Some physiological and biochemical adaptations to diving in three species of ducks

Abstract 1. 1. Heart rates before, during and after diving and serum lactate concentrations before and after diving were measured in three species of ducks ( Oxyura maccoa, Netta erythrophthalma and Anas smithii ) which differ in their feeding behaviour and diving ability. 2. 2. Oxyura maccoa (a specialist diver) showed a greater diving bradycardia and a greater post-dive tachycardia than either of the other species, but the build-up of serum lactate during diving was less in O. maccoa than in either of the other species. 3. 3. It is concluded that, in the three species of ducks, physiological and biochemical adaptations are positively correlated with feeding behaviour and diving ability.