The Endangered Wildlife Trust (EWT) and the South African National Biodiversity Institute (SANBI) launched the 2016 Red List of Mammals of South Africa, Lesotho and Swaziland in December 2016. Each week, we’ll be bringing you new species assessments, and introducing you to our Mammal of the Week, based on this updated Red List.

Blue Whale
Balaenoptera musculus

This week’s mammal of the week is the Blue Whale. Weighing in at 140,000 kg, the Blue Whale is the largest mammal on the planet. There are two Blue Whale subspecies found within the assessment region: the Antarctic Blue Whale and the Pygmy Blue Whale. These whales only appear blue (hence their name) when seen through the water and, in the air, their bodies are more aptly described as gunmetal grey. They also have variable mottling of lighter grey spots scattered over the back and flanks, which may only be seen clearly when the sun is behind the observer. Like other Cetacean species, they have been exploited in the past by whalers. For example, more than 8,000 Pygmy Blue Whales were illegally killed by Soviet whalers in the 1960s and 1970s. Very little is known regarding the population size of Pygmy Blue Whales and they are therefore listed as Data Deficient. The Antarctic Blue Whale, on the other hand, is listed as Critically Endangered – it is the only Cetacean species with this listing. Critically Endangered means that the species faces a very high risk of becoming extinct.

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The 2016 Red List of Mammals of South Africa, Lesotho and Swaziland was funded via the South African National Biodiversity Institute (through a grant by the Norwegian Government that aims to build capacity in the southern Africa region for undertaking assessments), the Endangered Wildlife Trust, the Department of Environmental Affairs, E Oppenheimer & Son and De Beers Group of Companies.