A Moment of Science

Older Dinosaur Herds 

George Washington Comes Out Right Side Up 

Whiskers, the Shameless Freeloader      

Hurricane Damage That Lasts 

Is Earth Getting Dimmer? 

Juiced Up 

The Elusive Beaked Whale 

14,400-year-old Bread 

Too Warm or Too Cold to Fly 

Eye Movements and Personality 

Shark Tourism 

Can Lightning Strike You in the Shower? 

Moth Wingtips Confuse Bat Radar 

Elephants Smelling Far Away Food 

Modern Biology in a Monastery Garden 

If a river has a chance, it will meander, winding over the land in a series of loops. Geologists even call these loops "meanders."You can see meanders on a map--along the lower Mississippi, the Alabama River near Selma, The Arkansas near Tulsa, the Ohio near Evansville, and on thousands of smaller streams--wherever there's a steady flow of water over nearly flat land of fine-textured soils.Rivers meander because any small bend in a river tends to grow.Water flowing around a bend in a river is a little like a car speeding around a bend in a road. The water is thrown toward the outside of the turn. That fast-moving water erodes the riverbank on the outside of the bend.Meanwhile, on the inside of the bend, the water flows more slowly. Sediment held by the water can settle out and accumulate along the inside bank.So the water eats away the outside of the bend while it builds up the inside of the bend. The bend in the river grows into a big loop.When the loop gets big enough, the water cuts across the narrowest part of the loop and starts the meandering process all over again. The cut-off loop becomes an oxbow lake.A meandering river often alters its course. Mark Twain, in his book Life on the Mississippi, says that steamboat pilots of his day traveled up and down the river even when they weren't working, just to keep track of the latest changes in the course of the water.Read more How geodes form in the Middle West What's the history of the Jordan River? Earth's climate history Sources Scientific American - River Meanders Geology Illustrated - Armchair Field Experience Fredrick Lutgens, Edward Tarbuck - Essentials of Geology

Hummingbirds have a voracious appetite for nectar, the sugary fluid secreted by flowers. To survive, they usually drink between five and fourteen times their weight in nectar every day. Finding all that nectar isn’t easy. Some flowers may have already been emptied of nectar by other visitors, or might be occupied by dangerous insects such as ants.Biologists want to understand how hummingbirds use their senses to find the right flowers to feed at. They have long known that these tiny birds can locate flowers by vision. Although vultures are known to use the sense of smell to detect the corpses of dead animals, smell didn’t seem to play a role in the foraging behavior of hummingbirds. Earlier studies, for example, found no evidence that hummingbirds could use smell to tell whether or not a flower contained nectar.In 2021 a team of researchers from California published the first evidence that hummingbirds do use smell to avoid danger. The researchers showed that hummingbirds could detect and avoid the smell of a chemical secreted by Argentine ants to attract other ants, and the smell of a defensive chemical released by some other ant species. The researchers allowed more than one hundred hummingbirds to choose between two feeders. One contained sugar water alone, and the other contained sugar water scented with one of the ant chemicals. The hummingbirds specifically avoided the chemicals secreted by dangerous ants, but didn’t avoid harmless smells. They ignored the scent of a common food additive not found in nature, and the smell of European honeybees.The finding helps biologists better understand how animals use their senses during the complex task of foraging for food.Reviewer: Danielle J. Whittaker, Michigan State UniversityRead more How do birds navigate migration? Do hummingbirds hibernate? The duality of hummingbird bills Sources ScienceDaily - Hummingbirds can smell their way out of danger Treehugger - Hummingbirds are able to smell danger StudyFinds - Nose knowledge: Hummingbirds use sense of smell to avoid danger SciNews - Hummingbirds use sense of smell to make foraging decisions; study Ornithology - Hummingbirds and nectar Behavioral Ecology and Sociobiology - What is that smell? Hummingbirds avoid foraging on resources with defensive insect compounds

Have you ever wondered why some cuisines, like Indian and Thai, are so spicy and others, like English, are so bland?India and Thailand are very hot countries, while England is cold and damp. The answer does have something to do with the climate associated with each cuisine, but maybe not in the way that you'd first think.You might wonder why would you want to eat spicy food when it's hot outside in the first place. Does it cool you off by making you sweat more? While that's an interesting theory, there are a few better explanations. The first one is that spices mask spoilage, and in a country with a hot climate and without refrigeration, that can come in handy.For the second theory, some scientists suggest that the spices in hot cuisines help protect humans from certain kinds of bacteria found in food. In fact, the hotter the country, the more likely it is that its recipes will use the kind of spices that slow down the growth of bacteria.For example, onion, garlic, oregano, and allspice alone all kill or inhibit up to twenty-nine different kinds food-borne bacteria. In fact, most spices inhibit bacteria to some extent. And if you think about it, this makes sense. As plants evolved, they had to learn to fight off parasites and bacteria in order to survive. That's how they got their distinctive flavoring in the first place.All this talk about food is making me hungry.Read more Cool down with a hot drink on a hot day Earth Eats - Cooking up food and identity in Palin Chongchitnant's "Hot Thai Kitchen" Earth Eats - Here's why the smell of pumpkin spice moves us, according to science SourceWhy Files - The Spice of Life

What legendary creatures of the deep fill you with wonder? The squid-like kraken, able to tear ships pirate apart with its tentacles? Or the megalodon, an enormous shark from millions of years ago? Or sirens, mermaids who lure sailors to their death?These monsters haunt old stories of the ocean. We’re fascinated by their supernatural mystery. And perhaps no epic animal of lore enchants, inspires, and awes like the mighty dragon.  Science hasn’t discovered any giant, flying, fire-breathing lizards quite yet. But if we look very carefully off Australia’s southern coast, we can find a creature straight from a maritime fairy tale: the leafy seadragon.Of course, it might take a good long look to actually find any leafy seadragons. While not mythical like their namesakes, these foot-long fish are masters of camouflage, able to blend in with the kelp and other seaweed of their habitat.Leafies, as they’re affectionately nicknamed, have long, undulating bodies, reminiscent of their relatives the seahorse. If you’re lucky enough to spot one, you’ll notice around twenty delicate, leaf-like appendages extending from their ribs and backbone, gently wafting in the water. As they swim, they create the illusion of floating seaweed. Shallow water leafies are often yellow or olive toned, while deep water leafies tend to be dark brown, or rich burgundy.Their hypnotizing, magical appearance makes leafies a favorite of aquariums worldwide. In the wild, however, leafy seadragons are listed as near threatened, possibly due to over-capture and habitat loss. Will the beautiful leafy seadragon soon be reduced to myth? Conservation efforts bring together science and enchantment to save a real-life dragon.Reviewer: Greg Rouse, the Scripps Institute of OceanographyRead more Camouflage is not infallible The hidden benefits of marine biofluorescence Long-lived sea species Sources Aquarium of the Pacific - Leafy Seadragon National Geographic - Leafy Seadragon Oceana - Leafy Seadragon

If you’ve seen a grove of quaking aspen, you’ll recall trees with smooth, grey-white bark fissured with black streaks and flat leaves of green and yellow that shimmer with the lightest breeze.A forest canopy of quaking aspen is often dense where sunlight is plentiful because they’re intolerant of shade. This growing pattern allows quaking aspen to colonize large swaths of land, with individual trees of fairly uniform arrangement, size, distribution, and health quality. We call this community of trees a “stand.”A stand of quaking aspen may account for an extensive plot or just a minor part of a larger forest, sure to crowd out conifers or shrubs that attempt to invade its space. When one aspen tree falls, often another will quickly take its place and sprout from its roots, rather than a seed. Aspen grow aggressively and take advantage over shade-loving plants to repopulate their own stands. While relatively few of its seeds will become established, an aspen can regenerate individual trees by shoots along its long, lateral roots. A single root system can reproduce hundreds of individual trees in this way—each one genetically identical to the parent tree. A group of aspens with a single root system is called a “clone.” Clones can be less than an acre or up to 100 acres in size. These single organisms become immense and live much longer than any one tree could.Individual aspen often don’t live beyond 150 years or so; while a clone can live for generations. The Pando Clone of Utah is one prime example, having outlasted its conifer competitors for the span of many eras.Read more The bizarre life of the pyrosome The sex lives of reindeer lichen Trees know when something's eating them Sources U.S. Forest Service - How aspens grow U.S. Forest Service - Aspen ecology Wikipedia - Populus tremuloides