THEY may only be doing what comes naturally, but a flock of pigeons yesterday had the High Court in a flap.

The country's finest legal minds have been poring over pigeon droppings to determine who is responsible for cleaning up - and the decision may have legal implications for a similar long-running wrangle in North Yorkshire.

Railtrack will be left to pick up the bill for dealing with the nuisance caused by pigeons nesting underneath a railway bridge in south London.

The London Borough of Wandsworth argued that the fouling amounted to a public nuisance and Railtrack was responsible for preventing the birds from roosting.

Railtrack had denied responsibility for the pigeons or for the cost of putting up netting to keep them away.

But Mr Justice Gibbs said that although Railtrack was not to blame for the presence of the pigeons, it had failed to solve the problem within a reasonable time.

He said Railtrack should pay any "reasonable" cost for dealing with the nuisance, although he said it did not mean all bridge owners were responsible for problems caused by roosting pigeons.

Immediately after the case, Hambleton District Council seized on the possible implications for its own wrangle with Railtrack over pigeon nuisance at two bridges at Romanby, near Northallerton.

David Steele, the authority's environmental unit manager, said the droppings had caused problems for pedestrians by making the pavement slippery.

Netting had been put up to stop the pigeons settling, but was taken down after some got trapped and died.

He said: "We will be looking at this again in the light of this case to see if there is anything more we can do. We will talk to our solicitors to see if it is setting a precedent."

A Railtrack spokesman said the judge had not created a precedent and the droppings problem at each bridge would have to be considered separately.

He said: "We're considering whether to appeal against the decision. We're not responsible for actions of wild animals.