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Peacocks, panther chameleons, scarlet macaws, clown fish, toucans, blue-ringed octopuses, and so many more: The animal kingdom has countless denizens with extraordinarily colorful beauty. But in many cases, scientists know much more about how the animals use their colors than about how they make them. New work continues to reveal those secrets, which often depend on the fantastically precise self-assembly of minuscule features in and on the feathers, scales, hair, and skin—a fact that makes the answers intensely interesting to soft-matter physicists and engineers in the photonics industry.

Many of the colors seen in nature, particularly in the plant kingdom, are produced by pigments, which reflect a portion of the light spectrum while absorbing the rest. Green pigments like chlorophyll reflect the green part of the spectrum but absorb the longer red and yellow wavelengths as well as the shorter blue ones. Which specific wavelengths get reflected or absorbed depends on the pigment’s molecular makeup and the exact distances between the atoms in its molecular structures.

Because plants are masters of biochemical synthesis, their cells can concoct many types of pigments, but animals by and large have lost the metabolic pathways to make most of them. Melanin, the predominant pigment in animals, is either brown (eumelanin) or reddish yellow (pheomelanin)—a rather limited palette. To make the richer rainbow of colors they need for decorating and disguising themselves, courting mates and warding off predators, many animals can obtain the needed pigments from their diet. Birds’ bright reds and yellows, for instance, mostly come from carotenoid pigments in their food.

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Fossil records show that roughly 90 percent of the planet's open-ocean sharks inexplicably vanished.


Sharks are some of nature’s greatest survivors. For more than 400 million years, the marine predators have plied Earth’s waters, from shallow reefs to the heart of the open ocean. Sharks are older than the oldest fossil forest. They’ve made it through at least four mass extinctions.

And yet, 19 million years ago, something mysteriously dealt open-ocean sharks a huge blow—one from which they’ve never recovered.

Records of this extinction, detailed for the first time in the journal Science, come in the form of shark scales, called denticles, found in seafloor samples from the Pacific Ocean. Based on the shapes and abundance of denticles in the samples, the researchers estimate that the planet’s open-ocean shark populations suddenly and inexplicably fell by more than 90 percent. By contrast, during the extinction event that killed off the non-avian dinosaurs 66 million years ago, sharks suffered losses of roughly 30 percent.

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What's your favorite thing about puppies? Is it their cute yawns, wiggly bottoms or the sweet way they lick your nose? Or maybe it's those doleful eyes that stare into yours as if they know what you are thinking.

Whatever it is, rest assured that puppies are primed to communicate with you soon after their birth, says Emily Bray, a post-doctoral research associate at the Arizona Canine Cognition Center at the University of Arizona's School of Anthropology.

"Puppies will look at and return a person's social gaze and successfully use information given by that person in a social context from a very young age, all prior to any extensive experience with people," Bray said.

Bray has been studying guide dog development for the last decade in collaboration with Canine Companions, a nonprofit organization that provides dogs at no charge to adults, children and veterans with physical or cognitive disabilities.
The pool of service dogs is an excellent one for research because they often have known pedigrees going back multiple generations and are raised and trained in very similar ways. That gives researchers more options to determine how much of a dog's behavior is due to genetics versus environment or training.

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Populations of the insect, which once swarmed across the United States on their annual migrations from Mexico to Canada, have fallen off a cliff over the last century. California’s butterflies are on the brink of extinction, while eastern monarchs, which fly up the Great Plains or over to Maine, have declined 80 percent.

In their winter habitats in the mountains of northern Mexico, the monarchs cluster together so tightly that their populations are tabulated not by the number of individual butterflies, but by the total area they cover. The long term restoration goal for the eastern monarchs is a stable winter population of 6 hectares—an area of about 11 football fields.

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Most Uber drivers need a smartphone to get to their destinations. But sharks, it seems, need nothing more than their own bodies—and Earth’s magnetic field. A new study suggests some sharks can read Earth’s field like a map and use it to navigate the open seas. The result adds sharks to the long list of animals—including birds, sea turtles, and lobsters—that navigate with a mysterious magnetic sense.

“It’s great that they’ve finally done this magnetic field study on sharks,” says Michael Winklhofer, a biophysicist at the Carl von Ossietzky University of Oldenburg in Germany, who was not involved in the study.

In 2005, scientists reported that a great white shark swam from South Africa to Australia and back again in nearly a straight line—a feat that led some scientists to propose the animals relied on a magnetic sense to steer themselves. And since at least the 1970s, researchers have suspected that the elasmobranchs—a group of fish containing sharks, rays, skates, and sawfish—can detect magnetic fields. But no one had shown that sharks use the fields to locate themselves or navigate, partly because the animals aren’t so easy to work with, Winklhofer says. “It’s one thing if you have a small lobster, or a baby sea turtle, but when you work with sharks, you have to upscale everything.”

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Environmental groups have accused a prince from Liechtenstein’s royal family of shooting and killing the largest bear in Romania, in contravention of a ban on the trophy hunting of large carnivores.

The Romanian NGO Agent Green and the Austrian NGO VGT alleged in a statement that the bear, who was called Arthur, was shot in March in a protected area of the Carpathian Mountains by Prince Emanuel von und zu Liechtenstein.

According to the NGOs, the prince, who is a resident of Riegersburg in Austria, had been given special approval by the Romanian environment ministry to shoot a female bear that had been causing damage to farms in Ojdula.

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Like members of a street gang, male dolphins summon their buddies when it comes time to raid and pillage—or, in their case, to capture and defend females in heat. A new study reveals they do this by learning the “names,” or signature whistles, of their closest allies—sometimes more than a dozen animals—and remembering who consistently cooperated with them in the past. The findings indicate dolphins have a concept of team membership—previously seen only in humans—and may help reveal how they maintain such intricate and tight-knit societies.

“It is a ground-breaking study,” says Luke Rendell, a behavioral ecologist at the University of St. Andrews who was not involved with the research. The work adds evidence to the idea that dolphins evolved large brains to navigate their complex social environments.

Male dolphins typically cooperate as a pair or trio, in what researchers call a “first-order alliance.” These small groups work together to find and corral a fertile female. Males also cooperate in second-order alliances comprised of as many as 14 dolphins; these defend against rival groups attempting to steal the female. Some second-order alliances join together in even larger third-order alliances, providing males in these groups with even better chances of having allies nearby should rivals attack.

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The ancient Egyptians are famed for their fondness of all things feline. There's no shortage of cat-themed artifacts — from larger-than-life statues to intricate jewelry — that have survived the millennia since the pharaohs ruled the Nile. The ancient Egyptians mummified countless cats, and even created the world's first known pet cemetery, a nearly 2,000-year-old burial ground that largely holds cats wearing remarkable iron and beaded collars.

But why were cats so highly valued in ancient Egypt? Why, according to the ancient Greek historian Herodotus, would the Egyptians shave their eyebrows as a mark of respect when mourning the loss of a family cat?

Much of this reverence is because the ancient Egyptians thought their gods and rulers had cat-like qualities, according to a 2018 exhibition on the importance of cats in ancient Egypt held at the Smithsonian National Museum of Asian Art in Washington, D.C. Specifically, cats were seen as possessing a duality of desirable temperaments — on the one hand they can be protective, loyal and nurturing, but on the other they can be pugnacious, independent and fierce.

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A big event in the insect world is approaching. Starting sometime in April or May, depending on latitude, one of the largest broods of 17-year cicadas will emerge from underground in a dozen states, from New York west to Illinois and south into northern Georgia. This group is known as Brood X, as in the Roman numeral for 10.

For about four weeks, wooded and suburban areas will ring with cicadas' whistling and buzzing mating calls. After mating, each female will lay hundreds of eggs in pencil-sized tree branches.

Then the adult cicadas will die. Once the eggs hatch, new cicada nymphs fall from the trees and burrow back underground, starting the cycle again.

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Tiny holes in three fossil clams reveal that by 75 million years ago, ancient octopuses were deviously drilling into their prey. The find pushes evidence of this behavior back 25 million years, scientists report February 22 in the Biological Journal of the Linnean Society.

The clams, Nymphalucina occidentalis, once lived in what is now South Dakota, where an inland sea divided western and eastern North America. While examining the shells, now at the American Museum of Natural History in New York, paleontologists Adiël Klompmaker of the University of Alabama in Tuscaloosa and AMNH’s Neil Landman spotted telltale oval-shaped holes. Each hole was between 0.5 and 1 millimeters in diameter, thinner than a strand of spaghetti.

A modern octopus uses a sharp ribbon of teeth called a radula on its tongue to drill a hole into thick-shelled prey — useful for when the shell is too tough for the octopus to pop apart with its suckers. The octopus then injects venom into the hole, paralyzing the prey and dissolving it a bit, which makes for easier eating. Octopus-drilled holes were previously found in shells dating to 50 million years ago, but the new find suggests this drilling habit evolved 25 million years earlier in their history.

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Pigs have a "remarkable” ability to learn how to play video games — an ability that's nothing to be snorted at. The pigs are unlikely to be taking home an E-sports trophy anytime soon, but their aptitude for learning this skill has highlighted their surprisingly high level of intelligence and cognitive flexibility.

Their exploits were recently the subject of a study in the journal Frontiers in Psychology. The research saw two Yorkshire pigs, named Hamlet and Omelette, and two Panepinto micro pigs, Ebony and Ivory, being taught how to play a simple video game. The pigs were trained to move a joystick with their snouts in front of a computer screen. If they successfully moved the pointing using the joystick toward one of the targets on the screen, they were rewarded with a snack. Even once the pigs stopped receiving the reward, they were able to complete tasks using only verbal and touch cues.

The researchers, who have previously explored the depths of chimpanzee cognition, described their ability to pick up this skill as "remarkable."

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The number of wild bee species recorded by an international database of life on earth has declined by a quarter since 1990, according to a global analysis of bee declines.

Researchers analyzed bee records from museums, universities and citizen scientists collated by the Global Biodiversity Information Facility, (GBIF) a global, government-funded network providing open-access data on biodiversity.

They found a steep decline in bee species being recorded since 1990, with approximately 25 percent fewer species reported between 2006 and 2015 than before the 1990s.

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