This stunning footage shows tens of thousands of birds crammed onto tiny patches of ground in Norfolk, England for the winter roost. David Tipling, 57, has travelled up to The Wash in Snettisham annually for three decades to capture the incredible scenes. And he was there again this year to film the natural phenomenon, where thousands of knot birds stand shoulder-to-shoulder, moving in restless waves. The birds come from colder climates, and undertake one of the longest migrations of any animal. They come from their Arctic breeding grounds to the coasts and estuaries of Europe, Africa and Australia, where they spend the winter feasting on invertebrates. Professional photographer David said: “At this time of year we have some of the highest tides of the year. "On the really high tides, the seawater covers the mud on The Wash which pushes the birds off the mud flats. “They have to find other ground to roost on – there’s a couple of gravel pits with islands in the middle which are safe roosting places for the birds. “They come onto these islands for a couple of hours during the high tides. There are so many birds crammed onto these small islands. “When they first come in they’re quite excited and do this rush, like a football crowd charging forward. “It’s one of the world's great wildlife spectacles and occurs on the highest high tides in autumn.