Preliminary analysis of reproductive parameters of the boutu, Inia geoffrensis, and the tucuxi, Sotalia fluviatilis, in the Amazon River system.

Abstract

Sotalia calves are born at lengths between 71-83 cm after a calculated gestation period of 10.2 months. Calving is apparently seasonal, with a peak between October-November (the low-water period of the Amazon River system). Inia calf size at birth is 79.4+ or -3.3 cm, the calving season is during May through July, coincident with the peak water levels of the river system. This seasonality in the calving period in both dolphins is linked to relative food availability in relation to the river flooding cycle. -from Authors