Crows remember your face (and tell the others)

In 2006, biologist John Marzluff ran an experiment on the University of Washington campus in Seattle. His team captured and banded several crows while always wearing the same rubber mask: one specific, recognisable face. The birds were released unharmed, but they did not forget.

From then on, whenever someone crossed the campus wearing that mask, the crows greeted them with alarm calls and dive-bombing flights. It didn't matter who was underneath it, or whether they wore a hat or different clothes: the crows recognised the face.

The astonishing part came later. Over the years, the number of crows scolding the mask didn't drop — it grew. Crows that had never been captured joined in, including chicks born long after the experiment. They had learned from their own kind that this face was dangerous.

More than a decade later, the mask still couldn't take a quiet walk. Crows don't just have memory: they have collective memory. They tell each other about faces, generation after generation. Think about that before you shoo one away.