Wetland birds in particular have found frozen reedbeds and ponds difficult to cope with and some have resorted to desperate measures.

Startled observers at the Yorkshire Wildlife Trust's Potteric Carr reserve, near Doncaster, saw a bittern stalk, kill and eat a brown rat in front of the Willow Pool feeding station and also probe into a freshly dug molehill.

Water rails and snipe have also been coming away from cover in search of food while barn owls have been hunting throughout the day across the frozen fields around the Bempton Cliffs RSPB reserve.

Ducks have been congregating in large numbers on any remaining stretches of open water with some large flocks of goosanders, 46 at the Old Moor reserve, South Yorkshire and 30 on a drain near Preston Road, Hull.

Three species of sawbill ducks, goosanders, four red-breasted mergansers, and a drake smew were at the Calder wetlands, within walking distance of Pugney's Country Park, Wakefield.

The drake ferruginous duck has also moved there from Pugney's and has been joined by another rare vagrant, this time from North America, a drake ring-necked duck.

Both are with the same mixed flock of pochards, mallards and tufted ducks.

Bird feeders continued to be replenished by volunteers during the Christmas break when nature reserves were closed while garden bird feeders have continued to attract large numbers of hungry visitors, including more blackcaps which have been aggressively chasing away the other birds.

Fieldfares and redwings have also been coming into gardens in search of berries and any remaining windfall apples although there are no waxwings this year.

In keeping with the snowy conditions, two rough-legged buzzards have been seen in Bilsdale, North Yorkshire, a regular winter haunt for them while 25 snow buntings were on the slopes of Pendle Hill in Lancashire.

Along the Yorkshire coast, a red-necked grebe, two great northern divers, two velvet scoters and a long-tailed duck were in Filey Bay, while two great northern divers, a female velvet scoter, two scaup and a red-crested pochard were at Covenham reservoir, north Lincolnshire.

A flock of 15 twite and two Lapland buntings were seen in stubble fields at Flamborough Head where a white stork was also seen, presumably the same bird as one seen at Scalby Mills, Scarborough.

The prolonged freeze will have been difficult to cope with for overwintering chiffchaffs, although Cetti's warblers are continuing to be heard at several sites in the region. How colonies of Dartford warblers in southern England have fared has yet to be discovered.
There was a huge reduction in numbers after the very cold weather in February and recent conditions have been equally severe.