Transcript

2.19.26 · Science Show KY

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Speaker 1: This is radioi's Diary of Science and Nature. I'm Kelly Taylor.
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I'll be your reader with stories related to science and nature.
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But first a reminder that RADIOI is a reading service
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intended for people who are blind or have other disabilities
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that make it difficult to read printed material. We'll start
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off today with an article from Scientific American dated February sixteenth.
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Celebrate the Year of the Horse with equine science. The
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new moon on February seventeenth marks the start of the
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lunar New Year, which is celebrated in many Southeast and
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East Asian countries. According to the Chinese zodiac, It's also
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the start of the year of the Horse, offering a
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perfect excuse to Winnie about the science of horses and
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their animal relatives. Domestic horses are the most famous members
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of the genus Equus, which also includes a wild relative
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called the Rswalski's horse, in addition to three species of
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asses and three species of zebras. All trace of their
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roots to North America, which was home to the very
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oldest known horse relatives up to fifty five million years ago,
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but horses went extinct on the continent at the end
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of the last ice age. Modern equids all hailed from
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Africa and Eurasia, where domestication also occurred. The development changed
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history for humans and horses alike. Horses carried many civilizations
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to their heights, only to find themselves something of an
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anachronism in modern society. Tellingly, scientific investigation into horse behavior
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is mere decades old, says Sue MacDonnell, an equine behavioral
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scientists at University of Pennsylvania's School of Veterinary Medicine. Scientific
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Americans spoke with McDonald and Sarah King, a behavioral ecologist
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at Colorado State University who specializes in horses and other equids,
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to highlight some of the most interesting science around these years.
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Star animals. Domestic horses have three basic needs, freedom, forage,
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and friendships with other horses. That's because the social nature
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of these animals runs very deep. Turn horses loose and
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something remarkable happens, McDonald says, they immediately reassemble in the
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social structure that they had when they first when we
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first domesticated them. She says, in that structure, each herd
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includes several so called harems, consisting of one stallion and
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a handful of mayors and their offspring plus a bachelor
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band of younger related males that faces down threats to
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the herd. Studies have shown that the stallions with the
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most folds are also the ones with friendly relationships with
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their mares, not those who rely on aggression and violence. Quote.
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Horse society really is held together by affiliative bonds. King
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says for domestic horse owners, hoofs are a headache. They're
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prone to splintering and require regular trimming and shoeing, But
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those problems only arise because of the hard surfaces domestic
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horses must walk on. Horses in the wild quote have
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zero problems end quote. McDonald says, and the hoofs of
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these horses go through seasonal changes in response to local
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climate and surfaces. She notes, in spring and fall, horses
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tend to develop longer hoofs, which act like little skis,
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she says, to help animals navigate softer ground. In winter
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and summer, when the ground is harder and animals don't
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move as much, hooves naturally become shorter. Of the wild
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equid species, King is most worried about the critically endangered
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African wild asses that's Equis africanus, which live around the
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horn of Africa. Quote, they're in a very inhospitable environment.
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There's real deserts there, and of course there's a lot
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of political issues in that part of the world as well.
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She says. The animals are also hunted for food and
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medicine and must compete with the livestock for foraged food.
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In contrast, their distant cousins, the Praswalski's horses of Central
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Asia are rebounding after becoming extinct in the wild as
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of the nineteen sixties. After a careful program of breeding
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in the zoos. Scientists began reintroducing the horses to the
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wild in the nineteen eighties and now King notes some
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populations are fully self sustaining. They are a real conservation
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success story. She says horses really can smell human fear
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and won't surprise people who have dealt extensively with horses.
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But research published last month experimentally proves that horses can
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smell human fear. Quote. Our emotions are central when interacting
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with horses, said study author Ploteen Jardat, a horse behavior
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and welfare researcher at France's National Research Institute for Agriculture,
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Food and Environment. Better Research about exactly how human emotions
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affect horse responses is vital for animal welfare. McDonald says,
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For example, defensive behavior and a horse can easily be
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misinterpreted as aggression, and that can make people fearful, which
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the new research shows can further put the horse on edge,
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resulting in a tricky feedback loop. Horses have spent millennia
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evolving to avoid predators, and this has left them loathe
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to show signs of pain or weakness around humans, McDonald says.
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In recent years, veterinarians have begun trying to get around
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this by pouring through video footage to look for cues
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that a horse is ailing. Once a horse is alone,
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she says, you can detect a lot of subtle behaviors
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indicating discomfort, but it's not a quick technique. That's why
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McDonnell is working with artificial intelligence specialists to train a
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system that can skim through horse footage to hunt for
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the small cues veterinarians pick up on, but much faster
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than any human could. If cats mew and ducks quack,
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horses stereotypically nay, but they also winny and nicker and
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huff and squeal, and those noises have been for the
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most part overlooked. Quote. We're beginning to understand that there's
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probably a lot more communication going on in those noises,
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King says, quote. Understanding the context and what those noises mean,
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I think is really interesting in quote. Now turning to
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popular science, and the headline for this article is how
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do birds stay warm in winter? This is from February
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to tenth. You're at the park wearing a heavy winter coat,
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a beanie, gloves, a scarf, and warm boots, and you're
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still numb and shivering from the cold. Then you'll notice
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a robin hopping from branch to branch. Nearby ducks are
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calmly swimming in the pond and waddling around on the ice.
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How do birds survive such freezing conditions? Birds have a
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big advantage over us feathers in winter. Birds actually grow
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more feathers. Quote. Their feather density increases anywhere between thirty
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five to seventy percent in the colder months, says Ava Michelangelo,
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a teacher naturalist at the Connecticut Audubon Society. Quote. So
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just like how our attire goes from t shirts and
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shorts in the summer to jackets and long pants. In
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the winter, these birds go through a similar change. Birds
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have different kinds of feathers, and one type is especially
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important in cold weather, down feathers. These feathers are very
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fluffy and grow close to the skin, essentially acting like
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a thermal base layer. Quote. Of the several types of
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feathers birds possess, down feathers are excellent at trapping body heat,
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says Anna Pigeon, professor of Forest and Wildlife ecology at
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the University Wisconsin Madison. Unfortunately, this has also led to
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down feathers being used to stuff jackets, duvets, and other objects,
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although ethical brands now use synthetic insulation that mimics down.
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You might also notice birds looking extra round and fluffed
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up on cold days. Quote. What they are doing is
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trapping air between their feathers, which is then getting warmed
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by their body, explains Michelangelo. Birds also reduce heat loss
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by covering their featherless body parts, says Pigeon. For example,
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they might tuck their beaks into their back feathers or
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under their wings and squat down to cover their bare
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legs and feet. They might also stand on one leg
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with the other leg tucked up among their breast feathers.
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This reduces by half the surface area of bear skin
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exposed to the coal. When it gets extremely cold and windy,
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birds seek shelter, just like we humans do. Pigeon explains
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that some birds, like horned larks and snow buntings, hide
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behind small bumps in the ground to block the wind.
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Others like rock ptarmigen and grouse, burrow in the snow,
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using the snow as insulation. Quote. Some birds are lucky
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enough to have a suitable cavity within their winter area,
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for example, within a dead tree or one with a
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decaying branch, says Pigeon. Woodpeckers often sleep alone in these shelters,
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but smaller birds like chickadees, bluebirds, and tit mice sometimes
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huddle together inside cavities, taking advantage of each other's body heat.
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While many birds avoid winter altogether by migrating, the ones
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that stay behind are often specially equipped for cold weather quote.
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The birds that we see year round in Connecticut, like
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the beloved black capped chickadee, are species that do really
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well here in winter, says Michelangelo. Quote. They are constantly
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shivering to generate heat while searching for high fat foods
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like seeds. Shivering works the same way in birds as
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it does in people. Moving muscles burns energy, and that
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energy becomes heat. Ducks, gulls, and other water birds have
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an amazing trick too. On the days that the salt
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marshes frozen over, you'll still find these birds resting on
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the frozen ice, says Michelangelo. Water Birds also have very
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few pain receptors in their feet, so they don't experience
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the cold weigh a human wood if standing barefoot on ice.
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On top of that, they reduce heat loss using a
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process called counter current heat exchange. Heat from warm blood
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traveling down to the feet is transferred to cooler blood
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flowing back toward the body before it reaches the core.
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This way, the bird's core temperature doesn't plummet, yet the
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feet still receive enough oxygen to function. Research has also
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shown that goals can restrict the amount of blood going
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to their feet. Pigeon says this reduces the amount of
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body heat lost to the icy surface or water. Now,
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staying with Popular Science, we have an article this relates
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to the Winter Olympics. Headline is downhill skiing's biggest hurdle
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friction from February thirteenth. Every ski and snowboarding event at
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the twenty twenty six Winter Olympics is one through a
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combination of sheer athleticism, quick thinking, creativity, and persistence. But
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like so many other sports, competitors know their choice of
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equipment can mean the difference earning the gold or silver metal.
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A ski is built for function over form, and manufacturers
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have spent decades adapting and honing their products to ensure
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wearers get the best results. The fine tuning has very
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clear results too. If the nineteen sixty four Winter Olympic
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gold medalist for downhill alpine skiing faced off against every
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qualifying participant in the same event at the Beijing Games
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in twenty twenty two, Egon Zimmermann would have returned to
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Austria solidly in last place. While his antiquated accessories wouldn't
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be the only limiting factor, they would play a major
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part in his hypothetical humiliation. Aside from better made components,
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today's ski shapes are also dramatically different from their forebears.
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Quote The shape determined stability and the maneuverability of the ski,
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says Northwestern University physicist Stefan Couch, For example, racers will
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likely opt for straighter and lengthier skis if they anticipate longer,
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wider turns on a giant slalom. Faster and tighter pivots
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meanwhile necessitate shorter and often curvier footwear. But no matter
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the shape, racers must always account for one common physics
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denominator quote, It's all about the friction. The lower the
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friction coefficient is, the faster the person can go, said couch.
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Kinetic friction is an inevitable byproduct two objects sliding against
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one another. The molecular surface interactions are a response to
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exerted force, resulting in resistance and a reduction in speed. However,
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many people often misunderstand the implications of this. One may
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assume the trick to a record breaking alpine run is
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simply strapping on the thinnest equipment available, as less surface
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area means less friction. In actuality, it's more to do
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with a smooth ski than the width of the skis themselves.
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Quote Simply, the smoother the material is, the less granulated
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the surfaces, the lower the friction coefficient is, and the
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faster the person can go. Couch summarized to illustrate the
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concept couch used a pair of differently sized lego bricks.
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When sent down an inclined wooden board at the same time,
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both bricks reach the bottom simultaneously. The same result happens
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on a smoother plastic surface, but faster. While friction isn't
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the only influence on the slopes, it is definitely something
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at the top of a skier's mind, especially when they're
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staring down their race from the top of a very
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large hill. Now an article from New Scientist magazine, Amazon
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is getting drier as deforestation shuts down atmospheric rivers. This
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is dated January twenty seventh. Deforestation has reduced rainfall over
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the Amazon, suggesting the rainforest could reach a catastrophic tipping
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point sooner than expected. Satellite observations and rain gage measurements
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show that the amount of rain falling in the Southern
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Amazon basin declined by eight to eleven percent between nineteen
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eighty and twenty nineteen. Tree cover in that part of
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the Amazon shrank by sixteen percent in roughly the same period,
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mainly because the forest was slashed and burned for beef
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cattle ranching. The Northern Amazon basin has suffered far less
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deforestation and saw only a slight increase in precipitation, which
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was not statistically significant. While a research study linked deforestation
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to drier weather within three hundred kilometers, the new research
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found this connection across a basin more than three thousand
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kilometers wide. That shows destroying rainforest can also hurt nearby
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ranches and soy farms. Says Dominic Sprachlan at the University
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of Leeds in the UK, quote some people in agribusiness
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might see a bit of forest as wasted land. They
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could go clear. He says that bit of forest is
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working really hard to maintain regional rainfall, that our bit
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of agriculture is benefiting from. Global warming has also been
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drying the Amazon rainforest, with extreme drought leading to record
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wildfires in twenty twenty four, but atmospheric modeling by Sprackland
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and his colleagues showed deforestation caused fifty two to seventy
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five percent of the decline in rainfall. Prevailing winds transport
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moisture from the Atlantic Ocean that falls as rain over
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the Amazon. Evaporation and transpiration by plants return three quarters
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of that water to the atmosphere. Further downwind it falls
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as rain again and returns the atmosphere for half a
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dozen cycles or more, fueling flying rivers that's in quotes
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that carry moisture across the entire rainforest. If an area
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of fourths is raised, more than half of the rainwater
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in that area runs off into streams and begins flowing
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back to the ocean. That starves the flying rivers of
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moisture and red uses rainfall. It also diminishes the atmospheric
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instability that leads to storm cloud formation. Spracklin and his
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colleagues sound with fewer trees to slow it down, the
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wind blows faster and carries more moisture out of the region.
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Unlike past research, the study marries both data and modeling
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to explain exactly how deforestation weakens rainfall. Quote. The atmosphere
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becomes smoother in some ways, it glides, the moisture can
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travel further out of the forest region because there's less
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friction on the ground, says Yad Vendor Molly at the
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University of Oxford. So there's some interesting secondary atmospheric processes
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that aren't normally captured in quote. Scientists are concerned that
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the combined effects of heat and deforestation could push the
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Amazon to a tipping point that sees it transform into
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a savannah, but there is uncertainty on how close this
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is to happening. Spracklin and his colleagues found that climate
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models underestimate the impact of deforestation on rainfall by up
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to fifty percent, which suggests the rainforest could reach this
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tipping point much sooner than expected. A study last year
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found a thirty seven percent chance of some Amazon dieback
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by twenty one hundred if global warming, which currently stands
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at one point four degrees reaches one point five degrees celsius.
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While that wouldn't be necessarily wouldn't necessarily mean the forest
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will turn to savannah, it would mean a shrubbier forest,
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holding fewer species and less carbon. Sprackland says, quote, the
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Amazon is more sensitive than we think, which is bad news.
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He says, maybe we're closer to a deforestation threshold than
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we thought, but I think there's a lot of uncertainty now.
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From the Washington Post, we have an article headlined why
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changes in a Florida Ocean current could wreak havoc worldwide,
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dated February fifteenth. This is written by Kasha Patel at
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two am oceanographer Ryan Smith was headed into his twelve
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hour of work with little sleep when trouble started. From
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the rear deck of the University of Miami's research boat,
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he guided the vessel's winch to lower a cage containing
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fourteen long gray tubes, collectively weighing about one thousand pounds
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hundreds of meters deep into the Atlantic Ocean to record
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the temperature, salinity, and density of the water. But after
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running smoothly for the first two thirds of the trip,
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the sensors now suddenly stopped transmitting data. There was no
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time for a hiccup. With urgency mounting, Smith signaled to
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bring the cage to the s at C. There is
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no helpline to call for a broken instrument at this
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hour or any hour. If the team couldn't fix it,
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they would need to make a twelve hour slog back
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to Miami through the fast moving Florida Current, the precise
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subject they were trying to measure. For forty three years,
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scientists have been studying the strength of the water flow
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between Florida and the Bahamas to learn what drives its
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changes over time. The information could help scientists answer a
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pressing question. Is the Florida Current, one of the world's
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fastest ocean currents, slowing down. If so, it could indicate
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weakening of the larger circulation system in the Atlantic Ocean,
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what scientists call the Atlantic Maridonial I'm sorry, yeah, meridional meridional.
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There we go, the Atlantic meridional overturning circulation, the AMOC,
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which could be disastrous. Even Hollywood has imagined the harm
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they could result from a collapse of this system of currents,
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which acts like a conveyor belt as it transports water, nutrients,
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and heat through the Atlantic. While scientists doubt the scenarios
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sketched out in the two thousand and four movie The
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Day After Tomorrow, in which the AMOC's failure prompts a
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calamitous of an ice age across the Northern Hemisphere, researchers
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say rain patterns could change or fail in Southeast Asia
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and parts of Africa, disease may spread to new populations,
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and temperatures would probably drop across Western Europe. Iceland has
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even declared that the risk of such a collapse is
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a national security threat, but climate scientists are at odds
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over how soon or whether the circulation system may weaken
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Researchers largely agree that the AMOC may weaken over this
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century as the world warms, but they differ on whether
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the system is already slowing down. Direct observation of the
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AMOCS and the Florida Currents flow, velocity, temperature, and salinity
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could help clarify this. The Florida Current, which helps shuttle
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water north, is a key component in calculating the system's strength.
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Traveling between Miami and the Bahamas accrue from the University
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of Miami and the National Oceanic and Atmospheric Administration. Honed
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in on the Florida Current, the world's longest nearly continuously
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observed ocean current. Over thirty six sleep drived hours, six
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researchers and seven crew members traversed the ocean, dove under water,
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and collected gigabytes of measurements. These expeditions gather data that
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generations of scientists can use to better understand the state
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of our oceans and humanity's future. For more than four decades,
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scientists have almost continuously measured water flow across the Florida Current,
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largely with the help of a decommissioned AT and T
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telemon munications cable running from West Palm Beach to Grand
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Bahama Island. The telephone line wasn't intended for ocean research,
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but Noah scientists noticed that it picked up tiny voltages
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induced by seawater flowing across the Florida Straits, which changed
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depending on the current's flow. Using direct measurements of the
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waterway from research cruises, scientists can convert the voltages into
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the volume of water carried each second through the strait.
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In two thousand and five, British oceanographer Harry Brydon tapped
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these cable measurements and the limited available ship measurements in
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a seminal paper that suggested a possible slowdown in the
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AMOC between nineteen fifty seven and two thousand four using
23:46
data across the Atlantic Basin. Today, scientists have found that
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the AMOC varies daily and seasonally. Yet it also appears
23:54
to have experienced a slight weakening over the past two decades.
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But is it on a long term climb because of
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human induced planetary warming debatable. The fourth the Florida Current
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is one of the main forces that make up the
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western boundary of the AMOC. The warm Florida waters feed
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into the Mighty Gulf stream, which merges with the warm
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North Atlantic current headed toward Europe. As the current reaches
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the Arctic, air temperatures cool the water, which becomes denser.
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The water sinks and moves south toward the equator, where
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it again is warmed by the sun and returns north. Quote.
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The role of the AMOC in the climate as is
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it carries a huge amount of heat from the Equator
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towards the poles, says Dennis Volkoff, who is a co
24:41
principal investigator of Noah's Western Boundary time series project. Along
24:46
with Smith, The scientists say a warming world is throwing
24:49
off this balance. As Arctic ice melts, fresh water enters
24:53
the North Atlantic, making the ocean water less dense, so
24:57
it is less likely to sink. As a result, scientists
25:00
propose that it cannot power the ocean conveyor belt as well,
25:05
so less salty warm water is getting transported northward. A
25:10
major shift in the Atlantic ocean circulation could create severe
25:14
drought in some areas and damaging floods in others. Sea
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level could rise by a foot or more along the
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US East coast if it collapsed. Scientists have typically used
25:25
data that indirectly hints at the current's movement, such as
25:29
sea surface or air temperature, to reconstruct the oceans in
25:34
models and track whether the overall system is weakening, but
25:38
they have reached mixed conclusions. For instance, a twenty eighteen
25:43
study plugged at sea surface temperatures into computer models to
25:47
show that the AMOC is weakening. Then a paper release
25:51
last January reported no evidence of weakening over the past
25:54
sixty years after examining data on heat exchanges between the
25:58
air and the ocean called air sea fluxes. Volkov and
26:04
his colleagues are being are helping approach the puzzle with observations.
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In twenty twenty four, they reassessed the cable data from
26:13
the Florida Current, adjusting for changes from Earth's geomagnetic field. First,
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they found that the current had remained stable over the
26:20
past four decades. Then they updated calculations of the AMOC
26:24
in this region, which has been monitored for over twenty
26:27
years or so, with the corrected data, and found that
26:30
the AMOC wasn't weakening as much as previously calculated at
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this latitude. Quote, but there is a caveat that observational
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data is very short, said Volkov. He said scientists would
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need another twenty years of AMOC observations to determine if
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the small decline is a robust feature and not part
26:50
of natural variability, and the AMOC can still weaken even
26:55
if the Florida Current remained strong, he said, since it
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is the sum of currents across the basin, but long
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term changes in the Florida Current can serve as an
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indicator of trouble for the rest of the system. One snag,
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said Volkov. The serendipitous cable that provided data for more
27:15
than forty years malfunctioned in twenty twenty three, perhaps broke
27:20
until it's fixed. Researchers are ramping up their diving operations
27:24
to recover data from underwater acoustic barometers on the ocean floor.
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When the research vessel departed from the university's dock around
27:32
four am on September third, the sun and most of
27:35
the science staff were down for the night. A few
27:38
shipmates gazed at the illuminated city scapes from the stern
27:41
deck next to the diesel engines deep rumble. After traversing
27:45
rocking waves, the crew reached scenic Bahamian waters eight hours later.
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The green F G. Walton Smith ninety sixteen long in
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Its crew make this overnight trip about six times a year,
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traveling ninety three nautical miles from Miami toward the Little
28:01
Bahama Bank. From there, they go west and collect data
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at nine sites from the boat and dive under water
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at two others. Well, that's all for today's Dire of
28:12
Science and Nature. Reader was Kelly Taylor. Now stay tuned
28:16
for further programming on RADIOI