They're back

The swifts have been back overhead for a few days. But tonight's the first time that I've seen and heard real screaming parties over our street.  I spent a happy half hour walking around the neighbourhood, as the light faded, watching and listening.
The numbers still look small to me, I hope they'll build up a bit more in the next week or two. News reports suggest that bad weather has hampered their migration, and we know that the numbers are already in severe decline.  Our local swift conservation and rescue network is back in action, with daily WhatsApp reports about numbers sighted and nest sites protected or thought to be under threat. 
Our own swift box, up under the eaves, hasn't attracted any residents yet. Maybe this year...