A group of parrots at a zoo had to be put back into isolation when they all started swearing at customers after coming out of quarantine.

The five African grey parrots were adopted by Lincolnshire Wildlife Park on August 15 and put into a room together.

But it appears they used their time in isolation teaching each other foul language, which left park staff in hysterics - but swift action had to be taken when they started using obscenities with guests.

Steve Nichols, CEO at the Friskney park, said the birds were put into a 'time out', but admitted over the last 25 years he's taken in many parrots "that have sometimes had a bit of blue language".

The parrots have brought a smile to people's faces at Lincolnshire Wildlife Park, which is set to have lost £400k this year

He told LincolnshireLive: "Every now and then you’ll get one that swears and it’s always funny. We always find it very comical when they do swear at you."

However, with nothing better to do in isolation and because by chance the latest crop were all adopted at the same time, they quarantined together leaving a room "full of swearing birds".

"The more they swear the more you usually laugh which then triggers them to swear again," continued Mr Nichols.

The park chief said they learnt to swear and laugh at each other swearing, leading to something akin to "an old working men's club scenario".

Within 20 minutes of them being on display to the public there were reports of the parrots swearing at a customer, and things quickly escalated.

"We found it highly amusing and the customers were fine – they were no problem at all.

"But we worried because we had a weekend coming up and children coming," explained Mr Nichols.

While the swearing birds helped to put a smile on everyone's faces despite the worries of Covid-19, they were placed in an off-shore enclosure in the hopes they would be influenced by other parrots to behave more appropriately.

Mr Nichols said African grey parrots are particularly adept at "learning vocalisations from all sorts of noises".

The plan now is to release the five birds into separate areas so they can't encourage each other.

However, everyone has appreciated the humour the mischievous parrots have afforded at the park because the pandemic has meant the charity will likely have lost up to £400,000 this year.

"It has been a real rough year, but we are the eternal optimists and we have no option. We have to keep moving forward," said Mr Nichols.

He added that everything is geared towards next Easter and they hope things will be in "some kind of normality by then".

The park has also made headlines around the world after a video of Chico, a parrot at the park, singing Beyonce ’s ‘If I were a boy’ went viral.

Mr Nichols said people have come to see Chico and then heard about the fouled-mouthed parrots, meaning both have been good for business.

"It is quite an unusual place where you are walking around and people are swearing at aviaries trying to get a parrot to swear back at them."

He joked the site has become an "adult theme park".