Harlequin duck : white water specialist

Updated September 7, 2010


The pounding, crashing winter seas of the Pacific Coast and the turbulent, churning summer streams and rivers of the interior mountain ranges are home to one of the most spectacular ducks in North America.

Description

The harlequin duck – named after the 16th century Italian comic character in diamond-patterned multi-colored tights – is a small sea duck only half the size of a mallard. The female is rather plain which allows her to be virtually invisible on the nest. She is mostly a cryptic brown with three white patches on each side of the head and a pale belly. The male, however, is magnificent with a slate blue body, broad white stripes bordered in black and large chestnut side patches. He is well camouflaged against the wet, shiny rocks of his watery habitat. Vocalization is a rather mouse-like squeak.

Feeding habits

This is the only duck capable of feeding in the strong currents and standing waves of both the Pacific coast and mountain streams further east. The pounding well-oxygenated water creates the perfect habitat for invertebrates. Harlequins are visual feeders and use their wings and their large, strong feet to propel themselves along the bottom while feeding with their short, thick bills. They spend eight months in their winter habitat where they feed close to shore on snails, small crabs, limpets and mussels. In late winter a bonanza of herring spawn will help to fortify them for their long flight to the interior mountains. Once on their summer range they feed on the various larvae of mayflies, stoneflies, black flies and caddisflies as well as the eggs of spawning fish.

Breeding

Harlequins do not mature and attain full adult coloration until they are two years old. Adults pair up during the winter on the coast; the male living up to his Latin name Histrionicus histrionicus, meaning ‘actor’, with courtship dances, head nodding and whistling. The paired adults leave together for their breeding range in the mountains in late April or early May. On arrival, the female will feed to regain her strength for the egg-laying and brood-rearing season ahead. She will be closely guarded by her mate from the attention of unattached males. She will then select a nest site above water’s flood stage usually in dense vegetation and often on an island but she will still face many weeks of possible predation by bears, wolves, otters, mink and eagles.

Egg laying begins between mid-May and mid-June. After five to seven eggs are laid in a down-filled nest during a two week period the female will begin incubating. At this stage the male will return to the coast. This eliminates any possibility of re-nesting but on the other hand frees up more food for the female and young. Twenty-eight days later the eggs will hatch and in a short time the small downy chicks will be able to negotiate the strong rapids of their breeding streams. By mid-September the young will be fledged and will soon take off with the female for the Pacific coast. Migration from the Rockies is non-stop or very quick – possibly no more than two days. After their arrival on the coast molting takes place and the young will remain there until their third year. Males and females reunite in October-December. New pairs form bonds from March to early May before migrating to the female’s natal breeding area.

Survival

Research has shown that about 82% of males survive this annual cycle but only 74% of females. This would indicate that most of their deaths occur during nesting and brood rearing. The annual production and survival of juveniles is also low possibly indicating that predation is a major problem.

Status

Beside the western population of harlequins numbering possibly 150-200,000 there is an eastern population along the Atlantic seaboard of no more than 2000. Although the western numbers may look strong, research is showing that numbers in the wintering area are in slow but steady decline. This is a species that can live for 17 years making it difficult to identify a decrease in population. Harlequin ducks are ‘yellow-listed’ in both Alberta and British Columbia and classified as ‘sensitive’. Their decline has been attributed to over-hunting, oil pollution and water-based recreation activities as well as hydro-electric projects, logging, mining and road building. The harlequin population of Alberta is between 1600 and 4000 birds spread over a breeding range of about 53,000 sq. km.

Jasper locations

While there are places, particularly along the Athabasca river, where visitors can see a few pairs or individual harlequins from the beginning of May until the end of June, there is one place where one is almost certain to see them. Maligne Lake – 50 km south of Jasper town site – is deep and more than 20 km long and serves as an entrapment for the silt that is washed off the glaciers at the south end of the lake. The north end is therefore silt free and the Maligne river that runs out of the lake is crystal clear. It passes under a bridge at the lake outlet that allows an excellent view of the ducks. In May and June the trout spawn at the outlet and the harlequins can be seen trying to steal their eggs in spite of defensive tactics by the fish. Further downstream the relatively narrow and almost inaccessible river provides some of the best undisturbed habitat for the ducks. There is thick over-hanging vegetation along the shore, fallen trees and logjams create ideal invertebrate habitat and braided channels form islands for safer nesting.

Jasper is fortunate to have such an unusual species and to have a place where visitors are able to watch it diving and feeding in the clear water. Hopefully Alberta and British Columbia will manage the harlequin more wisely in the future so that spring in the Rockies will always be heralded by the return of this colourful little duck.