Table 1.

Comparison of the metabolic costs of Adélie penguins and great cormorants resting (RMR) in air and water, and swimming horizontally underwater in a shallow tank.

	Adélie penguina	great cormorantb	percent difference
body mass (kg)	2.56	2.31	−10
RMR in air (W kg−1)	3.8	3.1	−18
water temperature (°C)	4	13
RMR on water (W kg−1)	8.4	14.1	+68
underwater swimming (W kg−1)	15.6	36.7	+135
optimum speed (m s−1)	2.2	1.9	−14

^aCulik et al. (1994).

^bSchmid et al. (1995).