Distribution and status of wintering ShovelersAnas clypeatain Great Britain

Abstract

The distribution and status of Shovelers using British wetlands in autumn and winter was examined using ringing recoveries and National Waterfowl Count data. Maximum counts have been around 8500 and suggest a total population of c. 10 000. Some of these birds originate from north-west continental Europe, eastern Scandinavia and the Western former USSR, whilst others originate from British breeding populations. Numbers peaked in October, after which there was a steady emigration from Britain as birds moved to France, the Iberian Peninsula and Mediterranean for the winter. The population fell sharply during the early 1960s and then increased up until 1971/72. Since then there has been a gradual, though slight, decline. The number counted decreased nationally during periods of cold weather, suggesting cold weather emigrations. Wintering Shovelers have increased their usage of reservoirs and mineral workings, and slightly decreased their usage of natural lakes. Patterns of seasonal occurrence varied between regions and habitats. Numbers peaked early in northern Britain and progressively later in regions to the south. An early season peak was evident on natural lakes and reservoirs, but occurred progressively later on gravel pits, on the coast and on floodlands. Shovelers were recorded at 10–20% of the c. 1800 sites visited during the period 1985/86 to 1989/90 and, of these, 84% held fewer than 50 birds. A total of 51 sites supported nationally important numbers (>90) and these held 46–¸70% of the population. Whilst protection of these sites is a high priority for the conservation of this species, wider countryside policies are needed to maintain the population throughout its range in Britain.