Development of Endothermy and Existence Energy Expenditure of Nestling Double-Crested Cormorants
- 31 December 1975
- journal article
- research article
- Published by Oxford University Press (OUP) in Ornithological Applications
- Vol. 78 (3) , 350-356
- https://doi.org/10.2307/1367695
Abstract
Double-crested cormorant [Phalacrocorax auritus] nestlings can effectively maintain homeothermy in the natural environment at about 14-15 days after hatching, when 25% of growth is completed. Parental brooding ceases at about the same time. Feather development seems closely correlated with the extent to which the young are exposed at different ages. Existence energy expenditure of resting birds was estimated, and about 38% represents the cost of thermoregulation. Nestlings are completely exposed to the elements after brooding ceases, and there appears to be little behavioral thermoregulation. Nestling cormorants expend more energy per unit of metabolizing tissue than do adults, with the extra cost probably directed to the work of growth. The costs of thermoregulation in cormorants are substantially higher than for Starlings raised in a nest-box, and other examples are cited suggesting a substantial effect of insulation in reducing existence energy expenditure in wild nestlings.This publication has 1 reference indexed in Scilit:
- The Timing of Endothermy in the Development of Altrical BirdsOrnithological Applications, 1975