At first glance the drained muds of the Blyth estuary were dotted with shelduck, redshank, curlew, wigeon, pintail and black headed gulls. But the telescope revealed a distant, tightly-packed group of black-and-white waders. Avocets!
All were busily feeding, constantly sweeping upturned partly-opened bills in shallow pools. Approaching a still deep creek all swam readily and buoyantly, constantly up-ending like ducks.
The avocets' fortunes have certainly changed since the excitement of seeing my very first pair in this country. The location: Breydon Water. During the opening years of colonisation at Minsmere Level and Halvergate Island who would have dreamt that the Alde and nearby Butley rivers would become the most important wintering site in Britain and the only site of international importance for these highly aristocratic birds.
Access to view the Alde estuary is gained from the district council picnic site at Iken. From there, ramble eastwards along the footpath to the church.
Peak numbers of avocets may be expected during January to early February. Where do they come from?
Breeding colonies in East Anglia doubtless a partial answer, but large numbers nest in the Netherlands and in Germany. A nestling avocet ringed in Scheswig-Holstein was caught and then released on the Butley river near Orford four months later.
It would be interesting to see if high numbers continue to be present through a very cold winter. Although ever-increasing numbers of avocets are wintering in this country, still larger numbers move south in autumn from breeding grounds in north-west France, Spain and Portugal. Many continue to North Africa and yet others cross or circuit the Sahara en route to West Africa. Avocets are described as exploiting even the smallest temporary desert pools, only departing as these dry out.
Many immature avocets
spend their first summer after fledging well south of breeding areas,
as do immature grey plovers, bar-tailed godwits and knot. Others return
on a leisurely northward journey and it may be well into June before they
put in appearances here.
Avocets nest on sandy or muddy strands. After trying several sites, the female settles on one and enlarges it by lowering her breast on to the ground with tail high in the air and scraping backwards with long blue legs. If the nest is at the water's edge and threatened by rising levels after storms, it can become a quite substantial structure as it is added to during the incubation period. Nestlings leave the nest within a few hours of hatching.
On occasions long treks are involved. The new family may be led by highly alert parents several hundred yards from the nest site during its first 24 hours wading in the shallows and at times swimming. These journeys often run the gauntlet of attack by other nesting avocets. The young feed themselves from birth normally by pecking. But even young ones with short beaks occasionally 'sweep' for food.
Spectacular aerial demonstrations, often in the form of group mobbing by several adults, are accompanied by intense and prolonged shrieking. Such attacks often culminate in dive-bombing the intruding gull, crow or heron and striking with wings and feet. The momentum of the dive carries each avocet upward again, almost vertically, on stiff outstretched wings. Even so an avocet colony often includes a bird with an injured leg - the possible result of a misjudged dive.
Low-level attacks against creches of Canada geese and shelduck are another spectacle, the avocets performing highly attractive 'butterfly' flights. Remarkably, young avocets from the age of a mere week will threaten and drive off ringed plovers.
During cold, wet weather in the early days and also at night the parent avocet rests on its tarsi and the young shelter beneath the wings and among the breast feathers. Such brooding adults present a delightful scene appearing to possess almost endless sets of legs. When just over five weeks old, the young are able to fly.
By Michael J. Seago