Abstract
Sexual morphological differences were examined based on functional aspects of skeletal and muscular characteristics in breeding Tufted Puffins, Lunda cirrhata collected near the Aleutian Islands in summer 1987. Males had larger sized bodies, bones, and heavier muscles than females. Total fresh weight of leg muscles ranged from 25.0g to 31.0g with an average of 28.1g in males and from 21.7g to 26.3g with an average of 24.1g in females.
The gravimetric proportion of wing muscles to leg muscles was larger in females than in males. The averages of the two groups of muscles which were related to elevation and depression of the humerus were 76.9% and 193.9% in males, and 82.4% and 216.2% in females, respectively.
It is therefore suggested that females have greater propulsive force for subaqueous and aerial movement, and less agility for subaqeous and terrestrial locomotion. Females would have a tendency to take food organisms with less mobility than males.
