the sea.

'In the long history of evolution, snakes and other reptiles came on land more than 100 million years ago. But about 60 million years ago, several groups of reptiles, including some related to dinosaurs, re-invaded the sea. We want to find out how - and why.'

Their diet could provide a clue.

Prof Voris found that these snakes feed on fish, crabs, and other shelled food, unlike the land snakes that tend to favour small animals like mice, rats and lizards.

What is less palatable is that Homalopsinae snakes are slightly venomous, though they seldom bite, and even if they do, they leave no more than a stinging sensation.

This did not deter more than 30 people from responding when the Raffles Museum sent out a call last month for'snakehunters'.

They ranged from university students to volunteers from the Nature Society (Singapore) and the Singapore Zoological Gardens.

Undergraduate Marilyn Cheng, 20, was among the first to sign up. She has since gone on about six trips. 'It's a real thrill when you spot the snake,' she said.

'My friends were shocked when I told them I was catching snakes, but how often does one get a chance to do something like that?'