Can scientists pull off a real-life version of Jurassic Park?  This intriguing question received a lot of attention earlier this year, when Revive & Restore (a project of the San Francisco-based Long Now Foundation) announced their goal of reviving extinct species using cutting-edge DNA technology. Dinosaurs have been gone too long for DNA to still be intact, but animals that went extinct during human history could potentially make a comeback. One of the first candidates for “de-extinction”—the iconic passenger pigeon (Ectopistes migratorius).

In the early 1800s, the passenger pigeon was the world’s most abundant bird species, even though its range was limited to eastern and central North America. Flocks of passenger pigeons—which sometimes included millions of birds—were so vast, they darkened swaths of sky up to a mile wide. But intensive hunting and habitat destruction by humans drove this species to extinction in a shockingly short span of time. The last passenger pigeon, “Martha,” died in 1914 at the Cincinnati Zoo. Her body remains at the Smithsonian’s National Museum of Natural History.

The Academy’s research collection houses nine specimens and three eggs of this species, dating to the late 1800s. Century-old specimens like these can still provide valuable information for modern-day studies. For example, Academy curator Jack Dumbacher and his colleagues published a paper in 2010 revealing that the closest living relative of the passenger pigeon is not the mourning dove, as many had suspected, but the band-tailed pigeon (Patagioenas fasciata), which is found along the Pacific coast and in the southwestern U.S., and can be seen in oak forests in the Bay Area. DNA sampling from museum specimens provided crucial data for this study. And the study’s conclusion provides critical information about which living relative could serve as a surrogate parent for the passenger pigeon, as scientists move forward with trying to revive this lost species.

Science Today sat down with Jack Dumbacher, who is also a scientific advisor to the Long Now Foundation, for his insights into de-extinction.

Where does the process currently stand?
JD: The Long Now Foundation has assembled a team of scientists to tackle different aspects of this project. Graduate student Ben Novak, working in Beth Shapiro’s lab at UC Santa Cruz, is refining the sequencing of the passenger pigeon genome from museum specimens. The genome of the band-tailed pigeon (the closest living relative) is also being sequenced.

Once the genomes are assembled, what happens next?
JD: You have to compare the genomes to determine which stretches of DNA make a passenger pigeon a passenger pigeon. Then you take the genome of a band-tailed pigeon and convert those important stretches of DNA into passenger pigeon DNA. George Church’s lab at Harvard is working on ways to do this using “CRISPR” technology—using bacterial proteins to genetically engineer specific DNA sequences and direct mutations to occur in a predictable way.

Let’s say scientists successfully get this DNA into an embryo, and the embryo becomes a chick. Is it a true passenger pigeon?
JD: That’s the big challenge. It may still have some band-tailed pigeon DNA. And you have to think about its behavior. How will it learn to be a passenger pigeon, find food, and avoid predators? Teams of researchers are tackling these numerous considerations and challenges.

Some might say that extinct animals went extinct for a reason, and bringing them back is not a good idea. How would you respond
JD: Animals like the passenger pigeon and moa went extinct due to human activity. So going extinct “for a reason” was humans to begin with. Also, developing the technology to successfully de-extinct an animal would itself be an intellectual coup, one that might have unforeseen benefits. The technology could be useful in other aspects of life, like agriculture, animal husbandry, conservation of endangered species, and, potentially, even human health. Think of the Space Race and all the accompanying benefits to society that resulted from that fundamental scientific research and development.

What other ethical concerns have come up?
JD: The ideal goal is to release de-extincted passenger pigeons back into their native habitat. But you have to be careful not to harm any other species whose survival may be on the brink. Their original ecosystem (the forests of the eastern and central U.S.) has changed. You don’t want to upset the balance in a way that threatens additional species. But the idea of restoring a habitat with native species is not a new one. Biologists restore habitats all the time. Had the pigeon survived only in captivity, we would be excited to be able to re-release it. Having survived only in our freezers or museum drawers, is that so different?

How many years away are we from seeing a real, live passenger pigeon?
JD: Optimistically, I would be very excited if this could happen in the next five to ten years. If not, I am confident that some day, we will have the technology to do this. Now is a good time to start thinking critically about what such a technology and ability would mean.

Andrew Ng is Communications Manager at the California Academy of Sciences.

The closest I’ve ever come to a whooping crane, perhaps like many folks, is reading Even Cowgirls Get the Blues:

The whooper enters one’s spirit the instant it enters one’s senses. It is perfect radiant sky monster and I cannot describe it.

(Come on, it was written in trippy 1976…)

And it’s likely a good thing that we keep our distance, remarked Greg Smith, of the USGS, on NPR last week:

The more fear they have of humans, the better off we think their survival chances are.

But the potential benefits of staying away from humans makes it difficult to understand the migration patterns of the rebounding bird.

The whooping crane (Grus americana) is North America’s largest bird, standing five feet tall, and survives 30 years or more in the wild. The species neared extinction in the 1940s, as unregulated hunting and habitat loss pushed its population to fewer than 25 individuals. Today there are about 600 whoopers, with more than 150 in captivity.

Humans played and continue to play a huge role in helping the species rebound, despite Smith’s quote above. At captive breeding sites, adult whooping cranes produce chicks which are then hand-raised by biologists using special methods designed to prepare the chicks for life in the wild. Each summer in a Wisconsin marsh, experts train a group of captive-raised chicks to follow an ultralight aircraft, leading them on a 1,300-mile journey to their Florida wintering grounds.

Only this first migration is human-assisted; from then on, the young birds travel on their own, usually in the company of other whooping cranes. Their movements are monitored daily via satellite transmitters, radio telemetry, and on-the-ground observers. All this human activity results in a record of the movements of individual birds over several years, all with known parentage and the same upbringing.

Researchers at the University of Maryland studied these data from whooping crane migrations from 2002 to 2009 to understand whether their migration route is encoded in their genes or is instead a learned behavior.

Publishing their findings in the recent issue of Science, the team determined that the whoopers learn their migration route from older cranes, and get better at it with age.

Whooping crane groups that included a seven-year-old adult deviated 38% less from a migratory straight-line path between their Wisconsin breeding grounds and Florida wintering grounds, the researchers found. One-year-old birds that did not follow older birds veered, on average, 60 miles (97 kilometers) from a straight flight path.

Individual whoopers’ ability to stick to the route increased steadily each year up to about age five, and remained roughly constant from that point on, the researchers found. The scientists hypothesize that older birds are better at recognizing landmarks and coping with bad weather.

“This is a globally unique data set in which we can control for genetics and test for the effect of experience,” says co-author William F. Fagan, of the University of Maryland. “It gives us an indication of just how important this kind of socially learned behavior is.”

So, whatever the role humans play in whoopers’ survival, they clearly need one another to survive and flourish. Here’s to those radiant sky monsters!

Image: US Department of Agriculture

Can birds read? While a new study provides evidence of avian intelligence, no, our feathered friends aren’t literate (as far as we know).

Canadian researchers, working in France, have found that birds foraging on roads and highways vary the amount of time they take to leave the asphalt when they see a car approaching. And it appears to depend on the posted speed limit.

During Pierre Legagneux’s commute he noticed that birds let him drive closer if he was traveling on a slower road. Using a modern, hi-tech tool—a stopwatch—the scientist monitored the birds’ “flight initiation distances” (FIDs) from the safety of his speeding car.

“FID is basically the distance that the car is from the bird when the bird takes off,” explains Academy bird expert Jack Dumbacher. “When a car is moving slowly, the bird can wait until the car gets pretty close, but when the car is moving fast, it has to begin taking off when the car is still very far away—just to make sure that it can avoid being hit. He was able to measure this pretty easily on his commute by multiplying his speed by the time it took to reach the bird.”

Over a year’s time, Legagneaux measured the FIDs of 134 birds from 21 different species, including many crows (Corvus corone), sparrows (Passer domesticus), blackbirds (Turdus merula) and unidentified songbirds.

And what he found was astonishing! His actual speed had nothing to do with the FID. But the posted speed limit did. The birds’ FID was consistently farther away for faster roads. For roads with a 20 kilometers per hour posted sign, the birds’ FID was 10 meters; 90km/hour signs, 25 meters; and 110km/hour, 75 meters.

“The authors aren’t exactly sure how the birds know, but it appears to have more to do with the AREA than with the oncoming car,” Dumbacher says. “The birds are not assessing the speed of the car, but what speed they THINK the car OUGHT to be going in that area.  And thus, the best predictor in the models was the actual posted speed limit.

“The method is simple and elegant—and something that he was able to do while commuting and paying attention to traffic. (Apparently there aren’t laws against operating a stopwatch while driving in Europe.),” Dumbacher continues.  “All he had to do was jot down 1) his speed, 2) the speed limit, and 3) the time it took to reach the spot where the bird took off.  From his citations, it looks like something like this has been studied before, but this is a cool and interesting article—something that a high school student could do for her science fair project (if she were old enough to drive…).”

The research is published in Biology Letters.

Crow image: Mostly Dans/Flickr

Now this raven-sized early bird has had its brain examined. Amy Balanoff and her colleagues from the American Museum of Natural History recently took CT scans of more than two dozen specimens, including modern birds, Archaeopteryx, and closely related non-avian dinosaurs such as tyrannosaurs, to size up the different species’ brain power.

“Bird-brained” is actually a misnomer. (Crows demonstrate this again and again.) Modern birds are distinguished from reptiles by their brains, which are enlarged compared to body size. This “hyperinflation,” most obvious in the forebrain, is important for providing the superior vision and coordination required to fly.

By stitching together the CT scans, the scientists created 3D reconstructions of the skulls’ interiors. In addition to calculating the total volume of each digital brain cast, the research team also determined the size of each brain’s major anatomical regions, including the olfactory bulbs, cerebrum, optic lobes, cerebellum, and brain stem.

The researchers found that in terms of volumetric measurements, Archaeopteryx is not in a unique transitional position between non-avian dinosaurs and modern birds. Several other non-avian dinosaurs sampled, including bird-like oviraptorosaurs and troodontids, actually had larger brains relative to body size than Archaeopteryx.

“If Archaeopteryx had a flight-ready brain, which is almost certainly the case given its morphology, then so did at least some other non-avian dinosaurs,” Balanoff says.

“Archaeopteryx has always been set up as a uniquely transitional species between feathered dinosaurs and modern birds, a halfway point,” she says. “But by studying the cranial volume of closely related dinosaurs, we learned that Archaeopteryx might not have been so special.”

If not unique, where should we place Archaeopteryx in the tree of life? More research is needed. The current study is published this week in Nature.

Image: Amy Balanoff, American Museum of Natural History

How will climate change affect different species? Will organisms be able to adapt quickly enough to survive in a rapidly changing environment?

Researchers at the University of Oxford are attempting to predict this with small, short-lived birds like the great tit (Parus major). In a study published this week in PLoS Biology, the scientists discovered that great tits living in a forest near Oxford have been able to survive and adapt to a 1°C temperature increase over the past 50 years.

After analyzing those 50-plus years of data collected on the birds in their habitats, the authors studied when the birds lay their eggs relative to spring temperatures, as well as how the birds have tracked the shifts in peak caterpillar numbers caused by the changes in temperature. They found that the birds are now laying their eggs an average of two weeks earlier than they did 50 years ago, primarily as a result of phenotypic plasticity.

Phenotypic plasticity enables organisms to adjust their behavior rapidly in response to short-term changes in the environment. Jack Dumbacher, curator and department chair of Ornithology & Mammalogy here at the Academy, explains, “It’s heritable but it’s not an evolutionary, or genotypic change. There’s no change in the genes.”

The authors’ predictions show that phenotypic plasticity could allow the great tits—and similar birds—to survive warming of 0.5°C per year, easily outpacing the current worst-case scenario of 0.03°C from climate models.

Dumbacher says that while this study is interesting and a good reminder how adaptable one species may be, he emphasizes that temperature increase is just one effect of climate change. Temperature variance and extreme weather are other effects with unknown results to various ecosystems, he says. In addition, Dumbacher reminds us that the great tits and caterpillars play roles in a much larger ecosystem, where the web of relationships is so interdependent that one small change to one small organism in that web could easily affect other species.

One effect of climate change that Dumbacher stresses (and the study does not mention) is invasive species. As temperatures change, habitat ranges change for different species, which can result in one species invading the habitat of another. One example Dumbacher gives is the Northern Spotted Owl (Strix occidentalis caurina). These birds have been able to adapt to a 1°C temperature increase over the past 100 years but are now facing a fierce competitor in the Barred Owl (Strix varia), an eastern species that now finds itself in the same territory as the Northern Spotted Owl.

“Climate change is more than a one degree temperature increase,” Jack says. “And while a species may demonstrate plasticity within different temperature regimes, it’s likely that ecosystems are not as adaptable. This why climatologists have such a difficult time predicting the effect of climate change on organisms.”

Image: Luc Viatour/Wikipedia

Just like humans, some birds have better luck than others. From city life to dance moves to penises, the natural endowments of birds vary in so many ways! Several recent science publications demonstrate diversity in the bird world, so we thought we’d provide a sampling for you…

A study last week in the Proceedings of the Royal Society B determines that city birds keep much longer hours than their forest-dwelling brethren. Researchers studied European blackbirds (Turdus merula) in different environments in Germany and discovered that the artificial lights and noises of the city mean the blackbirds start their activities earlier in the day and keep on going later in the evening.

In fact, studies in the lab revealed that the city birds’ biological clocks were sped up compared to the forest birds’. And the authors are convinced that birds aren’t the only animals affected by city life. From the abstract:

Urban environments can significantly modify biologically important rhythms in wild organisms.

City dwellers, take note!

Australia’s superb lyrebird males possess some of the most brilliant plumage in the avian world, and researchers have now determined that the feathered creature is also a brilliant song-and-dance bird. Scientists found that the birds have a distinct dance for each of four distinct songs. Wired posted a short video of a male lyrebird strutting its stuff that you have to hear and see to believe!

This mating ritual demonstrates that “the coordination of independently produced repertoires of acoustic and movement signals is not a uniquely human trait,” according to a recent publication in Current Biology.

Maybe the male lyrebirds song-and-dance routine makes up for the fact that these males have no penises. 97% of birds simply lack the organ, using an opening called the cloaca instead. Originally, all birds had penises, but along the evolutionary path, most birds lost them. There are theories for why the organ was no longer needed (lighter for flight, more female control over mates), but the reason is still not known.

However, a new study, also in Current Biology, uncovers the mechanism behind the loss. Researchers compared embryos of the well-endowed Pekin duck (it has a corkscrew penis that can grow the entire length of its body) to those of the cloaca-ed rooster and found that both embryos begin to form penises, but around day eight or nine, the roosters’ stop growing. The scientists determined that one gene, Bmp4, caused the rooster embryo’s penis to stop growing.

Carl Zimmer, writing in the New York Times, explains why this research not only paints a bigger picture of bird evolution, but also illustrates how understanding these genetic mechanisms can help humans, too.

Superb lyrebird image: Melburnian/Wikipedia

At Science Today, we love stories that highlight bioinspiration—tales that reveal how close inspection of the natural world lead to problem-solving in the human realm. Engineering-wise, nature has had millions of years of trial and error to get things right, so why not learn from evolution and adaptation?

This week, the Academy will open Built for Speed, a new exhibit that explains the adaptations by fast fish and marine mammals that make them swift and speedy underwater and how boat designers use a similar process of adaptations to create ultrafast sailboats to compete in the America’s Cup race.

To get ready for Built for Speed, we’re featuring a few recent news stories about robots inspired and refined by the study of nature. Enjoy!

UC Berkeley

One of the leaders in bio-inspired robots is right across the Bay from the Academy. Biologists and engineers at UC Berkeley have been collaborating for several years on biological inspiration. And the researchers find inspiration from the most unlikely of sources. We’ve covered their gecko-inspired bot, but earlier this year news outlets featured Cal cockroach robots. Did you know that cockroaches are able to balance without using their brains? According to Discovery News, this is fabulous news for robot builders:

… One of the recurring challenges of designing a mobile robot is writing an algorithm that keeps it from falling over.

VELOCIRoACH, is a Berkeley roach bot and happens to be one of the fastest robots in the world. TAYLRoach uses its tail to make fast turns. New Scientist says that smaller is better for these robots:

Small-legged robots are being developed for search and rescue, for situations where a location is inaccessible or too dangerous for humans.

More Insect-bots

Berkeley isn’t the only academic biorobotic institution. Last week, Harvard scientists published their engineering breakthrough—the first flying insect-like robot. Ten to fifteen years in the making, this bug-bot was inspired by the biology of a fly. It has submillimeter-scale anatomy and two wafer-thin wings that flap almost invisibly, 120 times per second! Check out the video.

Do you feel like you’re being watched? Another publication last week describes a new camera, inspired by insect eyes. Made of 180 tiny lenses, the camera can take panoramic pictures that offer similar compound views to those of ants, bees and praying mantises. According to Ed Yong in National Geographic, this tiny biomimetic camera is “ideal for surveillance. Perhaps in the future, we’ll be watched by man-made flies on the walls.” Creepy!

Speaking of creepy, how about small robots that work together like a colony of ants? French and American scientists wanted to understand how individual ants, when part of a moving colony, orient themselves in the labyrinthine pathways that stretch from their nest to various food sources. They hope their robotic findings reveal “possible improvements for the design of man-made transportation networks,” according to an abstract in PLoS Computational Biology.

Snakes and Seahorses and Birds, Oh My

Want more? How about a soft snake robot that slithers? A robotic arm as flexible and protected as a seahorse’s tail? Airplane wings fashioned after the wings of a herring gull? What about a swimming and crawling robot as efficient as a salamander? All of the above? Help yourself—many of the links above have videos detailing the creations.

Speedy Virtual Robots

Finally, just because it’s super cool, check out this video on Discover’s site. Researchers at the University of Wyoming and Cornell created a computer program to design fast virtual robots. Each robot could be made out of four different materials, and only the fastest would “reproduce.”

Essentially, the researchers incentivized forward motion, so the faster the robot, the more successful it would be in the evolutionary race.

You have to see the simulations created in this “Evolution in Action.”

Image of insect-eye camera: John A. Rogers, University of Illinois at Urbana-Champaign

With their short wings relative to body size, hummingbirds are built for hovering. Their relatives, swifts, have super-long wings, built for gliding and high-speed flight. Their common ancestor, Eocypselus rowei, had wings sized between the two and they were built for… well, it’s hard to say.

“[Based on its wing shape] it probably wasn’t a hoverer like a hummingbird, and it probably wasn’t as efficient at fast flight as a swift,” says Daniel Ksepka of the National Evolutionary Synthesis Center.

Ksepka and his colleagues discovered a fossil of E. rowei in southwestern Wyoming at a fossil site known as the Green River Formation. The small bird—only twelve centimeters from head to tail—lived about 50 million years ago. Feathers account for more than half of the bird’s total wing length.

The researchers compared the specimen to extinct and modern day species. Their analyses suggest that the bird was an evolutionary precursor to the group that includes today’s swifts and hummingbirds. “This fossil bird represents the closest we’ve gotten to the point where swifts and hummingbirds went their separate ways,” says Ksepka.

Their study was published last week in the Proceedings of the Royal Society B.

The shape of the E. rowei’s wings, coupled with its tiny size, suggest that the ancestors of today’s swifts and hummingbirds got small before each group’s unique flight behavior came to be. “Hummingbirds came from small-bodied ancestors, but the ability to hover didn’t come to be until later,” Ksepka explains.

Closer study of the feathers under a scanning electron microscope revealed that carbon residues in the fossils—once thought to be traces of bacteria that fed on feathers—are fossilized melanosomes, tiny cell structures containing melanin pigments that give birds and other animals their color. The findings suggest that the ancient bird was probably black and may have had a glossy or iridescent sheen, like swifts living today. Based on its beak shape it probably ate insects, the researchers say.

Hummingbirds and swifts are two of many animals built for speed. Later this week, the Academy will open a new exhibit called Built for Speed, that will feature fast fishes and marine mammals. Learn more here.

Image: Mdf/Wikipedia

Evolution takes time. Or does it?

Evolution can happen rapidly—it all depends upon how strong selection is and how much genetic variation there is in the trait being selected.  We tend to look at fossil bones, for example those along the horse lineage, and it seems like only a few millimeters of length are added per hundreds of thousands of years.  But in fact, these traits can vary quite a bit—even within populations—and if you have lots of individuals and lots of points in time, sometimes you can see really noticeable changes in short times.  The classic examples are Darwin’s Finches, that can significantly evolve larger or smaller bills during times of great stress.

That’s the Academy’s bird expert Jack Dumbacher. I asked him about a paper published this week in Current Biology about birds evolving shorter wings over a time-span of a mere thirty years. The evolutionary advantage? To avoid becoming roadkill.

In the US alone, an estimated 80 million birds are killed each year by cars. But the paper’s two authors, Nebraska researchers Charles and Mary Brown, noticed that fewer of the swallows they’ve studied for the past 30 years were becoming roadkill. This finding was surprising, since there are more cars on the road now than in the 1980s, and more of the swallows make their homes near the highways.

The researchers recently collected hundreds of dead cliff swallows from roadways, railroad tracks and other nesting areas, and noticed that “there were fewer road kills, and the birds found dead along highways had longer wing spans,” Charles Brown says. “I wanted to know if there was selection for particular characteristics in those dead birds.”

So he and his colleagues began a retrospective analysis, measuring the specimens in his 30-year collection. According to ScienceNOW:

The birds that were being killed, further analysis revealed, weren’t representative of the rest of the population. On average, they had longer wings. In 2012, for example, the average cliff swallow in the population had a 106-millimeter wingspan, whereas the average swallow killed on the road had a 112-millimeter wingspan.

The results suggested cliff swallows were undergoing morphological changes through natural selection.

Jack explains this adaptation. “Shorter wings—just like shorter cars – usually means a shorter turning radius. So if the birds need to make a rapid change in course, smaller wings might help facilitate this.”

The cliff swallows aren’t the first bird species to evolve quickly in response to human impacts. “One of my favorite examples is bird song in human habitats,” Jack says. “Our roads and neighborhoods are full of noises—air conditioners, traffic and other machines. Some of these produce noise in certain frequencies that can drown out or obscure bird song.  Researchers here and abroad have shown that many birds have noticeably shifted their song frequencies to avoid our ‘white noise’ and be better heard in human environments.”

Jack appreciates the work of the Browns in determining these shorter wingspans. “We often drive our commute and watch this or that, and sometimes we even ask ourselves whether, ‘Hmm, sure does seem like there are fewer roadkill than last year.’  Even a simple question like this can be incredibly difficult to even verify, but then to do all of the work to find the cause of the change—that can be very difficult to do.  They clearly have that restless scientific mind that doesn’t rest until they find a solid answer…”

I guess it takes one to know one.

Image: Ingrid Taylar/Wikipedia

If we tried to turn our heads like owls, we’d die. It’s that simple. Sudden gyrations of the head and neck in humans have been known to stretch and tear blood vessel linings, producing clots that can break off and cause a deadly embolism or stroke.

So medical researchers and illustrators at Johns Hopkins decided to find out how owls can rotate their heads up to 270 degrees in either direction. Using several previously frozen dead owls, the team injected contrast dye into the birds’ blood vessels, which were then meticulously dissected, drawn, and scanned to allow detailed analysis.

The team discovered four major biological adaptations that help prevent injury from rotational head movements in the owls. Variations to the animals’ bone structure and vascular network support its top-heavy head.

The owl illustrations won first-place in the posters and graphics category of the National Science Foundation’s 2012 International Science & Engineering Visualization Challenge.

We have to go to the salon for a fancy hairdo, but for some breeds of pigeons, it’s all in the genes! “There are some 350 [pigeon] breeds with different sizes, shapes, colors, color patterns, beaks, bone structure, vocalizations and arrangements of feathers on the feet and head—including head crests that come in shapes known as hoods, manes, shells and peaks,” says Michael D. Shapiro of the University of Utah.

Shapiro led a team of researchers who sequenced the genomes of several different breeds of pigeons and found a single mutation in a gene named EphB2 that causes head and neck feathers to grow upward instead of downward, creating head crests. And the diversity in crests is amazing, says Shapiro. “Some are small and pointed. Others look like a shell behind the head; some people think they look like mullets. They can be as extreme as an Elizabethan collar.” This research appears in the current issue of Science.

Homing pigeons certainly use compass-like techniques to find their way, but that doesn’t entirely explain their homing skills. U.S. Geological Survey scientist Jonathan Hagstrum was curious, why, for instance, tens of thousands of pigeons were lost in a 1997 race that crossed paths with the Concorde.

Hagstrum believes that homing pigeons also use infrasound—a low-level sound that many animals, but not humans, can detect. The birds make a kind of mental map from the sounds. According to Science Now:

Infrasound is generated when deep ocean waves send pressure waves reverberating into the land and atmosphere. Infrasound can come from other natural causes, such as earthquakes, or humanmade events, such as the acceleration of the Concorde. The long, slow waves move across vast distances.

You can find this research (without an infrasound map, alas) at The Journal of Experimental Biology.

Spinning, cresting, and finding home… We hope you enjoyed this bird’s-eye view of recent research headlines.

Image: DickDaniels/Wikipedia