Animals
Do crows remember human faces?
The short answer
Yes, for years. University of Washington researchers trapped crows while wearing a rubber mask, then found that for years afterwards crows across campus scolded anyone wearing that mask, even crows that had never been caught and crows hatched after the experiment. They recognise individual faces and pass the warning on.
In 2006 wildlife biologist John Marzluff and his students put on a caveman mask, netted seven crows on the Seattle campus, put leg bands on them and let them go. It was not pleasant for the crows. From then on, whenever anyone walked the same route wearing the caveman mask, the crows went up in a storm of scolding and dive-bombing. A different mask, worn by the same people on the same route, drew no reaction at all.
The surprising part came later. The share of crows joining in the scolding roughly doubled over the following years, and most of them had never been trapped. Some were not alive when it happened. They had learned the face from the others, the way a child learns to avoid a particular dog without ever being bitten.
Seven years on, the crows were still at it, despite seeing the mask for only a few hours twice a year. In later years the grudge faded as the original birds died of old age, which is roughly how grudges go in people too. The lesson, if you ever upset a crow, is to be very sorry very quickly.
Source
- Crows Can Distinguish Faces in a CrowdNational Wildlife Federation