Autumnwatch: Ballet of the knot

Thousand of knot provide a spectacular site in north Norfolk

One of the most spectacular wildlife events in the UK takes place in north Norfolk, when thousands of migratory birds fly in for their winter roost.

"If you want an autumn gathering that just blows your mind come to Norfolk," said presenter Kate Humble.

To witness the balletic flight of the knot requires specific weather and tide conditions, making it a rare treat.

"There are possibly just three or four mornings a year when they'll do this," said Chris Packham.

"Life is not that long so get here as soon as you can, next winter if you can't squeeze in in this. It's undoubtedly one of the greatest wildlife spectacles we have in the UK," he added.

Snettisham and the surrounding area is a prime location to watch knot, pink-footed geese and other species.

The knot undertake one of the longest migrations of any animal from their Arctic breeding grounds to the coasts and estuaries of Europe, Africa and Australia where they spend the winter feasting on invertebrates.

When the weather and tide conditions are right, they often form large, wheeling flocks that contain in excess of 100,000 birds.

The best time to see the waders is when there's a full or a new moon, at the high spring tide, early in the morning.