A scattered flock of white dots, distant on the dark soil of a fenland field and some way back from the railway, can only be a group of wintering swans. Two days ago the swans were too distant and the light too poor to permit identification. Today, on a later train and in better weather, the birds are feeding much closer to the curving track. As the train approaches so the dots resolve themselves into whooper swans, long-necked and with wedge-shaped bills. A rough and ready count suggests a flock in excess of 200 individuals; winter visitors from their Icelandic breeding grounds.
Over the long term we have seen an increase in the size of the population wintering in Britain, something which has been brought about by an increase in the Icelandic breeding population. A successful breeding season is reflected in the ratio of young to adult birds, the swans helpfully arranged in family parties and the youngsters readily identifiable from their soft grey plumage tones. Calculating that ratio is not something I can do from a fast-moving train and I am tempted to return by car on another day.
The numbers wintering here may change from one winter to another, the birds distributing themselves in relation to the weather and feeding opportunities. There is also a degree of movement within a winter and a period of cold weather on the Continent can push birds into the southeast of England and East Anglia. My impression is that there are fewer here this year but we will only know for certain once the results of monitoring projects, like the Wetland Birds Survey, are published.
Although I encounter wintering swans across East Anglia there is something about the fenland landscape that seems to fit best with these birds. Perhaps it is the way in which their crisp white plumage contrasts with the richly dark soils or the often-brooding skies that are such a feature of the fenland washes. Late winter is very much the time for these birds and trips out to search for them have become part of my winter birdwatching routine. The swans will be here for a few more weeks yet, so there is still time for more encounters.