how long does it take for a blue whale to give birth
Blue whale Females typically give birth once every two to three years at the start of the winter after a gestation period of 10 to 12 months.[60] The calf weighs about 2.5 tonnes (2.8 short tons) and is around 7 metres (23 ft) in length. Blue whale calves drink 380–570 litres (100–150 U.S. gallons) of milk a day. Blue whale milk has an energy content of about 18,300 kJ/kg (4,370 kcal/kg).[62] The calf is weaned after six months, by which time it has doubled in length. The first video of a calf thought to be nursing was made 5 February 2016.[63]