Common name Blue Whale (Balaenoptera musculus)

Distribution Blue whales were plentiful until the end of the 19th century because their speed (30 kilometres per hour) gave them the edge on non-motorised chaser boats. Their numbers have plummeted. Blue whales still migrate past the New Zealand coasts, but are rarely seen close to shore. On their migration between the summer feeding grounds in the Antarctic and the equatorial waters where they spend the winter, blue whales used to swim through Cook Strait.

About The blue whale (Balaenoptera musculus) is the largest animal ever to live. The whale’s heart weighs 2 tonnes and pumps about 270 litres with each beat. Its heart rate is no more than 20 beats a minute – compared with a human rate of 60–80. On average, adults weigh between 100 and 120 tonnes, and males are 23 metres long, while females are 24 metres. A whale calf gains 90 kilograms daily on 200 litres of milk. An adult can have up to 1 tonne of food often krill, in its stomach.e loudest voice underwater of all animals, and their low frequency sounds travel hundreds of kilometres.