Good stuff from NPR today.
Enjoy...
Hank
https://www.npr.org/2018/08/01/634456181/scientists-are-spying-on-whales-to-learn-how-they-eat-talk-and-walked#storytext
Scientists Are 'Spying On Whales' To Learn How They Eat, Talk And ... Walked?
Nick PyensonAugust 1, 20182:15 PM ET
Humpback whales feed at the Stellwagen Bank National Marine Sanctuary near
Provincetown, Mass., on July 9, 2014.
J. Scott Applewhite/AP
We think of whales as creatures of the sea, but scientists now believe that 40
to 50 million years ago, whales had four legs and lived at least part of their
lives on land.
"We can tell that they're whales based on key features of their anatomy —
specifically parts of their skull," paleobiologist Nick Pyenson says. "But they
were certainly not like the whales that you would see today."
As the curator of fossil marine mammals at the Smithsonian Institution's
Natural History Museum in Washington, DC., Pyenson has examined whale fossils
that are tens of millions of years old. He has also learned about modern whales
by attaching sensors to them in the wild and by studying their carcasses at
commercial whaling sites.
"We live in the golden age of whale science, because there's so many new tools
that we have to investigate their hidden lives," he says.
Pyenson notes that the largest whales alive today are the biggest vertebrates
that have ever existed: "No dinosaur was heavier. No other mammal exceeded
their length or width," he says. "They are absolutely the largest vertebrate
animals to have ever evolved in the history of life on Earth.
Pyenson's new book is Spying on Whales.
Interview Highlights
On how long whales can hold their breath before coming up for air
Some species of whales — especially the deep diving ones — can hold their
breath for over two hours. And that's a remarkable feat in its own right, but I
think even more so when you consider that in those cases they're diving over
9,000 feet deep in search of prey. ... It's kind of like holding your breath
while chasing after your food for over two hours and then coming back to the
surface.
And these species of whales — the deep-diving, beaked whales — they do this
routinely many times a day. And you can think there's all kinds of great
physiological questions about how this works, how these animals are able to
achieve this amazing feat multiple times a day.
On the difficulty of studying whale carcasses
They are so big and they are so cumbersome to investigate. The tools you need
to open up the carcass of a 70-foot mammal are too big to really comprehend.
And your opportunities to actually investigate a carcass like that where it
hasn't started to decay are very rare and fleeting.
So [at a commercial whaling operation] in Iceland, we had this unique
opportunity to work with whatever material was not actively being processed. It
was time-sensitive in many ways and it was also a bit like walking back in
time, at least from the accounts and photos that I've seen of industrial
whaling in the early 20th century. ...
You would think that for all the whales that have ever been killed through the
process of whaling all around the world — in the 20th century alone some 2 to 3
million whales were killed through whaling by many nations — yet very few those
whales were actually investigated by biologists of any kind.
On a scientific discovery he made about whales' jaws
One of the most startling finds was the strange tangle of blood vessels and
nerves that we found lodged right in what would be the chin of these whales —
sort of the tip of the snout on the lower jaws. ... We're talking about
jawbones that are almost the size of telephone poles — each the right and the
left jaw — and there's the space between them.
And when we started examining that in more detail, we realized it wasn't just
space filled with cartilage or some kind of extra bits of tissue, it actually
had blood vessels and nerves and so that seemed unusual to us and worthy of
more investigation. ...
We started putting the different pieces of evidence together ... which told us
that the nerves and blood vessels were really what we thought they were:
pressure sensor devices. And when we look at the biomechanics of how these
animals feed, it appeared to be a way for these very large whales to coordinate
just how much their jaws were able to open and close in the course of this
lunch feeding activity that they undertake every day.
On echolocation by toothed whales
You can think of it as a kind of acoustic flashlight on the forehead of these
whales. So the same way that if you run around the woods at night and you have
a flashlight [on] you, if you look at the flashlights of your friends, you can
tell what they're doing and they can tell what you're doing, but that's pretty
much it. ...
The power of that signal varies based on the body size of these whales. Sperm
whales have an incredibly powerful echolocation organ on their skulls that can
be up to 20 feet long.
By the 1960s the U.S. Navy was funding a lot of research into understanding how
echolocation works, because it had such an important technological consequence.
And even today, still, the sonar that's used by the military is not as
sophisticated as that of the ones that toothed whales use to navigate the world.
Even today, still, the sonar that's used by the military is not as
sophisticated as that of the ones that toothed whales use to navigate the world.
On common environmental threats to whales
The oceans have gotten to be a lot noisier places and this is a big issue for
whales whose habitats that they want to feed in overlap directly with the
places where our cargo ships and cruise ships most frequently go.
And I'm thinking about places like Boston Harbor or port of Los Angeles. Those
are two prime spots where there's a lot of shipping activity, big ships moving
out frequently and it is right next to prime habitats for very large baleen
whales and so ship strike is a big concern.
Whales, even the largest ones, can't move quickly enough to get out of the way
of these ships, which move much faster and are much, much larger. So,
unfortunately a lot of whales are victims of ship strike, which is just
incredible trauma.
Another feature is ... the noise, the churning in those engines, makes those
environments much noisier. And if you're a whale a lot of your livelihood
depends on acoustics being able to hear and also being able to make sounds, so
there's good evidence that in these busy ports, whales are having to sing and
communicate louder and at different frequencies just to get over the noise.
Lauren Krenzel and Thea Chaloner produced and edited this interview for
broadcast. Bridget Bentz, Molly Seavy-Nesper and Rhitu Chatterjee adapted it
for the Web.
Hank Mitchel
818-451-9502 (mobile)
