Most of us don’t give much thought to drops of liquid that end up outside our drinking glasses. But physicists care a lot about liquid droplets, and study their whole lifespans—from the first splash or drip to the moment a drop disappears.
Liquids that contain three different substances, though, haven’t been studied as much. Detlef Lohse, a physicist at the University of Twente in the Netherlands, and his colleagues took a deep dive into one such liquid: ouzo. Read More
The rectal exam is a delicate art to learn. Doctors perform this procedure entirely by feel, with just one finger. Students who are learning how to do such an exam have no way of showing their work to their teachers. And volunteer subjects are—unsurprisingly—rare. In the entire United Kingdom there’s only one person registered as a test subject for rectal exams, says Fernando Bello, who works on surgical computing and simulations at Imperial College London.
Rectum models made of plastic exist to help train new doctors. But these are limited in how much they feel like the real thing. That’s why Bello and his colleagues built a robotic rectum. Read More
In the mountains of Central Africa, scientists who study critically endangered gorillas have a new tool. They’ve discovered that they can learn what viruses gorillas are carrying by stealthily collecting half-chewed plants the apes leave behind.
If this sounds reminiscent of that class clown at the third-grade lunch table who would ask if you liked seafood and then say “See? Food!” and open his mouth wide to display his sloppy Joe slurry, don’t worry—mountain gorillas are vegetarians. And researchers aren’t looking inside the animals’ mouths. They decided to search gorillas’ plant scraps for viruses exactly because they don’t want to get too close. Read More
In the open ocean, it’s good to have friends. Some young fish like to buddy up with stinging jellies to stay safe from predators. Hiding under the shelter of a jellyfish’s bell, they can grow up unharmed (as long as they dodge its tentacles). These fish include some species that humans rely on for food. But in a warming ocean, that buddy system may fall apart.
Many types of fish take advantage of hop-on jelly trolleys. Ivan Nagelkerken, a marine biologist at the University of Adelaide in Australia, and his colleagues focused their new study on the fish living with one jelly in particular: the delightfully named blue blubber jellyfish, or Catostylus mosaicus. Read More
Honeybees may seem like nature’s perfect little automatons: organized, efficient, self-sacrificing. But in reality the insects are imperfect individuals. Their dance language is sloppy and imprecise. They lose self-control when they’re hungry. And, a new study has found, worker bees have distinct personalities.
Iowa State University ecologists Alexander Walton and Amy Toth explain that animals need to meet three requirements before you can say they have “personalities.” First, individuals have to behave differently from each other in a way that’s consistent over time. Second, those behavioral differences also have to show up across different contexts. Finally, there should be sets of behaviors that tend to clump together, like personality types. Read More
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