Deep Dive – Inukshuk the Humpback

Inukshuk is back. We saw him back for the first time this year in the feeding grounds near northeastern Vancouver Island on May 23, 2022. We know he migrated to the breeding grounds of Mexico because he was photographed there by CaboTrek on February 19th (known thanks to Happywhale).

Of all the male Humpbacks in our study area, he is the one where it has been the easiest to know HE is the one singing. Why? Because most other male Humpbacks in our study area sing at night when we can’t identify the singer in the dark. But Inukshuk, he often sings during the day. So, if you put in a hydrophone into the water to listen below the surface, you can then identify it is him making the amazing repertoire of sounds. [See below for samples of him singing.]

Why is he different in this regard? We think it is because he more often feeds on krill at night where the other Humpbacks, specifically in our study area around NE Vancouver Island, often feed on juvenile herring during the day.

ID photos from our public catalogue.

To put to pieces together between feeding and when a male Humpback might sing.

• – If you are Humpback who likes to snack on krill, it’s often the case that you will be feeding at night because that’s when the krill is often closer to the surface (unless there are big upwellings of current during the day). Birds are active during the day and krill moves deeper to avoid being eaten by them.
  
• – If you are a Humpback Whale feeding on herring, it often helps that the birds are also going after that prey. The herring goes into a dense mass to try to get away from the birds which makes for a big mouthful of herring for Humpbacks. Because birds roost at night, Humpbacks feeding on herring near the surface is more likely to happen during the day.
  
  So, if Inukshuk is more often feeding on krill. He is likely to be feeding at night, and resting, socializing and singing during the day. For the Humpbacks feeding on herring near the surface, they are more likely to be feeding during the day and resting, socializing and singing at night.

Do we have anything other than his daytime singing to support our hypothesis? Why yes we do!

• 1) We have often documented Inukshuk pooing and it’s pink = krill diet. In fact, people have even mistaken the krill poo as blood. Humpbacks feeding on fish have silvery poo.
  
• 2) Where we rarely see other Humpbacks resting during the day, we have repeatedly found Inukshuk doing so. We’ve even had people report him to us as a whale that might be dead because he was just lying at the surface and, once, we even mistook him for a log in the tideline where he was resting.

Inukshuk pooing at the surface. The red colour indicates he has been feeding on krill.

Nickname:
We nicknamed Inukshuk for the black markings in the lower center part of his tail, which – to us – look like an inukshuk, the rock figures traditionally built in northern Canada by the Inuit as “helpers” in communication. His catalogue designation is BCZ0339.

More on Humpback Whale song:
Humpback males sing more in the breeding grounds and the songs are unique to each area. All males humpbacks in the same area sing the same song (not in unison), and if the song changes, all the singers will adopt the change together. The leading hypothesis is that they are establishing acoustic territory through song. While both male and females Humpbacks can vocalize at any time of the year and for many reasons, the males may feel a greater urge to practice fragments of song toward the fall in the Northern Hemisphere. This is when their energy budget shifts from being largely about feeding to include mating related behaviours.

Samples of Inukshuk singing:

Recording by Scott Turton.

More on whale poo:
Know that whales pooping at the surface is not only important to researchers (and whales). It’s important to all of us! As whales feed at depth and poop at the surface, they transport nutrients up the water column and help fertilize the phytoplankton. This process is literally termed the “whale pump”. Just like plants on land, phytoplankton need sunlight to photosynthesize so they need to be at the surface. Whale poop fertilizes them there so they pull more carbon out of the atmosphere, helping regulate our climate. They also produce the oxygen we breathe and food to fuel the marine food web. At least half of the oxygen we breathe comes from the ocean.

Minke Whales Vocalize off the Coast of British Columbia

Have you ever wondered what sounds minke whales make? Given that they had never been acoustically recorded in the eastern North Pacific, we wondered too. Thanks to a collaboration with University of Victoria  marine mammal acoustics expert Katrina Nikolich and funding from Mountain Equipment Co-op and the North Island Marine Mammal Stewardship Association, our research on this topic is now published! 

Minke whales DO vocalize while off the coast of British Columbia. 

Female minke whale M001 (Rapid) breaching in Cormorant Channel where over 1,500 hours of acoustic recordings were made in the presence of six minke whales. Photo ©Jared Towers, MERS, taken under Marine Mammal License MML-42. 

Spectrogram analysis revealed that the minke whales we studied off northern Vancouver Island occasionally emit very quick and barely audible downsweeps and pulse chains. Sexual segregation, predation risk and acoustic masking (vessel noise) are all proposed as reasons why this small cryptic baleen whale doesn’t have much to say.

Figure 2 from the paper shows spectrogram examples of pulse chain vocalizations that increased in pulse rate, decreased in pulse rate, and remained constant in pulse rate. To attempt to hear these vocalizations check out this link: 

For the full report, please click here. The first 50 downloads are free!

Note that our previous research reveals that rather than there being many minke whales off NE Vancouver Island, it’s the same individuals over and over again. 

Abstract: Nikolich and Towers 2018. Click the image to download the full paper. 
The first 50 pdf downloads at this link are free!. After that please contact us for reprints or purchase 24 hour access for $50 USD

MERS Minke Whale Research Papers: 

• Katrina Nikolich & Jared R. Towers (2018): Vocalizations of common minke whales (Balaenoptera acutorostrata) in an eastern North Pacific feeding ground. Bioacoustics. DOI:10.1080/09524622.2018.1555716
• Towers, J.R, C.J. McMillan, M. Malleson, J. Hildering, J.K.B. Ford, and G.M. Ellis (2013): Seasonal movements and ecological markers as evidence for migration of common minke whales photo-identified in the eastern North Pacific. J. Cetacean Res. Manage. 13(3):221-229.

Transient Killer Whales – not so transient anymore

[Update: Transient Killer Whales are now more often referenced as “Bigg’s Killer Whales”. See our colleague’s blog at this link for why this is.}

When Fisheries and Oceans biologist Dr. Mike Bigg began research on wild killer whales in BC in the 1970s, he and colleagues quickly discovered that two different types of orcas inhabited the coastal waters. Resident orcas could reliably be found in large pods socializing and foraging for salmon while another type of orca was only seen occasionally and always in small groups. These whales typically acted evasive and only appeared to target mammalian prey. Due to their random movements and unpredictability Bigg called them Transients.

Transient Killer Whale T079 hunting porpoises.

One interesting trait that Transients exhibited was their tendency to usually remain silent. This was because the species that Transients hunt have good hearing abilities and some prey populations such as harbour seals, Steller sea lions and harbour porpoises were low in the 1970s. This meant that Transients had to be relatively anti-social in order to not scare away what little prey they could find. However, over the last few decades seal, sea lion, and some porpoise populations have slowly rebounded in BC. During this time dolphins have also colonized coastal waters. Subsequently, Transient killer whales have become more common and are now typically found traveling, socializing and hunting in larger groups. Interestingly, these groups are often very vocal, especially after a kill.

For example, in the summer of 2012, MERS conducted a shore-based visual and acoustic study of whales off northern Vancouver Island. Late on the night of July 7th, the underwater monitoring device recorded what can be interpreted as a successful attack on Pacific white-sided dolphins several miles in the distance. On the clip below one can hear a few faint Transient calls and echolocation, followed by panicked dolphins and what killer whale acoustic expert Dr. Volker Deecke has referred to as a killing, ramming and crushing sound or KRACS.

These sounds were followed by more KRACS and then a huge amount of acoustic activity from the Transients including whistles, echolocation and both typical and aberrant calls as well as splashes. This behaviour continued for hours. The short clip below is a sample of these calls while the whales passed directly over the recording device.

On site MERS research volunteer, Rebecca Piercey, was awoken by the blows of these passing whales at around 1:00 am on July 8th. From the number of blows audible it was clear that several whales were present but interestingly, she could also hear these whales vocalizing above the surface. She made this recording with her iPhone at the same time the above clip was recorded underwater.

Although we have never heard of anyone else ever hearing Transient calls repeated above the surface of the water, encounters with these whales are becoming increasingly common. Several hydrophone networks regularly report detecting Transient killer whales and more people are observing predation events and social behaviour from whale watch boats, ferries and even from shore. Collectively, we are coming to realize that these whales are actually no longer transient.

In fact, because of renewed prey resources Transient killer whales have become more common than Resident killer whales along some parts of the coast. In addition to the behavioural differences between these types of orcas, geneticist Dr. Phillip Morin and colleagues recently discovered that Transients diverged from Residents and other killer whale types around 700,000 years ago. Consequently, it has been argued that Transient killer whales deserve their own species status and a more appropriate name. As Mike Bigg is acknowledged all over the world as the first to recognize how unique these whales were, most killer whale researchers agree that the name Bigg’s is more appropriate than Transient for this population of killer whale.

T055A and T055 swimming side by side.

To learn more about these whales check out the sources below. To listen to Bigg’s killer whales live check out Orca-Live. If you see a Bigg’s killer whale let the BC Cetacean Sightings Network know. For more background on the proposed name change see The Marine Detective. And for more educational items and updates from the field from MERS researchers and educators, follow this blog, “like” us on facebook, check out our website and subscribe to our youtube channel.

~JT

Sources:

-Bigg, M.A. 1982. An assessment of killer whale (Orcinus orca) stocks off Vancouver Island, British Columbia. Rep. Int. Whal. Commn. 32: 655-666.

-Deecke, V.B., Ford, J.K.B., and Slater, P.J.B. 2005. The vocal behaviour of mammal-eating killer whales: Communicating with costly calls. Anim. Behav. 69(2): 395-405.

-Ford, J.K.B. 2011. Killer whales of the Pacific northwest coast: From pest to paragon. Whalewatcher (J. Amer. Cetacean Soc.) 40 (1):15-23.

-Ford, J.K.B., and G.M. Ellis. 1999. Transients: Mammal-Hunting Killer Whales. UBC Press, Vancouver, British Columbia. 96 pp.

–Ford, J.K.B, E.H. Stredulinsky, J.R. Towers and G.M. Ellis. 2013. Information in Support of the Identification of Critical Habitat for Transient Killer Whales (Orcinus orca) off the West Coast of Canada. DFO Can. Sci. Advis. Sec. Res. Doc. 2012/155. iv + 46 p.

-Morin, P.A., Archer, F.I., Foote, A.D., Vilstrup, J., Allen, E.E., Wade, P., Durban, J., Parsons, K., Pitman, R., Li, L., Bouffard, P. Nielsen, S.C.A., Rasmussen, M., Willerslev, E., Gilbert, M.T.P., and Harkins, T. 2010. Complete mitochondrial genome phylogeographic analysis of killer whales (Orcinus orca) indicates multiple species. Genome Res. 20, 908–916.

–Towers, J.R., Ellis, G.M., and Ford, J.K.B. 2012. Photo-identification catalogue of Bigg’s (transient) killer whales from coastal waters of British Columbia, northern Washington, and southeastern Alaska. Can. Data Rep. Fish. Aquat. Sci. 1241: v + 127 p.