Fin Whale at Feeding Time: Dive Deep, Stop Short, Open Wide

By CARL ZIMMER

Published: December 11, 2007

The word “big” doesn’t do justice to whales. Humpback whales can weigh up to 40 tons. Fin whales have been known to reach 80 tons. Blue whales, the biggest animals to have ever lived, reach 160 tons — the same mass as about 2,000 grown men or 5 million grown mice.

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Photographs by Peter Howorth

A lunge-feeding blue whale, top, and a dolphin, near top above, riding a blue whale’s bow wave.

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It takes a lot of food to build such giant bodies, but how exactly the biggest whales get so much has long been a mystery. “We don’t have much of a sense of these animals in their natural environments,” said Nick Pyenson, a biologist at the University of California, Berkeley. For decades, whale experts had only indirect clues. “It’s primarily from dead animals or from a few people standing on a ship seeing whales come to the surface,” he said.

With so little information, scientists have struggled to make sense of several enigmas about the biggest whales. “It’s always been a mystery why they have really short dives for their body size,” Mr. Pyenson said. The bigger a marine mammal is, the longer it should be able to dive for food, because it has more muscle tissue in which it can store oxygen. Other species follow this pattern, but the biggest whales do not.

Mr. Pyenson and his colleagues may have solved some of the gastronomical mysteries of these leviathans by creating the first detailed biomechanical model of a feeding fin whale. In essence, they have created the world’s biggest gulp.

The model was made possible by a happy accident. In 2003, scientists at Scripps Institution of Oceanography in La Jolla, Calif., chased after fin whales and stuck small monitors to their backs with suction cups. After several hours, the monitors fell off and the scientists retrieved them. They hoped that the monitors would record fin whale songs, but they had the bad luck to encounter whales that were feeding, not singing.

Jeremy A. Goldbogen, then a graduate student at Scripps, realized that the project was not a failure. Mr. Goldbogen, who is now at the University of British Columbia, was interested in how fin whales feed. The monitors had logged lots of valuable information about the movements of the whales, like their speed and depth, that he could analyze. “This is the first time we’ve ever seen this kind of data,” Mr. Goldbogen said.

Working with Robert Shadwick at the University of British Columbia and Mr. Pyenson, Mr. Goldbogen applied some basic laws of physics to the data, combining it with information about the size and shape of fin whale bodies. They ended up with a surprisingly detailed picture of what the whales do when they feed, which they recently published in the journal Marine Ecology Progress Series.

It turns out that a fin whale dives very deep for food. It plunges more than 600 feet below the sea surface, most likely in search of giant swarms of krill. What the whale does next came as a complete surprise to the scientists. “It was still swimming, but it was slowing down really fast,” Mr. Goldbogen said. Even as the whale pumps its powerful tail, it comes to a compete stop in three seconds.

The whale grinds to a halt, the scientists concluded, by opening its mouth. Water floods in, pushing its giant lower jaws back until they hang perpendicularly from its body. Suddenly the whale is producing colossal amounts of drag. “The whales are beautifully streamlined so they can swim fast and efficiently, and then they’re throwing it all out the window,” Mr. Goldbogen said.

In fact, a fin whale’s body turns out to be exquisitely adapted for increasing its drag. The underside of its mouth is made up of a unique set of pleats that can stretch to four times their normal size. By continuing to beat its tail, the whale forces more water in, causing its mouth to expand like a parachute. And just as race car drivers use parachutes to slow them down, the whale’s inflated mouth brings it to a dead stop.

Mr. Goldbogen and his colleagues calculate that in just three seconds, the mouth of a 60-foot fin whale fills with more than 18,000 gallons of water. That’s the same volume as a school bus, and weighs more than the whale itself.

The whale then takes three seconds to shut its jaws. As its pleats begin to snap back in place, it pushes the water out of the sides of its mouth. The water must first stream through a set of thin plates known as baleen. Any krill or other animals in the water get stuck there. Once the whale has pushed out all the water from its gulp, it can swallow its prey and move forward again.

If Mr. Goldbogen’s model is accurate, it means that fin whales use a huge amount of energy to feed. This cost of lunge feeding, as this style of eating is known, could explain why the whales spend so little time underwater. While they can store a lot of extra oxygen in their muscle, they burn it up quickly with their peculiar way of sweeping up food.

For all this effort, a bus-size gulp of water yields a fin whale only about 20 pounds of krill. But fin whales can gulp every 30 seconds. In about four hours a whale can catch a ton of krill, which provides enough energy to fuel its gigantic body for an entire day.

Fin whales belong to a lineage of giant whales known as rorquals, which includes other heavyweights like blue whales and humpback whales. All rorquals share several unique traits, like the stretchy pleats on their undersides. Scientists have suspected that all rorquals feed in the same way, and new data supports that hunch. Researchers at the Cascadia Research Collective in Olympia, Wash., have been tagging blue and humpback whales with data monitors, and Mr. Goldbogen sees the same patterns of stopping and starting that he and his colleagues saw with fin whales.

Now Mr. Goldbogen and his colleagues are investigating how rorquals got to be so big. Whales moved from land to sea starting about 50 million years ago, but they remained relatively small until the rorquals evolved about 7 million years ago. “They really evolved very fast,” Mr. Goldbogen said. “We think this lunge feeding opened up a new door, evolutionarily speaking.”

To test this hypothesis, Mr. Goldbogen and Mr. Pyenson want to compare the size and shape of living and fossil whales. “When we look at all the sizes and shapes, we’re going to be able to figure out exactly how lunge feeding evolved and whether it’s responsible for these really big whales we see today,” Mr. Goldbogen said.

The scientists have been visiting museum warehouses in recent months to make measurements of whale skeletons. It can take hours _ — and forklifts in some cases — to gather the data on these enormous bones.

“I was amazed that no one has measured these things before,” Mr. Goldbogen said. “But when I got there, I realized, ‘Wow, this is why.’”

Both Tehran and Washington must swallow the rhetoric and seek a deal

If the US can reach an accommodation with Iran before quitting, there is still the chance of a tolerable outcome in Iraq

Max Hastings
Tuesday December 11, 2007
The Guardian

A few months ago, I suggested here that all of us who are sceptics about Iraq should subject ourselves to regular brain scans, just in case we were wrong. That is to say, enthusiasm to see George Bush's nose rubbed in his follies must never tip over into eagerness for US failure in Iraq. Its consequences for the world, and above all for the Iraqi people, are far too grave to indulge schadenfreude. There are three reasons today to revisit our thinking about Iraq even if, at the end of the process, we end up back where we started.

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James Forysth rightly remarked in the Guardian's media pages yesterday that the British press has under-reported the success of the US troop surge. It is a notable achievement by General David Petraeus and his forces that insurgent attacks have fallen by two-thirds, and civilian fatalities have declined steeply.

Second, Gordon Brown told British troops outside Basra at the weekend that their role is almost over. Within weeks responsibility for security in the southern province will pass to local Iraqi forces.

Finally, last week's amazing US national intelligence estimate, which declared that Iran has no current nuclear weapons programme, could carry critical significance for Iraq. It removes the overriding obstacle to dialogue between Tehran and Washington, which itself is indispensable to stabilising Iraq.

For years, both sides have been acting irrationally. Iran should perceive a neighbourly relationship with a peaceful Iraq as a key national interest. Instead, however, its militants have chosen to regard embarrassing and harassing "the Great Satan" as a superior objective. For this, their country pays a heavy economic and political price. Washington, likewise, has preferred to conduct a war of words with Tehran - and to threaten a war of weapons - rather than build bridges to the many Iranians weary of their national isolation as a terror state.

Of these strands, the easiest to dismiss is the weekend claim by Britain's prime minister. Almost everybody who has recently visited Basra agrees that, far from being on the road to "peace and prosperity", it is dominated by unpleasant Shia militias, committed to repressive social policies, especially towards women. The Baghdad government's writ does not run there.

The British - politicians, soldiers and diplomats alike - tacitly concluded at least 18 months ago that Iraq was a lost cause. Everything they have since done has been aimed at extricating our forces as swiftly as possible. The judgment may well prove to have been right. But it seems implausible to dress up our policy as a success. If the US defies probability and amazes the world by delivering a stable Iraq, Britain will be able to claim scant credit for its contribution.

We are still a long day's march from such a happy outcome, though. Overriding doubts persist about whether America's military successes, however real, can be translated into lasting political progress. Even the most committed US officers remain dismayed by the stunning incoherence of the Iraqi national government. Its security forces are making negligible progress towards viability; its interior ministry is a byword for incompetence and corruption.

Many insurgents have concluded that it is futile to keep battering at the overwhelmingly superior US forces . They watch CNN. They know that a reduction of troop strength must begin soon; that the Bush presidency has only a year to run; and that the new incumbent will be desperate to get out of Iraq. There is therefore much to gain, for every Iraqi with aspirations to political power, by watching and waiting. So it may be rash to read too much into the decline of assaults on US and allied forces.

Could the picture change dramatically as a result of some US accommodation with Iran? A week after Washington's release of the intelligence report, there is much uncertainty about its significance. We know that some administration insiders, notably vice-president Dick Cheney, opposed its publication because they reject its findings. They believe intelligence chiefs have allowed themselves to be fooled by the Iranians.

No one knows whether president Bush supported the document's publication because it opens new political opportunities, or merely acquiesced because it was bound to leak anyway. All we can say with confidence is that if Iran and the US can contrive a deal in Iraq, there is a chance of a tolerable outcome there. If they do not, there is not.

If the Iranian militants continue to perceive a US military humiliation as their foremost objective, constructive dialogue will remain impossible. But if they are sufficiently eager to see an end of economic sanctions to abandon the promotion of insurgency in Iraq, then the Bush administration might be willing to swallow a torrent of past rhetoric, and deal.

An intriguing article in the International Institute for Strategic Studies journal argues that the consequences of a swift US withdrawal from Iraq could prove much less cataclysmic than pessimists have suggested. Christopher Fettweis of the US Naval War College suggests that "the unprecedented is also unlikely ... imagined consequences are usually worse than what reality delivers". He acknowledges the real risk, even probability, of intensified civil war for a time. But he is highly sceptical of scenarios for a regional war.

He cites the example of Vietnam, where the US's departure was delayed for years because of fears of mass slaughter in the South if the communists gained mastery. This did not happen. Fettweis suggests that those who predict worst-case scenarios in Iraq are in part influenced by a visceral distaste for acknowledging American defeat. He forecasts one of two outcomes after a US withdrawal - "political accommodation or a civil war that eventually someone wins, putting an overdue end to the bloodshed".

American hawks would find this argument abhorrently cynical. Yet some of us share Fettweis's instinct, that the consequences of a rapid US departure are unlikely to be worse than those of a protracted one. There is a strong case for trying to reach an accommodation with the Iranians before quitting. But there seems no reason to believe that Iraq's institutions and security forces are profiting from continued US engagement.

It would be absurd to underestimate the political difficulties of extricating the US from Iraq. In every predicament of this kind, fear that an unknown future could prove worse than a familiar present, however bloody, becomes an overriding influence upon governments.

Let us stick to the fundamentals, which have not changed much. Any tolerable outcome in Iraq demands dialogue between Washington and Tehran, and if possible also Damascus. Conditions for this look more favourable, thanks to the intelligence report, than at any time so far this century. The odds against anything Bush - or Brown - can plausibly call "success", remain great. But there is a window of opportunity, promising much to the Iraqi people, if all the parties can narrow their objectives sufficiently to use it.