Breeding ecology of the Harlequin duck Histrionicus histrionicus (L.) in Iceland

Publication Type:

Journal Article

Authors:

Bengtson, Sven-Axel

Source:

Ornis Scandinavica, Nordic Society Oikos, Volume 3, Issue 1, p.1-19 (1972)

Call Number:

A72BEN01IDUS

Keywords:

Harlequin Duck, Histrionicus histrionicus

Abstract:

The Harlequin Duck breeds exclusively at running water. The size of four populations studied intensively since 1966 were not subject to marked yearly fluctuations, except in 1970. Mean density was 1.3 pair/km. The Harlequins arrive at the breeding grounds at the end of April and the ♂♂ depart at the end of June and the ♀♀ and young in early September. Both sexes showed a strong year to year site tenacity. Mean clutch-size was 5.7 eggs. Hatching (87% of the clutches) chiefly took place in late July, and survival of young to fledging was about 55%. Adults and young fed mainly on larvae of Diptera: Simuliidae. Daily exploitation of simuliid food resources was about 2-7% and varied with the time of the year. In 1970, when food was relatively scarce, reproductive success was low. Time of breeding and migratory movements were associated with food abundance. The populations are limited by food available on the breeding grounds.