The Cephalorhynchus dolphins are among the smallest dolphins. Indeed, in length, Hector's dolphins from New Zealand's South Island (maximum 145 cm; ca. 50 kg) and South American Commerson's dolphins (maximum 146 cm; ca. 45 kg) are the smallest of all dophins. Both Hector's and Commerson's dolphins have isolated populations in which individuals grow larger. Commerson's dolphins at the Kerguelen Island grow to 174 cm (86 kg) and Maui's dolphins (North Island Hector's dolphins) reach at least 152 cm (65 kg). In both Hector's and Commerson's dolphins females are 5-10% larger than males.