A pair of swans in Austria have been forcibly removed from the lake they called home after a series of violent, escalating attacks to defend their nest from intrusive humans.

The twist in this case is the swans weren't biological parents, but appear to have been two gay male swans who had formed an inseparable bond – and the nest they were protecting didn't actually contain eggs or cygnets, but at least one colourful plastic cup.

That minor technical point didn't seem to matter too much to the doting dad and dad, though, who treated the responsibility of protecting their plastic proxy with dangerous, almost deadly seriousness.

Last summer, the pair were known to approach people and boats and display aggressive gestures, but this year the attacks "reached a new dimension", according to the mayor of Grundlsee, Franz Steinegger, in the Austrian state of Styria.

"They have thrown themselves on the swimmers, trying to submerge them," Steinegger told Kleine Zeitung. "That was the biggest danger."

Gay swans moved from lake after attacking people while protecting their nest of colourful plastic cups:https://t.co/RjrFuAE5zk … pic.twitter.com/rlJvrjsUBd — Attitude (@AttitudeMag) June 26, 2018

While nobody drowned, numerous bathers and people simply strolling beside the lake are reported to have suffered attacks – and some of them were serious.

Several swimmers in fact required hospitalisation, with one of them receiving a deep flesh wound to the head courtesy of the protective parents.

"We had to act urgently," Steinegger told the Daily Mail. "But I simply didn't have the heart to have the two swans killed by a hunter."

Luckily, the mayor found animal wildlife expert Alexander Groder, who with his wife runs a wildlife sanctuary specialising in difficult animal rescue situations.

Groder and his wife were able to remove the swans from the lake, and has transported them to a special pond without boundaries in the state of Tyrol in Austria's west.

As for the exact circumstances of the pair's relationship, it's difficult to be certain – as it is with many cases of animal homosexuality – but Groder at least has some ideas about where the physical aggression could be stemming from.

"It may be two male swans living in a relationship," Groder told The OÖNachrichten.

"But one of them is strongly suppressed by the other, and I could imagine that the aggression comes from there as well."

It's not known whether the plastic cup will be making the trip with them, but in light of all the drama caused – and how committed these would-be parents are to protecting their unlikely offspring – we at least hope the family finds some well-deserved peace and quiet in their new home.