The White Whales of Algoa BaySunday, 22nd August 2021
By Lloyd Edwards
Every now and again we get treated to seeing a “white “whale in Algoa Bay. Well they are not really all white and do change colour with age.
Our cruise yesterday started off really slowly . . . after an hour nothing had been spotted. We stopped at the large dunes north of St Croix Island at Hougham Park. I asked Jake if we should carry on towards Sunday’s River as Thea and Cara-Lee were on their way to the mouth to check for whales. We decided to head in that direction and after two minutes we spotted a massive Southern right whale. Even more exciting was that it was very white with a dark “collar” and some other black markings. How is this so?
Early whalers in Algoa Bay referred to Southern rights as “black whales” as this is their normal colour. While their backs are black, most animals have a white blaze on their belly around the naval. Variously sized white blazes are also found on the backs of 5% of adults of both sexes. Some animals also display grey markings on their backs which are irregular and chevron shaped, pointing towards the head. These markings are almost white at birth and difficult to distinguish from blazes, except that unlike blazes they darken with age. These marks are only present on females on about 10% of the population.
Algoa Bay has had its fair share of white calves over the years. Around 3,5% of all Southern right calves born are white, except for a black collar and black patterns just behind the head. Like the grey markings in the female, they gradually darken with age and become what is referred to as “brindled”. Have a look at photo 5 of a white calf and photo 6 of an adult brindled animal. About 94% of these brindled animals are male. A female can only be brindled if she is the offspring of a brindled male and a female with grey markings. These markings have not been recorded in their Northern hemisphere cousins, the Northern right whales.