The winter geese arrive

The first of the winter’s geese have arrived, the end of a journey that has brought them south from breeding grounds in eastern Greenland and Iceland. These are the pink-footed geese, harbingers of the approaching winter, and a welcome addition to the soundscape of bleak November and December days. They are our very own spectacle, vast flocks that fill the early morning sky as they set out from overnight roost sites to feeding grounds scattered along the North Norfolk coast. Changes in hunting pressure and wintering grounds have led to an eight-fold increase in the numbers wintering here since 1950 and there are now some 250,000 using Britain between September and the end of April. This represents over 85% of the total world population, making Britain an incredibly important place for these birds.

Historically, the pink-feet would have wintered on saltmarsh, feeding on the mixed grass and short herb swards, but over the last century there has been an increasing tendency to feed on arable land, particularly on sugar beet, waste potatoes and barley stubble. Such opportunities last through into February, when the fields are ploughed, and then the geese move on to utilise pasture. Their numbers are monitored through the Wetland Bird Survey (WeBS), coordinated by researchers based at the British Trust for Ornithology. Vast flocks can be difficult to count and an expert eye is needed to work out the numbers of birds present.

Other geese species may be seen feeding alongside the pink-feet, including rare visitors from further afield. The breeding grounds used by the pink-feet overlap with those of other species and, on occasion, birds may migrate with the wrong group, ending up many thousands of miles from where they should have spent the winter. This year, for example, a snow goose, which normally breeds from Arctic North America to north-west Greenland and winters south to Mexico, was tracked down the east coast, arriving with the pink-feet in Norfolk at the end of September. This may well be a genuine vagrant but there is also the possibility that the bird belongs to the small feral population that has arisen due to individuals escaping from private collections here in Britain. That genuine snow geese do reach Europe has been demonstrated by bird ringing, with an individual ringed in Manitoba turning up in the Netherlands three years later. Another unusual visitor to Norfolk has been the lesser Canada goose, one of which spent the 2005/06 winter in the company of pink-footed geese at Holkham. This species breeds in northeast Canada and is noticeably smaller than the naturalised British Canada geese. While these vagrants excite twitchers it is the scale of the pink-feet flocks that enthral more casual birdwatchers.