In this episode of “Marine Mammal Highlights” , PacMam’s intern Trevor Derie discusses why he thinks humpback whales are the coolest cetacean:
The humpback whale (Magaptera novaeangliae) is perhaps the most well recognized and commonly seen whale throughout the globe, becoming a charismatic and iconic animal of the ocean. Found off and near the coast of every continent during some point of their seasonal migration, humpback whales (receiving the term “humpback” from their humped diving motion) give the opportunity for people all across the world to catch a glimpse of these massive world travellers. However, despite their ubiquitous sightings and interactions with people, there is still plenty we do not know and are just beginning to understand about them.
From what we do know, the humpback whale as a species is a bit of a success story. During the whaling years when most whale species were highly valued for their oils, humpback numbers dwindled, but with the international ban on humpback hunting in 1966 (1986 for all whales), they present an astounding success story with their numbers soaring to nearly pre-whaling numbers. Now, rather than whaling, they are one of the more popular cetaceans that whale watching companies pursue, especially here in the Salish Sea.
The humpback whale can grow to the size of up to 50 feet and 30 tons, easily one of the larger whales (though dwarfed by the up to 98 foot, 190 ton blue whale). During the summer months, this species feeds primarily on krill and bait fish near the poles, such as in Alaska in the North and Antarctica in the South. Like most mysticetes, the humpback feeds by engulfing large masses of krill or fish and filtering out water through their comb-like baleen in their mouths, trapping the prey inside while expelling the water. During the winter months, this species halts feeding and takes part in one of, if not the longest migration known to mammals, travelling from the poles towards warmer watered breeding grounds near the equator, offering a less harsh environment for calf birth and growth.
Humpback whales are also well known singers of the ocean, similar to the “canaries of the sea,” the beluga whales (check them out in our last post!). Though both sexes can vocalize, it is only the males that sing, producing lengthy and complex songs that are hypothesized to attract females or compete with other males for courtship. Some research has also found that different populations of whales produce different songs, indicating a possible cultural or regional aspect to various humpback whale populations.
When looking at a humpback whale, perhaps the more noticeable deviation from the norm from other cetaceans is the pectoral fins of the whale, appearing much more elongated and slender than other species. These fins are agile and easily maneuverable, aiding with locomotion (primarily steering) as well as communication, such as by loudly slapping them on the water’s surface. However, new research also suggests they may occasionally help with propulsion, a first in whales, primarily through a flapping motion (much like a flying bird) for a quick burst in speed, such as for gulping food, as discovered by Stanford researchers: https://news.stanford.edu/2017/07/10/humpback-whales-flap-foreflippers/
This species also exhibits curious intelligence that we are still learning more about and trying to comprehend, a particular interest of mine. For example, populations of humpbacks in both Alaska and Antarctica have learned a successful method of feeding known as “bubble net” feeding. This technique involves the whales circling prey and blowing bubbles around them in tighter and tighter circles, corralling them in a “net of bubbles” to be easily gulped up and eaten once all bunched together at the surface. This behavior is incredibly clever and is learned through teaching each other, where these normally more solitary animals will work together in larger groups to collectively feed on the same food resource.
Though not proven and only theorized, humpbacks also occasionally exhibit potentially altruistic behavior – putting themselves in harm’s way to aid others. A curious animal in general with multiple instances of interspecies interactions, there have been numerous documentations of humpbacks interrupting killer whale hunts by separating the prey from their pursuers. In one case, a humpback was documented swimming upside down while a Weddel seal rode on top of its stomach away from the killer whales. Though the humpbacks may just be interrupting killer whale hunts in case they are attacking one of their own kind, this behavior is perplexing as to why they may put themselves at risk to potentially help others of another species.
During my undergraduate years, I had many opportunities to see humpbacks in various parts of the world, starting with the local migrating population here in the Salish Sea, those in Alaska and Hawaii during their migration and those migrating off the East coast of Australia travelling from Antarctica. Previously working on a whale watching boat in Anacortes, I had the opportunity to see these animals nearly every day presenting a vast array of unique activities, whether it was breaching in the distance, curiously checking out the boat, or congregating in a myriad of individuals. Hopefully, with continued conservation and efforts to help this species and the ocean, we can continue observing these activities that make them special.