Emu Winter Incubation: Thermal, Water, and Energy Relations
The general pattern of avian life histories commonly displays minimal overlap of energy-demanding activities. For example, most birds reserve breeding and molting phases to times when their maintenance costs (e. g., thermoregulatory and foraging costs) are at their lowest annual levels. The emperor penguin (Aptenodytes forsten) and emu (Dromaius novaehollandiae) appear to contradict this tendency in that both species are midwinter breeders and, for breeding males of each species, incubation is performed to the exclusion of feeding for about 9 weeks in penguins and 8 weeks in emus. Male emperor penguins possess many physiological and behavioral qualities which ameliorate their protracted exposure to the Antarctic winter (Le Maho, 1977), however, little is known about the energetics of emu incubation.
KeywordsTotal Body Water Thermal Sensitivity Daily Energy Expenditure Tritiated Water Emperor Penguin
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