Waxwings in Oxford!

Waxwings are surely one of the most sought after bird sightings for a UK-based birdwatcher in the winter. These birds are winter visitors to our isles, but the numbers that visit fluctuate greatly year-by-year depending on the size of the local population in their Scandinavian breeding grounds. This winter has been a waxwing "irruption" in the UK, and I was waiting for some local visitors until today where there has been a small flock feeding in the housing estate where I live! It was great to see them on my walk into the office. It also made me wonder about the wider patterns of winter visiting birds in the UK. This year I have seen many more redpoll and siskin around Oxford, both of which are winter visitors to the UK (although siskins do have a moderate breeding population restricted outside of central England). I wonder whether waxwing irruptions correlate with winters where we see many more numbers in the other species that come from their Northern breeding grounds?