There is no more exciting place to witness this than the flooded washes of the river Ouse at Welney on the Cambridgeshire Fens when the migrant swans arrive from Scandinavia and Russia.
They may look a lot like our native mute swan but as one keen birder put it "you can tell the Russians - they have the stiff necks."
Bird migration is an amazing thing. As the winter gets really cold in northern Norway, Sweden, Finland and Russia swans and geese head south and many of them end their annual journey in the British Isles.
We might think our winters can be cold but they are positively balmy compared to the habitats occupied by these hardy feathered northerners.
Thousands of these Whooper and Berwick swans make a spectacular sight as huge flying flocks darken the winter sky over the flooded Cambridgeshire countryside. Special early morning events are organised to see the truly breathtaking dawn flights when thousands of swans take off to search for winter food.
The Welney reserve is part of the Wildfowl and Wetlands Trust and the Trust also has a better known centre at Slimbridge on the Severn estuary - all kinds of swans, ducks, geese and other wildfowl make their home here.
The trust was the dream of the late Sir Peter Scott and today, as well as providing a safe refuge for our native wildfowl, resident and migratory, the centre works in conserving more exotic examples of water birds from all over the globe.
That's why you will find an army of bright pink flamingos standing to attention (if only on one leg) in this corner of rural Gloucestershire.
With all this talk of foreign seasonal swans we mustn't forget out own mute swan. Remember what you learnt at school - a swan can break a human's arm with a beat of its wing. It is the heaviest flying bird in Britain. Oh yes, and most of them are owned by the Queen.
Whoever really owns what is a free wild creature one of the best places to see these graceful and stately birds is the medieval swannery at Abbotsbury on the Dorset coast.
Abbotsbury offers lots to see and do for a great day out but highlight is still the mass feeding of one of the biggest flocks of mute swans anywhere in Britain.
Find out more about the wetland centres at Welney and Slimbridge at End www.wwt.org.uk and www.abbotsbury-tourism.co.uk