The two male swans have had 'some spectacular bust ups'
Two male swans at Abbotsbury Swannery have set up nest together, and seem to be hoping to lay eggs.
Of the entire herd of around 1,000 swans they are the only same sex pair. They were born in 2002 and have paired up for the last few years.
Abbotsbury manager John Houston said: "They share a nest and the two of them take it in turns to sit on it, defending it against other swans."
"They sit there like they're expecting eggs to appear."
Bulge on their beaks
The two swans have been identified as male birds by the bulge on their beaks, and all of the swans are tagged and sexed at birth.
John said: "They have had some spectacular bust ups, but they always make up and become friends again.
The herd at Abbotsbury is around 1,000 swans
"They've been like this for several years and are now 'attached', I think you can say.
"But this is very rare and has only happened once before at the swannery."
The swans at Abbotsbury arrive at the swannery in mid-March each year to breed and then hatch their eggs.
During the winter months, the swans go to nest out in the nearby Fleet [a lagoon] and then they return to Abbotsbury for spring and summer to mate and give birth.
Eggs take 35 days to hatch from when they are laid, and the first cygnet to appear at the swannery is traditionally said to mark the beginning of summer.
John Houston believes the harsh winter means the first cygnets should arrive later this year, in early June.
Swans have bred at the site in Abbotsbury since 1393 when the site was home to Benedictine monks.