The extraordinary spectacle of a crow picking parasites off a deer was caught on camera in Richmond Park, south-west London
You might think this bird was stark 'raven' mad to land on an unsuspecting deer's head.
But far from shaking off the crow, the roe seemed to actually enjoy the attention.
Harry Tsappas snapped this extraordinary spectacle during a visit to Richmond Park in south-west London.
The 57-year-old said the bird had swooped in on the deer to eat parasites from its fur.
He explained: 'The bird stalked the deer all morning. When the herd stopped for a rest, it landed on the deer's head because that's where most parasites are.
'It stayed there for several minutes. The deer seemed to be pleased to be cleaned.
'When it had had enough, it shook its head and the bird flew away.'
Mr Tsappas, a self-employed heating engineer from north London, added: 'I have seen birds stalking deer and landing on their backs but never their heads.
'Before this, I had only ever seen it in documentaries and I must say that watching it happen is something I will never forget.'