Transcript

1.22.26 · Science Show KY

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Speaker 1: Hellob Kelly Taylor and I'll be your host for Radioized
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Diary of Science and Nature. Will have articles on those topics,
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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. From Gizmoto,
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the headline is the World's oceans soaked up record breaking
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heat for the ninth straight year, dated January tenth. It
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would take roughly three hundred sixty five million Hiroshima sized
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atomic bombs to release the amount of energy the world's
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oceans absorbed as additional heat in twenty twenty five. This
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figure stems from the latest report on the global ocean
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heat content, which found record high marine warming for the
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ninth year in a row. Five scientists who contributed to
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the report, published Friday in the journal Advances in Atmospheric
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Sciences warn that the continued trend is exacerbating extreme weather,
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sea level rise, and the destabilization of marine ecosystems. The
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main driver is unequivocally rising greenhouse gas emissions. They say,
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we're already seeing the catastrophic effect marine warming has on
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communities around the world, particularly through stronger storms and more
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severe flooding. The researchers point to a slew of deadly
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events in twenty twenty five, from the unprecedented monsoon range
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that killed more than thirteen hundred people across Southeast Asia
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to flash floods that killed at least one hundred and
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thirty eight people, including twenty seven young summer campers and
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councilors in Central Texas. Quote. In the long term, consistent
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with projection from state of the art climate models, global
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ocean heat content is expected to continue breaking records until
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net zero greenhouse gas emissions are achieved. The author's right,
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Earth's oceans act as its primary thermal energy sink, absorbing
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ninety percent of the excess heat trapped by greenhouse gases
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in the atmosphere. The thermal state of the ocean therefore plays
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an important role in regulating global and regional climate impacts,
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mainly through increased atmospheric moisture and energy availability, which fuel
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storm intensification. To calculate how much heat the world's oceans
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absorbed in twenty twenty five, the researchers measured temperature fluctuations
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in the upper sixty five hundred feet of the global ocean.
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They found that the ocean heat content was about twenty
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three zeta jewels higher than it was at the end
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of twenty twenty four, making twenty twenty five the hottest
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year on record in terms of HC. Roughly fourteen percent
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of the global ocean area reached its warmest state on
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record last year, particularly in the Southern Ocean, Tropical and
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South Atlantic Ocean, Mediterranean Sea, and North Indian Ocean. About
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one third the global ocean area ranked among its top
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three hottest years on record, and more than half ranked
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among its five hottest. This underscores the pervasive and accumulated
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nature of ocean heat gain. According to the researchers, that
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extra thermal energy is supercharging storms, but it's also speeding
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the already rapid melting of glaciers and sea ice. In
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twenty twenty five, Arctic sea ice extent reached the lowest
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annual maximum since satellite observation began, while Antarctic sea ice
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extent fell to its third life lowest annual maximum year
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to date. Observations also show that both the Greenland and
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Antarctic ice sheets reached record low mass levels, and new
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studies suggest portions of them have crossed critical climate tipping points.
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These findings indicate continued long term contributions to global sea
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level rise. Ocean warming poses a deadly threat to coral
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reefs as well. When seawater temperatures exceed the thermal tolerance
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threshold of these fragile organisms, they expel the symbiotic algae
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that provide them with nutrients and energy, resulting in bleaching.
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The world is currently in the midst of its fourth
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global coral bleaching event, according to NOAH. That's National Oceanic
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Atmospheric Association, with bleaching level heat stress impacting roughly eighty
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four percent above the world's coral reef area. Since twenty
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twenty three, mass coral bleaching has been documented in at
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least eighty three countries and territories. The researchers don't expect
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this nine year streak of record breaking marine warming to
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end anytime soon. Until the world achieves net zero carbon emissions,
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the global ocean heat content will continue to rise. We're
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nowhere near reaching that goal, but rapid emissions reductions can
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still limit future impacts. To better understand and prepare for
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these impacts, the authors stress the importance of strengthening ocean
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monitoring and uncovering the mechanisms behind ocean heat redistribution. These
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efforts will help communities around the world adapt to a
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new climate reality and build resilience. Now from BBC Wildlife.
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It once numbered in the millions and even blocked out
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the sun. So why did the passenger pigeons suddenly become extinct?
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This is from January twelve. The passenger pigeon, an extinct
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American bird, was once so common that it flew over
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the deciduous forests of eastern North America in flocks numbering
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in the billions. Passenger pigeons were about the size of
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Europe's stock dove and ate acorns, beech mast and chestnuts.
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Oaks and beeches produced bumper crops of seeds every few years,
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and those massed years are synchronized over large areas of forests,
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so the pigeons were nomadic and each year sought out
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those forests with greatest mast abundance. A pigeon that hatched
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on the East coast in New York State in a
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good year for acorns, there might next year nest farther
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inland where there was plentiful beech mast, perhaps in Michigan
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in the Great lakes region in between. It might have
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wintered well to the south in Georgia or Arkansas, where
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the autumn seedfall is not buried under deep winter snow.
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From hatching until death, a passenger pigeon was always within
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sight of thousands, possibly millions, of other passenger pigeons that
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nested in colonies of sometimes hundreds of millions of pears,
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fed in huge flocks that scoured the forest floor like
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living harvesting machines, and migrated as a group. Their winter
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roosts were so dense that to sheer weight of birds
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broke large branches off mature trees. It is very difficult
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for us to imagine this abundance, but many consistent accounts
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have survived until to day. The artist John James Audubon
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painted the species for his Magnificent Birds of America. He
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wrote of passenger pigeons as follows quote. The air was
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literally filled with pigeons. The light of noonday was obscured
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as by an eclipse. The dung fell in spots not
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unlike melting flakes of snow, and the continued buzz of
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wings had a tendency to lull my senses to repose
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Autubon estimated that over a billion birds passed in three hours,
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and there were many other credible accounts of immense flocks
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taking several days to pass that could have numbered more
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than three billion. Unless all of the passenger pigeons had
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gathered into a single flock for each of these observers,
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then we can only wonder at what proportion of the
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whole population they saw. Previous estimates indicated that there might
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have been three to five billion individuals in total, but
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I wonder whether it could have been even higher, perhaps
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touching to touching to billion after years of high productivity.
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Recent genetic studies, albeit based on only three individual museum specimens,
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suggest that passenger pigeons might have undergone large natural population swings,
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as would be expected from a species who food supply
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fluctuated wildly. But this genetic work has produced an estimate
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of about three hundred thousand birds for the average population
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size in historic times, that is, before hunting and habitat
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loss became intense, which is just one ten thousandth of
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the lowest nineteenth century estimates. So even if eyewitness accounts
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were exaggerated, they differ substantially from the genetic information do
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you believe the genetics or the ecology. It seems to
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me unlikely that a species whose largest recorded colony numbered
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over one hundred million birds at a time when it
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was highly persecuted and when its forest habitat had been
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greatly reduced, could have added an average population size of
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three hundred thousand in the absence of such persecution and
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in pristine forests. Something doesn't add up. Nevertheless, despite its
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population ups and downs, the passenger pigeon was still the
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most abundant bird the world has ever seen only decades
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before extinction. The last passenger pigeons were lost from the
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wild in nineteen hundred. The species lived on in captivity
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until the very last one, named Martha, died at Cincinnati
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Zoo at lunch time on September nineteen fourteen. There's really
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rarely just one reason why a species becomes extinct. For
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the passenger pigeon, the main factor was the loss of forests.
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About half of the USA's native forest was felled by
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eighteen seventy two for firewood house construction and to clear
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land for agriculture, thus removing half of the species habitat.
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But that's not the whole story. Young oaks and beeches
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produced few acorns and beech masts, so areas of forest
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with young trees, or areas where old trees were selectively logged,
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would have furnished less food too. The introduction of avian
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diseases might have played a role as well. The arrival
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of the house sparrow in North America, introduced from Europe
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to Brooklyn, New York, in eighteen fifty one, occurred at
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the very time of the passenger pigeons rapid decline in numbers.
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It's a factor that seems impossible either to prove or
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to rule out with certainty. Other animals shared the passenger
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pigeons taste for acorns, chestnuts, and beach masts. The forests
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were now scoured not only by the native wild turkeys, bears, jays,
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and a wide range of small rodents, but also by
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domesticated and feral pigs. Hog farmers noted that their animals
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starved if a multitude of pigeons descended on their woods,
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and there must have been some impact in the other direction.
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Forest pigs would have depleted the food supply of the
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passenger pigeons. This was no trivial matter. Cincinnati was at
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the center of the US port business and was even
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nicknamed Porkopolis. The most eye catching impact, though that does
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not make it the most important, was human exploitation. For centuries,
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Indigenous Americans removed passenger pigeons from nesting colonies according to
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strict rules, Adults were rarely taken, and harvest was of
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the fat, young pigeons or squabs, which were also tastier.
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Indigenous American bands would relocate to take advantage of the
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arrival of pigeons in their neighborhood, but the bird's superabundance
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swamped by swamped any impact of the small human population
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until Europeans invaded the continent between eighteen fifty and nineteen hundred.
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As pigeon numbers plummeted, the US human population soared more
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than threefold through immigration and a high birth rate. Many
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of these folk had rifles, and the invention of the
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telegraph and the spread of the railroad meant that people
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with guns could travel quickly to wherever the passenger pigeons
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were nest to plunder their numbers, and they did. The
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culling of passenger pigeons at their colonies provides a case
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study of unsustainable harvesting it took place at the time
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of year that would have the biggest impact on the population,
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reducing nesting success through disturbance as well as by the
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direct deaths of adults and squabs. This was uncontrolled plunder,
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and regulation eventually introduced by state legislatures was not enforced.
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Trees were felled to get at the nests, sometimes over
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one hundred per tree, and bark was set alite to
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make the young squabs flee their nests and fall to
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the ground. Passenger pigeons were trapped by various ingenious means
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and shot in their millions. Trainloads of barrels of pigeons
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were sent east to New York, Washington, and Philadelphia to
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restaurants and markets. The passenger pigeon was a valuable resource,
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but we wondered it. No longer can you order pigeon
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pie as a treat. No longer can you see the
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sky darken as the pigeon search for the forests with
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the most acorns and beach mast We drove the passenger
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pigeon to extinction with a combination of a growing human
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population conquering the American continent, better guns, easier travel, and
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improved communications. Perhaps we should reconsider what we mean by progress.
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Our next article is from Smithsonian Magazine. The headline reads,
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some dogs are gifted word learners that learn language by eavesdropping,
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just like human toddlers. This is from January thirteenth. Eavesdropping
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on their owners seems to help some highly gifted dogs
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learn new words, a complex cognitive and social ability that
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may put them on par with human toddlers. New research
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published this month in the journal Science suggests some canines
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are even smarter than previously thought. The findings also add
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to the growing body of work that suggests language may
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not be entirely unique to humans. Scientists and pet parents
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already know dogs can learn words like sit and stay,
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as well as their own names, but some special pups
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can also remember the names of specific objects, amassing large
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vocabularies for all the toys in their households. These pups,
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called gifted word learners, are relatively rare and seem to
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be able to remember labels for years. Most of the time.
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These gifted word learners seem to pick up the names
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of their toys through direct interactions with their owners, such
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as playing or training. But researchers wondered whether these prodigious
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pups might also be able to learn new labels in
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indirect ways, such as listening in on human conversations. To investigate,
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they recruited ten gifted word learners, four laboratory experiments, seven
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border colleagues, one Labrador retriever, one miniature Australian shepherd, and
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one Australian shepherd blue healer mix. In one experiment, the
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scientists asked the pup's human family members to discuss and
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handle a new toy, taking care not to interact directly
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with the pooch, which was watching nearby. The humans used
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the toy's name while passing it back and forth amongst themselves,
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saying things like this is your armadillo. It has armadillo ears,
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little armadillo feet, it has a tail like an armadillo tale.
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The researchers repeated these interactions over the course of several days,
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ultimately introducing each dog to two new toys for comparison.
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In another experiment, the researchers had the family members introduced
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new toys to the dogs directly. The owners repeated the
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names of the toys and allowed the canines to play
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with them. Later, the scientists placed the new toys along
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with nine other objects the pups were already familiar with
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in a room they then had the owners asked the
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dogs to retrieve particular toys by name. The pooches that
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had been introduced to the new toys directly performed slightly
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better than those who had only heard its name while eavesdropping,
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picking the right toy ninety percent of the time compared
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with eighty percent of the time, but the researchers say
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that statistically this difference is negligible. Additionally, seven of the
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dogs did better that than chance at picking the correct
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toy in both experiments. With some of the dogs, it's
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like they had no doubt about what they were supposed
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to be doing, says lead author Shaney Droer, a cognitive
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researcher and animal trainer now at the University of Veterinary
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Medicine in Vienna. They would just go into the room
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straight to the toy that they knew was the new toy,
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and then brought it immediately. When the researchers conducted similar
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experiments with typical family dogs that did not have robust vocabularies,
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none of those pups performed better than chance, which suggests
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the ability may be unique to gifted word learners overall. However,
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the researchers argue the study provides convincing evidence that some
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dogs can learn words from overheard speech, a skill that
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had previously been found in bonobo's and possibly African gray parrots.
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The behavior is also similar to how some eighteen month
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old children pick up new words. As any parent who
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has uttered a curse word when they thought their toddlers
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out of earshot, only to hear it repeated back to
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them can attest, this means the dogs have sociocognitive skills
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that are functionally parallel to human eighteen months o month olds.
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The researchers write in the paper quote the fact that
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the dogs can hear and overhear people passing an item
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back and forth and labeling it, and then pick up
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on that word means that they are attending to that conversation,
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says Heidi Lynn, comparative psychologists at the University of South Alabama.
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That's a pretty sophisticated attentional and cognitive leap that they're making.
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The findings make sense within the context of domestication. Historically,
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the dogs that were good at understanding and communicating with
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humans were the ones that had the best chances of
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surviving and passing along their genes to their offspring per
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CNN's Amarachi or The studies results may also hint at
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the evolutionary origins of language learning. Quote. The fact that
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this skill also exists in a species that does not
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have language suggests that the skill itself predates language, dwar
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tells The Guardian. So humans first evolved in ability to
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understand complex social interaction and only later used this complex
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understanding to develop language. Overall, outside experts were impressed with
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the study, but they also cautioned against making direct comparisons
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between dog and human language learning abilities. Quote. The interpretation
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in terms of word learning in the linguistic sense seems
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a little too strong for me, says Julianne Kaminski, a
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comparative psychologist, in university reports within England. Others noted potential
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limitations of the experimental setup. For instance, the pups who
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participated have been influenced by the laboratory environment. Frederic Razzano,
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a comparative cognition researcher who was not involved in the research,
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says Ortells in New York Times. Quote, I'm looking forward
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to seeing it replicated in maybe a little more controlled way,
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he says, adding that future studies could instead be conducted
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in the dog's home environments. Still, Drawer hopes the findings
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might encourage all pet parents to respect their poocha's social
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and cognitive abilities a little bit more. Quote. This can
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really give us more appreciation to how exceptional dogs can be,
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she tells the Washington Post. And now we'll go to
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popular science, and the headline for this article is why
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do elephants have such big ears? There's not one answer,
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date of January the second. It's a classic Disney moment Dumbo,
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the elephant jumps out of a burning building, spreads out
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his huge ears, and flies. While real life elephants can't fly,
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they certainly have enormous ears. The African elephant, for instance,
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has the largest ears of any animal. Their ears can
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grow up to six point six feet long and four
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point one point one feet wide, making up twenty percent
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of their body's total surface area. Why are elephant's ears
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so large. It's nothing to do with flying, of course.
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Elephant ears play a vital role in how they cool
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down and communicate. Elephants are the world's largest land animal,
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weighing a staggering twelve thousand pounds. While elephant's size is
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often an advantage when it comes to warding off predators
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or reaching high vegetation, it also makes it harder for
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them to stay cool. Their massive bodies produce a ton
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of internal body heat even when they're just standing still.
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What makes this an even bigger problem is their habitat.
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Elephants typically live in warm climates where there is a
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higher risk of overheating. US humans cool down by dispersing
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heat through long, narrow body parts like our legs and arms. Elephants, however,
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with their bulky bodies and thick legs, have relatively little
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skin surface to release all that built up heat. Unlike humans,
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elephants also don't really sweat. They have a few sweat glands,
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mostly between their toes that can release a small amount
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of moisture, but this only helps to cool them down slightly.
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They also can't pant like dogs, so they developed other
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ways to cool down. Quote. Elephant ears are exceptionally deficient
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efficient at shedding heat, says Angela Stover Horwath, a professor
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in zoo conservation science in the University of Vienna. Their
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ears have a large surface area containing thousands of tiny
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blood vessels. When elephants pump blood to their ears, the
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blood moods along those thousands of vessels, cooling to the
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outside temperature. The blood then recirculates through the elephant's body,
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helping the animal return to normal body temperature. Ear flapping
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also helps to dissipate the heat. When elephants flap their ears,
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they increase the airflow across those blood vessels, further cooling
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the blood. Using a computer model, researchers have demonstrated that
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elephants mostly lose heat through their ears. Quote. The ears
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act as adjustable radiators, says Stoger Horwath. Elephants use them
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more or less depending on the temperature, activity, or time
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of day. In quote. This cooling strategy has even influenced
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elephant evolution. The African elephant has the largest ears of
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any species because it's exposed to hotter, open landscapes, while
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Asian elephants have comparatively smaller ears because they live in
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shaded forests. But as the planet warms due to climate change,
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elephants and their impressive ears may face new challenges. Quote.
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The ears of elephants are a really important adaptive mechanism,
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says George Whittmeier, Professor of Fish Wildlife in Conservation Biology
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at Colorado State. But they're getting exposed to heat in
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new and different ways with the planet warming. What's going
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to be beyond at their capacity to manage? Quote. Elephants
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also use their ears to talk to one another. They
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hold their ears in a variety of different positions to
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signal their emotional state or behavioral intent, says Michael Pardo,
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senior scientist at the nonprofit organization Elephant Voices. When facing
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a threat, they often spread their ears out ninety degrees
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from their body to make themselves look even bigger. This
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is often used as a warning for others to back off.
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In social situations, an elephant's ear movement can signal joy, agitation, dominance,
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and coordinate group behavior. When elephants are highly emotionally aroused,
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such as when greeting family members after a period of separation,
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they often flap their ears rapidly, says Pardo. It's their
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way of saying, Hey, I missed you, where have you been.
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Elephant's ears also help them hear a wide range of sounds,
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particularly in the low frequency range. While elephants certainly make
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many sounds humans can hear. Most of their communication is
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at frequency so low we can't These low frequency sounds
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have long wave lengths that trees and vegetation are less
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likely to interfere with. This allows these sounds to travel
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much farther through dense forests or wide savannahs, making elephants
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impressive listeners. Some elephants can even hear sounds for more
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than six miles away. Elephant's ears also help them locate
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where a noise is coming from more precisely. Quote Their
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large ears help channel sound waves into their ear drums,
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says Whitmire. Elephants are using that. You can see that
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when they're listening, they'll stand up and their ears will
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be out. This can help them pinpoint threats and improve
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their chances of survival for tomorrow. Although they don't give
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elephants the power to fly like Dumbo, elephant's massive ears
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are a kind of superpower. They help them communicate across
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long distances, cool down in the heat of the savannah,
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defend themselves, and even show how much they miss each other. Well,
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that'll be all for today's Diary of Science and Nature.
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Thanks for listening, and now you're invited to stay tuned
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for further programming on RADIOI