- Cumbria Wildlife Trust said it had received multiple reports of "alarming" incidents at South Walney Nature Reserve near Barrow.
- It is urging visitors to stick to clearly-marked paths away from beaches which are out of bounds.
Dog walkers, beach-goers and drone users are disturbing nesting birds at a nature reserve, conservation chiefs have warned.
Cumbria Wildlife Trust said it had received multiple reports of "alarming" incidents at South Walney Nature Reserve near Barrow.
It is urging visitors to stick to clearly-marked paths away from beaches which are out of bounds.
Dogs are not allowed on the site unless they are assistance animals.
Nature reserve officer Paul Waterhouse said birds such as Arctic terns, oystercatchers and eider ducks were ground-nesting and particularly vulnerable between March and April.
"Sadly we're getting lots of reports of recreational disturbance of wildlife by people and their pets, which is particularly alarming as nesting season is now under way.
"It can be really hard to see the speckled birds eggs and the little chicks can be extremely well-camouflaged too, and almost impossible to spot amongst the shingle that's found all around the shoreline at South Walney.
"[And] even a very well-behaved dog on a lead will scare birds away from their nests."
He added: "These wonderful birds need peace, and disturbance from people and their dogs could seriously threaten this year's nesting season."
Mr Waterhouse said further issues were being caused by people flying drones and taking part in water sports as both activities were "liable to disturb not only the birds but also the grey seal colony that hauls out at the nature reserve".