I stepped back and looked up expecting hoping to see a Sparrowhawk (Accipiter nisus) sailing through the air, in hot pursuit. Nothing, I looked around and in the distance I clocked a flash, plugging into the long grass on the far side of the bank.
As it took off and turned towards our side of the track it was clear for all to see, it was of course a Kestrel (Falco tinnunculus). I have never experienced the tunnel of silence with a Kestrel, only ever with a Sparrowhawk.
The silence remained for a long time. And only after the Kestrel moved off from its tree top advantage point, did the songs begin again.