a question : do swallows over winter?

This theme occurred some years ago in the Spanish avesforum and the question that follows has also been published today in fororoa, avesforum and my Spanish blog guiri-pajarero-suelto, so you can see that I'm hoping for some interesting discussion and comes about because of the Barn Swallow that I (and some others) saw this morning in the Guadalhorce reserve (Málaga).

We are accustomed to seeing records of apparently wintering hirundines, particularly so further west in the area of Brazo del Este, Guadiamar and Doñana, sometimes in relatively large numbers. Further east, here in Málaga, we also have occasional but much fewer winter records, although I once saw one on New Year's Day. This bring sme to the question: Was this a retarded migration bird?, or perhaps an early return migrant, perhaps ill? Or is it even a sign of global warming?

I should say at this point that I have my own ideas and reject the global warming one quite simply because this was happening and recorded long before the vogue of attributing all to global warming, just as we can discard the once accepted idea that they passed the winter in the mud of a pond, so we are left with either (a) was it late (b) very early or (c) ill?

What do you think, write if you wish and say what you think and why and by 7 January I shall synthesise all the replies and correspondence and put it all on to the various blogs and forums.

Meanwhile, dear readers, a happy New Year with good birding, be they rare or common, and I shall be celebrating 60 years birding! Gawd!