Some 50 of the birds, which have wing spans of nearly 5ft, were recorded in the 48 hours to yesterday morning - twice the number normally expected in an entire winter. And more are expected to arrive at the weekend to avoid worsening weather in Russia and northern Scandinavia.
Sightings have been reported along the east coast from the Shetland Islands to Kent, with the majority concentrated in East Anglia, the South-east and Yorkshire.
'The tendency is for them to stick pretty well to the east coast, Norfolk and Suffolk, because they like rough marshland,' said Derek Niemann, spokesman for the Royal Society for the Protection of Birds.
The largest previous invasion of the buzzards, in the winter of 1974-75, was when about 250 birds were seen along the east coast in the autumn, with about 100 lingering until the following spring.