Where are the whales? southern right whales SURVEY 2025

PDF Report by  Dr. Els Vermeulen, research head of the UP Mammal Research Institute Whale Unit

Report of the southern right whale count survey 2025_TheBateleurs.pdf

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Pilot Report: Jean Tresfon, Bateleurs pilot and Renowned marine conservation photographer

Where are the whales? Are there less whales this year? First aerial survey of southern right whales for 2025 in the bag, and another successful mission completed for The Bateleurs, giving some answers on whale numbers!

Navigating Weather Challenges for Southern Right Whale Aerial Surveys

Peak season for southern right whales visiting our shores is around the last week of August and the first week of September, so I was not surprised when I received a message from Dr. Els Vermeulen, research head of the UP Mammal Research Institute Whale Unit, during the middle of August asking about the possibility of doing an aerial whale survey. She put in a flight request to the Bateleurs, and I started watching the weather forecasting models for the Overberg coastline. The survey is conducted between Hermanus and Witsand (to cover the three main southern right whale nursery grounds), and includes Cape Agulhas, which is almost 100km further south than Cape Town. Practically speaking, this means that Agulhas juts further out into the Southern Ocean weather system and often has more severe weather than Cape Town. The Bateleurs board of directors approved the mission, but the weather decided not to be quite as accommodating. Each time we settled on a date, a day or two prior to the flight the models showed perfect weather in the Mother City but howling westerly winds with low cloud at Agulhas. With our peak season window closing, eventually everything lined up for a flight on Saturday 6 September and we were good to go.

Whale and Wildlife Aerial Survey from Morningstar to De Hoop

Arriving at Morningstar Flying Club I was relieved not to find the airfield fogged in, a very real possibility at this time of year! After a thorough pre-flight inspection and engine run-up, I took off into the chilly morning skies and set course for Grootbos Private Nature Reserve in Stanford, who very kindly allowed us the use of their airfield for the whale count. I landed, topped up the fuel tanks, collected Els, and then headed to Hermanus to start the survey. The Klein River Estuary (Hermanus Lagoon) was open to the sea, something that has occurred since I last flew the area a couple of months ago. The whale sanctuary area in Walker Bay had quite a few southern right whale cow/calf pairs visible, with the numbers decreasing as we flew east towards De Kelders. The total count for Walker Bay was 21 cow/calf pairs and 4 unaccompanied adults.

We rounded Danger Point Lighthouse, flew past Uilenkraalsmond and on to Pearly Beach, spotting only one shark tourism boat out in the usual spot near Dyer Island. From there it was very quiet in terms of whale sightings (total of 3 cow/calf pairs) until we rounded Northumberland Point and entered Struisbaai. There were quite a few cow/calf pairs spread out along Die Plaat, and also all the way past De Mond towards Struispunt, for a total of 33 cow/calf pairs and 1 unaccompanied adult. Rounding Die Baaken, we arrived at Waenhuiskrans/Arniston and found several more whales in the bay. From here, and into the De Hoop Nature Reserve and De Hoop Marine Protected Area, the coastal geology changes and has a very shallow rocky shelf that extends far offshore. Accordingly, we tightened the straps on our lifejackets and headed further offshore. There were a 17 cow/calf pairs and 2 unaccompanied adults between Arniston and Skipskop Point, where we noticed a massive surface disturbance and flew further out to investigate. This turned out to be a super pod of thousands of long-beaked common dolphins on the hunt, such an incredible sight to witness from above!

southern right whales SURVEY 2025: Aerial Survey Unveils Whale Activity Along South African Coast

Returning to Koppie Alleen and the main southern right whale nursery ground for the entire South African coast, we counted 70 cow/calf pairs and 3 unaccompanied adults with the bulk concentration at Koppie Alleen as expected, but still quite a few more whales spread out along the coast towards Uiterstepunt and the Infanta Lighthouse.

Rounding Cape Infanta, Els spotted a flash of white which turned out to be the belly of a young and super playful humpback whale. We routed towards Infanta and found more whales at the Breede River mouth, before finishing our survey at Witsand on the east bank with a few more cow/calf pairs stretching along the coast towards the Duiwenhoks River mouth, for a total of 10 cow/calf pairs and a group of 4 unaccompanied adults in St. Sebastian Bay.

After nearly 2.5 hours in the air a pitstop was required, which saw us landing at the Breede River mouth to refuel plane, pilot and passenger. Getting airborne again we headed back to Koppie Alleen for some pictures now that the survey was complete. The sea surface was boiling with baitfish in a few areas where the gamefish were smashing into the baitballs from below. Near Skipskop Point we found a freshly dead southern right whale calf on the beach, with the seagulls already gathering for a feast. The rest of the flight back to Stanford was more of a wonderful coastal scenic tour than a transit before landing back at Grootbos to drop off Els and refuel again. From there I re-routed to Hermanus, climbing up high to get over the mountains, and landed back at Morningstar after nearly 7 hours in the air for the day!

Southern Right Whale Migration Patterns Reflect Environmental Changes and Conservation Efforts

The 2025 peak season count was 154 cow/calf pairs and 14 unaccompanied adults for a total of 322 southern right whales between Hermanus and Witsand. This number is similar to the 2021 peak season count. Regarding these numbers Els says, “The persistently low numbers of unaccompanied adults (males and non-calving females) suggest that the migration patterns of this group have not returned to the levels observed prior to 2009. The lower number of cow-calf pairs observed this year, compared to 2023’s record counts (1,136 whales), reflects the ongoing cyclicity in southern right whale presence along our coast since 2009, driven by the predominant five-year calving interval of females”.

The shift from a normal three-year calving interval to a five-year calving interval is attributed to the reduced body condition of the whales visiting our shores compared to those visiting more than a decade ago. This points to an altered foraging strategy caused by changes in krill availability at their historic feeding grounds, which is linked to climate change. Southern right whales have become an important indicator species for changing environmental conditions.

As always, we are super grateful to The Bateleurs for funding the fuel costs and contributing massively to marine conservation efforts, to Grootbos Private Nature Reserve for graciously allowing the use of their airfield, and to Overberg AFB and the Denel Test Flight Development Centre for accommodating us in their airspace.

Please note that this survey was carried out under a permit from the Department of Forestry, Fisheries and the Environment to approach whales and under specific Marine Protected Area permits from the relevant conservation authorities. In South Africa the law prohibits any vessel, drone or aircraft from approaching closer than 300m to any whale species.