The mystery

All this happened before the pied wagtail showed up.

I went out with the afternoon refill for the feeders, and a blue tit was alone on top of the back lilac in full alarm mode. I wondered if he or she had lost their mate and were calling the other to come back. The bird was so loud, so insistent. He or she went on alone like this for a few minutes before being joined by other tits, all of whom ignored the food and stayed at the top of the tree. Then Tane started alarming from next door and other tits started from the other side.

I walked around and saw two crows looking not as if they were the threat but as if they too were on the alert.

The birds got louder. It must have been going on for five minutes.

I couldn't see a cat. I wondered if the sparrowhawk were eating someone on one of the neighbour's laws.

Then, suddenly, all together, the blue tits above me, as it were, screamed, it was like a train whistle or a siren. And the sound then stopped. Just like that. Silence.

I realised I had been holding my breath. I realised I had been hypervigilant. I sighed and my heart rate started to slow.

Gradually, birds started making normal sounds and started to get peanuts and forage. Tane came over, briefly.

The world was back on its axis.