Can any animals recognise individual humans?

Yes – and not only the more obvious contenders such as chimpanzees or dogs. Northern mockingbirds avoid people who have previously threatened them, while magpies mob them. And Gunnison’s prairie dogs issue specific alarm calls in response to specific people.

It’s not always clear how they tell us apart, but faces might be important. Pigeons will avoid a threatening person even if they swap clothes with a kindlier soul.

And studies show that jackdaws can tell humans apart solely on the basis of a mask – their behaviour towards individuals relates to previous experience with people wearing the same mask.