How Do They Know the Difference?

[littlecoopnextdoor]

Birds can hear all sorts of tones and frequencies we cannot, so it likely doesn't quite sound the same as a hawk to them. It's like hearing someone do a not quite realistic British accent

 

[littlecoopnextdoor]

It is not the hawk call that will get my chickens attention it is that moving shadow on the ground as they swoop over.

I do notice this. If they think they see a shadow overhead, even if it was not a bird, they run.