A Fortingall Yew tree standing in a church yard in Perthshire, Scotland, has been estimated to be male for 5,000 years because it produces pollen.

Yet, this year three red berries were spotted growing on its branches, which means that at least part of the tree is changing its sex to female.

Max Coleman, science communicator of Royal Botanic Garden Edinburgh, told Daily Mail: “It’s a rare occurrence… unusual and not fully understood.” He believes that environmental stress may have led to hormonal changes in the tree, causing the berries to begin sprouting.

Coleman acknowledges that other yews and similar trees have been observed to seemingly switch sexes.

Whatever change is taking place in the Perthshire tree is gradual, as the rest of the tree is still male. Coleman insists that the tree remains healthy and the three berries, which are also seeds, have been collected for further study.