You’d think one of the benefits of living in frigid Antarctica would be putting some distance between you and your warm-weather neighbors. But at least for Adelie penguins, the world seems to be a smaller place than that.

Enthusiastic use of potent insecticides became the ecological nightmare of the mid-20th century. And ever-increasing accumulation of greenhouse gases in the atmosphere promises to be the ecological problem of the mid-21st century. Adelie penguins may be dealing with both at the same time, according to a study reported this week in Environmental Science and Technology.

Along the Antarctic Peninsula, one of the most rapidly warming places on the globe, glaciers are melting. Mixed in with the torrents of meltwater are unusually high levels of organic pollutants. The alphabet soup of toxic compounds includes the infamous, long-lived insecticide DDT–the compound that helped curb malaria, but that also built up to poisonous levels in the food chain, putting predators like bald eagles, peregrine falcons, and ospreys on the endangered species list.
How does DDT wind up in a pristine glacier? As New Scientist explains, the pollutant molecules adhere to airborne particles and are carried around the globe on the wind. Over the poles, they come back down to Earth in blizzards and join the ice pack. There they sit, frozen in place, until the ice warms up.

According to the article, the Antarctic Peninsula’s glaciers could be releasing up to 4 kilograms of accumulated DDT per year. The steady trickle may explain why the study found that DDT levels in Adelie penguins hadn’t declined in the last 40 years despite major drops in worldwide use of the pesticide. (In 1959, the U.S. alone used 40,000 tons of DDT according to the EPA. Today, world usage is about 1,000 tons per year.)
(Image: Cape Royds, Ross Island, Antarctica, by H. Powell. Hat tip: sitta)

OK, ready for something perhaps a little more soothing? Now you can travel the world by ear. Icons on a map (choose from Google maps or Free Earth) let you choose from dozens of crystal-clear recordings of natural sounds. Accompanying text provides details of what you’re hearing, as well as recording data like date, time, and weather. For now, the recordings are mostly from the Western Hemisphere - though Old World offerings include the bells of Notre Dame, as well as chirps and rumbles from Africa and Madagascar.

Elsewhere, get dive-bombed by terns in Alaska or listen to songbirds on the Arctic National Wildlife Refuge. Head south along the 111th meridian through the American West. Listen to idling trucks and murmured Spanish at a U.S.-Mexico border crossing. On your way to the Galapagos Islands, stop off in a Costa Rican rain forest to hear screeching parrots and braying howler monkeys.

Stalled by all the choices? Visit the host website, Wildsanctuary.com to listen to a stream of natural sounds on Internet radio, or sign up for a free podcast. If you stumble across that one recording of distant surf or a chattering bulbul that you just can’t live without, I get the feeling the site’s proprietors would be happy to sell you a complete downloadable album, iTunes-style. For the rest of us, the site is a great way to take a brief vacation.

The site seems to owe its recordings largely to musician-turned-ecologist Bernie Krause, who has made it his job to travel the world making stellar recordings of natural symphonies (he calls them “biophonies”) - before the sound of the human race drowns them out. You may have read about Krause in the New York Times last year.
(Image: Google Maps; post title courtesy Yoko Ono)

The dinosaur-ness of birds has been suspected for many years based on anatomical similarities, but the new research is the first molecular evidence. For decades, dinosaurs were thought to be reptiles: big ones, to be sure, but basically cold-blooded, slow-moving, and dim-witted. The movie Jurassic Park popularized the idea of dinosaurs as quick, smart and birdlike. (The movie’s ideas had been proposed in the 1970s–a book by paleontologist Robert Bakker, called The Dinosaur Heresies, nicely conveys this change in thinking and the controversy that accompanied it.)

To get molecular evidence about dinosaurs, you need some actual molecules–a tall order for a group of animals that died out 65 million years ago. But in 2003, scientists Jack Horner and Mary Schweitzer discovered some unfossilized material inside a T. rex bone by a combination of luck, desperation, and sharp eyes (see Smithsonian, May 2006). Faced with flying a giant femur out of a remote Montana field site, they broke the bone in half so it would fit inside their helicopter. If they’d had a larger helicopter, we might never have known.

Unlike in Jurassic Park, the real-life researchers couldn’t recover any DNA from the ancient remains. But they did retrieve molecules of collagen, a structural protein that appears in slightly different forms in many animals. They compared the dinosaur version with 21 living animals, including humans, chimps, mice, chickens, ostriches, alligators and salmon. T. rex’s collagen proved to be most similar to chickens and ostriches; its next closest match was to alligators.

Chickens and ostriches are only distantly related to each other, so the research says little about what kind of birds might be the closest relatives of the famous carnivore. The scientists noted that answering that question would require data from more molecules than just collagen. Whether they are currently cracking into any more giant fossils in search of material was not divulged.

(Images courtesy Science)

One of the most talked-about outcomes of climate change is global sea-level rise–perhaps because the effects are straightforward and tangible: If sea level rises by this much, wipe this much of Florida (Bangladesh, Venice, Vancouver, Togo, the U.K., etc.) off the map. That’s a lot more immediate than envisioning the effect of a 3 degree rise in temperature on, say, the location of the world’s intertropical convergence zones.

Records show that on average, sea level has risen by about 1.7 millimeters (the thickness of a quarter) per year over the last century, for a total of more than 6 inches so far. But like many natural records, a graph of sea-level rise over time gives you a jittery line. Sea-level rise accelerated around 1930, slowed in 1960, and sped up again around 1990.

That is, until a correction arrived last week, when two Taiwanese scientists, writing in the journal Science, calculated that worldwide dam construction in the 20th century had kept nearly 11,000 cubic kilometers of water from reaching the ocean. The effect of all that withholding has been to slow the ocean’s rise by about 0.55 millimeters, or nearly a third of the total, per year.

The researchers went on to trace the timeline of dam construction, using a database of more than 29,000 of the world’s largest dams. They allowed for contradictory effects such as reservoirs not filling completely, water seeping into the ground below and small dams not being reported in the database. When they were finished, they added up the dam volumes year by year and superimposed the amounts on the historical, jagged graph of observed sea level rise.

The result: a much straighter line. It seems that the great dam-building bonanzas of the 1950s through the 1980s changed the Earth’s runoff patterns enough to be felt (admittedly, somewhat minutely) at sea level. Without dams, sea level would have risen at an average 2.46 millimeters per year. You can take this news as good or bad.

Good: it means sea-level rise may not have accelerated as sharply in recent years as it seems to have done. Bad: scientists can’t account for where all the rising seawater is coming from, and these new numbers mean there’s even more water to be accounted for. Which reminds me: new models suggest melting ice could raise sea levels by 4 feet this century, New Scientist reports. That’s nearly three times more than in the worst-case estimates from the Intergovernmental Panel on Climate Change.

(The Hoover Dam in 1933; Ansel Adams/Wikipedia. Hat tip: Zan)

It was just three years ago that Hurricane Rita stormed the Texas coastline, mere weeks after Katrina flattened Louisiana. While New Orleans struggles to rebuild, Texas seems to have forgiven, forgotten, and embraced the sunny weather. The Houston Chronicle reports that development values along the state’s picturesque Gulf Coast have tripled since Rita.Though real estate agents may be celebrating, the trend is causing consternation among insurance companies, which would be called upon to cover the region’s $64 billion of development should another bad hurricane season get Texas in its sights. At present, the Texas Windstorm Insurance Association has just $1.4 billion on hand for such an eventuality.

The Chronicle article gives a breakdown of how insurance firms might cover the remainder. But the upshot is that after such a payout, many insurance companies might stop selling insurance in the hurricane-prone areas entirely, leaving homeowners (anything but) high and dry.

But what’s the chance of another bad hurricane season? Well, hurricanes are fueled by warm water. And though the ocean is unruly, over the long term it’s slowly warming along with the atmosphere. That’s likely to make hurricanes more intense, a conclusion long argued by MIT’s Kerry Emanuel and covered on an insurance news site just three weeks before Katrina struck. Here’s one powerful industry, at least, that’s sitting up and taking notice of the problem - even if it’s largely by raising premiums or getting out of the market.

(Image: Rita wedges herself into the 500-mile gap between New Orleans and Cancun. Hat tip: Surfrider)

A few weeks ago we wished Darwin a happy 199th, so here’s three cheers for the Keeling Curve (above) passing the big 5-0.

Described by the Scripps Institution of Oceanography, in only a bit of a stretch, as “one of the iconic images of science, rivaling the double helix or Darwin’s sketches of finches,” the Keeling Curve is an unassuming sawtooth tracing a steepening path up a piece of graph paper. It’s also the longest continuous record of atmospheric carbon dioxide levels we have.

In 1958, Charles David Keeling began taking extremely precise measurements from an observatory 11,000 feet up on Mauna Loa, Hawaii. He had recently developed a new measurement method accurate to within 1 part per million (ppm). (Watch the pioneering scientist gleefully pouring liquid nitrogen barehanded into his equipment. He mentions he got interested in his field because it was a chance to build gadgets.)

The work is still going strong, and the Curve now charts a slow and unflinching rise in the carbon dioxide levels in the air, from an already-elevated 315 ppm in 1958 to some 380 ppm today. Keeling’s equipment was so precise, he later said, that the rise was already detectable with just 2 or 3 years of data.

As a representation of the natural world, the Keeling Curve is remarkable for its decorum. Pretty much any other historical record, from the temperature at your local airport to the vicissitudes of Wall Street, is a hysterical EKG of peaks and valleys, as each irregular day passes into the next. By contrast, the Keeling Curve looks like the work of an obsessive with an Etch-a-Sketch. The instrument’s location helps, stuck high into the atmosphere in the middle of the world’s biggest ocean, far from smokestacks and tailpipes.

In the absence of noise, any variation on the graph means something. That sawtooth pattern reflects passing seasons in the Northern Hemisphere, where most of the world’s vegetated land is. During summer, plants take up carbon dioxide to grow, putting a roughly 6-ppm dent in atmospheric CO2 levels. During northern winters, decaying matter releases carbon dioxide back into the atmosphere, and the Keeling Curve peaks again.

Notice anything else? The line is getting steeper. That means that carbon dioxide isn’t just accumulating - we’re adding more upon more each year. You could seek out appendices full of statistics on car ownership and megawatt production to calculate this, but the gist is right here on this graph.

And as Keeling noticed while plotting results a decade or so ago, the size of the sawtooths is getting bigger. That’s an ominous indication of a subtle shift: slightly more plant growth each year, a result of longer growing seasons stemming from earlier springs and later falls.

So while we’re at it, let’s save a birthday cheer for Keeling, who died in 2005. This year would have marked his 80th birthday.

(Scripps atmospheric scientist Ralph Keeling - Dave Keeling’s son)

As a native Michigander, I’m a sucker for news about the Great Lakes. (That’s HOMES, remember? Huron, Ontario, Michigan, Erie, and Superior.) Engineers at the U of M Marine Hydronamics Laboratory have now designed a boat without a ballast tank in order to prevent the introduction of non-native species.

A ballast tank is a compartment that sits at the bottom of any large boat. When the boat doesn’t have any cargo, its crew can fill the ballast tank with water to help it stay afloat. The mechanical details on how this works can be found here; but basically, the extra water lowers the boat’s center of gravity and makes it more stable on the water.

Trouble is, these ballast water pools typically harbor lots of aquatic species. Researchers have identified 185 non-native species in the Great Lakes, and guess that most of them got there via cargo ship. The most famous are Zebra mussels, which are native to the Caspian Sea and were first introduced to the Great Lakes in 1988. Since then, they’ve disrupted ecosystems all over the U.S., out-competing local species for food and wreaking havoc in harbors, boats, and power plants.

Those U of M engineers are clever, though. They’ve figured out how to keep a ballast-free boat from sinking. As a press release explains:

Instead of hauling potentially contaminated water across the ocean, then dumping it in a Great Lakes port, a ballast-free ship would create a constant flow of local seawater through a network of large pipes, called trunks, that runs from the bow to the stern, below the waterline.

This design concept has been around since 2001, but only now have its creators built a prototype. When testing their 16-foot, $25,000 wooden scale model (shown above), the engineers found that not only does it work, but propelling it requires 7.3 percent less power than regular ships. That efficiency translates to a savings of $540,000 per ship (which is only slightly less impressive when you consider that a typical vessel costs a whopping $70 million to construct).

(University of Michigan)

If you’ve ever gone swimming in places like the Sea of Cortez during summer, or even in a sluggish Florida bayou, you’ve probably noticed how it’s possible for ocean water to be too warm. Where you begin to suspect that you may still be sweating, even though you are under water.

Tropical corals suffer from the same problems–but new research suggests they may have begun to deal with them.

Despite corals’ longtime affinity for waters languid and warm, the recent, gradual creep of temperatures has led to widely publicized episodes of bleaching and die-off (reeffutures.org has a nice explanation). The problem, it seems, stems from a parting of ways between a coral’s two component organisms: a small, reef-building animal related to a jellyfish, and single-celled algae that it shelters in its cells in return for nutrients.

Tragically, cracks appear in this happy arrangement as the temperature rises. The algae (or “zooxanthellae”) start to produce toxic waste products. The host has no choice but to eject its guest, and both parties are the sorrier for it. Whole swaths of reef turn a ghostly white.

But recently, scientists working near the Great Barrier Reef found that a coral called Acropora millepora could distinguish between two strains of algae. One strain, originally quite rare on the reef, handled high temperatures ably, allowing corals to stay alive. Three months after a severe bout of bleaching in 2006, the researchers discovered that the heat-tolerant strain had proliferated, spreading to many of the surviving corals, and presumably lending them some protection from future heat waves.

New Scientist tells the story well–though be sure to read all the way to the end, where one expert dourly suggests continued warming may have all corals living on borrowed time. And no one even mentioned the problem of ocean acidification rendering corals unable to build reefs.

(Australian Institute of Marine Sciences/Charlie Veron)

A decade ago, thanks to the Federal Endangered Species Act, gray wolves were reintroduced into Yellowstone National Park. Conservationists have since used radio collars and overhead surveillance technologies to keep track of the animals’ whereabouts. But at the end of this month, federal support will dissolve—meaning scientists will no longer be able to use the expensive equipment.

But a new, cheaper technology might save the day. “Howlbox,” developed by scientists at the University of Montana in Missoula, is a $1,300 speaker-recorder system that broadcasts digitized wolf howls and then records any real howls that respond to the fakes. The system is pretty sophisticated: a precise frequency analysis of the recordings shows not only how many wolves responded, but which specific ones did.

The Howlbox was tested in one spot in Montana in January. The University of Montana’s pilot project, involving four remote sites in Idaho, is slated for June.

The biggest problem with the box might not be the response from wolves, but from humans. As this NYT article points out:

To the uninitiated, a Howlbox-enhanced forest could sound as if wolves were everywhere—a scary proposition. Montana wildlife officials are braced for a public relations campaign if the project moves forward.

(Flickr, by Hare Guizer)

You want monogamy? Elect a swan. Or better yet, a [worm called] Diplozoon paradoxum.

Surely there had to be a way to write that article without implying that unfaithful men make better politicians. Thankfully, science writer Jennie Dusheck promptly set Barash straight in the same newspaper, just six days later. She gets in some good ones, including:

Barash makes the threadbare argument that men just can’t help themselves, titillating his readers with the tattered news that male animals copulate with more than one mate…

Even Natalie Angier, in the New York Times, couldn’t resist wading into the fray on Tuesday. But both these writers seemed mostly content to point out that female animals are just as capable of faking monogamy as males. Cheating is entirely unoriginal, Angier says, no matter how much time a pair spends

reaffirming their partnership by snuggling together like prairie voles or singing hooty, doo-wop love songs like gibbons, or dancing goofily like blue-footed boobies.

The ubiquity of what academics delicately call extra-pair copulation is worth pointing out. But as an argument against male randiness, it’s a little like saying Clyde wasn’t so bad because Bonnie was also a mean person.

The really interesting lessons come from a bit deeper in the evolutionary textbooks. The great variety of romantic norms in the animal world stem from a few basic principles, such as how much care the kids require in order to survive. Does it take two parents working for months on end just to raise one fat, happy kid? Choose monogamy - just ask an emperor penguin. Or can a mother raise a kid or two on her own? Then she’s likely to look for no more than a hasty donation of genes from a strong male of her choosing. Think elk, bighorn sheep, elephant seal. Many fish don’t even bother to get acquainted, simply spewing gametes into the water and trusting to the wisdom of the currents. Kids never know either parent.

Take a still closer look, and the soap opera of the sexes gets positively bizarre. Some people may take heart in the stories of phalaropes - shorebirds whose females wear bright colors and dominate males, leaving incubation to them. Then there’s the across-species relationship between relative testes size and degree of monogamy (you don’t want to know where humans fall on that graph). And that’s just the beginning of the field of sperm competition. It’s a world nicely described (with appropriate nudges and winks) in Dr. Tatiana’s Sex Advice to All Creation (now a TV show!).

If it’s any consolation, all this does suggest that philandering politicians are just about as advanced as your typical weevil or prairie dog. Now about the rest of us….
(Wikipedia: Bonnie and Clyde)