Dose dependent effects of plumage-oiling on thermoregulation of Common Eiders Somateria mollissima residing in water

Thermoregulatory effects which occur during the first hours after plumage-oiling were studied under laboratory conditions by measuring the metabolic heat production of Common Eiders ( Somateria mollissima ) which were resting in water for up to three hours. The ducks were exposed to 10-70 mL Statfjord A crude oil while residing in water inside a respiration chamber at 5.5°C. The study demonstrated a dose-and time-dependent effect of plumage oiling on metabolic heat production during the first three hours after contact with the oil. The results indicate that the immediate, short-term effects following initial contact with oil at sea are lesser in scale than those which occur after the birds have preened the oil into a greater part of their plumage. After plumage contamination with 70 mL crude oil, the rate of heat loss exceeded the thermoregulatory heat production capacity and the Eiders became hypothermic within 70 minutes after contamination.