Killer whale vs Humpback whale A conflictual relationship

After learning many things about orcas through the serie of blogs by Kylie Veal, lets get back to Elding research, the result of the work made by two of our interns, Killian and Tijmen.

Do you know why we call humpback whales “the angels of the sea?”. Because of their big white pectoral fins shining through the water. They really deserve their name for another reason. Many observations were made of humpback whales protecting other species such as seals or other species of whales from the teeth of their enemy. At least 72 interactions were observed between 1959 and 2012, with humpback whales initiating the interaction with orcas hunting marine mammals. Humpbacks can put up a good fight with their large pectoral fins that end with sharp barnacles which they can use to violently slap the water,

Pectoral fin from a humpback whale, can measure up to 5m, Picture from Miquel Pons

or their large powerful tail that they can also use against an eventual enemy.

Peduncle throw from Liney, a humpback whale with orca rakes on the dorsal fin, Picture from Miquel Pons

The relationship between the two cetacean species can be cordial, sometimes observed feeding together on schools of fish.  However, some ecotypes of orcas actively hunt and kill whales. Orcas track young humpback whales, ram them and suffocate them by jumping on top, denying them the surface to breath. It could explain humpback whale animosity towards orcas.

What about humpback whales of Faxaflói? Do they also interact with orcas? 

We see orcas a few times a year in our bay, even though we have seen them three times between March and April 2025 already! When seen in similar areas than orcas, humpback whales seem to be feeding normally in these areas, undisturbed by their archenemy’s presence. The killer whale ecotype we see here is likely feeding on fish and would not be a threat for grown humpbacks.  

For over a decade Elding has conducted Photo-ID research in Faxaflói bay, this has resulted in a database containing 342 identified and named humpback whales with photographed fluke. We discovered that 22 of these individuals have visible “orca rakes” on their dorsal fin or fluke made by the teeth of orcas on humpback skin. It gives us an attack rate of 6.4% in the bay of Faxaflói which is lower than the 9.3% attack rate calculated on a large study in Iceland and east Greenland (Koilpillai et al., 2024). These attacks seem to be less frequent in Iceland, Norway and Northwest Europe than in the Gulf of Maine, Canada, and west Greenland.  

Liney, a humpback whale with clear orca rakes on its dorsal fin, Picture from Miquel Pons

By dividing the humpback whale body in a numbered grid we discovered that the most common place for tooth rakes (TR) to appear is at the points of the bottom side of the fluke.

Grid made by Tijmen and Killian

The right side of the humpback had the most orca rakes on the bottom trailing edge of the fluke and only a couple marks around the dorsal fin. Whereas the left side had more tooth rakes at the point of the fluke and more rakes spread on different parts of the body around the dorsal fin. 

Why the fluke?  

The presence of most of the orca rakes on the fluke could be related to the way orcas attack humpback whales, trying to grab their tail in an attempt of slowing them down or drowning them. If humpback whales come under attack by killer whales, they tend to slap and smash their flukes at the killer whales to defend themselves (Ford & Reeves, 2008).  

When they do this, their tails are easier for orcas to attack and bite. This also explains why the edge and the tips of the fluke show the most scars (Corsi et al., 2021).  

The attacks that do happen on adult humpback whales could show that orcas try to prey on and eat parts of humpback whales without killing them (McCordic et al., 2013), or a test to see if a weaker individual could be hunted. This could explain the tooth rakes found on and near the dorsal fin. The dorsal fin is a relatively small part that is high up on the body of the whale, this could prove to be an easy place for orcas to try and bite the humpback.  

Our most famous humpback whale Davy Jones II might be a good example of that, and his personality would probably not be the same without his turbulent past! 

Fluke of Davy Jones II with rakes on the right side, Picture from Miquel Pons

Dorsal fin of Davy Jones II with a clear cut at the top, Picture from Miquel Pons

Killer whales around Iceland are commonly fish eaters and mostly feed on herring. It is not likely that humpbacks get attacked when they are feeding in Icelandic waters. In Norway orcas and humpbacks are often seen feeding together feeding on the same school of herring during the winter. Scientists have also discovered that orcas almost never attack humpback whales in the breeding grounds to the south (McCordic et al., 2013). It means that humpback whales likely get attacked by orcas during their migration. This could be either the migration North to the feeding grounds or South to the breeding grounds. As most humpback whales show signs of orca attacks before they are observed at higher latitudes such as around Iceland, they are likely attacked during their migration North (Mehta et al., 2007). 

The scars on the dorsal fin tend to fade much quicker than those on the fluke, which could be the reason why we see more of those scars on the fluke. Dorsal fin scars are sometimes only visible for 2 to 3 years before becoming barely noticeable (Mehta et al., 2007).  

Miquel Pons

Bibliography  

Corsi, E., Calambokidis, J., Flynn, K. R., & Steiger, G. H. (2021). Killer whale predatory scarring on mysticetes: A comparison of rake marks among blue, humpback, and gray whales in the eastern North Pacific. Marine Mammal Science, 38(1), 223–234. https://doi.org/10.1111/mms.12863  

Ford, J. K. B., & Reeves, R. R. (2008). Fight or flight: antipredator strategies of baleen whales. Mammal Review, 38(1), 50–86. https://doi.org/10.1111/j.1365-2907.2008.00118.x  

McCordic, J. A., Todd, S. K., & Stevick, P. T. (2013). Differential rates of killer whale attacks on humpback whales in the North Atlantic as determined by scarification. Journal Of The Marine Biological Association Of The United Kingdom/Journal Of The Marine Biological Association Of The UK, 94(6), 1311–1315. https://doi.org/10.1017/s0025315413001008  

Mehta, A., Allen, J., Constantine, R., Garrigue, C., Jann, B., Jenner, C., Marx, M., Matkin, C., Mattila, D., Minton, G., Mizroch, S., Olavarría, C., Robbins, J., Russell, K., Seton, R., Steiger, G., Víkingsson, G., Wade, P., Witteveen, B., & Clapham, P. (2007). Baleen whales are not important as prey for killer whales Orcinus orca in high-latitude regions. Marine Ecology. Progress Series, 348, 297–307. https://doi.org/10.3354/meps07015