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
Minnesota is the “Land of 10,000 Lakes,” at least 13 of which are named Clear. But some of these lakes are clearer and cleaner than others. Does that matter to the tourists who visit them? Researchers found an easy way to answer this question by taking a deep dive into Flickr.
Bonnie Keeler, a scientist at the University of Minnesota’s Institute on the Environment, explains that it’s important to measure how the public is using various lakes, rivers and streams. Agencies that are trying to protect these resources, for example, would love to know that the cost of cleaning up a lake is balanced by the benefit of extra tourism. “We assume that tourists and other users prefer higher quality sites and pristine systems,” Keeler says. But it’s tough to prove, especially in the developing world. Surveying people about their vacations is expensive and hard to do on a large scale.
So Keeler and her coauthors tried to get the information without asking anyone. Instead, they asked people’s photo albums. Read More
We’ve all been there: it’s easy enough to follow our plans to exercise and eat healthily, until suddenly it’s 4:30 in the afternoon and we’re ready to plunge our faces into the first dandelion we see. Honeybees, like humans, can exert self-control when making decisions about food. But when they get hungry enough, that control buzzes right out the window.
For a bee, of course, self-control isn’t about Pilates and salads. Worker honeybees mostly consume nectar. When they get back to the hive they regurgitate that food and share it with the other bees. A responsible worker bee should choose the best nectar sources—not just settle for the first flower she finds—and communicate where they are to her sisters back home.
Researchers have found that honeybees show self-control. They’ll hold out for a larger or sweeter nectar reward instead of drinking a smaller or less sweet reward immediately. But will bees always choose the good of the colony over their own needs? If a bee is hungry enough, will she lower her standards? Read More
Imagine you’re on a particularly boring leg of a road trip and you start counting houses. You pass through long stretches of country without counting anything. When you do see houses, they’re clustered into towns, and may have spacious yards with tire swings. As you approach a city (finally!), rows of houses appear at regular intervals instead of clumping. And in the heart of the city they shrink into little apartments that go by too fast for you to count. European rabbits, it turns out, build their homes in a similar way—and since these animals are disappearing in the countryside, understanding their urban planning strategy matters to humans trying to conserve them.
Hunting, habitat loss, and disease have driven down populations of European rabbits (Oryctolagus cuniculus) in the countrysides of western Europe. Yet rabbit populations in some German cities are, well, hopping. Read More
Athletes don’t normally need to be chased down the track to get their training mileage in. But a green anole lizard is not a normal athlete.
Scientists wanted to know whether it’s possible to train a lizard at all. Human athletes and other mammals perform better with consistent exercise, but is this universal? Can a reptile increase its stamina? What about its sprint speed? So the scientists became lizard athletic trainers, which really means lizard harassers. Results were mixed.
The green anole lizard, or Carolina anole (Anolis carolinensis), is a common laboratory species. Basic rules of its biology—for example, how it responds to exercise—ought to apply to other vertebrates, such as humans. In the past, scientists have successfully used exercise to increase endurance in frogs, birds, alligators and crocodiles. But the same efforts with lizards have been inconclusive.
Jerry Husak, a biologist at the University of St. Thomas in Minnesota, studies lizards with the help of undergraduate researchers. He and his students decided to try creating “Olympic lizards.” Read More
Try to read up on the okapi and you won’t find much. This African mammal is most often seen next to the adjective “elusive.” But even if we can’t find any okapi, we can learn about their lifestyle through their DNA—and we can find their DNA in their feces.
The okapi is an ungulate, like a cow. Or really like a giraffe, its closest relative. It has an elegant face, a long bluish tongue, and a zebra-striped rear end. It lives in the dense rainforest of the Democratic Republic of Congo, chewing tree leaves in privacy. No one in the Western world knew the animal existed until the 20th century.
“One of the great things about studying okapi was that there was so little known about them in advance,” says David Stanton, a PhD student at Cardiff University in the United Kingdom. “So in this sense, everything that we found out was a surprise.” Read More
If a polar bear tells you to talk to the hand, don’t be offended. The animals seem to communicate with each other through scent trails left by their paws. Their tracks tell a story to the other bears roaming their habitat, helping potential mates to find each other—as long as there’s habitat left, anyway.
As they crisscross the snowy Arctic, polar bears are usually alone. In other solitary bear species, animals leave messages for each other by rubbing their bodies or urine onto trees or rocks, for example. These objects can become like bulletin boards for bear society. But the icy home of polar bears doesn’t include many vertical objects to rub up on.
In the past, people have noticed that polar bears sometimes sniff the footprints of other bears. Could there be chemical information hidden in the giants’ tracks?