Age-Specific Changes in the Major Body Components and Caloric Values of Herring Gull Chicks

Abstract

Herring Gull chicks are relatively variable in body weight gain and fat content, but are more regular in linear skeletal growth. Developmental patterns of the internal organs of the semi-precocial gulls resemble those reported for altricial nestlings, but age-related changes in body fat and water content are more similar to those of precocial species. Increases in live-weight caloric values with age, from about 1.0 to 2.0 kcal/g, are related to increasing fat and decreasing water contents throughout the growing period.