NATURE NOTES - Ducks all at sea

ONE of the few things that you can’t find in Wigan is a coastline (yet!) so as the tides were right for a bit of birding this weekend it was off to Marshside to see what was about. A walk down to the fast approaching sea gave us some fabulous views of the thousands of birds being shifted about as the tide came in.

The Ribble estuary which Marshside is an important part of is internationally important for the vast numbers of geese, ducks and wading birds that rely on its marshes for food during the winter months. Up to a quarter of a million birds may be present on the estuary on a good day and the tides push them way up to feed much more close to the end of the marsh than normal making them much more visible.

We saw all the usual suspects such as curlew, oystercatcher, redshank, godwits, ringed plover etc etc but the star of the day was a small group of scoter way out to sea.The Common Scoter is a diving duck, perhaps best known in Britain as a winter migrant from northern breeding grounds.  They commonly form large flocks of “sea-ducks”, which characterise sandy bays and firths around the British coastline in winter.  Less well known is that there is a small breeding population in the British Isles, nesting at a few sites, from western Ireland to northern Scotland. National surveys showed that the British population roughly halved between 1995 and 2007, from 95 to 52 breeding females. Earlier declines were also recorded, in particular affecting the population in Northern Ireland.  These declines, and the rare, localised nature of breeding scoters, have resulted in the species being red-listed in ‘Birds of Conservation Concern’. 

Dr Mark Hancock, an ecologist with RSPB Scotland, is at the end of the second year of a three-year study of common scoter in Caithness. His research so far suggests that warmer weather has led to insects the birds prey on hatching earlier. The study is part-funded by Scottish Natural Heritage and has been carried out with the co-operation of local estates.Dr Hancock said there were three possible factors affecting scoter numbers. He said: “These are climate change, the availability of insects, molluscs and other invertebrates to feed the chicks, and predation. “It could easily be a combination of all three but it is really too early to say at the moment.”

The ecologist added: “We believe climate change may be a factor because warmer winters and springs could lead to aquatic insects such as mayflies and caddis flies hatching earlier in the season and not being available to the scoter ducklings when they hatch out themselves. “And warmer winters may, over time, lead to more predators surviving and that could make an impact. Mink are definitely present in some scoter areas and part of the research is about finding out how many are about and what they are up to.”

Believe it or not scoter occasionally turn up at both Wigan and Pennington Flash – I suppose the ‘Wigan Pier’ on maps confuses them!