Nesting swans have had all their eggs smashed by vandals who threw bricks at their nest in east Dorset.
Andrew Stevens, who lives nearby, said he noticed on Tuesday that the nest and all six eggs had been smashed.
He told the BBC: "It's heartbreaking what's happened to them. She was clearly in distress and trying to incubate the bricks."
But swan rescue expert Ken Merriman said the birds were not injured and appeared healthy.
Mr Stevens said he cycles past the nest to and from work every day and the nest was targeted sometime during the day on Tuesday.
He said: "As I cycled away it brought tears when I noticed what had happened. It's awful, absolutely awful."
Richard Pogson, another local resident, said he had been following the pair building the nest over the past couple of months and last week noticed they had laid six eggs.
"I went past again on Wednesday afternoon and saw quite a few pieces of brick on top of the nest and all the eggs appeared to have been smashed.
"I am at a loss to understand the mentality of so-called human beings who clearly take some sort of pleasure in doing this type of thing.
"While I appreciate there are an awful lot of bad things going on in the world, what I saw saddened me greatly."
Mr Merriman, owner of the Swan Rescue Sanctuary in Holt, Wimborne, said he had checked the pair on Thursday and they were not injured.
"The parent birds are perfectly healthy, normal looking birds.
"My concern is primarily the welfare of the birds and they are not stressed, they are not agitated.
"She was preening herself next to the nest while he was swimming up and down the river chasing other swans off, like he should be doing."
The RSPB condemned the act but said swan nests can become targets for vandals because of their large size.