If snails used Facebook, all their relationship statuses would say “It’s complicated.” It’s also slimy, violent, and life-shortening.
Most species of snail that live on land are hermaphroditic—that is, they have a complete set of female and male sex organs. When they mate, both partners inseminate each other. The act may come after a courtship period. And in certain land snails, this courtship includes the launching of “love darts,” which are much less cute than they sound.
A love dart is a sharp dagger that a snail builds in its body out of calcium carbonate. Before mating, the snail thrusts this dart out of itself and straight into its partner’s flesh. A love dart is not related to a penis (each snail has one of those, too) and doesn’t carry sperm. It’s pure weaponry. You might see a fired dart still jutting from a snail’s neck while it copulates, as in the right-hand snail below: Read More
Do the sounds of dripping eaves and squelching slush heaps make you just the tiniest bit sad about winter ending? No more crunchy snow underfoot, no more picturesque flakes drifting past your window? Relegating all your sweaters and thick socks to the back of the closet?
For anyone else who wants a taste of winter in the off-season—or for anyone living in less wintry climes—now there’s the Icicle Atlas.
Over four years, researchers at the University of Toronto grew and photographed icicles. They may seem mundane when they’re sprouting from your gutters, but icicles are mysterious in how they form. Their shapes emerge from a complex set of interacting factors: air flow, water flow, the icy foundations they’ve already built.
The scientists grew 237 icicles on an icicle growing machine with a slowly rotating dripper nozzle. The apparatus turned about once every four minutes, ensuring that conditions were the same all around the icicle. “This is the same reason you rotate the meat in a BBQ; to make all sides the same,” says Stephen Morris, the physicist who supervised the project.
With their icicles rotisserie-ing away, the researchers tweaked several variables—temperature, air flow rate, water flow rate, the makeup of the water—and watched the effects. Read More
A drooling baby face is not equally exciting to everyone around it. A new study says that young women who like the idea of motherhood get more enjoyment than their peers from staring at infants’ faces. But they don’t love all of those chubby mugs equally. Even more than the baby-neutral, wannabe moms are biased toward the cutest ones.
Amanda Hahn is a researcher at the University of Glasgow’s “Face Research Lab,” directed by psychologists Lisa DeBruine and Benedict Jones. (On their website you can see an averaged photo of all seven lab members’ faces, because of course.) Hahn is especially interested in motivation. For this study, she wanted to know what drives people to look at photos of babies—or not.
Hahn focused on heterosexual women with no children of their own. She recruiting 200 subjects online; their average age was about 22.
As for the baby pictures, Hahn started with 10 photos of real babies. Then she digitally tweaked them to create a slightly cuter, plus a slightly less cute, version of each baby. (Information about what shapes make baby faces more or less cute had come from a previous study.) The differences were subtle, as you can see in the pair of faces below. Read More
A fellow who hides in his shell until danger has passed may not seem like the epitome of manliness. Yet among hermit crabs, the shyest males have the most to offer the ladies. It’s all part of their evolutionary strategy. Crabs that are long on bravery, meanwhile, are short on sperm.
Mark Briffa, an animal behavior professor at Plymouth University in the United Kingdom, and his colleagues found the surprising connection between sperm and shyness while studying “life history” in crabs. To a biologist, life history doesn’t mean the material for an animal’s tell-all memoir. Instead, it means how organisms invest their resources. Living things only get a limited budget of food and energy—so is it better to spend that energy growing big and strong, or searching for a mate? Making sperm or eggs, or building large claws or horns to fight off enemies?
The researchers already knew hermit crabs have personality. A little, anyway. Some crabs are bolder, while others spend more time tucked in their shells. And the researchers wanted to know how these personality traits relate to the rest of a hermit crab’s life-history strategy.
Usually, they explain, bolder animals have more reproductive success. They follow a sort of “live fast, die young” plan: if you have the resources, spend them on running around and mating. When you’re eaten by a seagull, at least you’ll leave some young behind. Read More
You won’t see a chickadee shoveling out a parking space and claiming it with a folding chair, no matter how good your binoculars are. But birds, too, have to be resourceful when they live in inhospitable climates. Travel just 600 meters up a mountain, and you’ll find chickadees vastly more clever than their peers living a more comfortable life below.
How do you test the cleverness of birds? Using tubes with tasty worms inside, naturally. Biologists don’t like to call animals “smart,” though, so in this case they were testing the “problem-solving ability” of Poecile gambeli, the mountain chickadee. These songbirds live in the mountainous western United States, ranging from the low foothills to the peaks.
Dovid Kozlovsky, a graduate student at the University of Nevada, Reno, and his coauthors wanted to compare a population of mountain chickadees from a higher elevation, where the weather is more severe, to one from a lower elevation. Read More
Nothing turns your internet procrastination time into feelings of goodwill and teamwork like a citizen science project. You can click through a set of penguin photos or moon craters and know that your data are contributing to real science. As more citizens take part, and more researchers discover the joys of free labor, these projects are gaining popularity. But not all citizen scientists pull their weight. In fact, most do nearly nothing.
Henry Sauermann, a management professor at the Georgia Institute of Technology, is interested in the economics and organization of science. He’s also curious about what motivates scientists. Sauermann and his coauthor, Chiara Franzoni of Politecnico di Milano, thought that citizen science would be “a wonderful new context to think about these general issues,” Sauermann says.
Sauermann and Franzoni gathered data on seven projects at Zooniverse.org, a citizen science web portal. Read More
In a world of shy, quiet-as-a-mouse rodents, one lemming is the exact opposite. It attacks when it should retreat to a hole. It squeals and shrieks when it should keep silent. One scientist is working to figure out how evolution created this animal—and wearing thick gloves while he does it.
First, forget what you think you know about lemmings. You’ve likely heard a rumor that these rodents hurl themselves off of cliffs in droves. It’s not true, though the makers of a 1958 Disney documentary promoted the myth by chasing a bunch of the poor animals into the ocean. Lemming populations do go through wild booms and busts, and lemmings may migrate to new areas when a local population gets out of hand. But otherwise the Arctic dwellers spend their time doing normal rodent things like burrowing, eating grasses, and not committing mass suicide.
Except that the Norwegian lemming, Lemmus lemmus, isn’t quite normal. Read More
“Opinions are my own,” declare countless Twitter profiles. Users want to make it clear that they aren’t speaking for an employer. Yet even when we think our words are our own, our circumstances may speak for us more than we realize.
Microsoft Research scientists Munmun De Choudhury and Michael Massimi studied how Twitter users’ language changes after they get engaged to be married. Actually, the researchers only studied a certain group of engaged people: those who announced their engagement in a public post on Twitter with the hashtag #engaged. Combining data from Twitter with the sharp eyes of Mechanical Turk workers, the researchers found 923 Twitter users who got engaged (and #engaged) between May and December of 2011.
Next, they collected these users’ tweets from before and after they were engaged. Drawing from the 9 months prior to each engagement and 12 months after, they ended up with more than 2 million tweets.
The authors also needed a control group to compare to their engaged tweeters. For this, they sampled tweets from 50 random Twitter users on each day of the study period (spanning both the pre-engagement and post-engagement months of the engaged subjects). This added more than 12 million tweets from more than 11,000 users.
There were striking linguistic differences in people’s tweets before and after getting engaged. Read More
As anyone who’s made valentines for a whole elementary-school class knows, kids are often pushed into social groups not of their choosing. Scientists tried the same thing with wild birds and found it pretty easy to coax them into new cliques. The birds hung out with their new social circles even when they didn’t have to. But once the experiment ended, those friendships dissolved faster than a candy conversation heart.
To create new social groups in birds, researchers essentially controlled which lunch tables they could sit at. Josh Firth and Ben Sheldon of the University of Oxford were studying wild birds in an English forest. As part of an ongoing experiment, there were feeders full of sunflower seeds set up throughout the woods. The birds came to the feeders in mixed-species flocks: great tits, blue tits, coal tits, marsh tits and nuthatches. Then all of a sudden, the birds found that some of these feeders had turned hostile. Read More
While the robot teaching itself to cook is still struggling, here’s a robot that’s nearly mastered another household task: laundry.
Putting dirty clothes into a hamper and moving them to a washing machine isn’t especially hard for humans. But for a robot, the chore is a challenge because it involves some uncertainty.
“The exact number of clothes in the heap and the number that may be picked up with each grasp cannot be determined precisely,” write University of California, Berkeley, computer scientist Siddarth Srivastava and his coauthors. “Doing the laundry thus represents a challenging planning problem.” When you start loading dirty t-shirts into a hamper, you may not know how many there are, or how many trips to the washer you’ll need to take. This probably doesn’t bother you too much. But a robot would prefer to know what it’s doing before it starts. Read More