Thursday, March 17, 2022

Top Predator: Oceans

Environmental & Science Education, STEM, Wildlife, Nature, Biodiversity, Biological Evolution 

Ed Hessler

Who trusted God was love indeed/ And love Creation's final law/ Tho nature, red in tooth and claw/ With ravine, shriek'd against his creed.--Alfred Lord Tennyson, In Memoriam A. H. H., 1850

In the 1800's, the phrase "Tooth and Claw" was once in common usage when describing nature and remains in use today although not so commonly. I thought of it when I first saw the footage of orcas (Orsinus orca) attacking and killing an adult blue whale (Balaenoptera musculus).

The event was captured on film in 2019 and this record plus two others was published in Marine Mammal Science (January 2022) was just recently published. There the first page--title, information about the author's affiliations, and some text may be read. The remainder is behind a paywall. I was going to share the video and glad I didn't for NPR (see below) just reported on the event with some details. Here are a few:

--John Totterdell, the lead author of the MMS paper referred to above, and his students were "off Australia's western coast," in March 2019. Some "'twenty black and white shapes" were "surrounding something." When they caught the color of blood in the water, they "realized...a pack of killer whales is attacking a blue whales.'" 

--The whale, about 70 feet long, "was fighting back" and the killer whales "were making coordinated attacks and working together to exhaust their prey. They took turns, biting chunks of flesh" from the whale. This "went on for hours and eventually, the blue whale got weaker" to the point when "two killer whales leapt on top of it, forcing the blue whale uner the water," to drown it.

--The tongue was eaten first--"probably while it was still alive." The reason isn't known but Totterdell told NPR that "it appears to be a 'preferred cut.'''

--This is the first documentation of such predation.

--Even Great White sharks (Carcharodon carcharias) are wary of them.

--Totterdell told NPR that "their work...definitely shows that killer whales...are the top predator in the ocean." You may remember the term refereing to this, apex predator--from a biology course when you learned about food chains

--This story by Lauren Somer and Vanessa Romo ends with some interesting comments on the enculturation of such behavior "within their family group," which is passed on" generation to generation. Killer whale societies consist of "pods...led by a matriarch.

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