Dog walkers are being asked to keep their pets on leads along parts of the East Lothian coast after sea ducks were found to be deserting the area.
Only 1,500 Eider ducks were found along the 25-mile stretch
A report published by Scottish Natural Heritage suggested that eider ducks were leaving the coastline to breed on offshore islands.
Disturbance by dogs was thought to be the main reason for the switch.
Researchers studied a stretch of the coast between Longniddry and Dunbar in East Lothian.
The report, Site Condition Monitoring of Breeding Eider on the Firth of Forth Coastline, was commissioned by Scottish Natural Heritage (SNH) from Murray Survey of Dunkeld as part of ongoing work on monitoring Sites of Special Scientific Interest (SSSIs).
The study's fieldwork took place last year. It showed that very little of the stretch of coast was used as a breeding ground by the birds, except for tidal rocks safe from disturbance.
Some eiders had tried to lay and incubate eggs, but the recreational pressure on that part of the Firth of Forth meant visitors and their dogs had caused the female ducks to leave the nests.
The study counted 1,500 eider ducks on the stretch of coastline between Longniddry and Dunbar.
That figure had not changed since 2000. Experts suggested that the population was remaining stable because because the birds had moved to the offshore islands to breed.
Lachlan Lamont, SNH's Firth of Forth officer said: "The East Lothian coast is a beautiful area to walk in but we would ask people to take care, especially in the dune areas, and if they see nesting birds to give them a wide berth.
"If you have a dog with you please keep it on a lead and never allow it to chase birds into flying off.
"Apart from frightening birds, it only takes a minute or two for predators to take advantage of a bird being scared off the nest."
East Lothian Council landscape and countryside manager, Maree Johnston, said: "The East Lothian coastline is very popular, with high numbers of visitors choosing to come to the area for recreational purposes."