Creatures as large as elephants are unusual; it takes a long time to evolve such size.

How long does it take for a mammal as small as a mouse to evolve into something as large as an elephant? A really, really long time, a recent study has found: about 24 million generations, at minimum.

To get that number, researchers looked at the evolution of body mass over the last 70 million years, after the dinosaurs went extinct and surviving animals expanded into the ecological niches they left behind. That estimate is far longer than earlier estimates, which, extrapolating from bursts of super-fast evolution in mice, range from just 200,000 to 2 million generations. Such speedy evolution, in actuality, is probably not sustainable over the long term—hence the lengthy new estimate.

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Three-dimensional model of an ancient whale skull.

What’s the News: Scientists have long held that archaeocetes, the precursors to modern cetaceans, had symmetrical skulls like most other mammals. Whale skulls only became asymmetrical as certain species evolved echolocation to hunt for food. But it turns out that archaeocetes actually had skewed skulls, which likely allowed the whales to hear better underwater, according a new study published in the journal PNAS.

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The anti-whaling movement hit its peak in 1986, when the International Whaling Commission banned all commercial whaling. Despite the ruling, however, the privately funded Institute of Cetacean Research in Japan has continued whaling by exploiting a loophole in the moratorium that allows some whaling for research purposes. But now, in a report by the government-run Fisheries Agency of Japan, the country has publicly considered ending its whaling efforts in the Antarctic Ocean (aka Southern Ocean), according to Yomiuri Shimbun, one of Japan’s five national newspapers.

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It takes a tremendous amount of energy to move the largest animal on Earth from a standstill to chasing food in a fierce dive. Could the krill that a blue whale catches in its gargantuan mouth really provide a high enough calorie count to make all this effort worthwhile? To find out, Jeremy Goldbogen tagged whales with data recorders and monitored hundreds of their dives. It can take 770 to 1900 calories to get the whale moving, but it’s worth it.

From Ed Yong:

When Goldbogen plugged the data from his recorders into a simulation of a feeding whale, he found that the lunge is staggeringly efficient. Despite the massive outlay in energy, the whale easily recoups anywhere from 6 to 240 times that amount, depending on how big it is and how tightly packed its krill targets are.

If a big whale attacks a particularly dense swarm, it can swallow up to 500 kilograms of krill, eating 457,000 calories in a single monster mouthful and getting back almost 200 times the amount it burned in the attempt. A smaller whale lunging at a sparse collection of krill would only get around 8,000 calories, but that’s still 8 times more than what it burned. Even when Goldbogen accounted for the energy needed to dive in search of prey, the whales still regained 3 to 90 times as much energy as they spent.

Check out the rest of this post at Not Exactly Rocket Science.

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Image: Wikimedia Commons

Whales don’t wear sunscreen. And because these massive sea mammals must surface to breathe, they are being exposed to more and more ultraviolet radiation sneaking through the weakened ozone layer. According to Karina Acevedo-Whitehouse, lead author of a study in the Proceedings of the Royal Society B, some whales are getting serious sunburns at an alarming rate.

From 2007 to 2009, her team sampled fin, sperm, and blue whales in the sun-drenched Gulf of California, which is the long, skinny expanse of water between mainland Mexico and Baja California.

Nearly all of the skin samples contained “sunburn cells,” abnormal cells associated with ultraviolet-induced DNA damage. These indicators were even found in the lowest layer of skin on the whales, suggesting that those individuals were suffering from very severe sunburns. [Discovery News]

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The newest climate researchers are those one-horned wonders of the sea, narwhals. Researchers recruited these marine mammals to gather data about ocean temperatures in Baffin Bay, an icy stretch of the Arctic between northern Canada and Greenland. The project was a collaboration between several climate scientists and marine biologist Kristin Laidre, who declared the experiment a success.

“Narwhals proved to be highly efficient and cost-effective ‘biological oceanographers,’ providing wintertime data to fill gaps in our understanding of this important ocean area,” said Laidre. [Discovery News]

Researchers were eager for assistance, because the difficulty of gathering data in the Arctic winter had led to a hole in the climate data. Says study coauthor and oceanographer Mike Steele:

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From Ed Yong:

On 7 August 1999, a lucky photographer snapped a female humpback whale frolicking off the east coast of Brazil. Two years later, on 21 September 2001, the same whale was caught on camera again, by a tourist on a whale-watching boat. But this time, she was a quarter of the world away, off the eastern coast of Madagascar. The two places where she was spotted are at least 9800 kilometres apart, making her voyage the longest of any mammal.

In American terms, that means the adventurous humpback had taken a trip of about 6,000 miles. Read the rest of the post–including info about how scientists are sure they were looking at the same whale both times–at Not Exactly Rocket Science.

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Image: iStockphoto

The oceans are getting louder and forcing some whale to speak up, according to a study published yesterday in the journal Biology Letters.

Lead researcher Susan Parks of Penn State University eavesdropped on seven male and seven female North Atlantic right whales by attaching acoustic tags to them via suction cups. Each tag recorded from 2 to 18 calls, which included the whales’ greeting “upcalls” (seemingly questioning “hmm?” sounds that go from a low to high pitch — see video), as well as background noise–believed to come from commercial shipping.

Bioacoustics researcher Christopher Clark of Cornell University, who did not participate in the study, says that ocean noise is becoming a serious issue.

“If I had to immerse you into the sea off Boston, you’d be shocked. You’d be like a country mouse dropped in the middle of Heathrow Airport,” says Clark. “In one generation, we have raised the background level for an entire ocean ecosystem.” [New Scientist]

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Twelve million years ago, one sperm whale was king. Between 40 and 60 feet in length the beast scientists named Leviathan melvillei wasn’t any bigger than today’s sperm whales, but look at those teeth!

As described in a paper published in Nature today, Olivier Lambert discovered the whale’s fossils in a Peruvian desert. The creature’s name says it all:

[It] combines the Hebrew word ‘Livyatan’, which refers to large mythological sea monsters, with the name of American novelist Herman Melville, who penned Moby-Dick — “one of my favourite sea books”, says lead author Olivier Lambert of the National Museum of Natural History in Paris. [Nature News]

The prehistoric sperm whale may have eaten baleen whales, and its largest chompers are a foot long and some four inches wide. For all the details, check out Ed Yong’s post on Not Exactly Rocket Science.

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Image: Nature

This week’s crucial whaling meeting continues until Friday has come and gone, but the result is… nothing.

As we reported last week, the International Whaling Commission (IWC) was ready to consider a proposal to lift a quarter-century-old moratorium on whaling, in exchange for agreements from whaling nations like Japan, Norway, and Iceland to reduce their catches over the coming decade.

Whaling in Antarctic waters, where Japan hunts hundreds of whales each year, would have been sharply curtailed. But that became the major sticking point in the talks. Delegates said that Japan and antiwhaling nations could not reach agreement on the size of the catch and that Tokyo had balked at agreeing to eventually phase out the hunt altogether [The New York Times].

The talks will continue into next year while some whaling continues under loopholes in the old rules. But given the present impasse it seems like the IWC nations are a long way from agreeing on anything.

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Image: Flickr/ Rene Ehrhardt

Brown pelicans smothered by BP’s oil spill may be the symbols of sadness for the disaster in the Gulf, but they are, of course, far from the only animals affected. Marine scientists are watching other species for signs of danger.

Whales

Late last week, scientists spotted the first dead whale seen in the Gulf since the leak began gushing oil in April. The National Oceanic and Atmospheric Administration found a 25-foot-long sperm whale washed up, and now it is testing the sea creature for cause of death.

“While it is impossible to confirm whether exposure to oil was the cause of death, NOAA is reviewing whether factors such as ship strikes and entanglement can be eliminated,” the agency said. Samples collected from this carcass will be stored until the Pisces returns to port on July 2, or possibly if another boat is sent to meet the Pisces. Full analysis of the samples will take several weeks [New Orleans Times-Picayune].

Manatees

So far, it at least appears that manatees have been spared toxic exposure to the ever-growing oil spill. However, a science team hunkered down at Dauphin Island in Alabama—in the path of the oil—say their luck may not hold.

Until recently, biologists believed that manatees rarely ventured west of peninsular Florida, where, so far, no oil has appeared. But in 2007, Ruth Carmichael, who leads the Dauphin Island team, began documenting a relatively large summer migration of manatees to Mobile Bay, Ala. — leading them directly into and through the path of the oil from the Deepwater Horizon leak. From a couple of dozen to as many as 100 come to Mobile Bay for the summer, out of a total North American population of 5,000, she said [The New York Times].

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And now, a sordid story about whaling.

This weekend, The Sunday Times of London published an expose charging the Japanese government with using foreign aid, cash, and even call girls to bribe nations on the International Whaling Commission into voting Japan’s way and supporting the country’s whaling.

Japan denies buying the votes of IWC members. However, The Sunday Times filmed officials from pro-whaling governments admitting:
- They voted with the whalers because of the large amounts of aid from Japan. One said he was not sure if his country had any whales in its territorial waters. Others are landlocked.
- They receive cash payments in envelopes at IWC meetings from Japanese officials who pay their travel and hotel bills.
- One disclosed that call girls were offered when fisheries ministers and civil servants visited Japan for meetings [The Times].

The full story is full of slimy details, like the allegation that Japan paid for Guinea’s IWC membership and that the latter country’s minister demanded a car and spending money, or the Tanzanian minister’s assertion that prostitutes would be made available in exchange for support. But most importantly, the story comes out with a crucial IWC meeting on the horizon. The annual get-together is in Morocco this month, where the nations will debate a possible end to the moratorium that dates back to 1986.

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Scientists have long thought humpbacks loners. New research shows this isn’t so: Researchers have observed some female whale form friendships that last for years. The behavior has only been observed in lady humpbacks of similar age, with the whales going their separate ways during the breeding season, but reuniting in the open ocean each summer. These bonds can be quite strong: the longest association endured for six years.

The study appears in the journal Behavioral Ecology and Sociobiology, and it also found that the whales with the longest-lasting associations gave birth to the most calves–another animal kingdom example that friendship is beneficial. The whales are probably improving their feeding efficiency, suggests lead author Christian Ramp.

“Staying together for a prolonged period of time requires a constant effort. That means that they feed together, but likely also rest together…. So an individual is adapting its behaviour to another one.” [BBC]

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There are about 20,000 gray whales living in the eastern Pacific Ocean today, plus another 200 in a small group in the western Pacific. And, in the Mediterranean Sea, scientists have found one.

Over the weekend, oceanographers saw a solitary gray whale cruising the Mediterranean off the coast of Israel. To say they were surprised would be a vast understatement: gray whales haven’t lived in the Atlantic Ocean or the Mediterranean since their population crashed in the 1700s, possibly because of whaling operations. Yet today a solitary gray whale swims by the shores near Tel Aviv, halfway across the world from where the rest of its species resides (the researchers say they photographed the animal to be sure it wasn’t a different species, like sperm whale).

So what happened to get this whale to the far side of the world? Says Phillip Clapham of the US government’s National Marine Mammal Laboratory in Seattle:

“The most plausible explanation is that it came across an ice-free North-West Passage from the Pacific Ocean, and is now wondering where the hell it is” [New Scientist].

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After 24 years of championing a ban on commercial whaling, the International Whaling Commission (IWC) will soon weigh a proposal seeking to resume commercial whaling. The plan would let Japan, Norway and Iceland hunt the ocean giants openly despite a 1986 moratorium on commercial whaling. In return, whaling nations would agree to reduce their catch “significantly” over 10 years [AFP]. These pro-whaling nations have kept up their hunts either by officially objecting to the moratorium or by insisting that they’re killing whales for scientific research.

The proposal is due to be submitted before the body’s annual meeting in June in Morocco, leading some conservationists to complain that the IWC should  “save whales, and not whaling.” The details of the proposal will made public on Earth day–April 22. Calling the withdrawal of the ban “the best chance to fight overfishing of these animals,” U.S Commissioner to the IWC Monica Medina said: “It’s a global problem, and needs global solutions” [Washington Post].

Making its case to pull back the ban, the IWC said that during the last few decades whale populations have substantially rebounded–with bowhead whale populations off Alaska increasing to between 8,200 and 13,500, eastern Pacific gray whale numbers rising to between 21,900 and 32,400 in 1999, and blue whale populations also rising. Conservationists, however, are seething, pointing out that 1,800 to 2,200 whales continue to be killed each year. “It’s great to be showing success, but should we be planting the flag and saying, ‘We’re there’?” asked Howard Rosenbaum, who directs the ocean giants program at the Wildlife Conservation Society. “We’re not out of the woods yet” [Washington Post].

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