SEXUAL SIZE DIMORPHISM AND AGING CHARACTERS IN THE LESSER SHEATHBBLL AT MARION ISLAND

Summary Burger, A. E. 1980. Sexual size dimorphism and aging characters in the Lesser Sheathbill at Marion Island. Ostrich 51:39-43. Mass and linear dimensions of adult, subadult and juvenile Lesser Sheathbills Chionis minor at Marion Island are given. Males were larger than females in all dimensions but were otherwise similar in external appearance. The larger size of males is attributed to selection favouring male dominance in aggressive territorial encounters. External features of the head and the voice could be used to differentiate adults, subadults and juveniles in the field.