Harem Structure and Reproductive Behaviour of Pteropus tonganus In American Samoa.

Abstract

We studied the reproductive biology of Pteropus tonganus on Tutuila, American Samoa from 1992 to 1994. Pteropus tonganus typically roosts in colonies consisting of harem groups averaging 5.3 females per male and peripheral single males and groups of males. The mating system appeared to have elements of both female defense polygyny and resource defense polygyny. The reproductive status of females within harems varied throughout the year so that some females appeared non-pregnant while others were pregnant or nursed large young (up to about 3/4 the length of the female). Post-partum mating was frequent, especially with females that had small dependent young. Mating, pregnancy, birthing, and young of all sizes occurred year-round. However, some evidence of bimodal peaks occurred during January and June- August.