THE return of a pair of rare migratory pied oystercatcher birds to nest at Maianbar for the first time in 20 years has ended in disaster.
Maianbar resident Julie Keating said the bird species was listed as endangered, with only about 250 left in NSW, of which there were only about 50 breeding pairs.
"We needed to quickly find out how to protect them because it was the first Tuesday of school holidays, with a full campsite," she said.
Members of the Southcoast Shorebirds Recovery group, Royal National Park and Sutherland Shire Council staff, WIRES and a small team of volunteers organised a roster to protect the eggs.
But the high temperatures over the long weekend saw record numbers of people using the beach.
"Volunteers were working in extreme heat with no shelter so we could let beach users know what was going on and where best to walk and sit," Ms Keating said.
"Human and dog interference is the leading cause of nesting failures.
"Few residents of the shire are aware that the beach at Deeban Spit is dog-free."
Despite the efforts of volunteers, a fox stole in during the night and took the eggs.
Ms Keating said it was heartbreaking watching the birds trying to find their chicks the next morning.
"After wandering the beach for some time, calling for their chicks, they returned to the nest," she said. "They both stood looking at the empty nest then sat down together. They hadn't actually sat at the nest site together before."
She said they now appeared to be nesting again.
Ms Keating said beach-nesting birds were suffering because people didn't know they needed to share the beach with them.
"Many resident shorebirds nest between September and March," she said.
"Nesting includes up to eight weeks where chicks are helpless on the beach as they are unable to fly. Both eggs and chicks are well camouflaged and are easy to accidentally step on, especially by dogs."
Port Hacking Planning Advisory Panel member George Cotis has been lobbying for a management plan for Deeban Spit and the entire intertidal zone through to Costen's Point.
"This should deal especially with the pressures recreationalists and domestic dogs are having on the intertidal flats," he said.
"Domestic dogs, some of which come from Maianbar, but many of which are taken there by boat, are viewed as the biggest threat and the biggest management problem."