Feathers fly as hunger bites and guillemots turn chick killers

HUNGER has driven guillemots to violence, leading adult birds to savage and kill chicks in neighbouring nests, researchers have found.

Two thirds of guillemot chicks monitored at a nesting site on the Isle of May in the Firth of Forth were killed by neighbouring birds, which either pecked them to death or hurled them off the cliffs.

Researchers believe the violent behaviour is due to shortages of food.

Usually, one parent would stay with the chick at the nest, while the other went searching for food. However, due to increased competition for food, both adults have started taking the risk of leaving the nest unattended.

Whereas in the past neighbouring adults would happily have sheltered a chick left alone, now they react by killing the helpless bird.

Kate Ashbrook, lead author of the report, in the Royal Society journal Biology Letters today, said: "The reason they are attacking chicks is because they don't want to provide any care for them because they have got their own chick."

Out of 99 chicks, 66 were killed during the nesting season in 2007.

The site has been monitored for the past 30 years, and in that time it has been rare to see a chick killed.

Ms Ashbrook, who is studying for a PhD at the University of Leeds, said: "It was very upsetting to see it happen, especially to so many chicks. It was really sad to see birds that are quite social and happy to shelter each other's chicks attacking as the aggressors. It's shocking."

She said when left alone, the chicks often wandered towards neighbouring nests, perhaps hoping for warmth or food, but instead were attacked.

As a result, an average of just 0.28 chicks per breeding pair fledged on the Isle of May in 2007, compared to normal levels of 0.7.

Professor Sarah Wanless from the Centre for Ecology & Hydrology, who has been monitoring the colony for 30 years, said: "This research highlights how fragile the social fabric of a seabird colony is. Having a stressed, hungry neighbour isn't good news if you're an unattended guillemot chick."

Dr Paul Walton, from RSPB Scotland said it was "very worrying" and "quite abnormal behaviour".