Saturday, December 28, 2013

Sea Smoke

Note: This program first aired on December 28, 2013.

We’ve had some very cold weather so far this winter, and beyond the obvious experience of stepping out the door on an arctically cold morning, I can tell it is cold when I am driving to work and I see sea smoke on the harbor. Sea smoke is the wispy mist that forms on cold days just above the surface of open water, and when you see that, you know its cold out.

Sea smoke is like fog, it results from the difference in temperature between the air and the water. I wrote about this many years ago on this show, but I think it is time for us to revisit it. The fog we encounter in the summer comes from warm air hitting cold water, or a rapidly cooling landscape. Warm air can hold more water vapor than cold air and when the warm air gets cooled, it can’t hold as much water vapor. The water vapor in the air has to go somewhere, and it condenses out as fog.

What we are really talking about here is relative humidity. Air of any given temperature can hold a certain amount of water molecules in the gaseous phase—water as a true gas. We can’t see water in this phase—its different than steam, or seeing your breath. The maximum amount of water vapor the air can hold at any given temperature is called the saturation point. When air is holding as much water vapor as it can at its given temperature, it is said to be 100% saturated. Its relative humidity is 100%, because, relative to its temperature, it is holding as much water vapor as it can. As air cools down, its relative humidity rises. The amount of water the air may contain doesn’t change, but the ability of the air to hold that water does, when air cools down to a temperature where it is 100% saturated, we call that temperature the dew point. If the air cools below that, liquid water will condense out of the air on any surface it contacts. In the winter when this happens, it forms frost.

Sea smoke is different than the regular summer fog we can see on land and in river valleys as well as on the ocean. In the regular fog scenario, the water vapor is in the warm air mass, and only condenses because the warm air gets cooled when it encounters cold water, or cools as it travels up over a ridge line or pools in a valley. The source of the water vapor in sea smoke is the sea, not the surrounding air mass. Very cold winter air can’t hold very much water. Its relative humidity may be high, but 100% of a tiny amount is still a tiny amount. That is why everything dries out in the winter, your skin, your wood flooring, your shingles, you get the idea. Sea smoke forms when a very cold air mass rests over warmer water, though again, its all relative. The water only has to be warmer than the air. For example, during this recent period of cold, the air temperatures were around zero many mornings; according to real time buoy data water temperatures are in the low 40’s, Fahrenheit. That is much warmer than the air was, but hardly what any of us would call warm.

The warm water warms the air directly above it, on a large scale this is the reason that the immediate coast tends to have milder temperatures in the winter. That slightly warmed up air can hold more water vapor, and water is constantly evaporating from the surface of the ocean. Warm air also rises, so this slightly warmed, more heavily laden with water vapor air rises up into the much colder air around it, where it cools off. When it cools, it can’t hold as much water vapor, and that water vapor must condense out into liquid form, or as often the case with sea smoke, as ice crystals. As the sun rises further and warms the air mass more uniformly, the sea smoke dissipates, so when you see it, you know you are seeing a special and ephemeral combination of elements; here one moment, gone the next. You also know, its cold.

From a class at the University of Illinois, a nice diagram showing the non linear relationship of temperature and the overall amount of water in the air mixture.


Great old article from the Woods Hole Oceanographic Institute:

Here’s a much better use of your time than Facebook, its real time buoy data from the Northwest Atlantic:

Thursday, December 26, 2013

La Luna: The Lunar Environment

Note: This program first aired December 21, 2013.

As we wrap up our lunar series with today’s program we’ll take this time to think about what its like on the moon. If we were to go there, what would we experience? Only 12 people can answer that question from first hand knowledge, here’s what one of them had to say: “It suddenly struck me that that tiny pea, pretty and blue, was the Earth. I put up my thumb and shut one eye, and my thumb blotted out the planet Earth. I didn’t feel like a giant. I felt very, very small.” Those are, of course, Neil Armstrong’s words, reflecting what I believe would be the near universal humbling of seeing our home planet from outer space.

If we fast forward forty four years, we find a renewed interest in the moon. China has just successfully landed a landing craft and robotic rover on the surface of the moon, giving the world fresh images and insight on the lunar landscape.

When you watch the images of the Chinese lunar rover leaving the landing craft, or of Neil Armstrong walking around during his moon walk, the first thing you will notice is the dust. It appears that the moon is covered with very fine dust. It results from the impact of millions of micrometeorites, which pulverize the lunar surface rocks. The rocks get so hot on impact that they vaporize, and then condense as tiny glassy spheres, the dust particles we know so well from images of rover tracks and footprints on the moon. Those footprints will be there a while, because the only thing that can make them go away is more impacts from these micrometeorites. There’s no wind or rain on the moon, so there are really no forces of erosion, at least like we have here on Earth. That’s why the moon is still covered with craters. There’s nothing to make those craters disappear. The only factor you can think of as erosive is the ongoing micrometeorite impact issue. It transforms the surface of the moon very slowly,  and not especially dramatically.

And why is there no wind on the moon?  Because for all practical purposes there is no atmosphere on the moon. Wind as we know it is a function of pressure differentials in the atmosphere, air moves from areas of high density (and pressure) to areas if low density (and pressure), at its root it is simple diffusion. If there is no air, or gaseous atmosphere of some other mix, there can be no wind, because there is nothing to move around. To be fair, the moon does have an incredibly diffuse amount of gas at its surface, sometimes called an exosphere. But these gaseous molecules are so few and far between, they don’t behave in ways remotely like an atmosphere.

Another impact the lack of an atmosphere has on the moon is temperature. By now we are all familiar with the concept of the green house effect here on Earth. The Earth’s atmosphere allows in light energy from the sun, and then traps that energy as heat, keeping the planet warm at night. Incidently, the other thing our atmosphere does is NOT let in all the light energy from the sun. A large proportion is reflected back into space, which prevents us from getting too hot! The atmosphere moderates Earth’s temperature in two ways, preventing excess energy from entering, and preventing heat from escaping back into space. You may see where this is going. The moon, lacking an atmosphere, also lacks temperature moderation. So during the lunar day, temperatures can reach 100 C the boiling point of water, or higher.  During the lunar night, temps can then plunge 250 degrees C, dropping to about 150 degrees below zero. 

And why doesn’t the moon have an atmosphere? The short answer is that it isn’t big enough. It is gravity that keeps the Earth’s atmosphere on the Earth, and the moon simply isn’t big enough to have enough gravity to keep gaseous elements around. It’s also no longer tectonically active, so there are no volcanoes to out gas and supply the surface of the moon with gaseous elements.

And lastly, I mentioned the lunar day. You might be surprised but a lunar day is quite a bit longer than an Earth day. An Earth day is 24 hours long, the time it takes for the Earth to complete one full rotation. For the moon to complete a full rotation it takes about 27 Earth days, which is also the same amount of time it takes for the moon for to complete its orbit of the Earth. You might have to let this sit in your brain for a little bit, but the net result of this is that the same side of the moon is always facing the Earth.

So there you have it; if we were to go to the moon right now, we’d take a walk around a dusty, very still, crater pocked vacuum. We would either be incredibly hot and well lit or incredibly cold and in the dark for nearly two weeks, and we would weigh about 1/6 of what we do here on Earth. These conditions may sound appealing to some and uncomfortable to others, but I think we would all benefit from the perspective the view of Earth rise over the moons horizon would bring.


Info about the 12 people to have walked on the moon:

New York Times article about the Chinese lunar mission:

Images of from the Chinese lander and rover:

Science Daily on lunar dust:

Great list serve on all things astronomical

Cool site with lots of interesting lunar info, widgets and apps:

La Luna: Moonrise

Note: This program first aired December 14, 2013.

A few years ago, I started to make my own little Stonehenge. From a single spot on my land, I watched the sun as it changed its position on the horizon, with the seasons. I wanted to mark the spots on the horizon where the sun rose on the summer and winter solistices, the days that are the end points of the sun’s journey back and forth across the sky. I think I understand this pattern, and by marking it on the landscape, I could check my reckoning on a yearly basis, and test my hypothesis that this pattern is unchanging, at least on the time scale of my life. I never did move any large rocks around , but the idea still stands.

A celestial pattern I find more difficult to follow is that of the location of moonrise. One might think it would be easier to follow, being a shorter cycle and changing every night. But when I looked into it I realized just why I’ve never been able to “get” the pattern of the location on the horizon of moonrise. Its because its fantastically complicated. This may be one of those examples where a picture really is worth more than a thousand words, but I will attempt to explain it anyway.

The first thing to know is that the plane formed by the orbit of the Earth around the sun is called the ecliptic. Star gazers know this term because it is the path that the sun takes through the sky. At night it is the line across the sky where you will find the planets, as all of the planets orbit the sun on this same plane. If the Earth were spinning on an axis that was perfectly perpendicular to the plane of the ecliptic, our observations would be oh so much easier to explain. The path of the sun would be in the same place in the sky year round, rising and setting at the same spots on the horizon each day. The height of the sun in the sky would correspond with your latitude, at the equator the sun would always be directly overhead at noon, at the poles it would be on the horizon. If the Earth were rotating perpendicular to the plane of the ecliptic, it would be an equinox every day. And there is something appealing and egalitarian about that, but its not how it works. The Earth’s axis of rotation is inclined 23.5 degrees off the plane of the ecliptic, which is why we have seasons and different day lengths and all that good stuff. Its also why the sun’s point of emergence on the horizon migrates north and south over the course of a year. For example, in the summer, the northern hemisphere is inclined towards the sun, leaning into the plane of the ecliptic. That means the arc of the sun across the sky is higher in the sky than it would be if the Earth were straight up and down. The arc of the sun is higher, and the points of the sun’s emergence and stetteing on the horizon are further north (going along with that higher arc). I go through all of this for the sun and the Earth because it’s the easy example. In this case, the slowness of the year long cycle makes it easier to keep track of.

For the moon it all happens much faster. Just like the Earth orbits the sun, the moon orbits the Earth. The plane of the moon’s orbit around the Earth is not the same as the ecliptic. The moon’s orbit is inclined off the plane of the ecliptic by about 5 degrees. So over the course of a month, the moon travels around the Earth, and is at times as much as 5 degrees above the ecliptic, and at times 5 degrees below it. Put another way, half of the month the moon is above the plane of the ecliptic, and the other half it is below. This also means that there are times when it is exactly on the plane of the ecliptic, these are called the nodes, and incidentally, eclipses can only occur when the moon is at the nodes of its orbit.

Image of moon’s orbital plane vs. Earth/sun (from the Hyperphysics instructional website):

 So we know that the latitude of sun rise changes as the Earth’s angle relative to the sun changes over the course of a year. The same holds true for the moon. The apparent latitude of the moon rise on any given night is determined by the combination of the Earth sun relative position and the position of the moon in its orbit. It’s a cycle within a cycle within a cycle, which is why it is so wildly difficult to follow. It has a regularity to be sure, but one that changes constantly. I think that only the most dedicated sky watchers, and mathematicians have sorted it out.

Perhaps that is the basis of the idea that the moon makes us crazy. Not only does it change shape every night, but it moves about the sky in a different pattern each month, in sharp contrast to the plodding regularity of the sun and its seasons. At this point, I think I will stick to my solar Stonehenge, and simply keep watching the moon, delighting and finding humility in the surprise of where I find it on the horizon and in the sky each night. Maybe some day I will have watched long enough to unlock the pattern, but I am many nights way from that as of yet.


Find the time of moon rise, and set and lots more data here:

Neat stuff from Cornell University, complete with podcasts:

Most of the stuff out there about the moon’s orbital plane stems from questions about eclipses. This website is an example, it has a nice visual graphic that shows the moon’s offset orbital plane, in the context of explaining why and when eclipses happen

La Luna: Phases of the Moon

Note: This program first aired December 7, 2013.

If you have been doing your homework and keeping a moon journal, by this time you will have noticed many things about the moon, the first of which is that it doesn’t look the same every night.

The only reason we can see the moon at all is because it is getting hit with light from the sun, that light reflects off of it and that is what we see. Recognizing that relationship with the sun is the first key to understanding why the moon looks different on different nights. No matter where the moon is in the sky, fully half of its sphere is getting hit with sunlight. The same is true for Earth by the way, hold a tennis ball up to a lamp and you will see what I mean. Light illuminates half of the surface area of the sphere, and the other half of the sphere remains in shadow. The moon regularly changes its position in the sky, relative to the Earth and the sun, and what this means in practice is that sometimes we see the fully illuminated face of the moon, other times we see only part of that illuminated face, and still other times we only see the unlit face of the moon.

When the moon is oriented so that we see its entire illuminated face, we call this a full moon. This occurs when the moon is lined up with the Earth and the sun (in that order) in a straight line. The sun’s rays pass by Earth and hit the moon.  The fully illuminated face of the moon is what is facing the Earth. If you are drawing this picture right now, you might say “Hey, isn’t the moon in the Earth’s shadow?” This does happen, but only very occasionally, and when it does, we call it a lunar eclipse.  For the most part, the Earth is quite small relatively speaking, and the shadow it casts does not line up with the exact position of the moon.

When the moon is lined up with the Earth and the sun, but on the other side of the Earth, the one between the Earth and the sun, the only side of the moon that is facing us is the non illuminated side. We see precisely 0% of the lit side of the moon. This we all know as the new moon. To say we see it is really not accurate, we don’t see it at all, but there are a few reasons for that, we’ll get into in another program.

When the moon is not lined up with the sun and the Earth, we see something between 100% and 0% of the illuminated face of the moon. For example, when the moon is oriented exactly perpendicular to the line created by the sun and the Earth, we see half of the moon’s illuminated face, the half circle hanging in the sky. It is called a quarter moon, because technically, it is only a quarter of the moon’s face we are seeing, and because it is one quarter of the way through the sidereal cycle of the moon’s path around the Earth.
The moon changes position because it is a satellite, and it is orbit around the Earth. Each day during its orbital path, it is in a different position relative to the Earth and the sun, so each night, it looks a little different because a little more or less of its illuminated face is visible to us.

We will talk more about this pattern in coming weeks, but for now realize that it is indeed a pattern. How dull it would be if the moon rose at the same time in the same place and was the same shape every night. We would forget about it. The moon’s actual recurrent pattern keeps us on our toes, our very bodies are calibrated to it. When we have a week of clouds and I lose track of the moon, the first clear night brings with it surprise—Can it really have changed that much in just a few days?

The moon’s daily shape shifting waits for no clouds, no over scheduled lifestyles, no busy evenings. It carries on relentlessly, without us. It needs neither our attention nor our devotion to continue its trip through space and time. The responsibility is entirely on us, to pay attention to that celestial continuity and the tidal rhythms in our own bodies. We ignore these at our peril.

La Luna: Lunar Geology

Note: This program first aired on November 23, 2013.

--> One of the questions that is inevitable when we contemplate the moon is how did the moon get there? Was it always there? And what does “always” mean anyway? The moon’s origins date back to almost the origin of the Earth 4.6 billion years ago. The Earth formed from material that slowly coalesced, gas and dust that were part of a nebula that collapsed and became our sun. All the planets were formed from the dregs of the remaining left over material.  Early Earth would have been a difficult place to visit, as it was covered by a magma ocean. The whole planet was liquid rock, heated by the radio active decay of elements in the core, and heat transferred to the surface by near constant asteroid impacts. The early days of the solar system were chaotic, and asteroid strikes were very common.

Because the Earth was at that time, entirely molten, fluids of different densities were able to sort themselves out, following the laws of physics. Denser materials were able to sink towards the center of the Earth, less dense materials floated outwards in response. By the time of the moon’s creation, 100 million years or so after the creation of the Earth, the Earth was already stratified, the layers we all learned in grade school, the core, the mantle and the crust were differentiated by their differing densities. This fact is im portant because it relates to one of the key clues we have about the origins of the moon.

The current most widely accepted theory of the origin of the moon is the impact theory, which states that the moon formed when a very, very large asteroid, or small planet collided with the Earth, and the force of that impact caused a huge mass of material to be ejected from the opposite side of Earth. That ejected material coalesced and became the moon. So the first point to remember is that the moon is made of Earth material. At the time of this collision, the earth was still covered by the magma ocean, meaning, it was still so hot at the surface that the rocks were still molten. The material that would make up the crust, when it cooled down enough to form, was what was at the surface, but in fluid form. When the asteroid hit, it was this material, and some of the underlying liquid mantle rocks, that were thrown up into space to become the moon.

We know this because the moon has differentiated layers, a crust, a mantle and a core, just like the Earth. This tells us that also just like the Earth, the moon was at one time, entirely molten. The only way the materials of a planet can differentiate by physical properties is if those materials are fluid enough to move. The moon is a great deal smaller than the Earth though, so those layers have cooled much faster than Earth’s layers. The moons layers also differ from Earth’s in their composition. The Earth’s core is made of metal, iron and nickel primarily, the heaviest of commonly occurring elements present when Earth formed. The moon’s core lacks large quantities those heavy metal elements which tells us that though the moon came from Earth material, most of that Earth material came from what would end up as Earth crust and upper mantle. The heavy material on Earth had already sunk down to the center of the Earth, forming the core, and was thus not available to be ejected from Earth when the asteroid hit. On a side note, the lack of iron in the moon’s core means that the moon as an incredibly weak magnetic field, as it is the spinning of the iron in a planet’s core that generates that field.

So when I said last week that the moon is made of us, I meant it. The stuff of our bodies, the elements we take in from our food, we breath in with the air came from no where else but the surface of the Earth itself. We are literally made of Earth, and Earth is made of star dust and elements formed inside long dead stars. And the moon is also made of Earth, so when you look up on these winter nights, see her for what she really, on some level, is: your sister.


Age of the solar system They also have many other terrific short articles on the age of the moon, and the Earth, and all kinds of other things astronomical.

From the Planetary Science Research group, info about lunar geology:

Many scientists are very devoted to the moon, and fund their own institutes pursuing lunar science:

Here’s an entire e-course on Astronomy from the University of Northern Iowa:

They like to chat it up at NASA, here’s the transcript of a NASA chat about the moon:

Wednesday, November 20, 2013

La Luna

Note: This program first aired on November 16, 2013.

Late fall is a time of quietude, of contemplation, and of reflection. The settling that is an inevitable result of the shortening days and the withdrawal that so easily comes with the cold wind, prepares us for the introspection of the long nights of the winter ahead. Along with darkness winter brings with it cold dry air, and nothing feels as naked and stark as staring up at a winter night sky, the cold infinity of deep space brought just that much closer by the utter lack of mist or cloud or earthly dampness of any kind. We are watery beings, full of fluid and lust, water is the fundamental unit of life. It is no coincidence that our most barren landscapes, our driest ecosystems are infact cold deserts, basic physical principles assure us that cold air can hold less water vapor than warm air, and all humidity is relative to temperature. So when we turn our eyes upward in the deepest of winter nights, the utter blank of the universe is just a little bit closer, we are just a little less insulated from it. That makes winter the perfect time, not only to contemplate our infinitesimal place in the universe, but also to watch the stars and the moon, and learn their patterns, learn their secrets.

When we look to the sky night after night, some things appear with regularity, though their positions change, they change so slowly that unless we are dedicated star watchers, we may not notice the subtlety of this gradual shift. Other things appear, on casual observation, completely randomly. In this shape, in this part of the sky one night, a different shape, at a different time in a different part of the sky on another. The worst offender in this second group is of course, the moon.

The moon is the closest celestial body to the Earth, by far. It functions as Earth’s natural satellite, a body captured in orbit, stuck in place by the perfect balance between the force of Earth’s gravity working the mass of the satellite, and the satellite’s own tendency as a body in motion to stay in motion in a straight line. Cut the cord of Earth’s gravity on the moon and where does the moon go? Not flying off perpendicular to us, straight out into space, but flying off on a path that follows the tangent line of whatever instantaneous location the moon occupied the moment gravity cut out.

We take the moon for granted, shining down on us on clear nights, keeping us awake but if you look at it long enough, and with a quiet enough mind, you will remember to ask the essential questions: what is the moon? What is it made of? And where did it come from? How did it get there? The simple answer is the moon is made of us. The same stuff that makes up the corporeal parts of our being is the material of the moon. As the song says, we are stardust, and it is worth remembering that every once in a while. We’ll look at those questions in more depth next week. In the mean time, as the moon is rolling towards full, take a moment each night to watch it with a quiet mind. And listen to the questions the moon asks you.

Photo by Rob Thomas, November full moon 2013.


From the Planetary Science Research group, info about lunar geology:

Many scientists are very devoted to the moon, and fund their own institutes pursuing lunar science:

They like to chat it up at NASA, here’s the transcript of a NASA chat about the moon:

One of the driest places on Earth:

How to Keep a Moon Journal and Support Community Radio at the Same Time

Note: This program first aired on November 1, 2013.

Its Funathon, the time of year when WERU raises the money it needs to keep itself going. And when I say, itself, I really mean everyone involved in the station, volunteers like me, professional staff, listeners around the state and the globe, business members and underwriters. We are all part of this ongoing project, this experiment in community building through radio waves.

Fall is the time when we hopefully stop running around like crazy, like we did all summer, when it gets cold enough and dark enough to hunker down around the woodstove, when we can take a moment to give thanks to those people and things that enrich our lives. As a listener, but even more so as a programmer, I am incredibly thankful to WERU for letting me do what I do week after week. I’ve talked about transgendered fish, glaciers and ancient volcanoes, baby birds and frog eating snakes, seasonal flu and the human microbiome. I’ve kids talking about science topics on their minds. I talk about sperm and eggs and sex on the air on a regular basis. Where else would this be encouraged, but on community radio?

Today’s show is all about action, things I want you to do. First I want you to call 1 800 643 6273 and make a pledge of financial support to this radio station. If you value locally produced news and short features like this program, now is the time to pony up. If you appreciate the coverage of science and nature topics on the air, let the station know by calling in or pledging on line now. You will feel better, knowing that you are even that much more engaged in the programing you appreciate. Pledging takes you from the role of passive listener to active participant, and we thank you for that support.

Now, for the rest of the show, I have another way for you to make that leap from passive to active as well. In the next few weeks I will be doing a short series on the moon. To get this series started, I want to begin with an experiment in everyday science. I want you, the listener to watch the moon, and keep a moon journal. All you need to do is, when you see the moon, you note what time it is, where it is in the sky, and what it looks like, what shape it is. Do this over time, a month at least, and if you skip a day, it doesn’t matter. There are plenty of cloudy days when you won’t see the moon. Just keep track of when you do see it.

What you will find is, once you collect this data for a while, you will begin to notice patterns.  The moon is incredibly regular in its patterns, and being on a monthly cycle, it enables us with our short attention spans to actually be able to follow them. After noticing the lunar cycle patterns, you will find yourself starting to make predictions, having expectations about when you are going to see the moon, where it will be in the sky and what it will look like. At that moment, you will have crossed the threshold from being a passive observer to having an active relationship with the moon. And I can tell you, it is incredibly gratifying when the moon is exactly where you expect it to be, when your expectation is based on your own observations and hypotheses. That is your homework, in preparation for the upcoming lunar shows. Having your own learning in process will make whatever I say to you that much more valuable.

So take this time to become an active participant in community radio, and an active participant in the world around you, around us all. It is a win, win, win situation, and I thank you in advance for your support.

PS, You can go online at and make a donation at any time!

A Visit from the Grackles

Note: This program first aired on October 26, 2013.

Just last week, my neighborhood was taken over; from high up in the tree tops came a sound like the rusty hinged doors in a creepy haunted house, opening and closing over and over again. Interspersed with the creaking came squacks and knocks, it was a noisy crew of interlopers up there. The tops of the trees in my home territory were full, at least for a fleeting moment, of grackles.

Grackles are icterids, a family of songbirds that includes blackbirds, cowbirds, meadowlarks, bobolinks and orioles. They are an entirely new world group that encompasses about 100 different species between North and South America. The grackles in my woods were common grackles, Quiscalus quiscula, and if you look in the bird books you will find that there are several different races of this species, geographically distributed around the eastern half of North America, though they are making their way west as well. Grackles are birds of edges, they thrive in patchy habitat, open areas interspersed with wooded cover. Before European settlement they were not especially common, because much of North America was thickly wooded, too thickly wooded for grackles to proliferate. The subsequent development of the landscape here has been a boon for them, and their population has increased right alongside ours, as we clear more land for our homes and farms, and they respond in kind. In a sense, their population is tied to ours.

Which is interesting and a little ironic, because many people don’t like grackles all that much. Bird books describe them as boisterous and noisy and they are noted agricultural pests.  Online bird forums are loaded with irate posts from backyard bird watchers, all desperate for ways to keep grackles out of their feeders, as the grackles are thought to bully the other birds and prevent them from accessing food. While they are in the Passerine order, the song birds, grackles are not likely to sing you to sleep, their chorus sounds more like this: (play chorus from ebird). People like sweetly singing, little rare birds; common, loud, indistinct markings? Grackles have all the chips stacked against them.

That being said, I have nothing against grackles, and in fact, walking out into the yard and having my attention drawn to the cacophony in the trees was a magical moment. It was the end of a gray day, and suddenly there was new life in the air. These gatherings are their good byes, they are massing in preparation for leaving, or perhaps are already on their way, using my oak trees as a rest stop to eat acorns as they make their way south. And eat acorns they do. Have you ever tried to bite into an acorn? Its not easy, yet acorns are a favorite winter and migration prep food for grackles. They actually have a sharp keel in their mouth on their upper pallet that allows them to cut open the acorn. They are smart too, they are among the birds that practice “anting”, a behavior in which they land on the ground and allow ants to crawl up into their feathers. The presumed function of this behavior is to rid themselves of parasites. And they are beautiful. From a distance or in flat light they appear black, but when the sunlight hits them just right, their feathers reflect a gorgeous array of irridescent purples and greens.

So I was sad to see them go. One moment they were there and the next it was just silent empty trees. The briefness of their presence made it all the more special. Perhaps, had the whole flock taken up residence for the summer, I would have grown tired of the squeaks and scratches. But that isn’t what happened. Instead they were here just long enough to draw my attention, and then before I got a really good look, they left, leaving me wanting more. It is a reminder to not take anything in nature for granted, regardless of how common place it may seem to those around you. One person’s mundane is always another’s magic.


From the Cornell Lab of Ornithology (the definitive online resource):

Nice info from a local North Carolina Audubon chapter newsletter

Saturday, October 19, 2013

Show your fall colors

Note: This program first aired on October 19, 2013.

This fall if you have been listening, you may have noticed I’ve been talking a lot about how it seems like everything in the world changes its behavior with the seasons, everything in the world except us, myself included. Yet I find that, as the end of October nears, my calendar is actually starting to clear, and for once I am in no rush to fill it. The signs of fall are all around us, flocks of sparrows and shore birds are arriving, resting a day or two as they migrate south for the winter. The golden rod and last of the asters have gone to seed, and the trees of course are turning color and gradually losing their leaves.

Leaves are green in spring and summer due to the photosynthetic pigment chlorophyll. Chlorophyll is the substance that allows plants to capture carbon dioxide and water and use the sun’s energy to recombine them into sugars and oxygen. Chlorophyll is what absorbs the sun’s energy and uses it to move electrons around in this process. Here’s the thing about the sun, its rays have a lot of energy, more than the plant can use, and some of it in wavelengths the plant can’t use. It is the same with us, many of us get a sunburn if we absorb too many of the sun’s rays. We stay in the shade or wear sunscreen to prevent over exposure to the sun, but plants can’t do that. They are, by evolutionary design, required to be in the sun as much as possible. Trees solve this problem by having other substances in their leaves that absorb some of the excess sun, and the harmful ultraviolet rays (the same ones that burn us). They have related substances that act as on board antioxidants, so that when sun damage does occur to the delicate chlorophyll molecule, it can be repaired as soon as possible. These substances are the carotenoids and xanthophylls, a group that includes over 60 different pigments. We are familiar with some of the better known carotenoids, beta carotene, the precursor molecule to Vitamin A is found in dark leafy greens and deep orange vegetables, and lycopene, the molecule found in tomatoes that is reported to offer cardiovascular benefits. We know these molecules to be beneficial to our health, and they play much the same role for the trees. Carotenoids also assist chlorophyll in the capture of light energy in photosynthesis.

When the season changes and the trees stop metabolically maintaining their leaves, as broad leaves are simply an energetic and hydration liability in the winter, the chlorophyll molecule breaks down rapidly. As the chlorophyll goes away, so does the green. The carotenoids don’t break down as fast and their yellow and orange color is revealed as the green chlorophyll decomposes. The yellow and orange were there all along, helping to protect the leaf as it did the important work of capturing and storing energy for the tree.

The red color of many a maple, as well as other trees, is a different group of substances called anthocyanins. They weren’t there all along, like the carotenoids. Anthocyanins appear to only form in the fall, and seem to play a role in helping the tree recapture the any remaining sugars or other nutrients that remain in the leaves before they fall off. It would be a tremendous waste to simply let all of that nutrition fall to the ground. They are powerful antioxidants, and this is at least in part an aspect of their role in the leaf in the fall.

So as the season changes productivity shifts from the external to the internal, resources are drawn in, and what is no longer needed is cast off. In the process we see a different side of the trees around us. The change in season provides an opportunity for us to show our other colors, and show appreciation for the hidden strengths and supports, be they friends, family, community that enable our fullest summer expressions. Enjoy this slow motion dive into fall, and take a moment to look at yourself, and see what hidden colors are now shining out of you.


Fun site about Autumn for kids, from the Wisconsin Department of Natural Resources:

Really nice info on the chemistry and roles of different leaf pigments, from the University of Georgia School of Forest Resources:

An authoritative voice, from the University of Illinois Extension service:

I (heart) Physics

Note: This program first aired on October 12, 2013.

Yesterday, I had something happen to me, that hadn’t happened in a very long time. I got a test back from a teacher, and I scored 100 on that test. I teach at a local institution of higher learning, and after years of wanting to take physics, I was finally able to fit it into my schedule this semester. My professor, and colleague welcomed me into the class, noting that no one had ever taken his class out of pure interest before. It was an auspicious start.

For the first five weeks of the class we studied kinematics, the study of motion without consideration of or regard for the causes of that motion (that’s the next part of the semester). Kinematics is the mathematical description of motion, it explains how positions change, what velocity does, and how constant acceleration affects the movement of a body. It is pure math, which I wasn’t expecting for some reason. The course I am taking is the non calculus based version of physics, but it turns out there is a lot of math out there that isn’t calculus. Algebra and trigonometry for example. I wasn’t expecting math problem after math problem, or having to pull the conceptual nuggets out of these equations and verbalize them on my own. And I wasn’t expecting it to be so beautiful. Physics is beautiful, in a way that biology is not. It is clean and clear and precise. The structure is relief and a comfort, with a set of coordinates I am oriented in space and time. The linkage of the abstract to the everyday is a revelation. And at the end of each problem, an answer.

For years I have used the word vector, without really knowing what it means. A vector is a movement that has both a magnitude and a direction. It usually is represented as an arrow, the longer the arrow, the bigger the magnitude, the direction of the arrow, the direction of the vector. If we put that vector on the Cartesian coordinate system (the x and y axises), we can learn even more about it. It turns out that it has an x component and a y component that are totally separate from one another. This separateness is the reason that whether I throw a ball horizontally or drop a ball straight down, both balls hit the ground at the same time. And here’s the truth, these words don’t do it justice, at all, not even close. You really have to see the math to understand how perfect this knowledge is. I don’t know enough yet to articulate everything I am learning, other than how powerful this experience is. Physics is an entirely different way of thinking about and experiencing the world around us, one that seeks to quantify and explain all physical phenomena in a language far more precise than English, or French, or any other language made of mere words.

I am in admittedly, physics kindergarten, but getting 100 percent on my first test in kindergarten was still a triumph. A triumph over all the tears and drama that accompanied my high school algebra homework, over the notion that women can’t do math, over the possibility that I am too old to learn something new,  and over the inertia that keeps us from seeing the world from an entirely new and wonderful perspective.

Monday, September 30, 2013

Fall Equinox

Note: This program first aired on September 28, 2013.

It’s fall in Maine. We’ve just passed the autumnal equinox, that point in the Earth’s orbit where, mathematically we can think of the spin axis of the Earth as a tangent line on the orbital ellipse. What this means in practice is everywhere on Earth has a day of 12 hours of daylight, 12 hours of darkness, more or less. After that, at least here at our middling  northern hemisphere latitude, the darkness increases dramatically, making the light sensitive among us go into mourning, and the snow lovers among us optimistic.

I recently received a weather alert on my phone, telling me that frost and freeze advisories had been suspended for northern Maine, as they had officially reached the end of the growing season there. The alert added that frost and freeze warnings would continue in my neck of the woods, coastal Maine, until the official end of the growing season here, noted as October 10, or earlier if we received a hard freeze before then. It made me wonder, what exactly is the growing season? How is it calculated and what does it really mean? How do we know the exact date when it ends?

Here in Maine, midway between the equator and the north pole, there are three components to growing plants, which when we talk about the growing season, is what we mean. We need light, water and we need warm enough temperatures. The light aspect is very predictable, at least in terms of day length. We know to within seconds how much time the sun will be above the horizon on any given day of the year. Temperature, however, is harder to predict. We can look at averages over time; the date of the first frost for a region, averaged over a period of years for example. I suspect that is where the October 10 deadline came from. Water is, for the most part, not a significant issue here, as we usually have plenty of it, with one major exception. In winter, there may be lots of water around, but it is frozen, and thus not available for use by living plants.

Information for farmers about the growing season is all about mitigating the effects of cold temperatures, really, unless you want very powerful grow lights, temperature is the only aspect of the growing season we can control, and only on a small scale at that. When it comes to light, 10 hours seems to be the magic number. Below that amount of daylight, plants can simply not fix enough of the sun’s energy to meet their metabolic needs and grow. They may be able to maintain, but not get any bigger, or reproduce. For that reason winter is a time of dormancy, a holding period that plants simply wait through. Here in Maine, our true non growing season runs from the beginning of November until the beginning of February, based on that magic 10 hours of light. Wild plants obey the same rules as their domesticated cousins, if my observations are correct. Trees lose their leaves, annual grasses and forbs die back to their under ground roots, or over winter as seeds. Even the hardy ever green trees are limited in their abilities to photosynthesize over the dark, cold winter months by low light, cold slowed metabolism, and lack of available liquid water.

We are tropical animals, living in a temperate climate. Even in the tropics there are patterns of growth and rest, wet and dry, exuberance and senescence. As the calendar rolls towards October 10th, the last day they will bother to warn us about a possible frost, or the beginning of November, when the daylight dips below the 10 hour mark and stays there for three whole months, take heart that this time of year plays a valuable role in the yearly cycle of plants, and people. Take this time to show your other, hidden colors; draw in and hunker down. The dark provides our excuse, our opportunity, finally, after the excitement of summer, to simply stay home and regroup. So don’t fight it. Look around you, are the trees in your yard, the weeds in your garden, or the ferns in the woods arguing with the solstice? Neither should you. Happy fall everyone.


Interesting info from Maine’s own Johnny’s Seed company

A frost free dates for my neck of the woods, from the National Climatic Data Center, featured on a gardening website:

Fresh Water Mussels

Note: This program first aired on September 21, 2013.

This past weekend I spent a perfectly lovely day at Hirundo Wildlife Refuge. Just 10 miles from the University of Maine in Orono, this private refuge straddles Pushaw Stream and showcases forested wet lands, open sedge meadows and miles of canoeing and hiking trails enjoyable by all. I was there as a teaching assistant in a class studying fresh water ecology, and we looked at trees and unique shrubs particular to wetlands, canoed on the stream in 28 foot peace canoes, seined for fish, and hunted for elusive fresh water bryozoans. As surprised as I was to learn that there was such a thing as a fresh water bryozoan, I was even more surprised to learn how many different fresh water mussels there are, and how different they are than the ones we have in the ocean.

Fresh water mussels! Who knew? As some one who specializes in the marine environment, moonlights with terrestrial botany and occasionally goes a little nuts over aquatic insects, I didn’t. We have lots of mussels in the ocean of course, mainly the ones we eat, blue mussels Mytilus edulis, and their deep water cousins, Modiolus modiolus, the big sub tidal horse mussel. Compared to these, fresh water mussels are mussels in name only. Taxonomically fresh and salt water mussels are both in the class Bivalvia, a group of Molluscs that has a common trait of having two shells. They then split off into two separate subclasses; the salt water mussels fall in the evolutionary line that also includes scallops and oysters. Freshwater mussels are out alone in their own subclass, whats called a monophyletic group; they are the only type of organism on that branch of the tree of life.

Unlike marine mussels which live as epifauna, strongly adhered to hard surfaces by anchors called byssal threads, freshwater mussels are infauna, they live buried in the sediment more like clams. Their relatively short siphons and weak feet ensure that while they are in the sediment, they cannot go deep into the substrate and will be found near the surface of the bottom. Like most bivalves marine or fresh, fresh water mussels make a living filtering organic matter out of the water. These food items can be algae, bacteria, or detritus. They have an inhalant siphon and an exhalant siphon (sort of like us, except in mussels the inhalant and the exhalant apertures are located directly next to one another, think about that for a minute.). To eat, which they do continuously, they suck water in and it flows over their large gills, which perform the dual function of not only absorbing oxygen from the water but also filtering out bits of food, and just about anything from the water. Food items that don’t agree with their palates are trapped in mucus and ejected before they can be digested. I had no idea that filter feeders could do this. All this time I was under the impression that they ate indiscriminately, and thus were always a net bonus for water quality. Little did I know that they can reject food, which in regions with the invasive Zebra mussel, is actually creating a water quality issue as the Zebra mussels preferentially eat planktonic algae but spit out cyanobacteria, leading to a large change in the planktonic composition in these lakes and waterways.

Besides living it the mud or sand, and not having byssal threads, the biggest difference between marine and fresh water mussels is reproductive strategy. Marine mussels simply release their sperm and eggs into the water column, employing fully external fertilization. If the sperm and eggs meet in the water column, free floating larvae are formed, which go through several stages of development as plankton before they settle out as what we would recognize as tiny little mussels. Fresh water mussels don’t leave it so much to chance. Males release sperm into the water but the females then capture that sperm with their incurrent siphon (think about that for a minute), it simply comes in with everything else they filter out of the water. The females fertilize the eggs internally and hold the eggs in special pouches on the gills for a period of days to months depending on species. When the larvae are big enough the female expels them into the water. Here is where it gets really interesting. The larvae have to find a fish, and not just any fish, to act as a host for days or months, again by species. If they find their proper fish, and there are many strategies for doing so, including stringy mucus lures meant to attract unsuspecting fish, the larvae attach themselves to the fish, either to its skin and fins or in its gills, again, depending on the species. They grow and develop and actually get encysted in the fish’s tissue, apparently at no cost to the fish, though at least one reference refers to the relationship as parasitic, which implies harm. At the end of their period of fishy development, they drop off and if they are really lucky, they drop off into appropriate sediment substrate, and don’t get eaten by a hungry predator.

So all this time, this has been going on in fresh water streams and rivers, and ponds all over the state, and I had no idea. I feel like some one just told me about another planet in our solar system. Somewhere I knew, in a dimly lit corner of my head, about the existence of what I thought of as fresh water “clams”, from a child hood of fresh water swimming, but it was a part of my brain I never funneled any light or energy to. Its nice to know that surprises exist, and not just on the frontiers of science, but right in your own back yard.  Seek them out, you will be glad you did.


Hirundo’s website:

Maine’s info page about threatened fresh water mussels

Nice site from Virginia Department of Game and Inland fisheries:

The American Museum of Natural History has an extensive website about the freshwater mussels of the New York and New Jersey area, many of which are the same ones we have here in Maine

NOAA document on zebra mussels and blue green algae (cyanobacteria) and changes to Great Lakes aquatic ecosystems

Monday, September 16, 2013

Frass Happens

Note: This program first aired on September 14, 2013.

I’ve been noticing lately, and maybe you have been too, what seems like an awful lot of insect frass around. Frass on my porch, my roof, my adirondack chairs. Put up a tent or a tarp, and as long as it is underneath some trees, it will be covered with the stuff. What this tells me is that there are a lot of insects in the trees, specifically, larval insects, and they are apparently doing a lot of eating. Frass is indeed linked to food, because frass, my friends, is insect poo. Just like you and me, the more they eat, the more they excrete.

Summer is the time of the insect, the warm temperatures bring plentiful food sources, and insects have evolved to take full advantage of this brief window. The insect life cycle is a fascinating one; I, for one, can’t stop thinking about how cool it is. There are three main paths to becoming an adult insect. The first is simple metamorphism, and it has a couple of sub categories. Of those, the first is gradual metamorphism (also called paurometabolous (small or slight change) metamorphism). The egg is laid by an adult, and what hatches out of the egg is essentially a tiny little adult, that eats and grows and molts its exoskeleton and grows some more, molting and growing until it gets big enough to be sexually reproductive and is considered and adult. This is the M.O. of grass hoppers, for example. The other form of simple metamorphosis is incomplete or hemimetabolous (half change) metamorphism. An egg is laid by an adult insect, and out of the egg hatches a juvenile stage that looks different than the adult. In this immature stage they are called nymphs or naiads and are aquatic. This nymph eats and grows, molting its exoskeleton, until its last molt, when what comes out is not another nymph but an adult insect. Dragon flies grow this way.

The second category is complete metamorphism also called homometabolous (whole change) metamorphisman. An adult lays an egg, from which hatches a larvae, (caterpillar, grub etc) which grows through several different stages, called instars, molting an exoskeleton or outer skin as it passes from one instar to the next. Then the larvae turns into a pupa, the stage of true metamorphosis, during which the cells of the insects body completely rearrange themselves. It is often referred to as a resting stage in the literature, but the insect is only appearing to rest. Inside there is a major transformation going on. This is the cocoon stage of the butterfly, as an example. From the pupa emerges the adult, totally and utterly reconfigured from the larvae.

Complete metamorphism is by far the most popular means of insect growth, found in approximately 10 times as many species as incomplete metamorphism. There are some distinct advantages to having such wide variation in the different stages of growth, and the first is division of labor. Ken Kaufman in his guide to insects refers to each stage of the insect as having a different job, and the analogy is a good one. The egg has it the easiest, it simply has to incubate. The larvae are “eating machines”, their job is to get as much nutrition as they can because the metamorphosis that occurs in the pupa stage is so incredibly hard and energy consuming. The adults may or may not eat, but their main job is to reproduce. Typically the larvae also live in different habitats than the adults (sometimes really different habitats, for example the larvae of black flies and mosquitos are totally aquatic, they live under water). This can reduce intergenerational competition for resources, always a good thing.

So it is larvae in the trees that is making all that frass, larvae doing all the work of eating, for many of these caterpillars turn into moths and butterflies that don’t eat at all. It’s a division of labor so stark it is hard to imagine. Its also perfectly synched to the rhythm of nature, those caterpillars, grown fat on summer’s greenery, will pupate and spend the long winter slowly rearranging their cells, preparing to emerge in the spring as new beings. It makes me feel crass and ill fitted in comparison. As the days grow shorter, we would do well follow their example, respecting the season and using what it offers, a break from the frenetic frass making of summer, to renew and reorganize ourselves as well.

References: The definitive internet insect resource, email in your photos to get identifications from an online community of bug nerds.

Ken Kaufman’s Field Guide to Insects of North America 2007 Houghton Mifflin, I love this book, it (like all Kaufman guides) uses actual photographs, but at the same time manages not to be too creepy.

Freeman, Quillin, Allison Biological Science 5th ed. 2014, Pearson
Most any modern biology textbook will give you some good basic information about Arthropods

Nice site from the West Virginia University Extention service, clarifying  different types of metamorphosis,

Monday, September 2, 2013

Frog and Snake Aren't Friends

Note: This program first aired on August 31, 2013.

Frogs and snakes are not known to be friends. Folktales from many parts of the world document this fact repeatedly. In fact frogs and snakes are on such unfriendly terms that snakes often eat frogs, and very occasionally frogs eat snakes as well.

I witnessed this very event, that being a snake eating a frog, behind a road side rest area bathroom on Rt. 9 in Beddington Maine. Yes nature can happen anywhere, even somewhere as unglamorous as behind the rest stop, in the gravel. The snake was a common garter snake, Thamnophis sirtalis. These snakes are the most abundant reptiles in Maine and are found in a wide variety of habitats, including water, they swim quite well. As ectotherms you will find them sunning themselves to regulate their body temperature, as they cannot internally generate enough heat to support a high enough metabolism to be active. In the winter they hibernate in groups. This time of year the females are giving birth to live young. Some sources state that up to 80% of the common garter snake’s diet is earth worms, but they eat a wide variety of prey depending on availability, prey that can include frogs, leeches, slugs, rodents, small birds, fish, insects and molluscs. Generally they eat size appropriate prey, the bigger the snake, the larger the prey they can consume. At one point in my life I came up with a rule for eating, one I think is pretty reasonable, and I have followed it, for the most part, ever since. That rule is: don’t eat anything bigger than your head, and it works for me. Snakes don’t follow that rule, to a pretty astonishing degree. And snakes can’t take bites, they don’t have the proper dentation, nor appendages with which to gain leverage. They have to swallow whatever the catch whole (and usually alive). In order to do this they have to make their heads a great deal bigger, which is accomplished by unlatching their jaws, and having very stretchy skin, which allows their mouths to expand around their prey. Even while their skin expands to accommodate the prey, the muscles of their throat strongly pulse and move the prey towards the stomach, completing the swallow. I don’t often think of snakes as having strong muscles, but when I saw the snake pick the frog up off the ground and slither away with it, I gained a new appreciation for just how robust these creatures are.

The frog in question was a pickerel frog, Rana palustris. They are wide spread in Maine, and after reproducing in wet areas in the spring, they disperse into fields, meadows and damp woods for the summer.

The scene I came upon was this: the snake was biting the frog’s ankle, having not swallowed any part of the frog yet. The frog, for its part, was just laying there, seemingly paralyzed. It looked to me like one good kick and it would be free, but I probably underestimate the power of the snake’s bite strength. The snake kept chomping away on the ankle, apparently trying to maneuver the frog’s foot deeper into its mouth, so its throat muscles could start helping pull the frog in, in this initial phase it was all about the snake’s mouth, and whatever progress it could make with its incurved teeth and biting action. As we watched, and at this point, quite a crowd had gathered, the snake reared up and dragged the frog a few feet away, the frog all the while passively submitting. An occasional twitch or light kick, and its breathing were all we had to tell us it was alive. By the time we left, the snake had managed to swallow one of the frog’s legs up to the hip, and even though I know that snakes can eat prey much larger than one would expect, I still had my doubts.

Watching this I had what I suspect was a typical reaction; I wondered if I should try to intervene and “save” the frog, especially right at the beginning when the snake just had it by the ankle. I thought about how terrible it must be to be eaten alive, to be fully conscious (as conscious as a frog gets) while being slowly swallowed, your head and face the last to be part of you to be drawn in. I realized though that it while it is easy to sympathize with the frog, the snake, even though it is the predator in this case, is no less vulnerable. It was going to take some time for the snake to actually swallow that frog, time when the snake was completely defenseless and would be easy prey. All manner of larger vertebrates, from hawks and owls, to foxes and raccoons, would be happy to munch on a garter snake who’s biting teeth were otherwise occupied. I began to feel real empathy for this snake, who, by simply eating, as we all must eat, was exposing itself to danger with no real means of defending itself, a true vulnerability. We often say that life isn’t fair, but maybe that isn’t true. Maybe life is completely fair, and when we see the balance of nature so dramatically illustrated, the frog losing its life, the snake endangering its life to eat the frog, we have to admit that. We’re the ones that don’t play fair, but we should remember, in the long run, nature wins, every time.


If you Google “ Frog and Snake” folk tales you will get lots of stuff. This is a nice one from Timor:

The standard reference for us Mainers, and useful throughout the northeast: Maine Amphibians and Reptiles, Mac Hunter, Aram Calhoun and Mark McCollough, University of Maine Press

From Northern State University in Aberdeen South Dakota:

Terrific series of photos of a garter snake eating a large green frog:

Saturday, August 24, 2013

The Baxter Flora Project

Note: This program first aired on August 24, 2013.

I recently spent a week in Baxter State Park, volunteering for the Baxter State Park Flora project, a multi year study to document and catalog all of the plants found in the park. We were based at Russell Pond, and made daily forays into various habitats, most of them wet, listing every plant we saw, and photographing the best specimens. Working from a hodge podge of older plant surveys, we had a functional list of plants that had been found somewhere in the park at some time.  The high point of any day was finding a plant not on the list, meaning we had found a plant new to the park.

To naturalists, nature geeks, botanists and all those who own dog eared copies of Newcomb’s Wild Flower Guide, this sounds like a terrific way to spend a week, botanizing in bogs, along streams, off trails and even from canoes. To many others though this may sound not so fun. The questions arise: “Who cares what plants grow in Baxter State Park? And why does it matter?”

Why do we name all the plants? Why do we identify everything we see? There are so many levels on which to answer these questions. Naming and identifying has a practical use, recognition and utility have been part of the human condition since before we were human; I can eat this plant, this one is a medicine, this one makes me sick. In the modern scientific tradition of Carl Linneaus and others the names of a plant are significant because they identify not only the plant itself but all its relations as well. Linneaus developed the conventions of naming and the system of taxonomy we still use today. Taxonomy starts with each individual type of plant, a species. Being able to correctly discern one species from another is the primary skill of botanizing, this is not the same as that. Species that are related to each other will share physical characteristics, and that relatedness will be reflected in a shared name at some taxonomic level. Botanists in Linneaus’s day did the hard work of classifying all the plants they found, essentially starting from ground zero. In modern times botanists who are also explorers may get lucky and find a novel species to identify, but everything most of us see around us on a daily basis has already been entered into the annals of science. No, modern botanists spend most of their time second guessing Linneaus, or perhaps more politely put, improving upon him. I said relatedness is based on physical characteristics, and modern technology allows us to assess these characteristics in greater and greater detail, all the way down to the genetic level. DNA analysis is the reason that, as any amateur botanist can tell you, the names of plants keep changing. There are over four type written, single spaced, pages of changes to names in Newcomb’s Wild Flower guide alone. As new genetic similarities and relationships are discovered, names have to change to reflect this. So to the outsider, the scientific names of plants look like an incomprehensible list of latin, to be drily memorized. To the naturalist, nature geek, and botanist plant taxonomy is no less than a vibrant and dynamic expression of our quest to understand evolution and the very nature of life on the planet.

And to the other question: Why does it matter what plants are found in Baxter State Park or anywhere else for that matter? It may come as a surprise to some listeners, but the truth is that not every plant lives everywhere. There is a community of plants that is distinct to Baxter State Park, and if we go in and figure out what comprises that community, we have set a base line from which we can measure change. Botanists today draw on the historical work of botanists from 100 or 200 years ago to document how plant communities respond to variability in environmental conditions and shift over time. So the Baxter plant survey is interesting for us now, but really it lays the ground work for some one else’s research in 100 or 200 years from now. We know that climate is changing in ways that are both predictable and uncertain. We also know that plants will respond to those changes, and we expect plant communities to shift. We can’t know how they shifted unless we know what was there to start. And that’s why we ask the question, and spend hours shin deep in bogs to answer it.


From the Maine Natural History Observatory, the originators of the Baxter Flora Project:

From the University of California Berkley Museum of Paleontology’s terrific educational website, a brief history of Carl Linneaus:

The Wild and the Domestic: Chickens and Broodiness

Note: This program originally aired August 17, 2013.

Last week’s show, was admittedly, very fun, and I hope you enjoyed it (to listen click here). This week however I want to take a few moments and relay some interesting information I discovered, pertaining to chickens and broodiness, and the poultry community in general.

It turns out that if you do any research on the causes of broodiness (the tendency of a hen to want to sit on a nest and incubate eggs, instead of just visiting the nest to lay a daily egg), two distinct conversations emerge. The first includes the backyard chicken community, those raising a small flock of birds for eggs and pleasure. Their information is purely anecdotal and covers a wide range of observations and advice. The other conversation is from the scientific community, particularly the scientific community working for the poultry industry. The thrust of their research is in preventing broodiness, as it interrupts the hens’ laying, and laying eggs is what it is all about (for that sector of the industry). Every day a hen lives but doesn’t lay an egg is a waste of resources in the eyes of industry. These two perspectives make for interesting reading, as you can imagine.

I am curious about what triggers a hen to go broody, and in asking this question we have to keep in mind a few things. First, chickens are birds, and second they are domesticated and selectively bred. In saying that they are birds, we acknowledge that they retain some physiologic and behavioral traits of wild birds. Their domestication has reduced or altered some of those traits. In the wild birds mate and then lay fertilized eggs, usually a set number, a clutch, and then incubate them. This is generally tied to environmental conditions, particularly day length. Chickens are birds, so yes, they lay eggs. They were domesticated approximately 4000 years ago from a south Asian bird called Red Jungle Fowl. These wild ancestors look a lot like chickens, but have a much more typical reproductive pattern, laying fertilized eggs in clutches a few times a year. In the domestication process however, the relatively rare (in the wild) trait of laying unfertilized eggs has been emphasized over and over again, to the point where domestic chickens can lay an egg nearly every day for a year or more, with the rate of egg laying tapering with age. Hens can lay eggs for their entire lives and never even see a rooster.

If you ask an online backyard chicken keeping forum what causes a chicken to go broody, or better yet, how to make your chicken go broody, you will get a plethora of responses which range from dumb luck, to leaving eggs under the hen, to putting dummy eggs or even golf balls under the hen, to day length and season, to breed. The most common theme seems to be the accumulation of eggs in the nest, which appears to trigger something in the wild bird part of the chickens’ wee little brain, something that says “yes, you have your clutch, now sit on it”. If we think about the implications for chicken neurology, that means that the part of the chicken brain that decides to be broody is separate from the part of the chicken brain that is used for mating; interesting, and based on our evidence, totally anecdotal. If you look in the scientific literature for the cause of poultry broodiness a totally different plot develops. It turns out there isn’t much in the literature about the causes of poultry broodiness, only how to prevent it. And that is because most of the research on chickens is done for the benefit of the poultry industry, either by industry scientists or agricultural extension agencies. These studies describe in detail what happens when a chicken goes broody (brain chemistry changes in ways similar to mammals, the pituitary gland triggers the production of the hormone prolactin, which among other things, inhibits gonadotropin stimulated ovulation, i.e. egg laying), but don’t really examine why chickens exhibit this behavior. It is sort of like the question is mute, chickens are birds, that’s why they go broody, what we need to know is how to stop it. And that is what the studies are all about—tests of what they can inject in or feed to chickens to prevent the surge of prolactin that causes the cessation of egg laying, which is the bottom line for the egg industry.

So I never got my question answered. Science has never looked at the question of why a chicken goes broody or how to make a chicken go broody, because industry has no need for that, they have machines that incubate eggs instead. On this I will throw my lot in with the backyard chicken crew, observing, questioning, testing and doing informal science with the best of them. And not knowing the answer doesn’t really bother me.  I actually prefer that some things lay beyond our control, and that mysteries in nature abound. If there were no mysteries, our curiosity would have no food, no medium on which to grow and flourish, and that would be as soul killing as any cement floored mechanized egg producing factory farm. So the next time you crack an egg, pause, and ponder, what you know about that egg, and more importantly, what you don’t know.


Advice from Mother Earth News:

Originally published in Backyard Poultry

From the USDA (mainly focused on how to prevent broodiness in commercial flocks):

 Way , way , way more than you ever wanted to know about prolactin:

The original chickens, Red Jungle Fowl:

A bit about chicken domestication:

Wednesday, July 31, 2013

Fire Ecology: East vs. West

Note: This program first aired on July 20, 2013.

I recently had the good fortune to travel to the Rocky Mountains, specifically the greater Yellowstone ecosystem. For people like many of my friends and me, East coast kids that we are, the mountainous west has long held an almost mythic standing in our minds. Besides the fact that it lacks an ocean, on its face the west seems to have everything an outdoorsy girl could want: bottomless powder skiing, endless trail running, essentially perfect weather all the time, no biting insects, wide open spaces, and more truly high mountains than you could climb in a lifetime. At the end of a solid two weeks of downpours and fog, or when the blizzard ends in rain, sometimes Maine doesn’t quite stack up.

There’s something Maine has though, that the West doesn’t, and it influences the biological community we find here, and minimizes our exposure to one of the more unpredictable, and frankly terrifying natural phenomena out here. I’m referring of course to water, we’ve got it, in spades, and to wild fires, which are pretty rare here in the Pine Tree State, but oh so common out west.

Fire ecology is a complicated topic; it includes factors like climate, weather, forest type and age, tree species, fuel load, and human management. All of these factors can change from year to year, and day to day, and some, like human management decisions, have had repercussions that are felt for decades. So bear with me when I simplify these factors in an attempt to get to some ground truths. Maine is a forested state, and the reason we have so much forest is that we have so much water, specifically, precipitation. Remove human interference and given enough time essentially the entire state would be forested (with a few odd and extremely localized exceptions). The west is different. It gets much less precipitation, and much of what it does get is in the form of snow fall. At certain elevations that is enough precipitation to support forest, but above and below those elevations, temperatures combine with water stress to yield treeless landscapes.

The first lesson you learn in fire fighting school is about the fire triangle, the three components required for a fire to burn. The first is oxygen, chemically a fire is the exothermic reaction that occurs when the carbons and hydrogens that are combined in any kind of carbohydrate molecule recombine with oxygen. No oxygen, no fire. The second leg of the fire triangle is an ignition source. Something has to ignite the fire, lightening and human carelessness are common sparks. The third leg is fuel, which brings us back to our two forests, east and west. Forests anywhere are nothing if not fuel for fires. The frequency and intensity of fires that occur, and they will occur, depends on the volume and flammability of the fuel; just how dry is it? Here in Maine we carry a potentially high fuel load, but it seems our flammability must be fairly low, as the average presettlement rate of fire return was something well over 1000 years. The disturbances to the forests here tend to be small scale (even the fires). The transitional “Acadian” forest that covers much of Maine is not particularly fire adapted as a result, though it is sandwiched between the much more fire adapted boreal forest to the north and oak forests to the south. Western forest and woody shrub communities tend to have much shorter rates of return for fire frequency, a few hundred years for high intensity stand killing fires, and just decades for lower intensity ground fires. The trees in these forests are adapted to high fire frequency, to the point where some of the species are actually dependent on fire at some point in their life cycle. Looking beyond the fact for a moment that as a result of climate change, summers are supposed to get hotter, winters warmer, droughts worse, and precipitation events heavier but less consistent, all of which will potentially lead to more fuel, we have to look at the other way human choices are impacting the effects of wild fires.

It is scarcely two weeks since 19 firefighters were killed in the line of duty in the Yarnell fire north of Phoenix, Arizona. They were working just beyond what is called the Wilderness Urban Interface*, the zone where housing butts up to forest vegetation. This is the big topic of conversation in western fire management circles, as housing development pushes further and further into naturally fire prone dry forest and shrub areas. And it is easy to sit here in Maine and shake our heads at those silly folks building houses in burnable canyons in Colorado and Arizona, but when I look out my window, you know what I see? Trees, and only trees. It turns out that I live in the wilderness urban interface too, though it is a stretch to call West Sedgwick urban. There is actually more housing in the WUI on the East coast than anywhere out west. The problem is that many western ecosystems are so much more fire adapted, they are supposed to burn. And as anyone who has argued with Mother Nature knows, its hard to stop her when she is doing what she is supposed to. So when the humidity is so high it is hard to breath, or the fog so persistent that things start to mildew, or the rain so torrential you can’t see across the yard, I thank my lucky stars I live in Maine, and although I know wild fire could certainly happen here, I don’t have to treat it as inevitable, as I think I would if I were living the western dream, enjoying that fluffy Rocky Mountain snow and hiking all those 14,000 footers. It was fun to visit, but I’ll take our vibrant, almost decadent temperate lushness here anytime.

*The Wilderness Urban Interface is also known by its acronym WUI, pronounced “woo-eee”, but that was just too silly to say on the air.


The Yarnell fire outside Prescott AZ is just one example of the complicated intersection of climate change, human fire management, and unpredictability in nature

Precipitation info for Yellowstone:

A good radio piece on the Wilderness Urban Interface (WUI) from Colorado College: