title: The development of homeothermy in common eider ducklings (Somateria mollissima).
abstract: Oxygen consumption (VO2), body temperature (TB) and electric muscle activity (EMG) were measured at varying ambient temperatures (TA) in common eider ducklings from the eggs pipped to 1 day after hatching. Eggs at pipping and ducklings still wet from hatching doubled their VO2 at TA = 2-4 degrees C compared with TA = 27 degrees C, but were unable to maintain constant TB. Increased EMG activity was recorded from ducklings 30 min after hatching. Artificially dried 1-h-old ducklings maintained normal TB (39.0-40.5) for at least 90 min at TA = 2 degrees C. Ducklings older than 24 h maintained homeothermy even when the pelt was artificially wetted. Oxygen consumption at thermoneutrality increased about 50% from hatching to 12 h of age. The specific thermal conductance of ducklings at different ages indicates that the youngest ducklings maintain homeothermy by having a cold periphery in addition to pelt insulation and increased VO2, while ducklings older than 12 h rely on pelt insulation and increased VO2 only.
authors.affiliation: Department of Biology, University of Oslo, Norway.
authors.forename: J B
authors.initials: JB
authors.lastname: Steen
authors.forename: G W
authors.initials: GW
authors.lastname: Gabrielsen
mesh_terms: D000367:Age Factors; D000818:Animals; D001831:Body Temperature; D001833:Body Temperature Regulation; D003081:Cold Climate; D004372:Ducks / Q000254:growth & development*; D009119:Muscle Contraction; D010101:Oxygen Consumption; D013538:Svalbard