“Posturing” Humpback Whales?

By The Marine Detective on August 17, 2014

Some experiences are best shared in photos. So here you have 20 images documenting the marvel of how 2 humpback whales interacted with one another for more than an hour. Huge energy was expended by both whales in head lobbing, lobtailing, pectoral fin slapping, and breaching. Back and forth it went, the sounds resounding above and under the water in the Great Bear Sea around Caamano Sound (proposed tanker route).

I witnessed this while with Pacific Wild as an educator for the SEAS program (Supporting Emerging Aboriginal Stewards).

What was this humpback whale exchange about?  In this case, I really don’t know.

I have had the privilege of learning from these giants for more than a decade now and have seen such exchanges in all sorts of contexts.

I reference the behaviour as “posturing” since the whales appear to making a display to one another. Outside of play behaviour and learning in young animals, my interpretation is that these incredibly powerful surface active displays between whales may serve the purpose of:

• Delivering a clear “I’m big don’t mess with me” message to a perceived threat e.g. the presence of mammal-eating killer whales (“Bigg’s”/”transients) or the vocals of fish-eating killer whales (“residents”) to which the humpbacks are not habituated;
• Communicating the presence of a perceived threat to other humpback whales since the slaps of humpback fins and bodies resound underwater;
• Striving to display dominance / greater vigour to other humpbacks which may be particularly relevant for mating;
• Possibly establishing spacing between humpbacks; and/or
• Some sort of social function that leads to them ultimately joining up and swimming away together as was the case in exchange for which I provide the photos below.

Here we go. Photos provided in chronological order.

Almost simultaneously, when both whales were within 200 m of one another, Humpback 1 (lots of barnacles and smaller but too big to be the 2nd whale’s calf) started breaching and Humpback 2 (larger) started lobtailing. [Note, there were also two other humpbacks in the area but at a greater distance away and they were not surface active.]

Humpback #1 then began repeatedly head-lobbing, advancing away from Humpback 2.

Half an hour later, Whale 2 advanced from the position where the exchange with Whale 1 began. S/he head-lobbed and breached down the same track as Whale 1.

Humpback 2 only stopped this highly surface active behaviour after half an hour when close to Humpback 1. And then . . . . then they joined up very close together and swam back in the direction that exchange had begun. What was it all about?!

With these whales being on the Central Coast, I am relaying fluke and dorsal photos to the wonderful Janie Wray and Herman Meuter of Cetacea Lab to find out if they might know the identities of the whales involved in this exchange. They are not known to us at the Marine Education and Research Society.

But will we ever know for sure what such a display was about? In having the extraordinary privilege of learning from the marine environment, one of my most valued lessons is to recognize how little we know and thereby to have the correct humility and precaution in decisions about marine resources.

Humpback whales are giants, they are easy to identify as individuals, they have been studied for some 40 years and still there is so very much we don’t know – including the benefit of expending so much energy in such an exchange.

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For related information see my previous blog “Might As Well Jump”

For an ethogram of humpback whale behaviours from the Whale and Dolphin Conservation Society, see here.