image courtesy of the ADFG.
From the Exxon Valdez Oil Spill (EVOS) Trustee Council Fiscal Year '95 Project Description:
"Harlequin ducks, like other sea ducks, are long-lived with relatively low annual reproductive output. Breeding philopatry of sea ducks is high. If wintering site fidelity also is high, winter survival would directly influence annual changes in specific wintering populations. Because harlequin ducks spend much of their annual cycle on wintering areas, assessments of limiting factors during that period are valuable for determining population health and sustainability.
Harlequin ducks suffered direct oiling mortality during the initial stages of the oil spill and were at high risk during the spill because of the high numbers occupying PWS during March. Continued oil effects might have affected harlequin duck recovery. It has been suggested that hydrocarbon metabolites, reproductive effort, and productivity of harlequin ducks were lower in oiled areas than nonoiled areas.
Harlequin ducks are inextricably linked to nearshore habitats. They are spatially limited by foraging depth and occurrence of prey. Harlequin ducks feed on a diverse array of nearshore benthic invertebrates. In general, sea ducks may be sensitive to constraints on food quality and availability because of the severe weather encountered in northern wintering areas; this may be especially true for harlequin ducks due to their small body size. Life-history traits of harlequin ducks, coupled with the concentration of oil-spill injury on nearshore habitats, suggest that these birds will be particularly sensitive indicators of system health."
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Last Reviewed: March 26, 2003