Goosander (Mergus merganser)
The elegant Goosander (males depicted) is a scarce winter visitor and passage migrant in my home county of Sussex. The British breeding population, located mainly in the Peak District and Scotland, is estimated at around 3,500 pairs, with a wintering population of 12,000 birds. Key sites are the county’s reservoirs, Pagham Harbour, the River Adur and pits around Rye Bay, though it can sometimes be found on any sizeable inland body of water. When birds are recorded in Sussex they tend to be very mobile with many only staying for a single day before moving on.
M. merganser nests in holes excavated by woodpeckers or natural cavities in mature hardwood trees with entry holes usually more than 15m above the ground. It shows a preference for cavities with openings c.12cm wide and internal diameters of c.25cm in trees close to or up to 1km away from water. When natural tree-nesting sites are not available the species will use artificial nestboxes or may nest among tree roots in undercut banks, on cliff ledges, in rock clefts or in dense scrub or loose boulders on islands. Sometimes several females may nest in the same tree, especially on islands that provide suitable nesting sites in lacustrine or coastal locations.
The accompanying images were taken in North Wales.
Cowser, R., 2014. Goosander. The Birds of Sussex. Thetford: British Trust for Ornithology (BTO) Books on behalf of the Sussex Ornithological Society, p. 133.
Wilson, T.J., 1996. Goosander. Birds of Sussex. Sussex Ornithological Society, pp. 184-186.
BirdLife International (2015) Species factsheet: Mergus merganser. Downloaded from www.birdlife.org on 25th January 2015.