The southern right whale was hunted to the edge of extinction in the early nineteenth century. While it is now making a steady comeback, it is still classified as an endangered species. It’s always a special event to see a southern right whale at relatively close range.
Skip the next five paragraphs and go straight to the photos below unless you are interested in some detailed information about the southern right whale.
There are two genetically distinct SRW populations in Australia, one in South Australia and Western Australia, and the other in south eastern Australia (Victoria, Tasmania and NSW). The 2020 paper referred to above estimated size of the south eastern population at 268 individuals, 68 of which are breeding females. At Logans Beach (Warrnambool), the only permanent calving ground for the south eastern population, there has been no significant change in the number of mother-calf pairs sighted there in the last three decades. But the total number of whales (adults and calves) using the south eastern Australian coastline has increased by 7% since 1985.
The southern right whale has an average length of 16m and weighs around 50 tonnes. They have congenital light coloured skin growths on their head (callosities) the pattern of which is unique to each individual. Individual whales can be identified by the pattern of their callosities. They live to about 60 years of age. The calving interval is 3.5 years, and the gestation period is 11 months. Mothers fast for up to four months while providing milk to their calf, before returning to their feeding grounds in sub-antarctic waters in the Southern Ocean between latitudes 40° and 60° south. They migrate annually from sub-antarctic waters to the warmer inshore waters on the southern coast of Australia. It has been estimated that 95% of the total Australian SRW population spends winter at the head of the Great Australian Bight in South Australia. In addition to the established calving grounds at Logans Beach, two other areas in Victoria are emerging as biologically important areas for SRWs: Portland and the Pt Campbell area. (The information in this paragraph is from the SWIFFT (State Wide Integrated Flora and Fauna Teams) network website at: https://www.swifft.net.au/cb_pages/sp_southern_right_whale.php
The callosities are home for small crustaceans (cyamids) as well as barnacles. Some researchers speculate that these freeloaders on southern right whales might cause itching or impede swimming. I have found no definitive answer as to whether this is correct. I am not aware of any evidence that they harm the SRW. But I have heard it said that whales scrape their barnacles off on rock or sand. One author has noted that grey whales have been observed rubbing against a gravelly seabed to remove barnacles (Busch, R. (1998). Gray whales: wandering giants. Heritage House Publishing Co. pp. 61–62. ISBN978-1-55143-114-7). But the large callosities near the front of the upper and lower jaws and around the head of the SRW are in very awkward locations for this 50 tonne creature to effectively scrape them on rock or sand. I have seen a large adult southern right whale at close quarters from my surf ski in shallow water close to shore (at Apollo Bay). It didn’t assume any angles that would have allowed any of its callosities to contact the sandy seabed. Not science I know, but I suspect the SRW has adapted to its little passengers.
Over the years I have occasionally sighted southern right whales, humpback whales and, rarely, orcas near the Apollo Bay coastline during winter. Typically a SRW with calf will rest for some hours or even days in the sheltered bays of Apollo Bay and Mounts Bay. The photos below were taken at Mounts Bay near Marengo late on the afternoon of Friday 16 July 2021.