The historic Cape Northumberland Lighthouse has stood tall through high seas and battering winds for more than a century.
But a flock of white cockatoos with a hankering for salt proved to be the ultimate test for the 140-year-old limestone tower, near Port MacDonnell in South Australia.
A $2 million refurbishment was completed this month after the birds ate parts of the stonework, drawn to its high salt content.
"This stunning piece of South Australian history is now bird-proof and ready to be enjoyed by future generations," Australian Maritime Safety Authority executive Mark Morrow said.
Builders restored the nibbled limestone, repainted the exterior with its signature red stripe and replaced the lighthouse's electrical system.
Port MacDonnell Maritime Museum chair Trevor Sheard said the birds also pecked at the mortar.
"There were cockatoos and corellas, they get bored with themselves and just wreck things," Mr Sheard told AAP.
"They go into destruction mode."
The lighthouse, at the southernmost point of the state, is a significant part of the region's history.
It was built on a cliff after a series of shipwrecks in the 1850s and first lit up the seas on January 1, 1859.
Eight months later the passenger ship Admella crashed into the rugged coastline at Carpenter Rocks, 25km away.
Two crew members made their way to the lighthouse for help, but the wreck proved difficult to access and 89 people died of exposure and starvation.
Within five years, coastal erosion and cliff collapses made the tower unstable, Mr Sheard said.
"It was shaking in the rough weather when waves came into that corridor of water and pounded the cliff," Mr Sheard said.
Another lighthouse was built on higher ground in 1882.
Mr Sheard said though its lights and technology have been upgraded over the years, the restoration is the first major structural work since then.
Grant District Council mayor Kylie Boston said the lighthouse was a favourite spot for locals and tourists.
"Because it's been there for years, it's iconic," Ms Boston said.
"It's a focal point and it means a lot to the region, as a point of difference."
