Wintering duck numbers down

The pools have been rather quiet this winter, with far fewer wintering duck than has been the case in recent years. A few dozen tufted duck and mallard mingle with single-figure counts of coot and the occasional gadwall, underlining the effect that a run of mild weather can have on their numbers. The duck that would normally be here, wintering on our lakes, gravel pits and quieter pools, have remained on the Continent. Of course, all of this could change with the arrival of some properly cold weather.

The run of mild winters has seen many migratory birds winter closer to their breeding grounds, a behaviour known as ‘short-stopping’. Britain and Ireland have provided important wintering grounds for many wildfowl and waders, the influence of the Gulf Stream lifting our winter temperatures by a few degrees to deliver more favourable conditions than are to be found on the Continent. As the average winter temperatures have increased, so the conditions elsewhere have improved and the benefits of moving to Britain have reduced.

Such changes in wintering behaviour can be seen in the counts of wildfowl collected at sites across Europe. These reveal a redistribution in wintering numbers for species like goldeneye, whose numbers have decreased in Britain and The Netherlands but risen significantly in Finland and Sweden, where waterbodies have increasingly remained unfrozen during the winter months.

One consequence of these changing patterns of winter distribution may be that our network of protected sites – many of which may have been designated because of their wintering wildfowl populations – might no longer provide protection. If duck no longer winter on a site where they are protected but instead winter at a site where they can be shot, then this could have important implications. The latest research suggests that while currently protected sites might lose some of their key species, they are likely to gain others and so remain important. However, there is a need to monitor what is happening at other sites, outside of the protected area network, and to establish to what extent they are now being used by wintering waterfowl and to assess whether they need protection. It is interesting to reflect that what is happening on my local waterbodies has such wider relevance.

Winter wonder

The ice changes everything; it shifts the focus away from familiar sites that I would normally search for wintering waterfowl. The lakes, so often packed with Coot and duck, are empty. Instead they carry a crisp skin of newly formed ice, highly polished thanks to the lack of wind and reflecting the bank side willows with photographic precision. The fishermen, quite sensibly, are nowhere to be seen and I have the reserve to myself.

Much of the activity is on the river which, ever in motion, remains ice-free. Small groups of Mallard drift away at my approach, while the more nervous Teal take flight, leaping into the air and away with a flurry of wings. Canada Geese and feral Greylags wander about the margins of the pits, unsure and seemingly bemused at the sudden change of state to their watery haunts. As they move across the shiny surface they slide each webbed foot forward, pushing down onto the ice. Am I imagining this or are they really indulging in something that resembles gentle skating? There is a sound to their somewhat unsteady movements, a harsh scratching noise, and I cannot work out if this is caused by their claws or comes from the ice itself, moving under the stresses of this additional weight.

In some places the ice is thinner and the occasional goose falls through; with much flapping of wings it tries to move forward, the ice sometimes breaking further but more often the goose shakes itself free of the cold, dark water. A larger area of open water holds a few dozen coot, a handful of Tufted Duck, a single Goosander and, amazingly, a drake Goldeneye. This stunning black and white duck is a rare visitor to the lakes, being more commonly encountered on the flooded margins of the East Anglian coast. This is probably only the second or third record for the site and a welcome one it is too. Although there is a small but expanding breeding population of this delightful duck in Scotland, this bird may have come from the larger Scandinavian population which breeds on freshwater lakes and pools surrounded by conifer forest. It is also remarkable that this particular bird is an adult male, since it is the females, which winter further south than the males, that dominate our wintering population.

Since the light is pretty good I get a decent chance to watch the Goldeneye through my telescope as it dives deep into lake in search of food, buoyantly erupting from the surface at the end of each dive. It won’t remain here for long, especially if the ice increases its grip on the lake, so I am fortunate indeed to stumble across it.