A vulture called Harold left staff at her bird sanctuary shocked when she laid an egg, after 20 years of them thinking that the bird was male.
Staff at the Eagle Heights Wildlife Foundation in Eynsford, Kent were left dumbfounded when they found the griffon vulture with an egg in its enclosure.
However, when the animal experts first got him 20 years ago, the paperwork said she was male.
Taking to social media, they wrote, “Today Eagle Heights staff are FLABAGASTED!!! 20 years ago we bought HAROLD our MALE Griffon Vulture only to find this morning that he is actually a SHE and has laid her 1st ever egg!!! We will now be searching for a husband for her so watch this space...”
After Facebook users pressed the spokesman on why staff never thought to check Harold's gender, he said they 'took the word of the seller'.
He said: '20 odd years ago when we got Harold he had paper work telling us he was a male. So we took their word for it, as sexing a bird can be rather stressful, as you have to take blood or pull out a blood feather and get a DNA test done.
'Males and females look exactly the same, so unless you use DNA there is no way of telling, especially in vultures.
Director of the wildlife foundation in Eynesford, Jonathan Ames, told the BBC: 'It's crazy. We're going to do everything we can now to find her a male partner.'
Ames added that birds of prey very rarely lay eggs in captivity and with her species 'on the brink of extinction', his team are going to try making sure she finds a mate.
He explained DNA testing was done on Harold when she was a chick in the Spanish island of Tenerife, but, tests are often only 80 per cent accurate and would have been even less so when she was born around 20 years ago. So, when they came back as female, no one suspected they might be wrong.
The spokesman said staff will continue to call her Harold, despite the revelation, and that the egg is unlikely to hatch into a chick.
However, social media users were not convinced. One Keian Gillett wrote, “Erm...as great as this is, should nobody have noticed that he is a she? Do you guys not have experienced bird specialists and vets to check that sort of thing?”
David Gooden said: 'That's the funniest thing I've heard in a long time, bless he/she? Maybe that explains why he can't fly properly??, he's a female driver after all ?'...