Autumn is a time of change for wildlife on the Fen. In September most of the summer migrant birds begin to leave, being replaced in October and November by those that have bred further north. Numbers of ducks, geese and swans increase, joining the residents on the meres in Holme and Woodwalton Fens. There are regularly Mallard, Pochard, Gadwall, Tufted Duck, Greylag Geese, Great Crested Grebes, Moorhens and Coot. More unusual visitors, such as Bitterns and Bearded Tits sometimes lurk in the reedbeds at this time of year.
The reedbeds themselves begin to change, both in colour and sound, as the seedheads ripen and rustle with the increasing autumn breezes. As the trees change colour, the birch woodland of Holme Fen begins to look at its best. Weird and wonderful fungi emerge: around 500 species have been recorded on Holme Fen making it a Site of Special Scientific Interest (SSSI).
Autumn is also a good time to see colourful berries on the bushes in Woodwalton Fen and Ramsey Heights. Hawthorn and Blackthorn (Sloe) berries ripen, ready to feed the arriving flocks of Fieldfare and Redwing. There are also the berries of more unusual shrubs and trees, such as Purging Blackthorn and Spindle.
Mere in Holme Fen in autumn. Guy Pilkington
Winter can be a very good time to see wildlife on the Great Fen. Winds can be harsh as they sweep unhindered across a vast bare landscape, but on clear days, with the sun low in the sky, colours seem brighter and clearer. The flocks of wintering wildfowl on the meres in Holme and Woodwalton Fens become larger and more vocal: listen for the whistle of Wigeon, sometimes drowned out by the yelping of Greylag Geese.
Increasing numbers of Whooper and Bewick Swans have been seen in recent winters, moving to the flat fields of Darlow's and Middle Farms after breeding in the high Arctic regions. There, too, you could see Harriers quartering across the fields: the resident Marsh Harriers are sometimes joined by Hen Harriers from the north. Male Hen Harriers are resplendent in their grey and white plumage, while females and youngsters are called "ringtails" because of the distinctive white patch above the tail on their otherwise brown plumage.