A nesting pair of swans have had their clutch of six eggs, which were due to hatch, destroyed by someone.

"It was such a senseless and barbaric act," said Janine Clement, who lives next to the Waimanu Lagoons, Waikanae Beach, north of Wellington.

"It's also one I don't understand."

Clement believed a person approached the nest and forced the swans, named Nola and Tommy, off, removed the eggs and threw them into the lagoons; the eggs were later seen in pieces in the water.

"Nola and Tommy would have been beside themselves with distress as their babies were ripped from them and destroyed in front of them.

"The cygnets would have been fully formed by this stage."

She didn't know why someone would do such a thing, considering "we don't have a swan population issue here".

"I don't understand why someone would do this, but living where we do we see daily abuse of the birdlife from members of the public.

Swan nest from which six eggs were taken and thrown into the Waimanu Lagoons. Photo / David Haxton

"This ranges from people letting their off-lead dogs chase the birds, people chasing the birds, and I'm not just talking children either.

"You also have people deliberately riding their bikes at them off track, people trying to hit them with sticks or throw stones, or try and grab and intimidate them.

"I don't think people realise animals are sentient beings and they do feel and grieve.

"Nola and Tommy were highly agitated after what happened to them and it was really upsetting to watch.

"All I can say is if you don't want a bird interaction, or can't respect the birdlife, don't come around the lagoons.

"Also if you can't walk your dog on lead on the track, don't come around the lagoons.

"This is the birds' habitat and home, and you, the human, are the visitor.

"If you can't respect that, and the bylaws of the area, stay away."