Why do otters juggle? It sounds like the opening to a joke, but many otters are frequently seen shifting pebbles back and forth between their hands, an activity referred to by scientists as "juggling." While animal behaviorists have thought that the juggling is a way for the animals to practice pulling meat from crustaceans and mollusks, a task that requires fine motor skills and coordination. However, researcher Mari-Lisa Allison and colleagues from the University of Exeter found that otters who frequently juggled didn't exhibit any better food-picking skills. Turns out they're probably just doing it because it's fun. From Science News:

The possible disconnect between play and real-life skills doesn’t startle Gordon Burghardt of the University of Tennessee, Knoxville. Over decades, he has analyzed play behavior, refining definitions and even reporting play in such unexpected animals as a turtle romping with a basketball in a zoo. The thinking about the evolution of play has by now expanded beyond simple notions of the benefits of instinctive practice, he says[...]

Otters that juggle may be doing so “for pleasure, out of boredom, or both,” he says.

"The drivers and functions of rock juggling in otters" (Royal Society Open Science) Read the rest

Darcin is a pheromone found in the urine of male mice. It's used to mark territory and signal mating availability, and was named after the character Mr. Darcy who appears in Jane Austin's Pride and Prejudice. In the new issue of Nature, researchers at Columbia University report on how darcin "takes hold in the brains of female mice, giving cells in the brain's emotion center the power to assess the mouse's sexual readiness and help her select a mate."

From the press release:

Pheromones, such as darcin, are processed somewhat differently. They interact with a second, parallel olfactory system, which exists in animals like mice but not in people.

"Unlike people, mice have essentially two functional noses," said Dr. Demir. "The first nose works like ours: processing scents such as the stinky odor particles found in urine. But a second system, called the vomernasal nose, evolved specifically to perceive pheromones like darcin."

For today's study, the research team, which also included Dr. Hurst, Dr. Beynon and co-senior author Adam Kepecs, PhD, of Cold Spring Harbor Laboratory, first exposed female mice to darcin-scented urine and monitored their behavior. Nearly all of the female mice showed an immediate attraction to darcin. Then, after about 50 minutes, some females began leaving their own urinary scent markings. They also started to sing, at ultrasonic frequencies too high for the human ear to hear. Both of these behaviors are an indicator of increased sexual drive.

Image by Rama - Own work, CC BY-SA 2.0 Read the rest

Cuttlefish have an intuitive understanding of quantity are able to discern between close numbers like four and five. Here's how scientists made the finding: Read the rest

Sometimes, you need to start off your week with a dose of happy news. For instance, this video from the American Museum of Natural History details two recent instances where scientists have observed a whale and several dolphins interacting in ways that are something we might classify as "play".

It's hard to talk about animal behavior without getting too anthropomorphizing, but think about it this way: In both instances, the whale and dolphins did not appear to be competing with other, they did not appear to be fighting, nor were they cooperating in a goal-oriented way. When scientists say "animals are playing" they don't necessarily mean "play" the way human children play, but they do mean behaviors that go beyond simple eat/sleep/defend/breed necessities. Play might be learning. Play might be about forming social bonds that help an individual later on. And however you interpret it, spotting examples of spontaneous, inter-species play in the wild is kind of a big deal.

And now, with those caveats out of the way, I'd like to highlight the top comment on YouTube, by one Bill Kiernan: "We both used to be land animals, isn't that crazy? clearly we need to hang out."

Video Link

Via Charles Q. Choi Read the rest