A swallow was seen in South Devon just a few days ago. I have seen swallows in the South Hams as late as Dec 7th. It makes me wonder if a handful now stay for the winter, and survive, and do not migrate to Africa? Certainly in places like South Cornwall, South Devon and the Channel Islands this must be a possibility if the weather is mild and there are enough insects around.
I have seen no records for swallows in January in the UK. Such records would tend to suggest over-wintering. Those that remain late could be indicative of very late broods or those that somehow lost (if they ever had it) their ability to migrate and perished when the weather turned colder.
Here in East Anglia, I rarely see a swallow before April 7th. When they return from Africa it is an important day for me. Swifts are usually first seen here around the end of April. Hearing swifts scream in the spring air makes me glad to be alive: it reminds me that all is still well with the world.
At the moment, we are approaching the shortest day with long, dark nights. Long light evenings seem a way off. Mind you, in just a few weeks' time the nights start to shorten and the days start to get longer. We'll blink and it will be spring again.
We are very lucky to have our seasons as each has its special features to be enjoyed.