Birds in the Pallikaranai marshland are facing a new form of threat — stray dogs.

Naturalists say a pack of about 10 stray dogs frequently enter the marshland and devour the birds found among the reeds.

Members of Environment Monitoring and Action Initiating (EMAI) E. Seshan and P. Ganapathy, said while visiting the marsh on Sunday evening they were shocked to see a pack of stray dogs wading into the water. Such behaviour among dogs had never been noticed before, they said.

“We thought they were trying to cross the wetland but as we watched them, we realised that they were on a mission. They were hunting down the water birds that dwell there. First the pack of dogs teamed up, surrounded a bird that was flushed out from the reeds and hunted it down. It seems to be a regular activity there. A similar incident occurred on Monday morning too,” they said.

On Monday, when they were at the marshland, they saw a small group of purple swamphen foraging among the water hyacinth. Suddenly, a pack of dogs entered, targeted one of the birds and charged at it. Within seconds three or four dogs had come together and in no time, the bird was ripped apart, and was taken into a bush to be eaten, they said.

The stray dogs particularly hunted water birds that can take to the air only after a small run-up. This dog population needs to be controlled to safeguard the birds of Pallikaranai, the volunteers said, adding that once they tried to shoo away the dogs, but they snarled and charged at them. This only indicated they had lost the fear of humans, they said.

The birds that inhabit and breed in Pallikaranai have always been under threat from humans poaching in the marshland, said T. Murugavel, project coordinator, EMAI.

Birds such as purple swamphen, Indian spot-billed duck breed among the water reeds and the red-wattled lapwings breed in the grasslands on the fringes. These birds, particularly the young ones, will be an easy prey for the stray dogs, he observed.

K.V. Sudhakar, president, Madras Naturalists’ Society, who has been visiting the marsh for the past 25 years, said the birds there used to face a threat from Narikurava poachers. Baiting the birds with a dead egret, they would shoot the birds as soon as a flock landed.