One of the most spectacular wildlife sights in Britain can be seen at a special family event at Holkham National Nature Reserve tomorrow.

Up to 40,000 pink-footed geese will fly over the reserve, near Wells, attracted by sugar beet, potatoes and grain on Norfolk's arable fields.

But because of the snow a day of family-friendly activities, including making model pink-footed geese, designing binoculars and casting your own pink foot, has been cancelled.

The pink-footed geese, which are smaller than a greylag goose and larger than a mallard duck, come from Iceland and parts of Greenland.

More than 85 per cent of the world's population of pink footed geese spend the winter months in Britain where conditions are not as harsh, until they return to north in the spring.

Natural England' Catherine Foreman said: 'Nothing compares to the sound of thousands of geese flying overhead; it really is a magical experience not to miss.

'The pink-footed geese flock to North Norfolk and Holkham as the feeding and roosting sites are ideal for them. They have plenty of harvested sugar beet fields to feed on during the day and the saltmarsh and grazing marsh provide the perfect place to roost on at night.

'Their feeding and roosting habits are influenced by the moon and tides. When there is a full moon they are able to feed for longer in the fields as it is usually brighter. During high tides the geese roost on grazing marshes, rather than further out on the saltmarsh.'

The event, which was to have taken place this Saturday, December 4, will be rescheduled.