Basin Notes - August 2001

Autumn is Coming

As the breeding season draws to an end for another year, many of our birds will now be moulting.

Out in the Basin the male eider are in eclipse (camouflage) plumage while they shed and then replace their flight feathers. Over the next two months they will gradually moult, from this eclipse phase and become resplendent again in their breeding finery.

A flock of over 100 female goosander come to the Basin every year and use it as a safe haven while they complete their wing moult. Meanwhile the number of mute swans has increased to over 200, as visitors join our resident flock while their wing moult renders them flightless for five to eight weeks.

Most of Britain's shelduck population is now undergoing its wing moult in Germany's Heliogoland Bight which provides a safe habitat and a plentiful supply of food in the rich mud flats. Only a few shelduck now remain on the Basin, mainly in young family groups.

In the past 10 days a gyrfalcon has been seen several times by the Basin. Local ornithologists believe it may be a third winter juvenile going into adult plumage. It has, however, rings on both legs and is almost certainly an escapee, so twitchers should not get too excited.

On August 12th a merlin was seen by the widgeon hide. This is our smallest falcon with low dashing flight and it preys mainly on small birds. In summer its habitat is upland and moor, and in winter it can be seen hunting by coasts and estuaries. Numbers are declining so it is heartening to get a local sighting of this diminutive raptor.

Over 70 grey heron have been counted recently around the west rim of the Basin, many of them young birds sharpening up their fishing skills. Other sightings have included whimbrel, black swan, osprey, three green sandpiper and a cuckoo on the old sea wall in front of the Visitor Centre.

In recent days over 30 house martins have been flying around the centre, mainly young birds having just discovered the joys of flight. They appear to have fledged from nests at nearby houses as swallows lay claim to all nest sites under the eaves of the Visitor Centre.

House martins have shown a decrease of 30% during the past 25 years and it is thought that changes at their African wintering quarters may play a part in this.

Early August is marked by black-headed gulls gradually moulting their brown caps and mid August by the swifts suddenly vacating our skies to start their migration south. By another three weeks the first pink-footed geese will be back on the Basin and then it is all downhill to winter!