Maybe you can catch more flies with honey than with vinegar, but if you’re trying to catch grasshoppers, the best method is bright white socks. The white patches on the front legs of certain Asian spiders make prey willingly flock to them—and scientists don’t really understand why.
Dolomedes raptor is known as a fishing spider. It lives near streams in the forests and cities of East Asia. Females are a little bigger than males—up to about an inch across—and the two sexes have different hunting strategies. Males actively pursue prey. But females hunt by perching on rocks at the edges of streams. They splay their legs out, often just touching the water’s surface. Then they remain frozen this way for hours. If any tasty prey approach (semi-aquatic insects, or tiny fish or amphibians), the spiders nab them.
Female D. raptor spiders are dark brown, with patches of bright white hairs on their front legs. Male spiders don’t have these patches. The white hairs don’t seem to be decorative—male spiders are indifferent to them. So scientists wondered whether the patches help female spiders with their particular hunting strategy. Read More
How do you know when a farm animal is unhappy? Animal welfare researchers wish they had easy ways to measure malaise in pigs, or stress in cows. But those tools are lacking—which is why scientists in Australia studied sheep they’d dosed with Valium.
“Animals are not able to talk to express their emotions,” says Caroline Lee, an animal welfare scientist at CSIRO in New South Wales. “We need to use other ways of understanding how they are feeling.”
One such way is to look for changes in behavior that give away an animal’s mood. Read More
“Not tonight, honey,” says the female burying beetle, chewing up a mouthful of mouse carcass before spitting it into the mouth of a begging larva.
For the first few days of their babies’ lives, burying beetles co-parent. They devote themselves to keeping their squirming larvae alive. That means mating and laying more eggs would be a waste of energy. And to make sure males get that message, females emit a pheromone that turns them off.
“It is quite surprising,” says University of Ulm behavioral ecologist Sandra Steiger, “and somehow intriguing.” Read More
How do you know when animals are working together? Just because two animals got something done jointly doesn’t mean they cooperated. They might have succeeded by dumb luck, or trial and error. Scientists who study animal minds, though, would really like to know when cooperation happens on purpose—and how animal partners manage to communicate with each other.
Studies in capuchin monkeys and chimpanzees hinted that the primates coordinated their actions by glancing at each other. (But this video shows some chimps who were stumped by a cooperative task, unless their partner was a human.) Baboons smacked their lips while working together. Lionfish used certain fin displays before hunting together.
Dolphins often cooperate to hunt. They may use regionally specific tricks to trap prey—dolphins in Florida, for example, slap their tails to scare fish out of the water and into their partners’ mouths.
Researchers from the University of Southern Mississippi and a Florida facility called Dolphins Plus studied captive dolphins to learn how they might communicate while working together. Read More
Like Snapchat abstainers or reluctant Slack users, adult parrots have a hard time learning new tricks. Older birds stay set in their ways while young birds innovate and try new things. Researchers say that’s just as it should be—even if it means the grownups miss out on a treat now and then.
Young animals might be better at creative problem-solving because they’re fearless and like to explore. On the other hand (or paw, or claw), older animals might do better because they have more knowledge and life experience to help them. Studies in monkeys and apes have suggested that adults are the better innovators. But a few studies in birds have found the opposite: juveniles outperform adults at solving problems. To shed some more light on the question, Julia Loepelt and her colleagues at the University of Wellington in New Zealand looked at a wild parrot called the kaka. Read More
Smashing out of its egg is only the first step in a baby sea turtle’s grueling early days. The turtle fights free of its eggshell only to find itself buried underground. It has to intuit which way is up, then dig out of the packed sand. As soon as it breaks onto the surface of the beach, it begins a mad sprint to the ocean. All around are its brothers and sisters, flailing toward the water as fast as their own flippers will carry them. In the sea they’ll keep swimming frantically, trying to escape the shallow areas where they’re most vulnerable to birds and other predators.
A newly hatched turtle can’t stop in the middle of this marathon for a PowerBar. All the energy for its journey from underground to ocean has to come from its reserves—the energy it took from its egg while growing. So it’s critical for a turtle to reach the ocean as efficiently as possible. Now, through a very tricky series of experiments, scientists have measured how much energy turtles spend while hatching. The more hatchlings are in a nest, they found, the better. Read More
People with sleep apnea are at war with their windpipes. But they might be able to get some help from a different kind of wind pipe—namely, the Australian Aboriginal instrument called the didgeridoo.
In sleep apnea, obstructed airways stop a person’s breathing over and over at night. It’s normal for the throat muscles to relax during sleep, but for sleep apnea sufferers this relaxation combines with other factors to make breathing impossible. Apnea leads to broken sleep, snoring, and exhaustion during the day. A device called a CPAP (continuous positive airway pressure) machine can treat sleep apnea, but it’s pretty drastic, involving a mask hooked up to an air-blowing motor.
Alex Suarez, a didgeridoo instructor in Switzerland, noticed that his own sleep apnea symptoms lessened after several months of practicing the instrument. Some of his students experienced the same thing. So Milo Puhan, a doctor and professor at the University of Zurich, and his colleagues set out to test the didgeridoo effect. Read More
“Dance like nobody’s watching” is fine advice, unless somebody is watching, and she needs to translate your dance steps into instructions to find food. That’s the case for honeybees. But even though the rest of the colony must interpret their dance moves carefully, it turns out honeybees are pretty sloppy dancers. Read More
The Amazons were a mythical race of warrior women who, in one version of the story, removed their right breasts to be more hardcore. But an all-female race of salamanders doesn’t suffer from missing body parts. In fact, these animals have super-powered regeneration: when they lose an appendage, they can grow it back much more quickly than other salamanders do.
The secret lies somewhere in the salamanders’ bizarre genetics. “They sort of defy definition,” says Rob Denton, a graduate student in ecology at Ohio State University. Read More
Did you know this is Hedgehog Awareness Week? The British Hedgehog Preservation Society has dedicated May 1 through 7 to the spiny garden animal. The society won’t go so far as to call it Hedgehog Appreciation Week—perhaps that would be too much of an imposition?—but it does want to highlight some of the problems faced by hedgehogs. For example, weed whackers, which apparently in the U.K. are called “strimmers.”
The society suggests posting pro-hedgehog leaflets around your neighborhood, and checking your compost heap carefully before stabbing any sharp tools into it. Another tip: “Ensure there is hedgehog access in your garden – a 13cm x 13cm gap in boundary fences and walls.” I’m not even going to bother translating that into inches, because there are (sadly, for those of us who appreciate them) no wild hedgehogs in North America. Read More