Size at birth 4.5m (15 feet) and 689kg (1500 pounds); Sexual maturity at 8 years; Females have calves every 2-3 years; Longevity over 40 years; Behavior; Short dives, usually flukes raised before prolonged dive; When feeding on benthic prey, often surfaces with mud streaming from mouth; Small groups, no lasting associations; Fiercely defend themselves and calf against predators/whalers