Natural Selections: Recent Episodes
NCPR - North Country Public Radio
Conversations about the natural world with Dr. Curt Stager and Martha Foley, from member-supported North Country Public Radio. 010329
(Oct 21, 2021) The pressure to keep billions of humans fed can have a transformative impact on amimal populations. Overharvesting that targets the largest animals can result in reduction of the average size of species, as seen in Caribbean conch snails. And sport-fishing pressure on large mouth bass can winnow out the most agressive in the gene pool, resulting in a "lazier," more passive remnant population.
Martha Foley and Curt Stager talk about the human factor in animal evolution.
(Oct 14, 2021) Keratin, the substance wool, hair, and feathers are made from, makes a pretty thin diet, but the clothes moth has been dogging humanity's closets and drawers for hundreds of years, unravelling the work of generations of knitters and weavers to feed its larvae.
(Oct 7, 2021) Of all the places a cat can hang out, why do do many of them want to hang out in boxes? According to researchers, cats that spend time in close confines are measurably less stressed than those remaining in the open. As Curt Stager tells Martha Foley, it's not just house cats who feel this way.
(Sep 30, 2021) Martha Foley has never succeeded in keeping a nature journal long-term, but Curt Stager finds them invaluable in his work. He records his observations on paper, but also finds great data through researching the journals of past observers, from Samuel de Champlain to Thomas Jefferson, to ordinary little-known North Country folk.
His hint - always put it on paper. Whatever became of all that stuff on your floppy diskettes?
(Sep 23, 2021) Humans, birds, and whales are not the only creatures who can sing. Martha Foley and Dr. Curt Stager discuss recent research that uncovered bats also use learned songs to communicate.
(Sep 16, 2021) We tend to think that dogs do this, and that cats do that. We think animal species have a recognizable set of behaviors that define the nature of their kind. But what about individual animals? Does each have something we could understand as a unique personality?
(Sep 9, 2021) The complex web of species interaction is full of odd associations. Stocking a lake with fish cuts down on dragonflies, which helps pollinators, which helps the flowers bloom. Or it can cut down on amphibians such as newts, which is bad for garter snakes. Invasive flowering purple loosestrife is good for insects and birds that feed on them, but hard on plankton, which is at the bottom of the food chain for everything.
Martha Foley and Curt Stager look an unintended consequences of human actions in nature.
(Sep 2, 2021) Martha Foley? - not a fan of bugs. And Curt Stager took a course on them to steady his own reactions. The Natural Selections team looks at the outliers on the spectrum, the largest and smallest of critters with too many legs.
New Zealand's weta makes a real handful. The fairy fly is nearly invisible. Some prehistoric dragonflies were big enough to make off with the cat.
(Aug 26, 2021) All creatures breathe in some fashion, but how the job gets done has changed from fish to amphibian to reptile to mammal.
Curt Stager and Martha Foley chart the evolution of animal respiration.
(Aug 19, 2021) The ubiquitous bird of cities and towns was designed for a different environment. The pigeon's distinctive style of flight is adapted for maneuverability in tight places - near vertical takeoffs and quick changes of direction. This adaptation to cliff and mountainside environments serves them well among our urban cliff dwellings. Curt Stager and Martha Foley discuss.
(Aug 12, 2021) Pigeons and doves, both domestic and feral, are the same species. Today's urban environment mimics their original favored habitat, seaside cliffs in Europe and Asia.
Martha Foley and Curt Stager discuss this commonest bird companion in densely settled areas.
(Aug 5, 2021) The Northern Flicker is one of the most recognizable birds. This distinctly-marked member of the woodpecker family, instead of browsing wood for their food like their relatives, digs for food in the ground. Martha Foley and Curt Stager explore its habits.
(Jul 29, 2021) Animals that resemble each other may not be closely related. Sometimes the setting shapes their bodies more than their ancestry. Manatees may look like whales or walruses, but that is only because they adapted to the marine environment in a similar way. Martha Foley and Curt stager talk about convergent evolution.
(Jul 22, 2021) The big marine herbivore, the manatee, is thought by some to be the origin of mermaid legends, but it's not closely related to humankind or even to whales and other marine mammals.
(Jul 15, 2021) Lake trout require a lot of cold, oxygenated water to survive. Lakes in the Adirondacks of upstate New York are at the southern edge of their natural range. Although about 100 Adirondack lakes and ponds are still home to lake trout, even a small increase in temperature could sharply cut that number.
(Jul 8, 2021) Researchers have found that variations in the wingspan of cliff swallows has a measurable impact on their survival in a human-dominated environment.
(May 27, 2021) A coral reef is kind of like Manhattan, a huge number of mouths to feed in a packed parcel of real estate. A reef doesn't have upstate farms to keep them all fed. So how do they get by?
(May 13, 2021) Few creatures move with more grace than deer. Martha Foley compares them to ballerinas. Curt Stager says there's a reason for that. As ballerinas often do, deer walk on their tip-toes.
(Apr 15, 2021) Curt Stager has his students start the semester by picking out a "pet rock." At the end of term, they have to tell the story of that rock - what it is, what it's made of, and what happened to shape it it over the ages.
(Mar 18, 2021) You can get the sugar out of a lot of trees, but there's something special about the sugar maple. Its trunk is highly efficient at storing and moving sap. That's in part because the sap is stored throughout the trunk, rather then down in the roots, as with most trees in winter. Martha Foley and Curt Stager look at that other "sweet science," the one behind our favorite breakfast condiment.
(Mar 4, 2021) Martha Foley and Dr. Curt Stager discuss cosmic rays. While many people may think cosmic rays only affect astronauts or satellites - objects in space - computers and other electronic equipment on Earth can be affected, too.
(Feb 11, 2021) In general, plants make food from sunlight, and animals fuel themselves by "burning" oxygen. But some animals think outside the box.
Curt Stager and Martha Foley look at a photosynthetic slug that hijacks the genetic machinery of the algae in its diet, and at a jellyfish that needs no oxygen, burning the alternative fuels of hydrogen and sulfur.
(Jan 28, 2021) It's the reason opposites attract and doorknobs shock, why lightning strikes, and the way bumblebees find the sweet spot in flowers. Whenever an object has more or fewer electrons than its neighbor, there is the potential for static discharge.
Martha Foley and Dr. Curt Stager talk about the mysterious and hair-raising ways of static electricity.
(Jan 21, 2021) What is a flame? Why is it shaped like that? How does it keep going? Martha Foley and Dr. Curt Stager answer some burning questions about rapid oxidation.
(Jan 14, 2021) Dr. Curt Stager tries once again to answer the classic child's question. It is a poser that was worthy of Einstein's time, who eventually came up with the best answer. But it's complicated. And when the sky isn't blue, why not? What's up with that? Martha Foley wants to know.
(Jan 7, 2021) The differing qualities of snow can determine the safety of structures, the back strain of shovelers and the danger of avalanche. Scientists look at how fast it falls, how it forms in the air, and whether or not it clumps into fat flakes to determine what impact it will have on those of us below. Every snowflake is unique, and so is every snowfall.
(Dec 31, 2020) Since our bodies replace most cells over a period of a few years, it raises the question "Is any part of us original equipment?" According to Curt Stager and Martha Foley, the answer is "Yes." Parts of the eyes and teeth, as well as many nerve and (bad news for dieters) fat cells last a lifetime.
(Dec 24, 2020) Rarely seen during the day, flying squirrels don't actually fly, but use flaps of skin that connect their fore and hind legs that enable them to glide up to a hundred feet, between trees and from tree to ground.
(Dec 10, 2020) Snowy owls are normally a rare sight in North Country. Their usual range is in the Arctic north. But a few years ago, a large number were seen all across the region. Martha Foley asked Dr. Curt Stager why that has happened.
(Dec 3, 2020) Unlike frogs, turtles don't hibernate through the winter. In fact, sometimes you can see snappers and other species moving around under the ice. While their metabolism runs at very low ebb in the cold, they remain alert to changes in light and temperature that signal the coming spring.
How do they survive without oxygen? As Paul Smith's College biologist Curt Stager tells Martha Foley, they get energy from their body tissues, and their shells neutralize the resulting lactic acid build-up.
(Nov 26, 2020) Martha Foley and Curt Stager talk about ochre. It’s more than just a color in the Crayola box.
(Nov 19, 2020) In the second in our series about the biological marketplace, Martha Foley and Dr. Curt Stager look into the beehive. Although some worker bees might try to "cheat" and introduce their own eggs into the genetic pool of the hive, other workers will detect and destroy them. The queen presides over a society that shares her DNA, but it is run more like a police state than a family.
(Nov 12, 2020) Symbiotes are species that must collaborate with another to survive. But some partners are more equal than others. Martha Foley and Curt Stager talk about how organisms monitor cheaters in symbiotic relationships. This is the first of two conversations about the biological marketplace.
(Nov 5, 2020) Horns and antlers are more than different variations on animal head gear. Antlers are temporary and contain no actual bone. Horns are for keeps. Martha Foley and Curt Stager discuss pointy-headed creatures.
(Oct 22, 2020) In Song of Myself, Whitman says, "For every atom belonging to me as good belongs to you."
(Oct 15, 2020) We all take thousands of breaths each day without thinking about it, yet it's one of the human body's most complex and interesting functions. Martha Foley and Curt Stager discuss what is actually happening when we breathe.
(Oct 8, 2020) A lot of different things are mixed with silicon dioxide to make different kinds of glass. Added lead makes crystal. Most ordinary glass is made with the addition of soda lime. Pyrex glass has boron to give it heat resistance. Fiberglass contains aluminum. Amorphous substances like porcelain and polycarbonate plastic can also count as glass, as can certain amorphous mixtures of metal.
One of the most interesting new technologies is Bioglass, where calcium, phosphorus and other bone nutrients are added to glass to serve as a matrix for replacement bone. Actual bone cells are attracted to the glass and new, healthy bone can form around it. Martha Foley and Curt Stager discuss.
(Oct 1, 2020) Glass is basic stuff - melted sand, pretty much. But your lovely crystal decanter or goblet gets its heft and clarity from a big dose of lead, up to one-fourth by weight.
(Sep 17, 2020) Mushrooms grow out of the soil like plants, but are fungi. Lichens may look leafy, but they are symbiotic colonies of fungi and algae. Seaweed looks like a plant, but is an algae colony. And Indian Pipe looks like a fungi, but is a plant. Martha Foley and Dr. Curt Stager discuss the ins and outs of botany.
(Sep 10, 2020) The success of the Clean Air Act in reducing acid deposition in Adirondack lakes is an under-reported good news story. Many lakes once devoid of life can now support healthy fish populations and other aquatic life.
But as Curt Stager discusses with Martha Foley, the life that returns to recolonize the water is not the same as what was lost. Sediment cores show that the original algae and plankton varieties that form the base of the food chain and were unchanged for hundreds of years are being replaced by different varieties. A balance has been restored, but it's a new balance, tipped perhaps by warming, and by invasive species.
(Aug 27, 2020) Cohesion, adhesion, magnetism: there are a lot of different ways that a lot of different things can stick together. Martha Foley and Curt Stager pry loose some of the secrets of stickiness.
(Aug 20, 2020) Science fiction movies aside, most spiders pose no threat to humans. Their venom may be fatal to small insects, but few species are powerful enough to hurt something human-sized and most are not equipped to penetrate our skin. Most spiders are not even aware that we are there.
(Aug 13, 2020) Curt Stager reports on a long-term study of flying insects in Germany that records an astounding 76% drop in the total biomass of flying insects entering their traps over the last 30 years. This is not a decline as happens in a single species, but appears to affect the whole spectrum of species.
Martha Foley wonders if this could explain the decline in insect-eating birds that appear around her house, or the steep decline in bug spats Stager observes on his car compared to decades ago.
Disturbing news from long-term study and anecdotal observations.
(Aug 6, 2020) We continue a conversation about that bane of sunbathers, the mosquito. But it's not just our blood the female of the species lusts after. Other insects, birds, mammals - even reptiles - can be the target of her search for protein rich foods to help her create and feed the next generation.
(Jul 30, 2020) Martha Foley returns to the first question she asked Curt Stager when the program (then called "Field Notes") began decades ago. Why do mosquitos bite?
(Jul 23, 2020) Martha Foley and Curt Stager continue their discussion of trout varieties in Adirondack waters. One variety that is found in streams and lakes in the region is the splake, a hybrid of the native strains of lake and brook trout. While some refer to them as "Frankenfish," fishery managers like the hybrid because it grows quickly, but does not breed well in the wild, which makes it manageable in a stocking program.
(Jul 16, 2020) Four species of trout can be found in Adirondacks waters. Of the mix, two were introduced from the outside, one from Europe and one from the western United States. The two species which are native to the area are technically not trout at all, but relatives of the arctic char.
Martha Foley and Curt Stager get into the genetic weeds with Adirondack sport fish.
(Jul 9, 2020) In most cases, we get half our genes from one parent, half from the other. But it doesn't always happen that way. Parts of the genetic inheritance can be turned on or off, and genes from other familial sources can play a role in shaping the individual body. Martha Foley and Curt Stager explore what happens when there are ripples in the gene pool.
(Jul 2, 2020) The first time Martha Foley went snorkeling on a coral reef, she was staggered by the abundance and diversity of marine life. Doing the same in an Adirondack lake one might see a lot of mud and a snail. She asks Dr. Curt Stager of Paul Smith's College what the difference might be.
(Jun 25, 2020) Before the last Ice Age, 100,000 year ago, the Adirondacks were a very different kind of place. The terrain was different, the climate, wildlife, and plant life bore little relationship to what we see today. Martha Foley and Dr. Curt Stager go way back.
(Apr 16, 2020) Unlike organic material, which can be dated using carbon-14, stone and fossils often contain no carbon, or may be older than the carbon method can track. Radioactive potassium dating measures the ratio between a radioactive variety of potassium and the substance it breaks down into, argon gas. That can age material back billions of years. One problem: you need the gas to have been trapped in bubbles of volcanic ash.
Martha Foley and Curt Stager discuss the problems of reading the geological clock.
(Apr 9, 2020) What happens when certain species of domesticated animals like chickens and pigs escape to live and breed in the wild? According to Curt Stager and Martha Foley, after a few generations they start to look and act like their wild ancestors again.
(Mar 12, 2020) Our atmosphere is about 80 percent nitrogen. Martha Foley and Dr. Curt Stager explore the ways this common element and necessary component of all life forms interacts with the biosphere.
(Feb 6, 2020) Besides making our food taste better, sodium chloride (salt) is necessary for our bodies to function. Martha Foley and Dr. Curt Stager whet their appetites on the science of salt.
(Jan 30, 2020) It's a delicious flavor, for humans and deer alike, but it's also so much more.
There's just something special about salt, a naturally occurring mineral that humans and many animals crave. Found naturally in its crystalline solid form, sea water and rock deposits left behind by ancient oceans, this chemical compound is among those that many of our cells need to survive.
Conversation with Martha Foley and Curt Stager gets a little salty.
(Jan 9, 2020) Martha Foley and Dr. Curt Stager talk more about three different types of moles that inhabit the region, and their habits. The Eastern American mole and the hairy-tailed mole prefer dryer soils and consume up to half their weight a day in worms and grubs. Their star-nosed cousin prefers a wetter environment.
(Jan 2, 2020) Martha Foley and Dr. Curt Stager reveal some interesting facts about the insectivores that tear up your lawn every year - moles.
The star-nosed mole, one of three species in the region, is semi-aquatic, but all varieties are lightning-fast foragers.
(Nov 28, 2019) Martha Foley and Dr. Curt Stager talk about tryptophan, and why you may need a new excuse for falling asleep after a turkey dinner.
(Oct 31, 2019) Bats are remarkably agile in flight, even more so than birds. How do they do that? Martha Foley and Curt Stager discuss the aerobatic anatomy of bats.
(Oct 24, 2019) Aside from their properties as biological dynamos, electric eels have other peculiarities; they are not true eels, but are a kind of fish - and a kind of fish that needs to breathe air. The South American predator of river bottoms can reach 40 pounds in size and deliver a fatal shock to humans.
(Sep 26, 2019) When infected, your tonsils may be useful to doctors to keep up their bottom line, and to Popsicle vendors to provide the means to soothe recovering children. But when healthy, they also have a use as part of the front-line in the human immune system.
Martha Foley and Dr. Curt Stager discuss an oft-removed portion of the human anatomy.
(Sep 12, 2019) Lake trout thrive in deep, cold water with lots of oxygen, and are stressed by being in warm summer shallows with lower pressure and oxygen levels. But as the climate warms, fewer Adirondacks lakes will have the right combination of factors they need.
(Aug 29, 2019) Most of the sounds in our environment are filtered out by the brain. And what we do hear can be altered in pitch and character by simply shaping the space around the ear with a hand or with a seashell. The volume and range of sounds we perceive can change dramatically, depending on whether the preceding environment was loud or quiet. And the brain is capable of generating sound where there is none.
(Aug 22, 2019) While the sub-Arctic and the Sahara are very different environments, both present extreme challenges to large mammals that live there.
Martha Foley and Curt Stager compare the camel and the caribou, which, while not closely related, have made similar evolutionary adaptations to survive in barren terrain.
(Jul 25, 2019) You can make cheese from the milk of any mammal, but who wants to go out and milk the pigs? Curt Stager came back from a trip to Italy with some Parmigiano-Reggiano cheese. He shares a taste with Martha Foley while they run down different processes used to make a number of varieties of cheese from the same starting point, milk. The official National Cheese Lovers Day is not until January 20, but isn't every day, really?
(Jul 11, 2019) An article in Science magazine highlighted the work of a French scientist who was the recipient of a 2017 Ig Nobel Prize. He posited that because cats can fill up the shape of whatever container they are put in, they must be liquid.
(Jun 27, 2019) Not all evolutionary change is good. Genetic changes can be neutral or harmful, as well as beneficial. And some change can be both, conferring benefit when a single copy of a gene is present, and causing a life-threatening disease when copies are inherited from both parents. Martha Foley and Dr. Curt Stager roll the dice on evolution.
(Jun 20, 2019) Dr. Curt Stager went to a conference in Scotland in where one of the topics was the possibility of lake monsters such as the famous denizen of Loch Ness, or Lake Champlain's Champy. Could the commonly reportedly long-necked monsters be plesiosaurs, left over from the Jurassic era? Probably not.
(Jun 13, 2019) What if dogs gave birth to kittens, and those kittens grew up to have puppies? That's similar to what some species, such as haircap moss, do. Each alternate generation has a different form and function. Dr Curt Stager and Martha Foley explore the biological oddity "alternation of generations."
(May 30, 2019) Vertebrates get around by using their muscles to apply leverage to the bones. But how does an animal move when there are no levers, only muscles? Dr. Curt Stager and Martha Foley look at some boneless examples: the worm, the elephant's trunk, and the squid.
(May 30, 2019) In an earlier conversation on the natural world, Martha Foley and Dr. Curt Stager talked about the longevity of atoms, and how atoms within our body may have once been in the bodies of dinosaurs. But the question remains, is that true of water? How old is it, really?
(May 23, 2019) Squids are ten-tentacled cephalopod cousins to the octopus. They are remarkable in many ways, but three features stand out for Dr. Curt Stager, who fills in the details with Martha Foley: the way they propel themselves through the water, and the air, their amazing use of changing color, and their unique methods of self defense.
(Apr 4, 2019) We think of evolution as moving in a linear progression from the sea to the land. But some creatures, such as whales and dolphins, clearly adapted to the land, then returned to the sea. Dr. Curt Stager and Martha Foley talk about convergent evolution.
(Mar 28, 2019) Can birds hear each other sing in the city? Birds listen closely to other bird songs and learn many things. Are they the right species? Do they sound healthy and attractive, like a good mate? But the loud urban environment can interfere with all that.
In one study, male birds raised the pitch and volume of their mating songs in order to be heard over the urban din. Unfortunately, the females of the species seemed to prefer the traditional deeper-voiced song. Martha Foley and Dr. Curt Stager discuss the mating and dating woes of city birds.
(Mar 7, 2019) Birds and other creatures have a sly side and will use deceptive communications to create an advantage for themselves in finding food and finding mates. Blue jays can imitate the sound of a hawk, scaring other species away from the feeder. Some birds mimic the alarm cries of other species, making them think that another of their kind is warning them about a predator.
But they can't pull the trick too often. "Crying wolf" has the same consequences in the animal world as it does in the fairy tale. Martha Foley and Curt Stager discuss the "tricksy" side of birds, and of cuttlefish.
(Feb 28, 2019) What can take on the big agressive poisonous fire ants that invaded the U.S. decades ago? The tawny crazy ant, also an import from South America. This new "superorganism" is immune to fire ant poison, and they are displacing the previous invaders.
Martha Foley and Curt Stager discuss a new addition to the invasive species list.
(Feb 21, 2019) While the North Country is not exactly the tropics, we do have our share of exotically-colored birds. Blue creatures, for example, are rare in nature but we have the bluebird, the blue jay and the indigo bunting.
Then there are the goldfinches and the cardinals, the ruby-throated hummingbird and more. Martha Foley and Curt Stager celebrate a little of the local color in colder climes.
(Feb 7, 2019) The battle for survival among insects is not always carried out with mandible and stinger. This branch of the animal kingdom also employs chemical warfare.
(Jan 31, 2019) While much of this winter's extreme weather has been blamed on polar vortex weather systems reaching farther south into North America, there is a another polar vortex in the Antarctic.
(Jan 24, 2019) Opossums may be thought of as a southern animal, but they are becoming more common in the North Country as they expand their range north and west. They are the only marsupial, or pouched mammal, in North America.
Martha Foley tells Curt Stager that they look a little weird, as if they were made from parts of other animals: the tail of a rat, the pouch of a kangaroo, funny little hands.
(Jan 10, 2019) Fresh ice, sometimes called black ice, can be nice and clear and great for skating, but after a while ice gets kind of funky.
(Jan 3, 2019) While genetically modified crops are the result of the intentional introduction of "foreign" genes by humans for a specific agricultural purpose, it turns out that nature uses the same trick all the time.
(Dec 27, 2018) Contrary to longstanding theories, the human sense of smell is roughly as acute as that of other mammals, with an equivalent amount of neural hardware devoted to the detection of odors. So why do we seem to be so nose-blind compared to the family dog?
Martha Foley quizzes Curt Stager about a sense that often operates unnoticed by our conscious minds.
(Dec 20, 2018) Flowers get pollinated, bees get nectar; that's supposed to be the deal. Except that some plants cheat. Known as "food decepters," they advertise rewards they don't deliver. Orchids are notorious for variations on bait and switch, with fully one-third of species giving bupkis to the hard-working insects that help them to propagate their kind.