it's bird chirping time, so I had merlin bird id running, but got distracted so stopped listening myself.
Then glanced at the screen and it said the most recent bird it heard was a peregrine falcon.
I went: nope, bird app, we don't just have rare falcons in the neighbourhood, try again. But then I noticed all the birds were quiet.
It's the last hour before sunset, they're all really chatty at this time.
But complete silent. Then a jackdaw doing a careful caw, then the jackdaws started again.
The sparrows came back into action 2 minutes later, and there's been goose honks, but the sky is still a lot quieter than usual. .

When I paused merlin bird id i noticed it had not just heard the falcon, but also an eagle-owl.
So now I think it's unlikely those were BOTH here, but I guess one of them was and really scared a lot of birds?