Here in the Salish Sea, we have two species of whale that we primarily encounter: humpback whales (Megaptera novaeangliae) and killer whales (Orcinus orca). The two are drastically different in both appearance and behaviour, so it’s not surprising that we’re often asked if these differences unite or divide them… or anything in between!
How the Killer Whale got its name
Killer whales earned their common name not for being whales who kill, but for being killers of whales. In certain parts of the world orcas are capable of hunting the calves of large baleen whales, and this includes humpbacks, with predation being documented off the coasts of Australia, Mexico, the United States of America, and South Africa.
Calf predation is believed to be incredibly rare in the Salish Sea (possibly because the calves are too large for the orca to take down by the time they arrive here, or possibly because of the abundance of alternative food that is easier for the orcas to catch), but many of our whales here do display signs of orca attack – for example Scuttle (BCX1795), a humpback with distinctive orca tooth scars on his tail, who would have passed through Mexican and Californian waters as a baby. Given the intelligence that these animals are known to be capable of displaying, it seems unlikely that the humpbacks would forget the threats previously posed by killer whales, and yet very possible that they know they are not in danger here.
In 2022, the T65As and the T99s were observed taking down a minke whale around 40km south of Victoria. Within half an hour they managed to subdue it and began feeding on it, which is a rapid attack indeed. While even this behaviour is rare in the Salish Sea, it’s clear these orcas are still living up to their reputation as the killer of whales.
Humpbacks Fight Back
There has only been one confirmed case of a humpback calf being attacked here in the Salish Sea, but it is unclear whether or not the calf perished as the pair were not sighted in the area again – potentially because the mother left the area (taking the calf with her, if it lived) to avoid a repeat of the incident. Mother humpbacks are known to fiercely defend their calves, and many young humpback whales will survive these encounters and grow to bear the scars they left behind – including those we see here.
Alongside this attack on the calf, there have been a few well documented reports of groups of orca and adult humpbacks engaging in seemingly aggressive encounters off our coast. One of these was between a pair of humpbacks known as Reaper (BCX1948) and Hydra (BCY1000), and a group comprised of three Transient orca pods – the T109As, the T233s, and the T252s. This encounter lasted over three hours and while all individuals survived, it’s unclear who was attacking who, or why.
Another documented brawl between the species in this area came from a humpback that is known to be more than a little bit hostile towards the local orca, named Valiant (BCX1773). In April 2022, Valiant came under the attack of nine Bigg’s orca from two families, but thankfully was able to fend them off with their own aggressive behaviour. This was not Valiant’s first run-in with Transient killer whales; in 2019, they were spotted chasing after a pod of orca in the strait of Juan de Fuca, and in 2021 they fended off yet another attempted orca attack not far away. Like Scuttle, Valiant has extreme scarring on their tail that is indicative of having survived an orca attack as a calf, so their aggression may well stem from first-hand experience of just how dangerous these killer whales can be. It seems that Valiant has neither forgiven, nor forgotten.
Humpback whales have even been reported taking their disdain for orca a step further, and have been documented around the world rescuing other species from hunting killer whales. Panicked seals, being chased by pods of orca, have sought refuge alongside humpback whales, with the whales going as far as to turn on their backs and carry the seals on their pectoral fins and chests to safety. This was even witnessed once off the coast of Sooke, just south of Victoria, where four humpbacks fought off the T100 orcas to save a sea lion!
A Seat at the Dinner Table
A key thing to remember about killer whales when discussing their choices of food, is that they don’t all eat the same things. While some killer whales, including the Transient (a.k.a. Bigg’s) killer whales we have here in the Salish Sea, do consume mammals, others will exclusively hunt fish. For us, that refers to the Resident killer whales, which will target salmon and other fish instead of the seals, sea lions, and porpoises that their Transient cousins prefer. While there has yet to be a documented interaction between Resident killer whales and humpback whales, it is presumed that there would be no reason for aggression here, though the humpbacks’ ability to distinguish between the two ecotypes remains untested!
In the fjords of Norway, the shared love of fish actually brings orca and humpback whales together during the herring migration. As the sound of fishing boats draws in orca from kilometers away like a dinner bell, it’s believed that the humpbacks will listen out for the calls of the killer whales while they feed, alerting them to where the enormous herring bait balls are. In this context, the humpbacks do not appear to be threatened by the killer whales, and the two are able to thrive alongside each other.
The Careful Balance of Mutual Tolerance
While it’s clear that humpbacks and orca have a varied relationship all over the world, it’s also safe to say that they are not known to be friendly with each other in this area. Fortunately, aggressive interactions between the two are incredibly rare here, and for the most part they are able to live in peaceful co-existence. There have been times where we have seen them apart, times when we know they are close by, and even times when we have had both species encountered at once, each minding their own business. With so much abundant food in the Salish Sea and plenty of space to escape or avoid each other, we’re hopeful that humpbacks and killer whales will continue to share these waters for many years to come!
Sources
Orcas filmed preying on minke whale south of Victoria. https://vancouverisland.ctvnews.ca/orcas-filmed-preying-on-minke-whale-south-of-victoria-1.6104480
Watch: Orca predators take down large minke whale. https://www.timescolonist.com/local-news/orca-predators-take-down-large-minke-whale-5941320
Orcas ‘attacked’ humpback mother and calf. Now the calf is missing. https://www.livescience.com/orcas-attack-humpback-mother-and-calf.html
Orcas and humpbacks clash in a violent melee of breaching and biting. https://www.livescience.com/whale-watchers-witness-orca-humpback-showdown
Killers confronted: humpback whale turns on orca pod in rare encounter. https://www.theguardian.com/environment/2022/apr/19/humpback-whale-orca-video-valiant
B.C. humpback whale Valiant wards off gang attack by killer whales. https://vancouversun.com/news/local-news/bc-humpback-whale-valiant-wards-off-gang-attack-by-killer-whales
Humpback whale (Megaptera novaeangliae) and killer whale (Orcinus orca) feeding aggregations for foraging on herring (Clupea harengus) in Northern Norway. https://www.researchgate.net/publication/315750998_Humpback_whale_Megaptera_novaeangliae_and_killer_whale_Orcinus_orca_feeding_aggregations_for_foraging_on_herring_Clupea_harengus_in_Northern_Norway
Why did a humpback whale just save this seal’s life? https://www.science.org/content/article/why-did-humpback-whale-just-save-seals-life
Humpback whales save sea lion from orcas off Sooke coast.https://www.timescolonist.com/local-news/humpback-whales-save-sea-lion-from-orcas-off-sooke-coast-4641144