A £50,000 project to strengthen a bridge has been halted by wildlife for the second time after nesting birds were found.

Work on the scheme to remove the 7.5-tonne weight limit on Little Ayton Bridge, near Stokesley, was due to start in March.

But work did not get under way until May because the bridge is close to the trout spawning area of the River Leven, which it crosses.

Now, the work has been stopped by the discovery of a grey wagtail nesting in the abutments.

The Wildlife and Countryside Act forbids any nesting birds to be disturbed.

North Yorkshire County Council conservationists say it will be about three weeks before the bird and its six chicks fly the nest so that work can resume.

John Smith, client manager for bridges, said: "They are nesting in the abutments so we can't do any work at all. It would be like cutting the branches off a tree where a bird had its nest.

"It is a problem because we have been trying to get the job done for a long time. This is one of those things that you can't really control.

"The cost of the delay in financial terms is minimal, but it is affecting people because the road closure will be going on until later in the year."

Wilf Noble Construction, of Whitby, is carrying out the work. A temporary bridge has been installed for pedestrians and a vehicle diversion is signed.

Councillor Peter Sowray, the county council's executive member for environmental services, appealed for people living in the area to be patient about the delays.

He said: "The county council has experienced some setbacks with the strengthening work on Little Ayton bridge. We hope that members of the public will understand that the delays are not of our making.

"While nature takes its course our contractors are working on other aspects of the job.

"The temporary bridge provides an adequate crossing and the fully strengthened bridge should be operational by the middle of August."