Southern Right Whales at Marengo

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.

The information in the following paragraph is from the paper: Stamation, K., Watson, M., Moloney, P., Charlton, C., Bannister, J., (2020) Population estimate and rate of increase of southern right whales Eubalaena australis in southeastern Australia; Endangered Species Research: Vol. 41: 373–383, 2020. pdf.

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. ISBN 978-1-55143-114-7). 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.

An offshore wind, intermittent showers and a small glassy shorebreak for the surfers were the conditions at Mounts Bay when two southern right whales arrived last Friday afternoon and stayed for a couple of hours.
The Apollo Bay grapevine works very well when a whale arrives in the area.
Head on the right, tail on the left. This is an adult southern right whale.
Prominent callosities on this adult’s head.
The callosity on top of the head is called the bonnet. This one is prominent. The eye is not visible in this photo.
This shot captures the underside of the large lower jaw of the adult whale.
This diagram is from the SWIFFT website at: https://www.ari.vic.gov.au/__data/assets/pdf_file/0027/531297/Using-photographs-to-identify-Southern-Right-Whales-FactSheet.pdf
With reference to the preceding diagram, this photo clearly shows the bonnet, the rostral islands, the lip patch and the coaming. It also shows other distinctive callosities on the side of the lower jaw and a line of evenly spaced and uniformly shaped small callosities directly behind it. The eye is not visible in this photo.
I submitted this photo and a few like it to ‘WhaleFace’, the SWIFFT online southern right whale photo identification project. The prompt and informative response I received was that visible features on my photos for identification of this whale were quite adequate, and that the preliminary view was that this is a new whale (not previously identified in the data base maintained by the whale photo identification project). Confirmation will not be forthcoming until after the whale season, when the cataloguing and matching process is undertaken. If it is a new whale and if I was the first photographer to capture it, I will be given the opportunity to name it (with guidelines which preclude names like whaleymcwhaleface, and John). I would be pleased to do that.
But also of great interest was that the whale I photographed is a grey morph which is apparently quite rare. This photo shows the grey colour of the skin on this whale. The skin on most SRWs is black. The SWIFFT database contains photos of over 400 individual whales, and less than 20 are grey morphs.
A further matter raised (not yet resolved) is whether I photographed a mother and calf or an adult accompanied by a sub-adult. Upon request I submitted further photos to SWIFFT to enable a conclusion to be reached in this regard. My ill-informed view was that I had photographed a mother and calf, based mostly on size difference. I will update this post if and when I learn more about exactly what I photographed. [Update 22.7.21: the SWIFFT expert has said that while it is difficult to tell from the photos as there is no shot showing both whales at the same time, it is most likely that I photographed two adults socialising].
Whales near the surface seem to enjoy displaying various fins and body sections in turn.
This tail fluke seems to have sustained an injury at its tip.
Tail flukes of a diving whale. I suspect this was the tail of the smaller whale.
This is the tail of the larger adult when she dived.
The skin of a southern right whale is usually black. This mottled grey skin is why it is a grey morph. The grey skin is genetic in origin (as it is with calves that are born albino).
The mottled grey skin colour pattern is particularly clear on this raised pectoral fin.
‘Bye.
The outer reef of the Little Henty Reef system just off Hayley Point at Marengo with some Australian fur seals visible on the rocks. The SRW, in common with some other whale species, has two blowholes. But unlike, for example, the humpback whale which has two blowholes which merge into one (producing a single stream and cloud of vapour when it exhales), the SRW has two blowholes, which produce a distinctive V-shaped vapour cloud, as shown in this photo. Another distinguishing feature of the SRW is that it has no dorsal fin. The humpback has a small but clearly visible dorsal fin.
After loitering for a while between the closer reef of the Little Henty reef system (250-300m offshore) and the outer reef (about 750m offshore, over which small waves are breaking in the photo) the two whales eventually swam south past Hayley Point to deeper water and the continuation of their journey. The light was fading rapidly as dusk approached. The seals (residents on Little Henty Reef) were very active around this time, and could be seen in the distance diving and surfacing near the small waves in the photo as they fed.

It lifts my spirits to be in the company of whales, even if only for a short time.

6 thoughts on “Southern Right Whales at Marengo

  1. Hi John. Like everyone who has seen this latest blog they would have loved to have been there to see first hand these majestic creatures. Loved not just the photos of course, but the descriptions from the literature that you tracked down. For instance I didn’t know those callosities on the southern right whale were congenital. I remember being told as a child by my father that they were barnacles and that the whale would scrape them off on the reef!
    I was also surprised to read that numbers had only increased by 7% over 36 years. I had thought it would have been many more. As a lad a whale sighting anywhere near Kennett River was a rarity. Not so now.
    Anyway, it’s still early in the season so a few more sightings and photos please John.
    Cheers, Richard

    Liked by 1 person

    1. Thanks Richard. Pleased to hear you enjoyed this whale sighting report. Your comment about barnacles and whales scraping them off reminded me that I failed to mention this aspect of the callosities. I have rectified that with the insertion of a further paragraph in the introduction. I too have long heard that the light coloured patches on southern right whales were barnacles and that whales would try to scrape them off. As noted in the newly inserted para above, barnacles are not the explanation for the callosities, but they are present on them. The notion that barnacles in the callosities bother the SRWs at all or enough to cause them to try to scrape them off seems at the moment to be more a matter of whale lore than science.
      Cheers, John

      Like

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