29 November 2005

The future of Southland boasting New Zealand's biggest population of the endangered black-billed gull, is under threat as the colonies become fast-food for predators.

Otago University PhD student Rachel McClellan is carrying out a three-year research programme to determine why the region's species is in rapid decline and was shocked at what she caught on infra-red camera.

In a little over two months one cat and possibly one individual ferret had single-handedly killed hundreds of young chicks.

Ms McClellan likened the colony to a fast-food joint for introduced predators such as cats and ferrets.

“They have food on tap, whenever they want it” she said. “They don't have to search – it's about as easy as it gets for a predator”.

Last week while changing the camera batteries on the banks of the Aparima River, Ms McClellan saw the ferret run into the colony in daylight.

“I couldn't believe my eyes” she said. “The ferret came in at high speed, paused at a nest for a few seconds, then hurtled over to where the chicks were gathered at the water's edge in crèches.

“Before I had time to think, it was running straight for us, with a chick in its mouth. It was so intent on what it was doing it didn't even spot us until it was just a metre away. It got such a fright it dropped the chick and took off”.

The ferret killed the two tiny chicks in the nest where it had briefly stopped.

The black-billed gull had undergone a huge decline in Southland – perhaps as much as 80 per cent in the last 30 years.

In June this year the World Conservation Union listed the gull as endangered, the same classification as the blue duck and the takahe, making it the most threatened gull in the world.

Ms McClellan said the colony being filmed was one of the largest in Southland this year numbering about 5000 gulls and should have produced several thousand chicks.

However, it looked like only a few hundred chicks may have survived, and most of the adults have deserted the colony.

The researchers are banding chicks this week which will help to verify the numbers.

Ms McClellan said she has had a great response from farmers, whitebaiters and other members of the public who have reported their sightings of the colour-banded gulls.

Over one thousand Southland gulls have now been banded.

“They are turning up all over the place”, Ms McClellan says, “I even got a report this weekend of a chick banded at Bayswater on the Aparima River last year that is presently part of a colony on the Waitaki River in Northern Otago”.

She is still very keen to hear from anyone who has seen banded birds following ploughs or on the coast. They can contact her on +64 3 218 2705.

Her work is being aided by two research assistants, Jennifer Lawn and Chris Garden with the work funded by Meridian Energy, Environment Southland, the Department of Conservation and Otago University.

ENDS

For more information please contact Rachel McClellan, Phone +64 3 218 2705, cell 0274 065 472 or email:  rachel.mcclellan@xtra.co.nz