In fall and winter you’ve probably heard large flocks of European starlings (Sturnus vulgaris) having loud conversations in thick trees or bushes.  Then suddenly the flock falls silent and takes off.

Here’s a good audio example:  Listen for 53 seconds to a lot of noisy chatter. Then the birds fall silent and you hear them take off in a whoosh.  (If you don’t want to wait 53 seconds, click in the middle of the audio bar after it starts rolling.)

What signal do starlings use to trigger their escape?  Is it an audio cue?  Or is it visual?

Please tell me how they do this.

p.s.  Did you know that female starlings sing, especially in the fall?

(Credits: Photo from Wikimedia Commons; click on the image to see the original.
Audio: Common Starling (Sturnus vulgaris), XC281737 from xeno-canto by Peter Boesman)