They might knock off a couple of leaves during their entrance and exit to the nest which will be more frequent until the nest is empty. There might be an unrelated problem developing too.

There are quite a few defoliated branches sticking out in a widespread area - unlikely to be birds nesting within causing that. Wait till they've finished nesting and gone, then have a good look at the shrub, inspecting backs of leaves, stems and trunk or woody stem at the base for any problems.Cut back the bare parts. Prunus laurocerasus, (common name cherry laurel) are extremely resilient, and usually need cutting back at least biennially if you don't want them to reach their treelike height of 25-30 feet anyway.

Yes Bamboo, we used to have laurels as a hedge around our garden and they were as tough as old boots - we just couldn't cut them back enough over the years. Great for screening road noise and pollution.

Thanks Bamboo. The laurel does need to be cut back. I at the moment I have nothing to cut them back with. Doves seem to have been mesting for a long time.

You will need a pair of loppers - Wilco's do some reasonably priced ones, as does Wickes.