EFFECT OF HUMAN DISTURBANCE ON BODY-TEMPERATURE AND ENERGY-EXPENDITURE IN PENGUINS

A new method to measure and quantify human disturbance in seabirds is presented. The stomach temperatures of moulting emperor penguin chicks and adults (Aptenodytes forsteri) were recorded continuously using te mperature loggers while the birds were exposed to various man-induced stimuli. Stimuli resulted in typical temperature rises that varied wit h the duration and strength of the stimulus. On average, the temperatu re rose by 1.5 K, the maximum reached being 2.6 K following a stimulus of more than 2 h duration. Minimal energy costs inducing the temperat ure rises could be estimated. Depending on the intensity of disturbanc e, minimal energy expenditure ranged between 3.2 kJ/kg and 9.7 kJ/kg, being slightly higher in chicks. This represented up to 10% of the dai ly energy demand during moult. The estimated minimal increase in metab olic rate during stress averaged 2.3 W/kg in chicks and 2.0 W/kg in ad ults (maxima of 4.2 W/kg and 3.3 W/kg, respectively).