Best Of

How do crows tell each other apart?

With the same black plumage, how do crows tell one another apart? Earlier research has shown that their calls are individually specific, functioning in the same way as human voices. Female crows tend to have higher voices than males, partly due to body size.

Crows also vary in body size and shape and have similarly diverse bills; the tips grow continuously, but the bill shape is stable nearer the base. One crow family that Clark has observed featured a member with a bill shaped almost like a Roman nose, while his mate had a petite, straight bill; their offspring exhibited one or the other.

Clark hypothesizes that, like humans, crows may also be able to recognize individuals by how they move — in their case, fly. One older crow, sitting in her territory at sunset, didn’t respond as other crows winged by overhead, returning home after a day of foraging. That is, until she saw one specific bird fly overhead; she perked up and apparently called a greeting, at which it looked down while in flight and replied, Clark recounted.

“Our recognition of the quality and identity of our social companions uses many sensory modalities,” Clark said. “What we’ve shown is that the black of a crow does vary and has information in it, even though it’s sexually monomorphic.”

https://www.newswise.com/articles/beyond-black-research-explores-the-feather-color-of-american-crows-as-seen-by-crows/?sc=dwhn&user=10024121