Red Knot, (Calidris canutus) flocking on salt marsh on morecambe Bay, Cumbria, UK, a high tide.

cumbria morecambe bay uk habitat winter sky bird flock flight wings flying behaviour migrant migration salt marsh coast tide high tide tidal wader waders red knot numerous flocking calidris canutus knot winter visitor safey in numbers swirling movement sea waves coastal habitat