Variations in body weight, fat-free weights and fat deposition of starlings in New Zealand.

The effects of age, sex and season on the live weight and weight of liver, ether-extractable fats, fat-free weight and gizzard contents were examined for starlings in Canterbury, New Zealand.
Starling live weights varied with age and with the seasonal deposition or mobilization of fat and other stored foods. In spring and summer, non-breeding first-year birds carried relatively more fat than adults. However, adults probably feed more successfully than younger birds as when the activities of both groups were similar (autumn and winter), adults were heavier and had relatively more fat.
Diomorphic patterns also existed. In adults these probably resulted from divisions of labour prior to and during breeding.