Story and photo by Kim Steutermann Rogers
It may literally be the biggest mystery in science. Humpback whales (Megaptera novaeangliae) reach 45 feet in length and tip scales, if such weighing devices existed, at 40 tons. Yet with a couple flicks of their tail flukes, they can propel their big-winged, knobby-headed bodies clear out of the water, from depths as shallow as a hundred feet, in a behavior known as breaching. But why do these endangered marine mammals breach? And, seemingly, so frequently? After all, during the humpback’s annual visit, the mid-Pacific Ocean of Hawai’i offer little in the way of nourishment, and surely the energy expenditure required to soar through the air is as enormous as the school-bus-sized marine mammal. The answer is: we don’t know. To be fair, scientists have only recently started researching humpback whales on the heels of the international ban on whaling in 1966. But there are theories. The first? To exfoliate. One theory posits barnacles and parasites cannot survive in Hawai’i’s warm waters and the act of breaching helps slough off unwanted hitch hikers and dead skin. Another theory suggests breaching as an active part of courtship, either males and females trying to attract one another. Or males exhibiting a form of territoriality. Researchers also report apparent mimicry between mothers and calves. That is, a mother breaches to teach her offspring how to use their bodies. And, finally, one cannot overlook the idea that humpback whales breach, because they can. And it’s fun.
For more information, read researcher Jim Darling’s book, Hawai’i’s Humpbacks: Unveiling the Mysteries. To read more on Hawai’i mammals by Steutermann Rogers, visit outriggerhawaii.com