Tuesday, 6 November 2012

Sea duck makes a rare appearance

I don’t make a habit of rushing off after work to look at rare birds but on this occasion I made an exception. After all, the bird in question had turned up on the nature reserve at work and was the first of its kind to put in an appearance in nearly two decades of my working here. The slightly foggy conditions, coupled with fading light, did not provide much of a window to take the bird in but there it was, a common scoter, sitting quietly alongside the local mallard and tufted duck. The fact that the common scoter is a sea-duck means I rarely get a good view of one anyway, so a bird sat fifty feet away on the flat surface of an old gravel pit was welcome whatever the conditions.

This was a male, jet black in colour with a splash of bright yellow across the bill, and rather smart in appearance. Although common scoter are present off the Norfolk coast throughout the year, it is in the winter months that we see peak numbers with an estimated 5,000 to 6,000 wintering in flocks, known as ‘rafts’, in those areas where the sea is fairly shallow. The association with shallow water underlines the scoter’s foraging requirements, diving to feed on molluscs, like the blue mussel, found on sandy seabeds.

Inland records are uncommon and usually involve birds that are simply resting, taking a break from overland passage. Nationally, such inland records tend to come from our largest waterbodies, particularly more northern reservoirs, so the presence of one on a relatively small gravel pit in the heart of the Brecks was a little unexpected. Mind you, the pits sometimes attract Smew in the coldest winter weather, another sea duck with a rather smart appearance. This bird stuck around for a few days, which again is unusual as most inland records involve birds that are gone within 24 hours.

There is a small British and Irish breeding population, restricted to the north-west fringe and breeding by remote Scottish lochans and Irish limestone lakes, so most of the birds that winter off the Norfolk coast will be from other populations, most likely those breeding in Scandinavia and east into Russia. As is the case with certain of wildfowl, scoter undertake a moult migration, with individuals drawn from over a wide area gathering together at favoured sites to undergo their annual moult. Many will make a substantial overland crossing so the origins of the male that dropped in at the Nunnery Lakes could be many thousands of kilometres from here. Having such a bird arrive on my local patch underlined the pleasure of watching a local site.

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