13 October 1995

Bar birds from barns

In this special feature we examine the latest ways to keep pigeons off crops, and a new computer programme to ease insect pest management in stored grain. Robert Harris starts the ball rolling with a look at keeping grain buildings bird-free – an important but often ignored part of management

TOO many grain stores offer an open invitation for birds to feed, roost and nest in all year round.

That cannot continue, says Carey Coombs, senior wildlife consultant at ADASs wildlife unit in Bristol.

"Birds have always been a problem in grain stores. But nobody worried about it too much until recently."

Direct grain loss from feeding is not the main problem. A feral pigeon can eat up to 30g (1.1oz) of grain a day, but it would take a major infestation to burn a significant hole in the farm budget.

It was the salmonella scare that changed the perception of birds from minor irritation to major pest, says Mr Coombs.

Current legislation – the ministry Code of Practice for the Control of Salmonellae and the Food Safety Act (1990) – ranks birds alongside rodents and insects as potential contaminators of food.

"There have been cases where disease has been traced to birds," says Mr Coombs. "For example, in the early 1980s, an outbreak of Newcastle disease in poultry in the midlands was caused by roosting pigeons in Liverpool docks contaminating food. Although such cases are not common, the potential is always there."

Droppings are the main hazard. But feathers and nesting material contain mites and insects and are equally likely to lead to rejection by buyers, he adds. Better traceability along the food chain increases that risk. "Buyers are entitled to come and look at suppliers facilities, and are likely to do so more in future.But the problem is avoidable."

Typical protection costs

19mm net£0.80-£1-10/sq m

38mm net£0.50/sq m


spikes from£ 4.50/m

Repellent gel£0.85/m

Wire coils£3/m