Field of Science


The Shambulance: Deer Antlers Are Not Unicorn Horns

The Shambulance is an occasional series in which I try to find the truth about bogus or overhyped health products. The chief navigational officer of the Shambulance today is Steven Swoap.

This Superbowl season saw a star linebacker forcefully denying that he'd ever sprayed juice made from ground-up deer antlers into his mouth. The player was Ray Lewis, and using deer antler spray would have seemingly violated the National Football League's ban on performance-enhancing drugs. Like the horn of a unicorn, this product is alleged to heal and strengthen its users. Also like the unicorn horn, it's probably not something the NFL needs to worry about.

Bottles of deer antler spray—also called deer antler velvet or IGF-1 spray—are legal and easy to purchase for $20 to $50. Though no one's checking what's actually inside the bottles, makers claim their products come from antlers that are harmlessly sawed off of male deer each spring, or from the soft skin covering these new antlers. A few times a day, you spritz the solution into your mouth and swallow it.

The suggestion is that deer antler spray will make your own muscles or bones regrow as rapidly as a deer's antlers. Some products make other claims that are variously expansive, including weight loss, better endurance, a boosted immune system, and higher sex drive. Fueling all these promises is a hormone called IGF-1 (short for insulin-like growth factor). Like medieval "unicorn horns" that were really the tusks of narwhals, IGF-1 is less glamorous in reality than in legend.

It's true that deer antlers "grow like crazy," says Steven Swoap, a physiologist at Williams College. "There are not many examples where a tissue grows faster than an antler. Except for maybe some pumpkins."

We humans are naturally curious about tapping into that growing power. And IGF-1 is certainly involved in growth. In humans as well as deer, it's mostly manufactured by the liver. We make more of it during growth spurts, Swoap says. Producing too much IGF-1 is linked to certain cancers—growth that can't be stopped.

"Does IGF-1 cause antler growth? It is possible," Swoap says. "A more likely candidate is testosterone." Female deer, which also make IGF-1, don't grow antlers; male deer have extra testosterone in their bodies during the antler-growing season. "There are likely many factors involved," Swoap says.

Whatever ingredient gives deer antlers their seemingly magical growing power, we aren't likely to capture much of it by grinding up the antlers themselves. "The antler is not a hormone producing factory," Swoap says. Antler growth is triggered by hormones sent from elsewhere in the body, such as the liver, thyroid, or testes. ("You would be much better off making a spray out of the testes of deer," Swoap suggests. "Or you could perhaps get the IGF-1 from the liver, where it is made, and have a liver milkshake with your deer nut spray.")

Even if a useful quantity of IGF-1 made it out of the antlers and into the spray, the molecule would have a hard time completing its journey into the hopeful athlete's body. Swoap says IGF-1 is a hefty protein that's unlikely to slip into your bloodstream through the soft tissues under your tongue. And once swallowed, it would break down in your digestive tract.

Swoap compares IGF-1 to another famous protein hormone: insulin. "For years, we had to inject it, and it is only recent technological advances that allowed us to deliver it subcutaneously," he says. "To say that the technology is replicated in a bottled spray is ridiculous."

Mitch Ross, the owner of the company that claimed Ray Lewis used its deer spray to recover from an injury, calls his products "technologies that are light years ahead of what people can understand." In other words, even if we can't explain the science, we should accept that deer antler extract helps people.

Except that it doesn't.

Researchers have given oral deer antler supplements to various groups of people, compared them with placebos, and looked for any effect. Men who took deer antler supplements during a strength training program showed no change in hormone levels (including IGF-1) and no difference in aerobic endurance. Rowers also showed no change in hormone levels and no difference in strength or endurance. (As for those other claims, a study in middle-aged men found no increase in sexual function.) A review paper last year concluded there is no convincing evidence that deer antler extract is useful to athletes.

It seems we haven't yet lopped anything special off the heads of those deer. Ray Lewis and (because even athletes who compete at a walk apparently want performance boosters) golfer Vijay Singh are busy defending their reputations against deer antler spray. Yet the product wouldn't have given them any extra powers except a placebo spritz of confidence. Professional sports organizations have plenty of real beasts to chase down in the world of banned substances, but this one is only a mythical creature.

Image: skipnclick (Flickr)

Baby Cuttlefish Are Cute, Colorblind Killers

The business end of a cuttlefish is no place a small crustacean wants to be. Cuttlefish are hunters who creep around in camouflage—virtually indistinguishable from a gray patch of gravel or a branching green seaweed—then lash out with their tentacles, turning a passing shrimp into shrimp toast. Oh, and they're colorblind. Despite this apparent handicap, though, learning to hunt doesn't take a lifetime. Baby cuttlefish figure it out almost as soon as they hatch.

"Newly hatched cuttlefish are mini adults," says Anne-Sophie Darmaillacq of the Université de Caen Basse-Normandie in France. They behave similarly to full-grown cuttlefish, that is, and look like toy versions of their parents. Yet those grownups are long gone. "Parents die after the spawning season," Darmaillacq says. Since cuttlefish are born as orphans, they have to be able to look after themselves right away.

For this reason, Darmaillacq and her coauthors wondered how the eyesight of junior cephalopods compares to that of their adult relatives. To find out how quickly a just-hatched cuttlefish's eyes get up to speed, they collected eggs of the cuttlefish Sepia officinalis off the coast of France. (The genus name describes a cuttlefish's brown ink, not its many-colored body.)

 Zero to 30 days after hatching in the lab, the tots were tested in a carousel-like device. While a cuttlefish sat stationary at the center, a cylindrical screen with vertical stripes rotated around it at various speeds. Animals that were able to distinguish the stripes spinning by would follow them with their eyes, or by rotating their whole bodies. One set of test screens had black, white and gray stripes. Another had stripes that produced different polarizations of light.

Human eyeballs don't distinguish light polarization, which is when light waves all wiggle in the same orientation as they travel, as after passing through a filter. Bees and some other animals can see this polarization and use it to navigate. Cuttlefish, too, can see light polarization, and scientists are familiar with the architecture in a cuttlefish's retina that allows this. But Darmaillacq says the ability hadn't been studied as much in young cuttlefish.

The tests in the striped carousel showed that cuttlefish who had just hatched were already great at tracking black, white and gray stripes, and got even better over their first 30 days of life. They also started life with some skill at seeing stripes of light polarization, and improved as they aged.

Watching stripes spin is less important than knowing when to pounce on a passing meal, though. In a second set of experiments, the researchers showed young cuttlefish two types of prey trapped inside glass tubes and waited to see which the cuttlefish would attack. One prey was mysid shrimp, which hide by being transparent—but they're much easier to spot if you can see light polarization. The other prey was crabs, which both cuttlefish and humans can see without the help of polarized light.

In a regular glass tube, cuttlefish eagerly attacked all the prey. But in a tube covered with a plastic film that hid light polarization, cuttlefish were more reluctant to attack the shrimp. As they grew older, they got faster at spotting all their victims, but they still didn't like to attack transparent prey unless they could see the polarized light coming off their bodies.

Darmaillacq says newly hatched cuttlefish seem to already have the cognitive skills that make a good hunter, such as learning, attention, and decision making. Her experiments also show that cuttlefish can see light polarization soon after hatching, and that skill helps them find transparent prey and decide when to pounce.

The cuttlefish's colorblindness is a deficit that's almost impossible to believe once you've watched this camouflage master in action. Darmaillacq says the ability to see light polarization may make up for the cuttlefish's missing color vision.

Polarized light helps young cuttlefish spot some of their favorite transparent snacks, which would otherwise be hidden. Additionally, "Wavelengths vary a lot depending on the depth [of the water]," Darmaillacq says. "Light polarization does not." In other words, colors can lie in the ocean, but polarization tells the truth. This means cuttlefish can see well enough that their prey—like the fish in this video from the New England Aquarium—never see them coming.

Cartron, L., Dickel, L., Shashar, N., & Darmaillacq, A. (2013). Maturation of polarization and luminance contrast sensitivities in cuttlefish (Sepia officinalis) Journal of Experimental Biology DOI: 10.1242/jeb.080390

Image: Leonard Clifford (Flickr)

Video: New England Aquarium

Sneaky Kids Teach Parents to be Environmentally Responsible

Don't trust your kids. Like a miniature, juice-fueled army with subliminal messaging tactics, they can get inside your mind and make you do things. You won't realize what's happening until you step out of your low-flow shower one morning, turn the calendar page, and see a smug endangered trout looking back at you.

Though we usually think of education flowing down from parents and teachers to children, some people would prefer it to go upstream too. Environmental educators, for example, may hope when they teach groups of children about recycling or saving energy that they'll go home and impose new habits on their parents.

In the Seychelles, an archipelago nation in the Indian Ocean, preserving the wetlands is a major concern. An NGO called Wildlife Clubs Seychelles runs extracurricular "wildlife clubs" in the schools; these groups organize projects and go on field trips to learn about the environment. Researchers from Imperial College London took advantage of the widespread clubs to find out whether environmental education can travel against the current.

During the year before the study, certain wildlife clubs had taught a unit on wetlands while others studied something else. Lead author Peter Damerell and his colleagues studied 7 wildlife clubs that had done the wetlands unit and 8 that hadn't, with kids in the groups ranging from age 7 to 15.

The researchers distributed a questionnaire for kids to fill out in school. A second set of questionnaires went home to the kids' parents. The forms included questions to test wetland knowledge as well as questions about how people used water in their homes.

When the questionnaires came back, there were 137 complete parent-child pairs in the batch. Kids who had participated in a wetland unit scored better on questions about wetland knowledge (what kinds of species live in local wetlands, what threatens these habitats, and so on). More surprisingly, the authors report in Environmental Research Letters, the kids' knowledge had rubbed off on their parents. Moms and dads of wetland-educated kids outscored parents of kids who hadn't studied wetlands.

The questionnaires also asked parents point-blank whether they'd learned anything about wetlands from their children. Their answers, it turned out, were totally unrelated to their actual scores. Even when kids had taught their parents something, parents didn't necessarily know it.

On questions about people's water use in their homes—whether they made choices that use less water, in light of water shortages in the Seychelles—families whose children had studied wetlands with their wildlife clubs again scored significantly better. (It's also possible, the researchers note, that these families just knew the "right" answers to water-use questions. It would take more research to find out whether they actually used less water.)

Since scores didn't increase with children's ages, Damerell and his coauthors don't think regular classroom time did the trick. The wildlife clubs' field trips and outdoor projects may have been just exciting enough to make a real impression on kids—and to get them talking about their fun swamp adventures with their parents. Er, indoctrinating them.

Damerell, P., Howe, C., & Milner-Gulland, E. (2013). Child-orientated environmental education influences adult knowledge and household behaviour Environmental Research Letters, 8 (1) DOI: 10.1088/1748-9326/8/1/015016

Image: jmb_craftypickle (Flickr)

From Mastiff to Miniature Poodle, Dogs Know Each Other by Sight

Anyone who's walked a dog and seen it spring to attention when another dogs rounds a corner—even though that animal is still a full block away—may have wondered how exactly dogs recognize each other. What makes a golden retriever perk up its ears and wag its tail at an approaching greyhound but not, say, a stroller? Why does it ever occur to a dachshund to play with a pit bull in the park? Why don't average-sized dogs chase toy breeds away as if they were squirrels?

You might assume dogs, with their powerful noses, are getting an advantage from scent. Perhaps dog breeds all smell the same, despite looking wildly different. A new study, though, shows that dogs can find each other by sight alone. Dogs are able to spot another dog, no matter the breed, from among a crowd of other animals. Scientists don't know how they do it.

Since other animals such as sheep, macaques, and cows have shown in the lab that they can recognize their peers by sight, scientists in France asked whether dogs could do this when challenged with a full complement of breeds. To understand the magnitude of the problem a dog faces, consider that there are 400 to 500 registered dog breeds. Dogs are more diverse than any other animal species on Earth. Furthermore, their vision isn't that great. If Fido wants to find a mate, though, he'd better know the difference between a Pomeranian and a fluffy cat.

Bertrand Deputte of the National Veterinary School at Alfort, France, and his coauthors recruited nine dogs for their study. All the dogs were pets owned by veterinary students. They were a mix of male and female, and mostly mixed-breeds.

In each stage of the experiment, a dog sat facing two screens on tables while a human stood behind it. (The human experimenter, to make absolutely sure he didn't give any hints, stood motionless and wore dark glasses.) On the experimenter's command, the dog walked forward and chose one of the two screens by placing its paw on a table.

Choosing the correct picture got the dog a food reward. But what was "correct" shifted over the course of the experiment, as the researchers took the dogs through a series of challenges.

In early sessions, dogs won a treat if they chose a screen showing a dog's face over an empty screen. They they had to choose a dog's face over a cow's face, where the dog and cow were the same every time but kept swapping screens. Then the dogs had to generalize: the screens showed dog and cow faces the subjects hadn't seen before, and they had to choose the dog. 

At last came the main challenge: dogs versus everything else. One screen showed a dog's face (a different dog every time) and the other showed some non-dog species (cow, cat, rabbit, human, bird, and so on). Every picture was zoomed in on the animal's head, so that the canine subjects couldn't get any clues from body size or shape—not to mention movement, sound, or smell. Some faces were shown straight on; others were in profile or three-quarters view. Nevertheless, every dog in the experiment succeeded.

"We were rather surprised by the ease dogs had," Deputte says, "in spite of huge variability of dog breeds and the variety of animal and humans faces that constituted the other category." All nine dogs, once they'd learned what the human experimenter wanted, could consistently pick out the dog faces on the screens.

To prove the dogs really knew their stuff, researchers also reversed the task and had dogs pick out the picture that wasn't a dog. They aced this test too.

"We couldn't tell how the dogs succeeded" at grouping dog faces from various breeds and different angles all into one category, Deputte says. He believes his results show that dogs have a "concept of dog." Somehow, our pets know immediately whether the animal walking toward them is dog or not-dog. Along with knowing when to sniff the approaching animal's rear end, this may be a power we hopeless humans will never understand.

Autier-Dérian D, Deputte BL, Chalvet-Monfray K, Coulon M, & Mounier L (2013). Visual discrimination of species in dogs (Canis familiaris). Animal cognition PMID: 23404258

Images: George Thomas (Flickr); Dominique Autier-Dérian/Animal Cognition

UPDATE: Bertrand Deputte has clarified that his coauthor Dominique Autier-Dérian did the experimental work for this study.

Help Desk: Relationship Edition

A couple months ago I introduced the Help Desk so I could answer real questions from Inkfish readers. These aren't questions people submitted intentionally, though—they're search terms that sent people to this site. (Take note, Googlers and Bingers of the world: anyone using web analytics can see your searches.)

This time, in honor of Valentine's Day, the Help Desk is focusing on relationships. I hope the unsatisfied searchers out there can now find the flower-pooping good twins they're looking for.

does music cause rodents to have more babies
It's been suggested that background music helps lab mice to relax and breed more, according to a 2005 paper in the Institute for Laboratory Animal Research Journal. However, they'll still startle easily at a loud noise, regardless of background sounds. In behavioral studies, new age music in particular seemed to calm mice down (compared to classical music, pop, or silence). So if you're looking to set the mood, try Enya rather than Bieber.

You can also teach mice to like music if you introduce it during a certain window in their development, according to a Harvard study. But this research looked only at Beethoven and bossa nova, and didn't give mice the option of getting romantic while the music was playing.

evil twin symptoms
Evil twin is not a medically recognized condition. Perhaps you should try consulting a psychotherapist or a screenwriter.

most inconvenient moments to have narcolepsy
Wheelbarrow race, optometrist appointment, listening to a deathbed confession, pairs ice dancing. And the obvious one.

(The most convenient moments to have narcolepsy include mattress testing, portrait sitting, and televised basketball games.)

how to make a sperm cell
Thankfully, it's not up to you.

that boy has a huge belly button
If a giant navel is the worst complaint you have about a person, things probably aren't so bad. Plus, that belly button is a hotbed of bacterial diversity—and so is yours! Look, the two of you have one more topic for dinner conversation already.

a pig look better than u
Pigs can be pretty charming (see below). If you're looking for a creative insult, what about "a giant land crab look better than u"? Or "a Chinese soft-shelled turtle has a smaller tube coming out of the middle of its face than u"? Zing! You're welcome.

pig repeller
If you didn't want the pig around, maybe you shouldn't have flattered it just now.

bloomers for older woman
It sounds like you're searching for a gift for your significant other. What kind of "older" are we talking about—like nineteenth century? If so, bloomers sound great.

how to stay tight with a big guy
Just because a guy has gained some weight doesn't mean you can't be friends with him anymore. (That is what you meant, right?)

girl that poops flowers
If you're wondering why OKCupid rejected your match criterion, I'm sorry to have to tell you that nobody poops flowers. However! If you or your normally excreting girlfriend are willing to commit to a juice cleanse, you can spend a few days pooping vegetables.

how to ruin a party you weren't invited to
That's tough, but I'm going to have to go back to giant land crabs.

mouse quiet too quiet
Maybe that Enya CD did the trick.

don't make sex in the forest

Earlier: Help Desk, Part 1.

Images: Help desk by Aryc Ogre; piglet by Ed Mitchell; robber crab by John TannChinese soft-shelled turtle by muzina_shanghai (all via Flickr)

Jays Know Which Worms Their Sweethearts Crave (Do You?)

Finding just the right gift for a significant other sometimes means relying on hints; this is especially true if you are a bird and your significant other is also a bird. Even the cleverest corvids aren't great with wish lists. Male Eurasian jays, though, seem to be able to deduce which treats their mates want most.

Sharing food is an important courtship ritual for the Eurasian jay (Garrulus glandarius). Passing snacks to each other helps the birds form, and nourish, long-term relationships. A female might accept any tidbit her partner gives her, whether she wants it or not, for the sake of boosting the bond—or just because she plans on stashing it for later. If a male can correctly guess what foods his mate prefers, though, he could increase his value in her beady eyes.

Figuring out what's in another animal's mind is no mean feat. Yet Eurasian jays are a member of the famously bright corvid family; relatives have been known to reenact Aesop's fables, outsmart small children, and sled down snow-covered roofs. Nicola Clayton and other researchers at the University of Cambridge looked for evidence that these birds are also capable of seeing from another's perspective.

The experiment relied on "specific satiety," which is when an animal gets tired of one kind of food but still has an appetite for a different food. This phenomenon is familiar to anyone who pushes away a plate of pasta, feeling stuffed, and then considers a dessert menu.

For the seven pairs of Eurasian jays in the study, the foods in question weren't pasta and tiramisu but worms and more worms. Specifically, wax moth larvae and mealworm larvae. When they were first fed on one kind of larva and then offered a choice between two bowls, both male and female birds preferred to eat the kind of larva they hadn't already had.

To see whether male jays understood that females felt this way too, the researchers fed female jays either wax moth or mealworm larvae while their male partners watched from the other side of a screen. Then they offered the male both kinds of larva, and let him choose which ones to pick up and pass to his mate through the screen.

After watching their mates eat one kind of larva, male jays were more likely to feed them the other kind, Clayton reports in PNAS. It wasn't because the males themselves were hungry for that kind of food; the researchers checked this in a separate experiment by offering the males their own bowls of larvae after watching females feed. Having already eaten meals of "soaked dog biscuits, cheese, seeds, nuts and fruit," the males had their own preferences about wax moths versus mealworms (two flavors you won't find in a Whitman's sampler). But when feeding their mate, they followed her preference instead.

Nor were the females telling their mates what they wanted, in some secret bird language, right there at the screen. The researchers know this because when males couldn't see the first feeding, they failed to give their mates their preferred larvae. The males had to see females being fed to guess what they'd want later.

The study used a small number of birds in unnatural circumstances. If Eurasian jays can truly put themselves in each other's shoes, though, they are members of the cognitive elite. Deducing another's intentions or desires is something we humans rarely admit other animals are capable of. But then, it can be hard to take a hint.

Ostojic, L., Shaw, R., Cheke, L., & Clayton, N. (2013). Evidence suggesting that desire-state attribution may govern food sharing in Eurasian jays Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.1209926110

Image: Eurasian Jay mating pair engaged in food-sharing, by Ljerka Ostojic.

Aging Makes People Colon-Close-Parenthesis

Getting older is not a recipe for crotchetiness. Although those two cranky Muppets will always be up in their balcony, Americans in general don't become less happy with age. If anything, they get happier.

The trajectory of people's happiness over a lifetime is tricky to study, because in a given year you're capturing not only your subject's age but also the current events. You need to follow a large group of people over many years, and you need them to be all different ages when the study starts.

Angelina Sutin and her colleagues at the National Institute of Aging in Maryland had just such a dataset to work with. Called the Baltimore Longitudinal Study of Aging (BLSA), this project has been running for more than five decades and has gathered data on people born everywhere between 1885 and 1980. These subjects have answered questions about their happiness on many occasions—some as many as 19 times—throughout their lives.

Want to find your own happiness score? Answer the following questions on a scale from 0 to 3, where 0 is "rarely or never" and 3 is "most or all of the time." In the past week of your life, how frequent were these feelings?
     I enjoyed life
     I felt I was just as good as other people
     I felt hopeful about the future
     I was happy

Summing the four numbers will give you your well-being score. If you were in the BLSA, that score would be your data point for today.

When the researchers put all 2,267 subjects together and looked at how their happiness changed with age, they got a decidedly downward slope. A frowny face, if you will.

age = : ( 

It looked like aging made people less happy. But then the researchers tried a different tactic. Instead of lumping all their subjects together, they grouped them by when they were born. That frown turned upside down:

age = : \

Within each birth year, the results now looked like a somewhat more optimistic "meh?" face. Every group's well-being slightly (but significantly) improved with age.

The first set of results had sloped downward because people who were born earlier reached lower endpoints of well-being. In the graph, you can see that someone born in 1905 or 1925 is likely to reach a 9 or a 10 later in life; someone born in the 1960s might make it nearly to 12 (a perfect score).

Sutin thinks this could have to do with the biggest national frowny-face of all: the Great Depression. People who lived through this time, she writes, may have felt lasting psychological effects. Although their well-being still improved as they aged, the cloud of the Depression may have lingered.

(Sutin notes also that younger and older adults, according to previous studies, treat this set of well-being questions and the 0-to-3 scale similarly. This suggests the results aren't just happiness inflation—say, younger people reporting a 12 for the same feelings that older people would rate a 10.)

Aside from increasing economic prosperity in the United States, there are plenty of other reasons people may have felt happier in more recent decades. Sutin cites increased life expectancy, decreased infant mortality, better nutrition, less disease, and more women in the workplace as possible factors. The twentieth century also saw faster travel, the invention of the Internet, and the eradication in America of both the polio virus and gelatin-based entrées. There's a lot to be happy about.

Now that Sutin has found that the average American seems to have an upward trajectory of well-being, she's interested in people's individual paths: what makes one person's happiness increase more or less (or decrease) over time?

In this study, subjects who were white had higher well-being scores on average, as did those with more education. Sutin hopes to pick apart the social, economic, and health factors that affect how happiness changes with age. When everyone can feel as :) as they want, we'll really be living in the future.

Sutin, A., Terracciano, A., Milaneschi, Y., An, Y., Ferrucci, L., & Zonderman, A. (2013). The Effect of Birth Cohort on Well-Being: The Legacy of Economic Hard Times Psychological Science DOI: 10.1177/0956797612459658

Image: a 102-year-old woman, by Uppy Chatterjee (Flickr)

Aphids Always Land on Their Feet

Pea aphids are even better at "stop, drop and roll" than elementary-schoolers. When a threatening ladybug or grazing deer approaches the stem where an aphid is sucking sap, it lets go and plummets toward the ground. By holding its limbs in just the right way, though, the insect can tumble into an upright position before sticking the landing.

The ground is a dangerous place for a small wingless animal, so it might help a falling pea aphid (Acyrthosiphon pisum) to hit it running. Or, better yet, to land feet-first on a lower leaf and never reach the ground at all. A group of scientists in Israel subjected pea aphids to predator scares, bouncing falls, and amputations to investigate their cat-like maneuvering.

In one experiment, the researchers placed a ladybug onto a fava bean plant where aphids were feeding. They covered the ground below with petroleum jelly so the insects would be caught however they landed.

As the ladybug crawled up the plant, alarmed aphids dropped to the ground. Falling from 20 centimeters, nearly every aphid landed right side up—"like a defenestrated cat," the authors note cheerfully.

If a live aphid is like a cat, a dead one is closer to buttered toast. The team used tweezers to drop upside-down aphids from 35 centimeters up. Some aphids started out alive and well; others were dead. The third (and least fortunate) group of aphids were still alive but had their limbs and antennae removed with a razor blade. Among the living, limbed aphids, 95 percent landed upright. Only about half of the dead aphids did, though. The number was even lower for the limbless group, reduced to flipping through the air like sesame seeds.

High-speed photography and mathematical modeling revealed the secret of the pea aphid. After letting go of a plant, it stretches its antennae forward and reaches its hind legs back and up. Then it freezes.

This position, the researchers discovered, it only aerodynamically stable when right side up. Holding its appendages stiffly in position like a skydiver, the falling insect will tumble until it's belly-down. Then it stays that way until it lands, the authors report in Current Biology.

"I was surprised and impressed by the simplicity of the righting mechanism," says Gal Ribak, a biologist at the Israel Institute of Technology and one of the lead authors. To land upright, the aphids only need to assume the right pose and stay that way. "All the rest is taken care of with the help of air resistance and gravity."

To see whether falling upright helped aphids land on a safe leaf, instead of going all the way to the groung, the researchers dropped insects directly over leaves. Those that were feet-first when they hit a leaf were able to stick the landing about half the time. When turned the wrong way, though, the aphids were guaranteed to bounce off the leaf and into danger.

The real danger in the lab, of course, came not from predators on the ground but from the scientists, who now snipped the ends off the aphids' legs to see if sticky pads there were helping them land. Once their wounds stopped oozing, the insects took another trip through the air. This time only 1 out of 20 caught the leaf.

Ribak studies animal locomotion within the university's department of aerospace engineering. That's because pea aphids, with their aerodynamical tricks, may have something to contribute to aircraft design. The species is also known for apparently capturing energy directly from the sun, something that's usually impossible if you're not a plant. Technologically, when it comes to these falling insects, we may never catch up.

Ribak, G., Gish, M., Weihs, D., & Inbar, M. (2013). Adaptive aerial righting during the escape dropping of wingless pea aphids Current Biology, 23 (3) DOI: 10.1016/j.cub.2012.12.010

Image: Ribak et al. (see the whole video here!)

When a Queen Dies, Wasps Know Who's Next in Line (and Next, and Next)

This post originally appeared in August 2012. Inkfish will return to its regularly scheduled wacky animals next week. 

The office of postmaster general to the United States used to come with a perk totally unrelated to mail. In the unlikely event that an accident wiped out the president, vice president, and every member of their cabinet, the postmaster general would become the leader of the country.

In reality, the line of succession has never gotten beyond the vice president. But there are 16 people lined up behind the VP to take over (a list that no longer includes the postmaster general and now culminates, less quaintly, with the secretary of homeland security). In the United Kingdom, the order of succession to the throne winds bafflingly through a giant family tree of princes, dukes, viscounts, and so on.

Wasps of the species Ropalidia marginata never have to argue about titles or families: when the queen dies or disappears, the other wasps in the colony unanimously agree on who her successor is. And if that queen disappears too, they know who comes after her. Though the ordering system is invisible to human eyes, the wasps adhere strictly to their line of succession and follow it all the way down (if necessary) to their equivalent of the postmaster general.

Alok Bang and Raghavendra Gadagkar, researchers at the Indian Institute of Science in Bangalore, have been determinedly assassinating wasp queens to try to figure out how the R. marginata system works. Until the researchers get to her, each nest's queen lives a peaceful life. She doesn't bother anyone, and no one bothers her as she pumps out new generations of fertilized eggs.

The queen's quiet lifestyle, like that of most royalty, is in stark contrast to the lifestyle of her subjects. All around their docile ruler, worker wasps live in continuous violence. Gadagkar says the wasps chase, bite, and "nibble" one another, pin each other in place by holding body parts in their mouths, and crash down on each other from above. These displays of aggression don't usually injure the wasps, but maintain a hierarchy of dominance among them.

When the peaceful queen dies, or is plucked from the nest by interfering scientists, things get shaken up. One worker wasp—and only one—suddenly becomes hyperaggressive. Within minutes of the queen disappearing, this worker begins attacking the wasps around her at 10 or even 100 times her usual frequency, Gadagkar says. She distributes her attacks evenly among anyone nearby, and no one fights back. It's all a show to announce that this wasp is the heir to the throne.

Over the following week or so, the heir's aggression dies down and her ovaries develop. She becomes another peace-loving, egg-laying machine.

The researchers believe that this successor is chosen somehow before the original queen disappears. Even though she's outwardly identical to the other wasps in the nest, she's predestined to be second in line to the throne. "The fact that there is invariably one and only one individual who becomes hyperaggressive" is one clue, Gadagkar says. That no one challenges this hyperaggressive individual is an even stronger clue. And in previous studies, the researchers have shown that the heir isn't simply the first wasp to get the news of the queen's death. The successor seems to know who she is ahead of time, and the other wasps know and respect it too.

If that weren't impressive enough, Bang and Gadagkar have now found that when they remove the first heir, a second one steps up just as quickly. In a new paper in PNAS, the authors say they've discovered a succession of at least five potential queens.

Each of these new queens jumps into action as soon as a the previous queen disappears, attacking any workers around her. Again, only one wasp steps forward, and no one challenges her. Within several days, this new queen starts laying her own eggs and maintaining the colony. In an entire nest of 20 or 30 individuals, the researchers say, there's no reason to believe the succession doesn't continue—maybe down to the very last wasp.

Having an agreed-upon order of succession makes sense for insects living in small colonies like R. marginata, the authors say. Unlike in a large honeybee colony, where queens are determined from birth and workers know they'll never lay their own eggs, workers in the termite colony actually have a shot at reproducing. Knowing where they are in the queen queue could help them decide whether to stay in their original nest or move out to start a nest of their own.

Even if it makes perfect sense for the wasps to have an orderly system of succession in place, that doesn't explain how on Earth they figure it out.

"That is the million-dollar question we are working on!" Gadagkar says. The researchers found that older wasps were more likely to be the immediate heirs to the throne, but the order doesn't go strictly by age. It also doesn't have anything to do with the dominance hierarchy in the nest.

"Perhaps it is something very subtle, related to the internal physiology of the wasp, that the wasps themselves can detect and which we have not yet discovered," Gadagkar says. Like obscure duchesses and earls, the wasps know their place in line—indecipherable as it may be to the rest of us—and wait for their day to step forward.

Alok Bang, & Raghavendra Gadagkar (2012). Reproductive queue without overt conflict in the primitively eusocial wasp Ropalidia marginata PNAS : 10.1073/pnas.1212698109

Image: Abhadra/Wikipedia