Stories tagged whales

Sep
26
2008

Could it be?: Precious ambergris? Or just beach cheese.
Could it be?: Precious ambergris? Or just beach cheese.Courtesy sarae
Oh, Fergie, you’ve ruined my life. And music.

Anyway, New Zealand seems to be a little grosser these days. Several huge, greasy “lumps” have been found on the shores of the North Island in the last week, leaving locals confused, disgusted, and hopeful that a fortune in whale puke is right around the corner. (This may be the default feeling for kiwis, but I don’t follow the news there enough to say for sure.)

The 1000-pound lumps are whitish, lard-like, and a little smelly. The dogs of the beachcombers who first discovered the objects were reportedly reluctant to touch or eat the material, which is a strange thing for a dog that has found something on the beach.

Locals were quick to assume that the lumps could be precious ambergris, highly valuable whale vomit used in cosmetics, and were seen hacking chunks off of the mystery blobs. Their retirements, they reckoned, would be full of featherbeds and yams. (Again, I’m sorry, I just don’t know what New Zealanders are into.)

Ambergris’ name comes from the French for “grey amber” (as opposed to “brown amber,” fossilized tree sap), and is in fact, for those of you behind on your cetology, sperm whale puke. Sperm whales, like the rest of us, love to puke. And it’s important that your average sperm whale gets a good puke in now and again to eject any sand or stones they might have taken in over the course of… you know, I don’t really understand sperm whales any more than New Zealanders. But somehow they get grit in them, and they regularly and easily hurl it out. It seems, however, that some materials, like the beaks of cuttlefish and squid, are particularly irritating to whale guts, and something different happens—a special puke. It’s not known if the ambrein (the fragrant main ingredient in ambergris) comes from the beaks themselves, or if the chemical comes from the whale’s digestive process acting on the offending materials, but eventually a big ball of pasty goo is formed inside the whale, ready to be puked out. The ambergris initially smells pretty foul, but after floating around for a while, and being hardened and broken down by sunlight, it becomes a very complex and valuable material. Depending on the quality, it can fetch up to $15,000 per kg from perfume makers, to be used as a high-quality fixative.

Giant squids come in, I like to think, as an appropriate source for this bizarre, valuable material. Sperm whales are, after all, the prime predators of the giant squid, and giant squid have awfully big, gut-irritating beaks. It’s a link I like to make.

Anyhow, a lot of New Zealanders were set on making their fortune with this so-called whale puke. Ambergris, however, is said to burn with a blue flame when lit, and give off a pleasant aroma. When the mystery material was subjected to this test “it just melted and really stank.” Ooh. Ouch.

After this revelation, guesses on the material compositions were downgraded from ambergris to lard or cheese—“possibly brie.” The lumps are, it should be noted, about the size and shape of 44-gallon drums, which should have been a tip-off. But whatever.

Sep
19
2008

The Ambulocetus: Not looking very fearsome at the moment, but it's thinking horrible, horrible thoughts.
The Ambulocetus: Not looking very fearsome at the moment, but it's thinking horrible, horrible thoughts.Courtesy ArthurWeasley
It’s Friday, y’all, and you know what that means!

No, not falling asleep at a booth in Applebee’s (should have gone to TGIF, right?)!

No, not a methadone suppository (not from me, anyway)!

And, no, not matching butterfly tattoos (that’s a Saturday thing)!

What’s left? Why a Science Buzz creature feature, of course! Sure, Friday has never been Creature Spotlight day before, sure, and, yes, it’s unlikely that I’ll remember to do it next Friday… But, hey, we’re Buzzketeers, right? We live in the now.

And so, with a small current science introduction, the creature of the week:

The crocowhale* (also known as ambulocetus, or “walking whale”).

If you’re keeping up on your cetacean evolution paleontology, you might have noticed this story recently. The ancestors of whales, paleontologists are quite certain, were land animals. Finding the evolutionary steps of their return to the water has been a challenge, however.

The distant ancestors of whales were carnivorous ungulates (ungulates are hoofed animals), that probably looked a little like dogs (with hooves). At some point these creatures began adapting to live and hunt in and around the water, eventually evolving into fully aquatic species.

Living vertebrates that swim employ a variety of propulsion methods. Several swimming styles seem to develop in sequence as a group of animals becomes more fully adapted to living in the water: swimming with four legs, paddling with just the back legs, undulation of the hips, undulation of the tale, and finally oscillation of the tail. The sequence of whale ancestor fossils seemed to follow this pattern (with modern whales having lost their hind legs to propel themselves with just their tails), except that for a long time it appeared that the step of swimming by hip undulation.

Recent fossil discoveries, however, show a whale ancestor that appeared to have a long fluke-less tail (it didn’t have big tail fins, like a modern whale), along with long hind legs and large, webbed feet. The skeleton seems to indicate that this creature would have propelled itself by undulating its hips, using its webbed hind feet as hydrofoils. And so, la de da, we have an important step in whale evolution in the bag. But, for the creature spotlight, we’re going back a couple branches in the cetacean family tree.

Before the group had evolved to the point of the hip wiggler above (called georgiacetus, by the way), there was the ambulocetus. Ambulocetus was a creature that probably still spent some of its time on land. It was about 10 feet long, and moved around on short, powerful legs. With its eyes and nostrils located on top of its long head, it probably looked something like a furry crocodile. Indeed, paleontologists think that ambulocetus probably acted very much like a crocodile, and filled a similar ecological niche.

Ambulocetus could have waited for large prey almost entirely submerged in shallow water, with only its eyes and nostrils breaking the surface. When something worthwhile came down to the water’s edge, it could have launched its body out of the water with its particularly powerful hind legs, ambushing its prey. The ambulocetus would have then dragged its struggling meal back into the water, and waited for it to drown. Yes! Crocowhale!

Here’s a cool illustration of ambulocetus in action.

* “Crocowhale” is a brand new term, and while I’m all for you using it in everyday life, don’t put it in any biology papers or anything. Yet.

May
12
2008

Mmmm...that's good eatin': It takes less energy to harvest seafood, including whale, than to raise animals on a farm.
Mmmm...that's good eatin': It takes less energy to harvest seafood, including whale, than to raise animals on a farm.Courtesy Sparky Leigh

The Norwegian whaling lobby has released a study, comparing how much energy is required to produce a pound of whale meat vs. a pound of beef, chicken, or other livestock. The results: one pound of chicken produces 2.4 times as much greenhouse gas as one pound of whale meat; pork produces 3.4 times as much; and beef 8.3 times as much.

Greenpeace quickly pointed out that this has nothing to do with whales themselves; all farm-raised meat requires a lot of energy. Catching fish and other seafood produce similar amounts of gas. Many whale species are threatened or endangered, and protected by international treaties. Nations that do a lot of whaling object to these restrictions.

Do you really know what's in that lipstick you're about to touch to your lips? Read this New York Times story to find out how whale puke and ground up beetles are among the key ingredients to today's cosmetics.

And speaking of whales, researchers in Australia are trying to decode whale talk. Eavesdropping on thousands of hours of humpback whale sounds, they have found certain calls occur only in certain social situations.

(Liza had a post on research into humpback whale speech last year.)

Nov
20
2007

A humpback whale throws itself from the water: in its enthusiasm to give its life for science.
A humpback whale throws itself from the water: in its enthusiasm to give its life for science.Courtesy National Oceanic and Atmospheric Administration
I mean, I think I’d have guessed that the best way to gather scientific data on whales would be to observe them, and maybe toss some electronic tracking tags on them. But then again, I’m no scientist, so I’ll leave cetacean biology up to folks like those on the Japanese “scientific research whaling” fleet, which disembarked on Sunday with the intention of catching 1100 whales to study the whales’ “population, age composition, sex ratio, and natural mortality rate.” Then, in accordance with the regulations of the International Whaling Commision, these 1100 research subjects will be butchered and sold as food.

It seems a little goofy, I know, killing all these whales in the name of science, but you know what they say: “You can’t make an omelet without breaking a few thousand whales.”

This hunt (we’ll call it a hunt, for simplicity’s sake) is just another episode in a decades long debate over whaling rights and practices. In 1986, the International Whaling Commission declared a moratorium on all whaling, in response to severely depleted whale populations. This cessation of whale hunting had just a couple exceptions: aboriginal subsistence whaling, which allows small scale whaling by aboriginal groups with a tradition of whaling, and the scientific research whaling, which says that whales can be taken for scientific purposes. The harvested whales can then be sold for consumption.

Japan has a cultural tradition of whaling, dating back a thousand years at least. Whaling became particularly important, however, after WWII, when whales became “a cheap source of protein in the Japanese post-war diet.” Whale consumption peaked in 1962, and has since declined in popularity, to the point where it is now a subsidized industry. The for-profit company behind the research expeditions sells about 60 million dollars worth of whale products each year.

The Japanese government maintains their country’s whaling is done for scientific purposes alone, although critics point out that the scientific whaling uses the exact same boats, crews, and equipment as was used for commercial whaling prior to the moratorium.

This year, the Japanese fleet plans on catching 1000 minke whales, a relatively plentiful species of small baleen whale, as well as 50 humpback whales and 50 fin whales, which are vulnerable and endangered species, respectively. Geenpeace plans on intercepting the fleet with their flagship Esperanza, and then, I don’t know, yelling a lot. It promises to be an exciting expedition, especially for the whales.

Fin whale: Courtesy Lori Mazzuca, NOAA
Fin whale: Courtesy Lori Mazzuca, NOAA

In a continuing world trend toward renewed whaling of endangered species Iceland whalers have killed a Fin whale. Fin whales are listed as endangered by the World Conservation Union.

Jun
17
2006

Solving the mystery of whales' missing legs: Credit: Carole Harwood/NEOUCOM  Solving the mystery of whales' missing legs
Solving the mystery of whales' missing legs: Credit: Carole Harwood/NEOUCOM Solving the mystery of whales' missing legs

Every week, as I stand under the Science Museum of Minnesota's whale skeleton, I wonder if there is any remnant of its back legs and pelvis? I learned in a recent exhibit that whales once lived on land - they actually share a common ancestor with hippos, camels and deer.
A recent paper by J.G.M. 'Hans' Thewissen in the Proceedings of the National Academy of Sciences helped me to understand what might have happened.
One way to figure out evolution is to watch embrionic development. By studying hindlimb development in dolphin embryos, Thewissen theorised that "The presence of the initiation of hindlimb development suggests that dolphins had terrestrial ancestors with four limbs." Several of these ancestors have been found as fossils.

In most mammals, explains Thewissen, "a series of genes is at work at different times, delicately interacting to form a limb with muscles, bones, and skin. The genes are similar to the runners in a complex relay race, where a new runner cannot start without receiving a sign from a previous runner."

In dolphins, however, at least one of the genes drops out early in the race, disrupting the genes that were about to follow it. That causes the entire relay to collapse, ultimately leading to the regression of the animals' hind limbs. By analyzing dolphin embryos, Thewissen showed that the dropout is a gene called "Sonic Hedgehog," which is important at several stages of limb formation.

In whales, however, the story is more complex. Between 41 million and 50 million years ago, whales' hind limbs did shrink greatly as the former land animals began a return to the sea. But their legs showed no change in the basic arrangement and number of bones, which proved that Sonic Hedgehog was still functioning. Its loss must have come later. In short, "the dramatic loss of Sonic Hedgehog expression was not the genetic change that drove hind limb loss in whales".

Instead, Thewissen and his colleagues conclude, whales' hind limbs regressed over millions of years via "Darwinian microevolution": a step-by-step process occurring through small changes in a number of genes relatively late in development.

Abstract from PNAS: Developmental basis for hind-limb loss in dolphins and origin of the cetacean bodyplan

Among mammals, modern cetaceans (whales, dolphins, and porpoises) are unusual in the absence of hind limbs. However, cetacean embryos do initiate hind-limb bud development. In dolphins, the bud arrests and degenerates around the fifth gestational week. Initial limb outgrowth in amniotes is maintained by two signaling centers, the apical ectodermal ridge (AER) and the zone of polarizing activity (ZPA). Our data indicate that the cetacean hind-limb bud forms an AER and that this structure expresses Fgf8 initially, but that neither the AER nor Fgf8 expression is maintained. Moreover, Sonic hedgehog (Shh), which mediates the signaling activity of the ZPA, is absent from the dolphin hind-limb bud. We find that failure to establish a ZPA is associated with the absence of Hand2, an upstream regulator of Shh. Interpreting our results in the context of both the cetacean fossil record and the known functions of Shh suggests that reduction of Shh expression may have occurred {approx}41 million years ago and led to the loss of distal limb elements. The total loss of Shh expression may account for the further loss of hind-limb elements that occurred near the origin of the modern suborders of cetaceans {approx}34 million years ago. Integration of paleontological and developmental data suggests that hind-limb size was reduced by gradually operating microevolutionary changes. Long after locomotor function was totally lost, modulation of developmental control genes eliminated most of the hind-limb skeleton. Hence, macroevolutionary changes in gene expression did not drive the initial reduction in hind-limb size.

photos and comments on whale limb rudiments
NSF press release
EurekaAlert

Mar
27
2006


Humpback Whale: A Humpback Whale dives beneath the surface Courtesy NOAA

Scientists Ryuji Suzuki, John Buck, and Peter Tyack used information theory to prove that humpback whale songs have syntax--rules that govern the structure of language.

Like humans, the whales use a hierarchy of communication: they make sounds to build phrases that they can combine in different ways to create songs that last for hours.

The scientists wrote a computer program that breaks down the elements of the whales' songs (moans, cries, and chirps) and assigns a symbol to each one. Then they analyzed the structure of the songs.

Suzuki says,

"Information theory was the right choice because it allows one to study the structure of humpback songs without knowing what they mean."

Sight and smell are limited in marine environments, so sea mammals often use sound to communicate. During the humpback whale breeding season, all the males in a population sing the same song. And the song evolves over time.

Suzuki says,

"Humpback songs are not like human language, but elements of language are seen in their songs."

Dec
14
2005

Whales and dolphins occasionally run aground on beaches around the world. In Cape Cod, near Boston, animal rescue workers deal with some 200 incidents a year.

But something unusual happened on Friday, December 9. A powerful storm, combined with low tides, trapped large numbers of whales and dolphins. Altogether, 39 animals died.

Mass strandings occur when groups of these social creatures get caught in shallow areas when the tide is heading out. The December event was unusual not only for the large number of animals involved, but that two different species were beached in two different locations.