Goosander of the UK and Ireland

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Goosander of the UK and Ireland

The Goosander (mergus merganser) is a large, attractive "sawbill" duck that may be found mostly on freshwater areas of Britain and Ireland. It is also known as the Eurasian Goosander, Eurasian Merganser, European Goosander.

Males and females are not alike. The drake has a glossy green-black head and back and pale salmon-pink underparts in the breeding season. The male has a noticeable mane of feathers on the back of the neck. The thin bill and legs are red. The plumage of the female, who is slightly smaller, is mostly grey, with a chestnut head and white chin. The beak is bright orange with a black tip. The rump and tail are grey.

Females and non-breeding males have crests on their heads, although the crest is shorter in females. Immature birds and non-breeding males resemble females but have a white stripe between the eye and bill.

Males and females also make different calls. The male's call is of a low-pitched croaking and the female makes a harsh "krr" and crackling sound. Adults start breeding when they are 2 years old. The average lifespan of these ducks is 7 years.

The Goosander is the largest member of the "sawbill" family of ducks. "Sawbills" earned their name because of the edges of their beaks have fine serrations, like a saw, that are designed to hold slippery fish. There is a hook at the end of the beak. They resemble their close relative the Red Breasted Merganser but a larger and heavier bird.

Gooseanders, who are sociable ducks, inhabit mostly clear freshwater inland areas (lakes, rivers, reservoirs, flooded gravel pits) throughout the year. They are also found in estuaries, along streams near the coast or on the coast. Breeding takes place inland in wooded areas near water. Most birds are resident although males fly to Norway in late summer for their annual moult.

Their diet is a wide range of small to medium fish (salmon, sandeels, trout, chubb, eels, rudd, tench, perch) from the habitats they are living in. Invertebrates (shellfish, insects and their larvae, snails), crustaceans (crabs, crayfish) and other prey (amphibians) are sometimes taken. They are opportunistic feeders who often forage in large flocks where there are shoals of fish etc and heard them into shallow water. (Cambridge Journals).

Goosanders use a variety of techniques when foraging for food and hunt by sight alone. One of the most frequently used hunting methods is persuit-diving. Goosanders hunt singly or in pairs by constantly putting their heads beneath the water and then diving to depths of 2 to 3 meters in the water usually for short periods of time. They can stay submerged for up to 2 minutes. Fish are eaten both above and below the water. The other most commonly used method is swimming on the surface with their eyes and bill beneath the surface scanning for fish. They chase fish just below the water or dive for them.

They probe "the river-bottom with the bill, to catch hiding fish more or less at random" in the day (Springer). The soft earth of river banks and vegetation along lakes etc are also probed where eels and amphibians are taken.

Sometimes they hunt by floating down a river for a few miles, diving for fish and then flying (or diving) back again. Small groups of can be found feeding on shoals of fish.

The population of the Goosander was mainly restricted to Scotland. Their numbers have increased since the 1970s and can now be seen all year in Scotland, Wales and the north and south-west of England. The first pair were bred in Britain in 1871. The first breeding pair was reported in Ireland in 1969 and disappeared until the mid-1990s. The Goosander is considered to be "one of Ireland's rarest ducks" with only a localised breeding population ( Birdwatch). The breeding population has not expanded and "the numbers breeding in Ireland remained stubbornly low (no more than six pairs in any year" (Birdwatch).

Goosanders in Britain and Ireland are mostly resident birds who may be seen on fresh water lakes, reservoirs, flooded gravel pits etc with fewer on the coast throughout the year. Wintering birds in Wales, Northern England and Scotland are resident breeding birds who only move short distances in winter from their breeding grounds. Resident birds are widespread in winter and are usually seen in small flocks. Communal roosting occurs in the evenings in autumn and winter on large lakes, rivers and islands.

Resident birds are joined in Britain and Ireland by large numbers of wintering birds from Scandinavia and northern Russia. Those found in central and southern England are mostly Goosanders from northern Europe and Russia. Wintering birds tend to inhabit freshwater areas (reservoirs and gravel pits etc).

Their flight is often low, fast and direct with a long and heavy shape. A whistling sound is made when flying.

Courting Goosanders can be seen in small groups along rivers ( Welcome to Scotland). Breeding pairs move inland to fast flowing rivers ( Taylor and Francis), lakes, streams, reservoirs, gravel pits near wooded areas in the spring (mid-March). Nests are made near or sometimes at a distance from from water in the hollows of trees, under rocks or nestboxes. Solitary pairs or small groups of Goosanders may nest together. Sometimes several females may nest in the same tree.

Seven to twelve cream coloured eggs are laid between April and May. Eggs hatch after 30 to 32 days and the young are fledged after 60 to 70 days. Males leave the female when the eggs are being incubated to moult in other areas. Chicks will jump from the nest to the ground and are led by their mother to find food. They forage without their mother's help. Creches of young sometimes occur with one female leading the chicks on foraging trips.

Males moult earlier than females. Most males leave Britain and Ireland in late-summer and migrate to northern Norway to moult their flight feathers. They return from their moulting grounds between October and November. Research in 1985 found that the population of male Goosanders in western Europe migrate and moult in one place, the Tana estuary in northern Norway (Taylor and Francis). Some females moult on their breeding grounds. Others leave their breeding grounds and fly short distances to moult on estuaries and the shores of lakes. Goosanders are flightless for about a month during the moult.

The Goosander's preference for salmon and trout has brought it into the conflict with the commercial fish farms, the game fish industry and recreational anglers who blame it for the decline in fish stocks. Special licences can be obtained from Natural England to cull these ducks as they are not a species of bird included on the General Licence.

Game fish "are all highly acclaimed and generate substantial levels of income for Scotland...There is evidence that these birds can, in some situations, remove large numbers of fish from stocked and natural fisheries" (Bio One). Some rivers in Scotland have been re-stocked with salmon because the "arrival of large numbers of goosander and meganser ducks and predatory fish species, including pike, are thought to be behind the changes" (Herald Scotland).

The global population is not considered to be Vulnerable by conservationist groups (such as Birdlife International) due to the wide range of these birds (Eurasia, North America etc). The European population is considered Secure with the global trend described as increasing.

The Goosander is classified as of Least Concern by IUCN.

The UK population increased by 18% between 2000 and 2009 (RSPB), where they are a green listed species of bird. The Goosander is amber listed in Ireland because of a small breeding population.

It was noted in Scotland that a "marked decline has occurred in the goosander population, which was five times higher in 1982 than it was in 1997"( Scottish Heritage - 2.1.6).

Fewer Goosanders were wintering Britain and Ireland in 2013. The reason given was climate change, with more resident birds remaining in Scandinavia because of warmer winters (BBC).

Other threats include loss of habitat, pollution (petroleum), avian flu, hunting (in countries such as North America and Russia), drowning in fishing nets, climate change and collection of their eggs in places such as Iceland.