How Baby Poison Frogs Could Escape Cannibalism

Siblings can be annoying, but for young splash-back poison frogs, they’re also deadly. If placed in the same pool, tadpoles of this species will gladly eat their brothers and sisters.

Now a new study suggests tadpoles have a way to escape their cannibalistic kin: Hitchhiking on the backs of adults.

Female poison frogs usually lay their eggs above water-filled plants, such as bromeliads. When the eggs hatch into tadpoles, prudent fathers often turn up and carry their hatchlings to different plant pools, one by one, so that their offspring won’t eat each other as they develop into colorful adults.

Read more at National Geographic. 

Darwin’s finches have nothing on these chameleons

When it comes to eating hard-shelled bugs, the wildly varied species in the Bradypodion genus of dwarf chameleons have evolved an incredible array of a special part for doing the work: their heads. Scientists long wondered why these closely related South African lizards had such diverse noggins—some wide, some tall, and some covered with scaly head or chin frills. So they looked at the diets of 14 of the 17 known chameleon species, and compared them with the lizards’ head type.

Read more at Science.

Bears are bigger killers than thought, gruesome video footage reveals

The scenes start out innocently enough, often with a springtime stroll through Alaska’s Nelchina River Basin. But without warning, things turn grim: tableaus of blood and gore, usually with an unlucky caribou calf at the center.

Such is the video footage collected by scientists over 3 years from cameras strapped around bears’ necks, offering the first “bear’s eye view” of life in this bucolic but harsh reserve. One of the team’s main findings: These bears kill a lot more than we think they do. A whole lot more.

“It was really exciting because it’s the kind of thing you know occurs,” says Christopher Brockman, a wildlife biologist with the Alaska Department of Fish and Game (ADFG) in Palmer and lead author of the study.

Read more at Science. 

Poaching Isn’t the Cheetah’s Only Problem

Ehsan Moqanaki once spent two years taking pictures of a cat. It wasn’t just any cat, though: It was an Asiatic cheetah, a critically endangered mammal that used to roam across lands spanning from India to Turkey and the Arabian Peninsula. In a camera-trap study published in 2010, Moqanaki and other researchers set up cameras over miles of territory in Iran’s Kavir National Park and Kavir Protected Area to try to track the number of these rare felines left in the region.

What they found was 18 photos of the same male cat, sometimes nearly 40 miles between camera trap stations. That was surprising, because the ungulate-rich region should have been great territory for the graceful and speedy cats. But Moqanaki, a researcher with the Iranian Cheetah Society and the lead author of a study recently published in Animal Conservation, suspects that the cheetah population has dwindled over time in the Kavir areas due to a lack of connectivity.

Read more at Smithsonian Magazine.

Meet Eight Species That Are Bending the Rules of Reproduction

When it comes to getting creative in the bedroom, we humans may think we’re the experts. In fact, we’ve barely scratched the surface of how varied and multifaceted reproduction can be—just look at species that do the deed through kinky-sounding strategies like sperm sequestration, “virgin births” via cloning or even hybridizing with other species. These may sound like show plots of a new series on the Space Channel, but they’re actually just some of the many tricks that Mother Nature uses to stay a few steps ahead of Cosmopolitan Magazine‘s sex tips.

Moreover, some of these unconventional methods are making scientists rethink the basic tenets of reproductive biology, says Ingo Schlupp, a professor of biology at the University of Oklahoma. His study subject, the asexual Amazon molly fish, defies the so-called rules of reproduction by making perfect clones of itself, sans males. With such a lack of genetic diversity, these finger-sized fish should have been wiped out by disease long ago, Schlupp points out.

Read more at Smithsonian Magazine.

Tracking the Scars of Dolphin-Shark Battles

Shark versus dolphin is an epic oceanic battle—pitting brain against brawn, social cooperation against rugged individualism. But while the war has likely run for millions of years, the skirmishes are fleeting, brief, and rarely witnessed.

“They happen so quickly that our chances of seeing them are low,” says Michael Heithaus, a marine ecologist at Florida International University who’s spent years in the water among dolphins and sharks. “I’ve seen one direct interaction in my life,” he says, describing a scene in Western Australia’s Shark Bay when a great white swam toward a pod of dolphins that scattered when they sensed the impending threat.

Read more at Hakai Magazine.

Arctic Search-and-Rescue Missions Double as Climate Warms

Joe Karetak heard broken propeller shrapnel whiz through the air as the blade of the sinking helicopter—sent to rescue him and his son, Joe Jr.—hit the ice. The chopper crashed into the floe somewhere outside the hamlet of Arviat on the western shore of Hudson Bay in Nunavut, Canada, a long way from everywhere. The pilot was frantically trying to get out of the cockpit. Twenty feet across the open water created by the crash, Karetak was powerless to help. He had already spent nearly 24 hours lost in a boat in the Arctic Ocean, and adrift on an ice floe, in frozen clothes at minus 70°F.

“This can’t be happening,” thought the Inuit hunter, then 53 years old. “This is just unbelievable.”

The pilot managed to kick open the door and started swimming through the water toward him. Karetak reached out his harpoon and pulled the man onto the ice. He immediately wrapped him up in a parachute and sleeping bags, trying to save the man who had come to rescue him and his son. “I tried to heat him up with my body, talking with him to keep him from shock,” Karetak says.

Read more at National Geographic Adventure.

Cottonmouths Attack When They’re Stressed Out in Life

Stress can put anyone on edge, and venomous snakes are no exception.

New research suggests that habitat loss, climate change, and other human-driven environmental stressors prompt cottonmouths to attack people more often than they otherwise would—a finding that turns a longstanding depiction of the snake as malicious aggressors on its head.

Read more at The Atlantic.

Drilling Deep: How Ancient Chinese Surgeons Opened Skulls and Minds

Near the beginning of the 3rd century in ancient China, Han Dynasty leader Cao Cao is said to have called upon a famous doctor named Hua Tuo to treat a headache. Cao Cao had received said headache from a hallucinatory dream that occurred after attacking a sacred tree with his sword, according to the classic 14th century historical novel Romance of the Three Kingdoms.

Hua Tuo, known today as the father of Chinese surgery, was already famous for treating a number of other patients successfully. Historical accounts credit him for his fame with acupuncture, surgery and for the use of an herbal drug mixture (possibly including marijuana or opium), which made him one of the first known doctors in the world to use anesthetics. The surgeon took the warlord’s pulse and determined a tumor was to blame. Then Hua Tuo made his best medical recommendation: Cao Cao needed to get a hole drilled in his head.

Read more at Smithsonian Magazine. 

Castaway Ghost Spiders Flew to Robinson Crusoe Island

Arachnophobes might be shocked to learn that some spiders can fly hundreds of miles across the ocean.

Two million years ago, airborne arachnids colonized remote Pacific islands by ballooning, a technique in which spiders use their silk as a kind of kite that can carry them long distances. (Read about spiders that can fly without silk—and steer in midair.)

These so-called ghost spiders likely landed on Robinson Crusoe Island (map), roughly 400 miles off Chile, where they blossomed into several new species. And now scientists have identified at least three previously unknown to science, a new study says.

Read more at National Geographic.