The Wood-Wide Web

So a mushroom walks into a bar and the bartender says, “I’m sorry, we don’t serve mushrooms here,” and the mushroom says, “Aw, c’mon—I’m a fungi!”

Admit it, it’s cute.

Susan and I photographed this delightful mushroom yesterday next to one of our favorite running trails.  It is called the fly agaric (Amanita muscaria), and it’s common in the Monterey pine forests here on the central coast of California, and also in lots of other coniferous forests.  They’re very poisonous.  They’re also very hallucinogenic, and if you research them on the Web you end up on the sites of some very interesting people discussing how to get high on them without dying.  (Don’t worry, I’m not going there with this article.)  They’re called the fly agaric because you can crush some of it in milk and flies will be attracted to it and poison themselves.  It was a common pest control trick in the days of old.

But here’s the thing about mushrooms:  When you see a mushroom in the woods, you’re only looking at the fruiting body.  In that sense, calling a mushroom a fungus is like calling an apple a tree.  The organism itself is not visible unless you paw down a few inches into the forest duff.  There you might see a network of tiny cobweb-like fibers organized into a mat called a mycelium which runs through the moist soil below the blanket of pine needles, sometimes for acres, and my friend, you have no idea how much we all owe to these mycelia here on the Planet Earth.

The fibers (called hyphae) of the mycelia are so tiny (a one-hundredth of a millimeter) that there can be a mile of them in a single cubic inch of forest soil, and the stuff they do for the ecosystem is just amazing.  They connect with the roots of all the trees in a symbiosis which gains the tree hugely superior water- and nutrient-gathering capabilities, because the fibers are so tiny compared to even the smallest roots, giving them a huge surface area, and also because fungi have the chemical chops to process some minerals that trees cannot, like calcium (which is why fungi colonized land fifty million years before plants managed it).  The tree, in return, provides the sugars it has manufactured, and sustains the fungus.  The mycelia fibers branch and radiate outward like any plant would, but they also do something more unusual:  They reconnect.  This is not a branching, it is a network, and in fact those mycelia fibers don’t just carry sugars and nutrients, they carry information.  The hormones that tell a tree’s leaves to drop have been found in these mycelia, and that’s what finally explained how an entire forest would hit leaf drop at the same time, even though some trees were up on sunny ridge tops and others were down in the canyons where the photoperiod is drastically shorter.  How do forests act in concert like this when the cues each tree is perceiving are so different?  They communicate, that’s how.  They share information hormonally, through what mycologists are starting to call the “wood-wide web.”  Even information about herbivore damage and pathogen attack is passed through the mycelia, with the result that trees can muster their defenses against a pathogen that hasn’t even reached their part of the forest yet.  Sugars and carbon also move through the mycelia from one tree to another, even across species.  Tagged carbon has been tracked moving from a birch tree in a sunny area to a Douglas fir in a darker spot where carbon is harder to come by.  The trees share, and they also talk, and all of this is a pivotal argument used by people who support the Gaia hypothesis.

The Gaia hypothesis is as fuzzy as it deserves to be, but I’ll try to distill it:  It is the idea that an entire ecosystem—or even the entire planet—can be viewed as a single super-organism, which proactively acts to maintain the conditions necessary for life.   If you open it up you can find some science inside it, but overall it’s a little fru-fru for my tastes, and it attracts a lot of people who need to believe that nature has some sort of a benevolent  personality, and maybe some mystical bling.  But that being said, all the interactions they cite are quite real, and by the way, they’re not always benevolent .  Some mycelial fungi can kill a stand of trees, and it happens all the time.  This is a good and normal thing—it opens up clear spaces, rejuvenates the soil and promotes biological diversity, but the Forest Service doesn’t like it very much, which is why the largest organism in the world got discovered.

It’s a honey mushroom fungus (Armillaria ostoyae) in the Malheur National Forest in eastern Oregon, and it is a single mycelial mat 2,200 acres in size and three and a half miles across.  That’s the size of 1,665 football fields, or, to quote an even more improbable comparison, almost four times the size of the Pentagon.  It was discovered by Forest Service scientist Catherine Parks, who got word of a large tree die-off that looked like root rot.  She did what any forester would do:  She reached for the most recent aerial photos and mapped out root samples from across the affected area, and ran their DNA to identify the fungus.

Well, you can observe a lot just by watching, says the great American philosopher Yogi Berra, and I’ve always loved the quote, and I’ve always loved a naturalist who has her eyes open.  Catherine Parks, apparently, noticed that most of the DNA samples she got back weren’t just of the same species—they were genetically identical.  She had discovered the largest single organism on earth.

Depending on what you mean by largest.  In surface area, the Oregon fungus takes the prize hands down.  But in mass, it’s probably surpassed by a stand of genetically identical quaking aspens in Colorado which all sprung asexually via suckers from each others’ roots, and share a single, 106-acre root system.  There are over 47,000 trees, and it’s estimated that taken together, they might be a 6,600-ton organism.

Depending on what you mean by organism.  When you dig into this literature you start to see a sort of a semantic religious war quietly raging beneath the surface of these scholarly papers about what constitutes an organism.  The Oregon fungus is genetically consistent across all 2,200 acres, but are all the fibers connected to each other and functioning as one individual?  No one really knows.  Lots of organisms reproduce asexually and are genetically identical.  Heck, by that standard the Great Barrier Reef would be a single organism the size of some small countries.  If a single logging road were to be cut through the middle of the Oregon fungus, it would roughly halve its size according to roughly half the scientific community.

General_Sherman_Tree
General Sherman Tree

            And if you don’t believe that merely sharing a root system and a DNA fingerprint qualifies an aspen grove to be single organism, then the biggest  organism on earth as measured by both mass and volume again becomes our old favorite—from my wife’s childhood stomping grounds—the General Sherman Tree, a giant sequoia (Sequoia gigantea) in Sequoia National Park in the Sierra Nevada Mountains of California.

Now you know.

Copyright © 2012 Randy Fry

 

By |2017-05-24T00:03:08-05:00December 21st, 2011|Nature Essays|Comments Off on The Wood-Wide Web
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Where the Buffalo No Longer Roam

Well, happy Thanksgiving to all!  Susan and I hosted it this year, and it seems that every time there is some such get-together, I come out of it with a Ranger Randy research assignment.  This time it was my brother Byron and his girlfriend Ronni, who had been wondering whether the American bison ever existed west of the Rockies.  Hell, I didn’t have any idea.  But I do have an internet connection, so I can’t be stumped.

We all grow up knowing a lot about the bison, and to be honest, I didn’t really expect anything very new or fascinating, but as usual I was wrong.  My God, what a fascinating animal!  First of all, the short answer is yes.  They reached through Idaho and Oregon almost to the coast.  Not so farther to the south.  They didn’t care much for those deserts, and they barely touched what is now California, only way up in the north-east corner.  But their range was huge, all the way to the East Coast, up into Canada and even down a little ways into Mexico.  They were all about the prairies, though, and it looks to me like they could handle the Rockies, which is a very old, worn-down mountain range with wide valleys and lots of open spaces, but I notice they never touched the Sierras.

Here’s something interesting:  Those horizon-to-horizon herds that are talked about so much in Nineteenth Century literature were probably unusual, and new.  The Native Americans controlled the bison’s numbers with hunting pressure, and preserved their ideal grassy habitat through the use of burns.  But in the nineteenth century, Native American numbers were decimated by waves of European disease, and the huge herds of bison we hear so much about were probably an example of an out-of-balance ecosystem.  Still, it is thought that at one time they were the most numerous large mammal on the planet.

They are now what is called ecologically extinct in most of their former range.  That means that though many animals exist in artificial circumstances, the places where they interact with their ecosystem as they always did are precious few—like Yellowstone National Park.

They are a relative newcomer to North America.  They migrated in from Asia across the Berring Straits from fifteen to twenty thousand years ago, replacing an earlier migrant called the steppe bison, which was even bigger, and perished along with the rest of the North American mega-fauna like the mammoth and the mastodon, probably with the development of the Clovis point, a projectile point capable of bringing down a really large animal.

Clovis_Point
Clovis Point

            Before the introduction of the horse from Europe, the Plains Indians would construct chutes out of rock and willow branches and stampede them off cliffs by charging at them dressed up as wolves and coyotes.  These are called buffalo jumps, and can still be visited today.  The Blackfoot Indians used one in Alberta called Head-Smashed-In Buffalo Jump.  Later, on horseback, they found that one skilled rider could easily supply an entire tribe with meat by simply chasing one down and sending a Clovis point through its hide.

It must have been a sporting proposition.  For a 2,200-pound animal they are amazingly fast and agile.  They can jump six feet straight into the air, and can run at thirty-five to forty miles per hour.  On top of that, they are very mean-tempered, which is why they have never been successfully domesticated, either by Native Americans or Europeans.  They can jump over or knock down almost any enclosure you put around them, and they don’t hesitate to do so.  The ones being raised domestically today are visually indistinguishable from the wild ones, but are actually a fertile hybrid of bison and domestic cattle.

But it’s possible that there are no genetically pure bison left, even in the wild.  Scientists find the genes of domestic cattle almost everywhere they look, even in a herd on Santa Catalina Island, off the coast of California, where they have been isolated since they were introduced in 1924 for a movie shoot.

They were a keystone species in the prairie ecosystem.  A keystone species is one which exerts a disproportionate effect on its ecosystem.  Remove it and the ecosystem collapses.  The term comes from the keystone at the top of a stone arch, which receives less pressure than any other stone, and yet cannot be removed or the arch comes down.  The bison was such a species, controlling the vegetation and trampling the earth and making the prairie what it was.  Another was the prairie dog, whose burrows reversed the compacting of the soil from all those hooves, and channeled water back down into the water table, preventing runoff and erosion and keeping the prairie flat.  (You could argue that another keystone species was the Native Americans, who were very much a part of the equation.)

Like most bovines, they are very social and have a complex social structure, and behaviors way more intelligent than the bovine stereotypes suggest (domestic cattle are no exception, and someday I’ll do an article on them).  When moving from one grazing area to another, the dominant female leads the herd.  When attacked by a wolf pack, they form up in a very precise configuration, stampeding with the females in the lead, the young in the center, and the large males bringing up the rear and fending off the pursuers.  There really isn’t a predator that can bring down a healthy adult bison, but of course the predators target the young and infirm.  Cougars also occasionally will prey on them, and a grizzly bear will take one on if he’s hungry enough.

When they travel between grazing areas, they do so in single file, and the paths they developed over the years became very compacted and still exist today where they have not been paved over.  They are called buffalo trails, and they were wisely laid out, following ridge tops and watersheds, and avoiding the valley bottoms with their mud and snow drift problems.  The Native Americans were hip to them and used them in their migrations, and later the pioneers did as well.  Daniel Boone widened a buffalo trail to blaze a route across the Blueridge Mountains through the Cumberland Gap, creating access from the Eastern Seaboard into Kentucky.  Later still, the railroads used several of the bison’s key east-west routes, crossings and passages, including the crossing points of the Ohio River in Ohio and the Wabash River in Indiana.  Really, the bison can be credited with mapping out our modern transportation system.

So the story has a sad, sad ending that we’ve all known since childhood.  The bison are gone, and the prairie ecosystem has collapsed, and our repurposing of the plains has resulted only in the sprawling cities of the Rust Belt, and epic ecological disasters like the Dust Bowl.  A public policy professor named Frank J. Popper proposed in 1987 to return 139,000 square miles of the drier parts of the Great Plains to prairie, and re-introduce the bison, pointing out that it has been resoundingly proven that the area is not sustainable for farming.  Wouldn’t that be something to leave our children?  It ain’t going to happen, but it’s nice to know that someone out there is trying to learn from our mistakes.

Now you know.

 

 

 
Copyright © 2011 Randy Fry
By |2017-05-24T00:03:08-05:00November 26th, 2011|Nature Essays|Comments Off on Where the Buffalo No Longer Roam
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Rattlesnakes, Little Brothers and Boy Scouts

Susan and I and our running buddies frequent an old Army base here in Monterey, California called Fort Ord, where there are numerous closed roads and lots of running trails where the firing ranges used to be, and lately there have been a lot of rattlesnakes around.  Hari saw one sunning on the pavement halfway up one of our favorite hills (and photographed it on the cell phone he never runs without), and Gary and Rob have seen several, and also one kingsnake, which is a harmless snake (but don’t call them harmless if you’re talking to a rattlesnake—more on that in a minute).  I was running behind Kate once when she almost stepped on one.  She has a good eye:  she saw it,  yelped and stopped dead, but the result was that I smacked into her back and almost sent us both tumbling onto the creature.

But as you can probably guess, I’m the guy who actually enjoys seeing a poisonous snake.  I’m also the guy who’s actually been bitten by one, proving either that I don’t harbor grudges, or that I don’t learn from my mistakes.

I was eleven years old, and he bit me because I picked him up to see if he was poisonous.

So when you’re done laughing, please read on, because it was not quite as stupid as that makes it sound.  You see, he was crawling under my little brother Byron, who was in a tire swing, and was age five.  That’s not so cool, I said to myself.  We were visiting North Carolina and everyone had been warning us about poisonous snakes.  I needed to get the snake out of there, but it was twilight and I couldn’t tell what he was, and I didn’t want to kill an “innocent” snake—so I picked him up.  I had read a lot of nature books and I knew how to pick up a poisonous snake, and I did so, correctly and successfully, grabbing him right behind the head like you’re supposed to, and I carried him into the light to identify him.

What I didn’t count on was his strength.  He wasn’t even a big snake—maybe two feet long—but man, was he powerful!  In the end he was too much for my eleven-year-old hand, and he broke his head free from under my thumb and nailed me.

The family scene that followed was somewhere in that magical space that exists between Three Stooges and Keystone Cops.  A doctor later said that the only intelligent thing that happened that night was when my older brother Gary, who was a Boy Scout, did the obvious Boy Scout thing and put a tourniquet on me (they don’t recommend that anymore).  My mom at one point actually had me drawing pictures of it next to the reptile book for ten or so precious minutes, trying to identify it (we didn’t have the snake—I’d gotten mad and frightened and hurled him into the woods), and we never did ID the thing (it was probably a copperhead), but we got to the part in the book about how poisonous snakes leave two fang marks instead of a U-shaped row, and we looked down at my finger and said, “Yep.”  That was when the venom hit me.

Three minutes later I was screaming at the top of my lungs as my dad careened wildly through the streets of Chapel Hill toward the hospital in our VW microbus.  I can’t remember the pain.  I just remember the screaming.  They say the mind will not recreate a memory of pain.  (Susan speculates it’s because the birth rate would plummet if women could remember the sensation of childbirth with any clarity, but that’s material for some other article.)

Anyway, obviously I lived, but it was a bit of a close one.  I tested allergic to the antivenom, which is a concotion of horse antibodies that will kill you summarily if you’re allergic to horses.  The test is unreliable, though, so when it was clear I was going to die anyway, they went ahead and gave it to me, and I got lucky.

But here are some things you might not know about rattlesnakes:

  • They’re not out to get you.  They just get cranky when someone tromps on them.  They know you’re not food, and they want to avoid you.  They only bite because they get stepped on by runners or picked up by eleven-year-olds who have read too many nature books.  Unfortunately, they, like many snakes, like to sun themselves (“thermal-regulate”) in the middles of trails or on nice warm asphalt, so they do get stepped on (they also get run over a lot).
  • They’re not even particularly mean, as predators go.  They inflict a quick death by lethal injection, which is really pretty humane when compared to, for instance, my very sweet and very cute kitty-cat, who will grievously mutilate a mouse and then play with it for twenty minutes.
  • They can control how much venom they inject, and when they bite defensively, about forty percent of the time they inject none at all.  These are called dry strikes, and they explain a lot of superstitions about why one person will be affected by a snake bite and another will not.  Venom is expensive stuff for them to produce, and they don’t waste it.  But the catch is that that kind of self-control only comes when they’re older.  The young ones are not able to regulate it, and the one I was handling was young, so I got hammered.  The moral here is that if you do step on a rattlesnake, you want to hope it’s a nice BIG one!
  • About 8,000 people per year get bitten, and of them, only about five die.  Apparently it was somewhat unusual that I had such a close brush.
  • Many people get bitten because they underestimate the striking distance the snake is capable of.  They can strike something two thirds of their body length away,  and they do not need to be coiled, and they do not even need to draw back first.  Worth keeping in mind.
  • When they strike, their jaws, which are unhinged like most snakes’ jaws are, open so far that the upper and lower jaws are vertical and the fangs are sticking horizontally out at the prey.  Really it’s more like being speared than being bitten.
  • But they’re bad shots, which makes me laugh for some reason.  I’m not sure why–it just strikes me funny.  Often they completely miss something the size of a wood rat, and he gets away.
  • They’re called pit vipers in reference to the small pits between their nostrils and their eyes.  These are thermal sensors which they use to detect warm-blooded animals nearby.  They can detect a difference of half a degree farenheit.
  • The rattlesnake doesn’t have many predators, but one is the kingsnake.  The kingsnake is into eating other snakes, even other kingsnakes, which works for him because when you swallow your prey whole, which all snakes do, it’s nice if it’s shaped like you are.  They are not immune to the rattlesnake venom, but they have a pretty good tolerance to it (so do opossums and hedgehogs).  Kingsnakes are constrictors, which means they kill their prey by looping around it and squeezing it to death (now, that’s a gruesome way to go!).  Apparently they are quick enough to subdue the rattlesnake usually without getting nailed.  At the height of the combat the two of them are just a tight, fist-like ball of snake coils, and it’s hard to tell who’s doing what to whom, but it’s the rattlesnake who is succumbing.  Then when he’s, well, not dead maybe, but not causing trouble anymore, the kingsnake swallows him.  Head-first.
  • Some people have been lucky enough to see two rattlesnakes doing a beautiful and mysterious dance, in which they weave upward, getting half their body lengths in the air, and face off and lean around each other in ritualistic moves (see the photo above).  People assume it’s a mating dance.  Well, yes and no:  It’s actually two males in mating combat.  They never bite each other—evolution usually (though not always) discourages same-species adversaries killing each other—but one will be driven off eventually.  But hey, there’s an easier way for a male to get his genes into the pool:  sometimes while two males are locked in combat, a third is several feet away in the bushes whooping it up with the female.  Scientists call this the “sneaky male strategy”.

Now you know.

 

 

 
Copyright © 2011 Randy Fry
By |2017-05-24T00:03:08-05:00June 11th, 2011|Nature Essays|1 Comment
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Oak Trees, Caissons and Clarion Calls

Recently Susan, myself and our running friends have noticed two things as we run the trails through the coastal scrub oak of our decommissioned military base here in Monterey, California:  All the oak trees are bare, and little caterpillars are crawling all over our running clothes.

They are the California oak worm (Phryganidia californica).  They are always around, but every five or ten years they have an outbreak like this one, and absolutely devastate the local oak forests.  It’s scary—the trees all look like skeletons.  It would seem there’s nothing left to photosynthesize with.  You honestly wonder if they’re going to survive.  The first time I witnessed one of these episodes I asked my elderly neighbor in some alarm whether the trees were going to die.  He gazed up with me at the sky, through what used to be our oak canopy, and said, “Aw, you can’t kill an oak tree.”  The dear fellow passed away many years ago, and so far he has not been proven wrong.

The outbreaks actually have nothing to do with the oak trees.  It usually happens because one of the oak worm’s predators is having a bad year.  Or it might be that both the oak worm and the predators had a bad year last year, and the worms bounce back faster, resulting in a crazy period like this while the predators catch up.  The thing about the balance of nature is that it may be a balance, but it’s not a stasis.  It is constantly in motion, and oaks and oak worms have been going through cycles like this for hundreds of thousands of years.

A healthy oak tree can survive a complete defoliation—even two or three of them in a row.  (And the oak worms, obligingly, can supply it—their life cycle has two to three generations per year.)  But the oaks don’t have to like it—it really does sap their reserves, and opens them up to secondary pests that attack weakened trees.  But one cute irony that inserts a little balance into the boom is that a weakened tree actually gets attacked less by worms, because the leaves are tougher and more dried up and less nutritious.  My friend Venu was commenting that two trees right next to each can look very different—one will be a skeleton, and right next to it will be a fairly healthy-looking tree.  We were wondering if maybe they were different species, and some species don’t get attacked.  But no, according to my reading they all do—anything in the genus Quercus is fair game.

But my neighbor had it right, oak trees are tough.  It’s estimated that they are host to 850 insects and 380 diseases, and most of them are present most of the time.  When you look at a serene, peaceful oak tree—or any number of other serene, peaceful things in nature—you’re looking at a pitched battle.  You can’t hear the clarion calls or see the caissons, but believe me, it’s war.  As long as all the combatants evolved together and know each others’ tricks, no one gets the permanent upper hand.  They all, in a sense, get along.

Now you know.

 

 

 

 
Copyright © 2011 Randy Fry
By |2014-10-12T13:35:37-05:00June 10th, 2011|Nature Essays|Comments Off on Oak Trees, Caissons and Clarion Calls
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Mountain Lions, Forest Fires and 73-Year-Old Women

What’s the most interesting thing that’s happened in your house at night?  Our 73-year-old neighbor in Big Sur, California was lying in bed reading at 11:30, and she had just dozed off when a mountain lion crashed THROUGH the glass of her front door, trying to get her pet cat.  I’m not making this up.  The cat streaked under her bed, with the lion in hot pursuit, and by the time this woman had her senses about her, there was a great tawny rump and tail sticking up beside her from under her bed.

It gets better.  She thought it was a neighborhood dog.  She smacked it on the rump and yelled for it to get out.  The mountain lion, somewhat taken aback, leapt back across the room, perched on a box, and looked at her.   At this point, the woman’s husband appeared in the bedroom door (blocking the lion’s only escape), and the lion, unnerved and disoriented now, started coursing around the room looking for a way out, knocking things over and breaking two mirrors.  The couple retreated to another room, and the mountain lion immediately vanished into the night.

It was 2008, and our small Big Sur, California  community had just survived the Basin Complex forest fire, and strange things happen after large forest fires.  This was probably one of them.  Huge areas of wilderness had been burned, and the deer, a mountain lion’s main prey, had moved elsewhere in search of food, or perished.  The lion was sighted several more times, and so was a cub that was probably hers, and people’s cats were disappearing.  The lion had probably lived its life in deep wilderness.  In all likelyhood she was displaced, disoriented, desperate, hungry, and—to make it even worse—a mother.  It can all add up to a very aggressive personailty.  She was probably unfamiliar with human settlements, and this was probably her first encounter with glass (and a pretty unpleasant one, I’m guessing).  We were just hoping to somehow make these first human encounters as negative as possible for her, so she’d move on.  Otherwise, Department of Fish and Game hunters would have to come into our canyon and kill her.

When you choose to live on the edge of a wilderness, you take on an obligation to co-exist with the elements of nature that drew you there, and it’s a for-better-or-worse contract.  You get the babbling brooks and the cute songbirds, and you also get fires, floods and the occaisonal mountain lion.  In the wake of this, I have not heard any voices in the canyon demanding indignantly to be made safe, and that’s a community sentiment I’m proud of.  We were keeping our pets indoors and hoping the lion moved on.  But we knew that she might not.  She’d already had several meals.  This was working for her.

As for the woman, a long-time resident of Big Sur who works at Esalen Institute, she said she never once felt frightened or threatened, and hoped no one would have to kill the big cat.  I’m jealous of her legacy.  How many people can say they’ve smacked a mountain lion on the butt?

As for the kitty cat, she escaped unscathed, though she didn’t come out from under the bed for two days.

As for myself, I love nature and I love mountain lions, but I seem not to have the steel nerves of that 73-year-old woman.  Lately I find our forest to be a very spooky place at night.

And since this is a Ranger Randy article, here are some interesting facts about mountain lions:

  • Statistically, it is about a thousand times less likely that you will be attacked by a mountain lion than that you will be struck by lightning.  (That’s a national statistic.  I figure my numbers are a bit higher at the moment.)
  • They are hugely successful, with a range that extends from the Yukon in Alaska to the southern end of the Andes, and from coast to coast in both Americas, but with this caveat:  we exterminated them everywhere east of the Mississippi, and they haven’t recovered yet.
  • Probably because of their huge range, they have over 40 names in English alone:  Cougar, mountain lion, panther, puma, catamount—it goes on and on.
  • They have the largest hind quarters of any cat, even proportionally (and they’re big cats) and it makes them capable of spectacular vertical leaps of up to 18 feet.  (That’s from the ground to the roof of a two-story house.)  Horizontally they can do 35 or 40.
  • They are what’s called a hypercarnivore, meaning that they are purists about eating only meat.  Yet they are generalists in their hunting practices, and the meat can take the form of anything from insects up to a moose.  In the US, deer are their main prey.
  • As with most animals including us, you don’t want to mess with the mothers:  they’ve been known to fight off grizzly bears in defense of their young.
  • They hiss, growl and purr just like a domestic cat.  They also chirp, and whistle.

Now you know.

 

Episode Two

 

Chapter two of the mountain lion saga is also a pretty good yarn, but with a sad ending.

Another of our neighbors in Big Sur, California has—or rather had—16 hens and a rooster in a chicken coop.  Several days after the above events, when they walked some guests over there to show them the chickens, they looked through the wire into the face of a mountain lion.

From what they could reconstruct later in a calmer state, the mountain lion probably jumped onto the roof of the chicken coop, fell through the wire into it, massacred every chicken there, and then couldn’t get out.  However, they didn’t know about this “couldn’t get out” part at that particular moment, and assumed themselves to be seconds away from dismemberment.  They retreated quickly into the nearest structure, which was a greenhouse, where, I assume, they looked apprehensively out at the lion and mulled over their situation with suddenly-focussed minds.  Finally, one brave soul made a run for an automobile and swung by to pick the others up, and got everyone to the safety to the house.  (Safety is a relative term here—this was, after all, almost certainly the same mountain lion that crashed through a glass door into a house in episode one.)

Fish and Game came out, and our neighbors agonized with the officer about what to do.  The officer was willing to consider releasing her, but argued that this cougar had picked up some habits that made her dangerous.  Relocating the lion was not an option.  The California Department of Fish and Game doesn’t do that, and I can think of several good reasons for the policy, the best one being that it seldom results in anything but the death by starvation of the relocated animal.  No, they were told, it was release her back into the neighborhood, or shoot her.

There was a two-month-old baby on the property, along with four adults and many more animals.  It was not an easy decision, but they decided to put the lion down.  The deed was done quickly, with a single shot through the heart.

It was necessary, but Susan and I went home that night feeling saddened, and I was lamenting that we could no longer live in harmony with the creatures around us.  Then the ghost of Ed Abbey that lives inside me piped up and said, “What harmony?”  Ed Abbey, in case you don’t know him, is a wonderful writer and uncompromising defender of the wild who hated the sentimentalizing of nature, and I had to admit, he spoke the truth.  The unsentimental fact is, nobody “lives in harmony” with a mountain lion, including other wild creatures.  Even our pre-historic hunter-gatherer ancestors did not, I’m sure, “live in harmony” with them.  They were probably killing and being killed, stealing one anothers’ prey and generally getting on each others’ nerves.  You can find harmony in those long-ago times, but you have to look a level higher, at the numbers:  Our ancestors were few enough that neither species threatened the other in a permanent way.  In that sense, there was, if not harmony, at least balance.

So Susan and I decided not to get weepy about a harmony that never existed.  We sat down on the deck and recited William Blake’s “Tiger, Tiger Burning Bright” into the woods, and raised a glass to the creature.  Adieu, magnificent one!

 

 

 
Copyright © 2011 Randy Fry
By |2017-05-24T00:03:08-05:00March 15th, 2011|Nature Essays|Comments Off on Mountain Lions, Forest Fires and 73-Year-Old Women
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Pyramids, Sacred Birds and Recovering Musicians

Susan and I have spent some time on the Yucatan Peninsula in Mexico, and the Maya ruins around there are wonderful places to haunt.  If you visit the ruin called Chichen Itza and hire a local guide, he will usually demonstrate an interesting accoustical phenomenon of the central pyramid called Kukulkan.  If you stand in front of one of the four staircases ascending this pyramid and clap your hands sharply, the echo that returns from the steps is not your handclap, but a short, descending chirp.  It’s very weird.  (Go here to hear it on Youtube.)  We were all standing around my little brother Byron’s hospital bed recently (he was finally getting his cervical spine patched up after years of having way too much fun) trying to explain this to ourselves.  Byron is a musician, and I’m a recovering musician, and we’ve both had to set up sound systems and make them work in God knows what kinds of rooms, so we both fancy ourselves to know a few things about accoustics.  But try though we did for a couple of hours, we were unable to make up a convincing theory.  I finally broke down and did some actual reading.

So:  If I understand this right, here’s what happens according to the Acoustical Society of America:

Chichen_Itza_CB
Chichen Itza

Each step riser (the riser is the vertical face of a step, for those of you who have never built a staircase) sends one shock wave from your clap back to you, and is perceived as a single sound wave, a single cycle—that is, exactly one impact on your eardrum.  Combined over the number of steps (91), it becomes a brief tone 91 cycles long, which ends after the furthest step has sent back its echo.  And the tone would be all on that one pitch and not drop—that is, not chirp—except for one interesting geometric effect:  The steps farther from you are also higher above you, so your line of hearing becomes slanted as they go up, which means that the steps farther up, when measured along that increasingly diagonal line, are farther apart from one another than the ones directly in front of you.  So the frequency of the sound slows down, which we perceive as a drop in pitch.  The result is a brief, descending chirp.

The chirp is suspiciously similar to the chirp of the resplendent quetzal (pictured), a sacred bird to the Maya (now endangered), and there is fun argument in the archaeological community about whether this was intentionally done by the Maya, and whether they could have had the acoustical engineering chops to pull it off (nothing would surprise me about the Maya).  In fact, there is now an emerging field in archaeology called accoustic archaeology.  Accousic archaeology is now being taken fairly seriously, but in the late sixties the claims were pretty out there.  Some were claiming that the singing voice of a mason could be recorded in the mortar as his trowel vibrated to his voice while he worked it.  Pretty fru-fru stuff, and it actually got debunked by none other than my favorite TV show, Mythbusters.  But now, in no small part because of this Chichen Itza thing, acoustic archaeology is being pursued more seriously, and taken more seriously, and according to the acoustic archaeologists, if the Maya did imitate the call of the quetzal intentionally in the building of this pyramid, it constitutes the first recording of a sound.

Another of the loved ones around Byron’s bed mentioned that it is odd that the stair risers on Maya pyramids are so high (10.3 inches in this case) while the Maya were a fairly short people.  (Susan and I can vouch for that–we’ve climbed several of those pyramids and our knees always pay.)  The quetzal theory offers a good explanation for that, since shorter risers would be far less effective at producing this chirp, and would not immitate the call of the quetzal as well.

Now you know.

 

 

 
Copyright © 2011 Randy Fry
By |2017-05-24T00:03:08-05:00March 14th, 2011|Nature Essays|1 Comment
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Birds, Magnetite and Unkind Scientists

Okay, I decided this warranted a Ranger Randy article.  I had origionally only emailed it to a few of my more hard-core friends, because it gets technical, but everyone loved it, so what the hey, here it is:

My friend, coworker and fellow curiosity-junkie Hari recently stumbled across an article about some bar-tailed godwits (that’s a bird) who flew 7,100 miles non-stop and over water.  On top of all the other reasons to be stunned and amazed by this feat, Hari wondered how these birds navigated all that open water.  I told him that many birds have compass-like sensory mechanisms containing a naturally occurring magnetic mineral called magnetite.  Hari, as if it was the most obvious follow-up question in the world, said, “I wonder what it does to them when the Earth’s magnetic poles reverse.”

It was the kind of great question that stopped me in my tracks.  For decades I’ve known that birds navigate using Earth’s magnetic field, and for decades I’ve also known that the Earth’s magnetic field reverses periodically and the south magnetic pole becomes the north—but I’d never asked myself Hari’s question.  How does a bird, whose behavior is largely instinctive, survive evolutionarily when the compass needle suddenly points south instead of north?  It was too fun to pass up.  I started digging.

The first thing I found out was that Earth’s magnetic field is even squirrelier than I thought.  It does, as I knew, reverse itself, on average every 300,000 years, but that time varies hugely, from over a million down to just a few tens of thousands.  The last time it happened was 780,000 years ago.  But that’s not the important number if you’re a bird migrating by a magnetic compass.  The important number would be “from a few hundred to a few thousand years.”  That’s the time it takes for the flip to actually take place.  That’s not very long in evolutionary terms.  If these birds’ lives depended on genetically hard-coded migratory behaviors, I imagined that it would be hard for them to adapt in just a few thousand years. 

But our magnetic field does even weirder things than that.  Even when the magnetic north pole stays roughly at the north end of the planet, it can move around, as much as a few kilometers a year.  I also knew this, because sailors, surveyors and hikers know it—it’s why they have to keep an eye on the copyright dates of their maps.  The magnetic declinations change.  But my favorite geomagnetic quirk was a weird thing called dipole tilt variation, in which the magnetic North Pole wanders south, even crosses the equator briefly, and then returns to roughly where it had been. 

You just can’t trust that magnetic field to stay put.  It’s all over the map.

Just as an aside, we know all this because of the ocean floors.  Ocean floors are created by mid-ocean ridges, which can be pictured as linear volcanoes running down the middles of most of our oceans, constantly oozing magma along their length and creating ocean floor, which constantly moves outward from the ridge in both directions, until it hits a continent and gets sub-ducted (driven under the continent).  When the magma at the ridge initially hits the cold ocean water and solidifies, that’s when the magnetic minerals in it get their orientation frozen.  Ocean floors are giant conveyor belts, and the magnetic minerals in them are a perfect record, complete with fossil datestamps, of where north was at any point in time.

Anyway, Hari’s question has indeed been studied.  Extensively.  In fact, there’s a great debate about all this, including how in the heck these magnetoreceptors even work, why they’re in the vicinity of the optic nerve, and whether that means that birds can “see” our magnetic field superimposed over the landscape as they fly.  (Dang, don’t you wish we spoke the language so we could ask them?) 

Fun stuff, all of it, but I’m sitting here at my desk where I get paid paid to rearrange the magnetic orientation of iron molecules on the surfaces of spinning disks, and I actually have to get back to work at some point, so I’ll just recount the study I found most amusing, and then leave you all alone:

You can’t conduct tests by changing the orientation of the earth’s magnetic field, so one scientist did the next best thing:  He changed the orientation of the magnetite in the birds’ brains.  A fellow named Winklhofer zapped bird brains with a strong magnetic pulse, fritzing their magnetite so the “compass needle” pointed in a different direction (scientists do unkind things like this to animals all the time), and an interesting thing happened.  Birds that had already flown their migration route at least once flew off in the wrong direction.  But young birds who had never flown the route before had no problem.  The conclusion?  

The compass is hard-wired—but the map is learned.

A compass needle that points south is still a useful thing—as long as you learn your map accordingly.

Now you know. 

 

 

 
Copyright © 2011 Randy Fry
By |2017-05-24T00:03:08-05:00March 13th, 2011|Nature Essays|Comments Off on Birds, Magnetite and Unkind Scientists
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Mockingbirds, Music and Soliciting Sexual Advances

Okay, spring is officially here.  A few days ago, and all at once, the mockingbirds started singing.

Mockingbirds are the most spectacular vocalists in the bird world, at least here in North America.  They are not only great mimics, but they are arrestingly powerful singers, especially the males.  The females sing a bit more quietly, but a male will perch somewhere prominent and absolutely blow you away, and if he’s a single male, he might go on all night.  I have so often stood spellbound on a quiet night, when the whole city is dark and silent but for a single song ringing across the landscape from the top of a chimney somewhere.  Mockingbirds are awesome.  And they’re common.  You don’t have to go anywhere at all to hear one.

They’ve been observed cycling through the songs of 55 different species in just one hour, and a single male can have a repertoire of up to 200 songs.  Not all of them are bird songs, either.  They’ll mimic car alarms, squeaky hinges, you name it.  And if you hear one singing, you’ll be able to find him.  It’s all about being seen.

But what I wanted to know was, why do they do it?  What function does mimicry serve?  I can be a hopeless romantic where nature is concerned, but I know that things in nature, for all their beauty, always have a purpose, and I was curious about this one.  Pick up any text book and it will casually say that they do it “to attract a mate.”  Well, okay, but I wasn’t satisfied with that.  Here’s what puzzled me:  Mating rituals, which is what this is, are there for several reasons, and one of them is  to prevent someone mating with the wrong species.  It may sound funny, but when you have a pea-sized brain it can be an easy mistake to make.  And, evolutionarily, it would be a fatal mistake.  So mechanisms have evolved to prevent it:  no one gets in an amorous mood until they hear the right song, or see the right display.

By that measure you would think this mockingbird must be crazy.  Is he trying to solicit sexual advances from the females of every species but his own?  It didn’t make sense to me.

I had to do a fair amount of digging through obscure research papers to get to it, but I finally found an explanation I liked.  It turns out that their songs may impress us, but they don’t fool the other birds.  In fact, they don’t fool the female mockingbirds either.  She knows full well that this inspirerd performance is coming from a male mockingbird, and in fact she assesses it with a critical ear.  Research has shown that the females are more attracted to a male with a larger collection of songs.  And here’s the point:  It takes time to learn them all.

She’s looking for experience, that’s what this is about.  She wants maturity.  She wants a mate who’s proven he knows how to survive.

Now you know.

 

 

 
Copyright © 2011 Randy Fry
By |2014-10-12T14:17:37-05:00March 9th, 2011|Nature Essays|Comments Off on Mockingbirds, Music and Soliciting Sexual Advances
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The Great Lightning Bolt Debate

A couple of weeks ago, after a Saturday thunderstorm, our running buddy Kate told me on a run that it had “sparked” a family debate about whether lightning strikes upward, or downward.  (I didn’t know it at the time, but that lightning storm had started some forest fires in Big Sur that would change our lives.)  Some were claiming that a bolt of lightning actually moves from the ground to the cloud overhead.  But what could that mean?  That when we are struck by a lightning bolt, it actually originates underfoot, and leaps up to the clouds through us?  Clearly some research was called for.  I leapt into action.

Alas, like so many things in nature, it is not as simple as either of those explanations.  But it’s pretty interesting.  Here’s how it all comes down—pardon me, here’s how it all transpires.  (There are a zillion kinds of lightning.  I’ll just describe the most common type of ground strike.)

Your basic thunderhead has a negative electrical charge at its bottom.  This induces an opposite electrical charge in the earth below it, which actually follows the cloud around like its shadow as it moves across the landscape.  So you have a humongous negative charge in the cloud, and a humongous positive charge in the ground, and they’re following each other across hill and dale.  They’re just itching to get together.  But there’s a problem.  Air does not conduct electricity.

What ends up happening is that a “leader” of ionized air molecules starts reaching down from the cloud toward the ground.  Ionized molecules have missing electrons, so they do conduct.  So this little tendril is a is a conductive channel, reaching tentatively downward, and often branching out in several directions, irresistably attracted to the positive charges below.  Its voltage is pretty small, as lightning goes, and it’s almost invisible.  It takes a long time to do this reaching down thing—a large fraction of a second.  But when one of its branches finally touches the ground, POW!  It’s like touching a hot terminal with a piece of wire.  As soon as it touches, all hell breaks loose.  That’s called the return stroke.

It’s the return stroke that does all the damage.  That’s the one you see, as roughly 100 trillion watts run explosively back up the channel opened by the leader, with all the ferocity that’s been stored up in the positively charged earth.  The return stroke is faster, only a few milliseconds.  The average bolt is about half an inch across—the diameter of a pencil—and it instantly superheats the air around it to twice the temperature of the surface of the sun (I’m not making this up), which creates a shock wave which we hear as thunder.  Usually it’s followed by repeat strokes, along the same ionized channel, until the charges are equalized or the channel dissipates.  Your average lightning strike is composed of three or four separate strikes back up the same path, which is why lightning flickers.

So here are the multiple answers to the debate:

  • In the sense that the whole thing starts with a leader reaching down from the cloud, lightning strikes downward.
  • In the sense that the major bolt is the return stroke following that leader back up, lightning strikes upward.
  • In the sense that in any electrical current the electrons move toward the positive, lightning strikes downward.

Glad I could clarify.  Now you know.

 

 

 
Copyright © 2011 Randy Fry
By |2017-05-24T00:03:08-05:00March 4th, 2011|Nature Essays|2 Comments
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Ghost Crabs and Tequila

Take a look at this guy.  Isn’t he a cutie?  Especially for the most ferocious predator in the sandy beach habitat?

He’s called a ghost crab.  They’re called that because they’re exactly the color of the sand, they come out at twilight, and they run swiftly across the beach and disappear into a burrow before you can figure out if you’re hallucinating.  I once spent a semi-drunken evening dashing around a beach trying to see if I could catch one (these guys live where the tequila flows).  I never even came close.  It’s estimated they can move at up to 20 miles per hour.

Being crabs, they’re multi-talented.  They are opportunists, thieves, scavengers and scoundrels, and they will eat anything that moves, and several things that don’t anymore.  They are quick enough to snatch flying insects from the air, and mean enough to kill and eat shorebirds, which is pretty impressive, because they only get about as big as the palm of your hand.  They are a problem for endangered plovers, which nest on the sand and have to be constantly defending their chicks from these things.

They did studies and found that when they run with that incredible speed, they have three distinct gaits, just like a horse or a dog does:  a walk, a trot and a gallop, and they have speed thresholds where they have to break into the next one.  The  physics of it all is very similar to what you see in those mammals.  This amazed scientists, because of course crabs evolved from a radically different background than mammals—and for that matter, have a radically different number of legs, and for that matter move sideways instead of forward.  But the physical laws of locomotion apparently don’t change, and it ended up being what scientists call convergent evolution, in which two species independently evolve the same solution to a problem.  (Other examples:  seals and fast fish are shaped the same;  bats and birds both fly.)

Those eyes can see 360 degrees, but cannot see straight up, leaving them vulnerable to bird attack.  To run around out of the water, they, like most shore crabs, fill their gill chambers with water, somewhat like a scuba diver filling a tank with air.  Periodically they have to take a dip and replenish it.  But they’re able to keep their expenses low when they have to:  when they hibernate, they go for six months without breathing at all.

Now you know.

 

 

 
Copyright © 2011 Randy Fry
By |2016-07-09T13:40:54-05:00March 1st, 2011|Nature Essays|Comments Off on Ghost Crabs and Tequila
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