Sheep able to recognise the face of Baa-rack Obama
Study could help scientists investigate Huntington's Disease and other brain disorders
Sheep know their Emma Watsons from their Baa-rack Obamas after demonstrating an ability to recognise famous faces.
The animals are already known to respond to familiar faces, both of other members of their species and humans.
But scientists showed they could be taught to recognise screen-shot images of celebrity faces.
They were even able to identify faces from an angle with about the same success rate as a human.
If they got the answer right, they were given a food reward.
The team trained eight sheep to recognise the faces of four celebrities - former US president Barack Obama, Harry Potter star Emma Watson, US actor Jake Gyllenhaal and TV journalist Fiona Bruce from photographic images displayed on computer screens.
Each animal in turn was shown two images of human faces, one of them the "target" celebrity.
A reward of cereal pellets was dispensed when a sheep crossed an infra-red beam in front of the celebrity image.
If it approached the wrong image, a buzzer sounded and no reward was given.
They correctly chose the learned celebrity face eight times out of 10.
Researchers also found sheep can recognise images of their human handlers without any previous training.
Shown a portrait of their handler alongside that of an unfamiliar person, they did a "double take" before approaching the face they knew.
Lead scientist Professor Jenny Morton, from Cambridge University, said: "Anyone who has spent time working with sheep will know that they are intelligent, individual animals who are able to recognise their handlers.
"We've shown with our study that sheep have advanced face-recognition abilities, comparable with those of humans and monkeys."
The face recognition ability of sheep could now be used to investigate Huntington's disease and other human brain disorders that affect mental processing, said the researchers.
The team has started studying sheep genetically modified to carry the mutation responsible for the devastating disease that affects mood, personality, memory, and muscle control.
One symptom of Huntington's is an impaired ability to recognise facial emotion.