The Mind of the Crow

Well, happy holidays, friends, family and fellow naturephreaks!  I hope that you had a good one, and got out on a hike or two in this beautiful, bright winter weather we’ve been having.

Good friend and gifted birder David send us a link to the video below, and you might want to take two minutes and watch it, because it’s pretty astonishing.  It’s a Russian carrion crow (Corvus corone) tobogganing down a snowy rooftop on a plastic lid he has found.  I’m not making this up.  He does it repeatedly, carrying it up the slope each time for the next run.  I have known for a long time that crows are pretty clever, but this one absolutely blew me away, and I decided it was finally time to write an article about corvids.

Corvids (family corvidae) are, roughly speaking, the crows, ravens, magpies and jays, and they are an amazing family of birds.  As I’ve mentioned in a couple of other articles, the owls, our favorite symbol of wisdom, are actually one of the stupider birds.  The corvids are the brilliant ones.  They are the innovators, the problem solvers, the ones who can adapt to anything and handle change at a pace few other creatures besides us can.  And the cool thing is that they’re all around us.  You don’t need to go anywhere at all to see a corvid, and if you pay attention, you’ll see that intelligence shining through.

The stories abound, and I’m going to entertain you with a few of them, but then I’ll look a little deeper, into the reasons that corvids are the amazing birds they are.

Scrub_Jay
Western Scrub Jay (Alphelocoma californica)
By Ingrid Taylar,

I’m a cubicle inmate now but I used to have an actual office with an actual window, and one day on a whim I brought in a bag of peanuts and set a few out on the windowsill.  Within two days I had scrub jays (Aphelocoma californica) taking peanuts out of my hand.  Within a week I had trained them to tap on the glass with their beaks to get my attention, because back then I was young and ambitious and there would be the odd moment when I was absorbed in my work.

Our friend Marty was driving behind another car once on a stretch of country road where ground squirrels were working the dirt shoulder, and he saw a crow positioned on a fence post ahead, right above a foraging ground squirrel.  The crow waited until the car in front of Marty was upon them, then he dive-bombed the ground squirrel, startling him out into the path of the car.  Thump-thump.  Dinnertime.  It could have been coincidence, but I have no problem believing it was intentional.  After all, crows have been documented herding sparrows into glass walls to stun them.

If you hang a piece of meat from a perch on a string, a common raven (Corvus corax) will figure out how to pull it up bit by bit, stepping on the string in between so it doesn’t drop back down.  They steal the fish off the lines of ice fishermen the same way if they’re left unattended.

In the city of Sendai in Japan, carrion crows (Corvus corax ) fly into intersections when the light is red and put walnuts in the paths of car tires, to get them crushed.  They started doing this in the 1990’s, and the behavior is expanding into other regions, because crows share information socially, so what they learn moves outward through the populations and also downward through the generations,  and that, it can be argued, could be called culture.  Culture among animals is controversial.  It’s one of those things like tool use, which we would really like to believe is ours exclusively.  But this writer believes that the news is bad, and we’re not as special as we think.

Crows are widely reported to hold funerals.  They stand around a dead flock mate—in silence.

Crows and ravens play.  Play can be defined as structured behavior that brings no material benefit to the animal, and people as auspicious as Sigmund Freud and Carl Jung spent a lot of research time trying to prove that it is exclusively human.  They failed.  Obviously they’d never seen a tobogganing crow (or raised a kitten).  Crows will break off a twig to just the right size and play with it socially in groups (by the way, that also constitutes tool-making), and ravens will even play across species—the ones up north enjoy playing catch-me-if-you-can with wolves, diving at them and veering away just as the jaws snap, for no practical reason anyone has been able to figure out.  The ravens up there will also lead wolves to a dead animal whose hide is too tough for them to break, so that the wolves will open up the carcass for them, which is a behavior that wildlife scientists call manipulation.

Ravens display an ability in communication called displacement, which is the ability to communicate about something which is displaced in space or time—that is, something which is not here, or which is not here now.  This seems commonplace to us but there are only four groups of animals who can do it:  Us, ants, bees, and the common raven.  It was a foundational development in the evolution of human language.  Here’s one way the ravens use it:  ravens mate for life and the pairs are pretty solitary and defend a territory, but the unmarried ones flock, and when one of them finds a nice carrion kill in an area defended by a mated pair, he’ll go back to the roost and muster enough buddies to return, often the next day, and drive the pair away so they can eat.  It’s a behavior called recruitment, and ants do it too, when a dead bug is too big to drag.

Ravens cache their food items one at a time all over the landscape (it’s called scatter hoarding) and can remember dozens of locations, and they rob each other blind, shamelessly pilfering one another’s goodies.  A raven will fly a long way to cache something somewhere safe.  Others will inconspicuously watch, remember, and return later when the owner is not around.  Sometimes a raven will pretend to cache something, then fly off and cache it somewhere else, which proves that they are capable of deception.

RavenMaskl
Ravens are huge in Native American folklore and creation mythology
By Daderot (Daderot) [CC0 or CC0], via Wikimedia Commons

Ravens have been famous for this kind of stuff for thousands of years.  They have a huge presence in folklore and creation mythology, going back at least to the Paleolithic (fifteen to thirty thousand years ago), and are always showing up in Native American stories as clowns, tricksters and mischief makers.  The Bella Bella people of coastal British Columbia believe that Raven created the world for his own amusement, and considered human beings to be the most amusing animals of them all.  Then, for his own amusement, he made all the rivers run only one way, to make it more difficult for us to get around, which I personally think was just plain unkind, but at any rate, now I know who to thank for all those car shuttles I have to set up any time I run a river.

Crow_1024px-Steller's_Jay_Sandia_Peak
Steller’s jay (Cyanocitta stelleri)
By John Fowler, [CC BY 2.0], via Wikimedia Commons

Some corvids are gifted mimics, and use the talent in very clever ways.  A Steller’s jay (Cyanocitta stelleri—another corvid you don’t have to go far to see) can mimic perfectly the beautiful, haunting cry of a red-tailed hawk.  I swear they even throw a little reverb on it so that it sounds like it’s ringing down from on high.  A naturalist friend of ours knows of a stand of trees in Point Reyes in central California where robins stop off on their migration.  At some times of the year there will be ten thousand robins in this grove, and it just ticks off the local Steller’s jays.  So now and then one of them will do a fly-over and let loose a red-tailed hawk cry, and ten thousand robins will rise into the air in a panic.

I was backpacking with my nephews once in Yosemite when I heard the sound.  “Hear that, boys?” said Wise Ranger Randy.  “That’s a red-tailed hawk!”

“Um, Randy…” my brother Byron said out of the side of his mouth, and pointed discretely to a Steller’s jay in a bush twenty feet away.  Damn.  Nailed by the oldest one in the book.

 

*          *          *          *

 

At the University of Washington some years ago, Dr. John Marzluff was trying to convince his friends and colleagues that he wasn’t crazy.  He was being attacked and harassed by crows far more than anyone else on campus.  Even when he was walking in a group, they would attack him and not the people next to him.  The reason this interested him was that he was an ornithologist, and in fact he studied crows, which meant that he spent a lot of time trapping and banding the crows on campus, and climbing up to their nests to band the chicks.  Dr. Marzluff was absolutely convinced that they were recognizing him as an individual, though birds are not supposed to be able to do that.  What he didn’t know was how they were doing it.  Was it his face?  His gait?  His hair color?  His fashion sense?  He did what any scientist would do, and conducted a study.

He went to a dime store and bought two masks, one of a caveman, and one of Dick Cheney.  He started wearing the caveman mask whenever he was doing his crow work.  After a while, he started getting attacked any time he wore his caveman mask around campus.  When he wore his Dick Cheney mask he would not (though it turned a few students’ heads).  When he put the caveman mask on a student and made him walk across campus, the student got attacked (research assistants live tough lives).  He tried wearing the caveman mask upside-down.  An approaching crow would roll over slightly in flight and cock his head, checking out the upside-down visage.  Then he would attack him.

 

*          *          *          *

 

It was amazing news to the scientific community that crows can recognize faces, but they can probably do it because they live with humans, and when you live with humans, quite literally one will feed you and the next will kill you.  And that takes us to the most fascinating part of this yarn, which is the shared history of crows and human beings.  Crows, and probably other corvids as well, have been co-habiting with humans since before we were humans, probably for over eight million years.  And since our intellects didn’t begin their spectacular ascent until about two million years ago, for several million years while crows shared our hunting grounds and encampments with us, our wits were about evenly matched.  Really we co-evolved with crows.  And when our intellects did begin their climb toward humanness, and we began to evolve culturally at a rate far outstripping the glacial pace of genetic evolution, crows had to keep up, and they began to evolve culturally as well, by sharing and handing down information.  When we started building cities, they came with us.  When we invented guns, they moved into the cities in bigger numbers, because guns are not allowed in cities.  As our inventions changed the landscapes and the ways we lived, the crows adapted, and handed down the tricks to their children.  As author John Marzluff says in his wonderful book, In the Company of Crows and Ravens, the more unpredictable we became, the smarter crows had to become.

So that’s the thing:  Our journeys are intertwined.  When you look at a crow, you are looking at a creature who goes way back with you.  You are looking at a creature whose ancestor shared a campsite with your ancestor—and had him outwitted a lot of the time.  You are looking at a creature who, just like us, survived the most harrowing passages of his evolutionary journey by using his wits—by innovating, and learning, and cooperating, and then teaching it all to his children.

Now you know.

 

 

 
Copyright © 2013 Randy Fry

By |2017-05-24T00:03:07-05:00December 28th, 2013|Nature Essays|Comments Off on The Mind of the Crow
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Yellow Jackets According to Yellow Jackets

 

In a mixed conifer forest in the mid-elevations of the Sierra Nevada Mountains in California, a yellow jacket wasp hovers an inch above the forest floor, fanning the pine needles with her downwash, shifting rhythmically back and forth a few times and then skimming to a new spot, checking things out.  She is a queen.  It is spring and she has just emerged from hibernation.  She is stiff from her long, cold sleep, but her flight muscles are starting to warm up.  She circles the trunk of a large ponderosa pine and returns to checking out the pine duff, using all her senses to detect what’s beneath.  She has a job to do:  she needs to find a nest site.

She’s fond of abandoned rodent burrows, but a number of things will work.  She settles on an old ground squirrel burrow, its entrance obscured by fragrant pine needles.

All alone, she goes to work.  She does the small amount of excavating that needs to be done to reopen the entrance, and then builds a small paper comb hanging from the ceiling, just a few dozen cells, and she lays eggs in them.  As she waits for them to hatch, she goes out on forays into the woods, learning the area, and fortifying herself with nectar from some wildflowers.

When the larvae hatch, she feeds and nurtures them, going out on hunting trips and feeding them noshed-up insects she has killed.  They mature quickly into adult wasps.  They are sterile females—workers—but she can create fertile males also, any time she wants, egg by egg.  The new worker wasps hang the next rack of cells beneath the first, and it is bigger, and she lays more eggs.  She has a crew now, and the crew is helping her create more crew.  The hive is bootstrapping itself, from almost nothing.  As the combs grow and the workforce strengthens, she begins staying inside, focusing on reproduction, and staying safe.  The workers around her are capable and armed, and they will stop at nothing to defend her.

The workers range out across the landscape to find food for the growing hive.  They are energetic, inquisitive and aggressive.  They have a lot of mouths to feed, and they don’t go in for subtlety.  They are predators, and they launch a brutal and resolute assault on the local insect population, quickly asserting balance into the explosive springtime hatches of flying and crawling creatures.

But they do not eat the meat themselves.  In fact, they don’t eat meat at all.  They only eat liquidy sweet stuff, like nectar, and now and then some fruit.  What they do with the insects they’ve killed is to feed them to the larvae, who need the protein.  The larvae, in turn, secrete a sweet liquid that keeps the workers fed.  There is no selfishness in this hive—you get fed by giving.  It’s a behavior called trophallaxis, and it’s pretty common in social insects.

As the colony grows, the workers start to fly farther, trying to find enough meat to feed the booming larvae.  When the catch of insects starts to get thin, their scavenging behavior kicks in, and they scour the picnic areas, getting waved and slapped at by slow and lumbering hands.

It’s late summer by now, and the colony is approaching 2,000 wasps.  It is bustling and humming, and their numbers in the woods and the picnic grounds are getting intense.  As the queen starts to wind down her egg-laying, and the larvae numbers begin to taper, an interesting mathematical problem emerges.  There are no longer enough larvae to feed all the workers.  The workers go out and scour the landscape anew, but now they’re not trying to feed the larvae, they’re trying to feed themselves.  Again the picnic area works for them, but this time they’re not looking for meat for the larvae, they’re looking for sweet stuff for themselves.  They’re not after the hot dogs, they’re after the soda pop.

 

*          *          *          *

 

Early fall.  There is a chill in the air, and these creatures do not handle cold well.  Already, some of the workers are dropping, or not returning from their foraging runs.  When the first serious cold hits, the entire colony will perish.  The workers, the handful of fertile males, even the queen who founded the hive, everybody dies—but there is a new queen.  Maybe more than one.  She has been carefully nurtured and generously fed.  She is young, strong and she has reserves.  She has spiraled up on the mating flights with the males, and had her moments of rapture in the sky.  And now, she flies off, all alone, leaving behind her the collapsing colony.  A few weeks from now it will be a scatter of dead bodies and some crumbling paper combs.  It will not be re-used.

She looks for a place to hibernate.  She crawls into a deep crevice in a western black oak tree.  She nestles carefully into her space, and there, with the existence of an entire colony resting on her survival, she shuts herself down and waits for spring.

 

 

 
Copyright © 2013 Randy Fry
By |2015-09-03T09:03:16-05:00October 20th, 2013|Nature Essays|Comments Off on Yellow Jackets According to Yellow Jackets

Yellow Jackets According to Us

When I headed out with the usual suspects that day for our usual lunchtime run, I didn’t expect to end up looking at a coworker’s naked buns, but that’s the way things worked out in the end.  She was trotting down the Frog Pond trail twenty feet ahead of me when, all at once, she reached back and pulled down her running tights.  As I was trying to figure out what to make of that move, she suddenly accelerated away from me, flying down the trail at an inspiring pace, and reaching back with her hand and slapping at one startlingly-white cheek.  “Ow! Ow! Ow! Ow! Ow! Ow! Ow!” she said—though she repeated it more times than that.  Finally she came to a stop and turned to face me, indignantly pulling her tights back up.  “I got stung by a bee!” she said.

“It wasn’t a bee,” I said.  “It was a yellow jacket.”

Sometimes being Ranger Randy can almost get you smacked.

 

*          *          *          *

 

Well, the correction needed to be made, okay?  Too many people in this world don’t know the difference between a honey bee and a yellow jacket and it’s my job to enlighten them at all the wrong moments.   They are very different creatures.  They are both yellow and black and they both sting, but there the similarity ends.  A yellow jacket is not a bee, it’s a wasp, and by the way, you’re much more likely to get stung by one, and not just because their personality makes honey bees seem downright cuddly by comparison, but also because they don’t nest where bees do, way up in some tree cavity, conveniently out of the way.  Nope, they nest in shallow burrows right underfoot, just beneath the forest duff.  Walk too close to a nest, and one or two of them can get irate.   Step on it, and they attack in force.

BeeAndYellowJacket2
European Honey Bee (Apis mellifera)                                                 Yellow Jacket Wasp (Vespula vulgaris)
By Bob Peterson
[CC BY-SA 2.0]                                                                                  By Audrey [CC BY 2.0]

I have a relationship with yellow jackets (vespula vulgaris) that is just way more intimate than a cross-species relationship should be.  I’d estimate that I’ve been stung by those things over two hundred times, though I don’t think I have ever been stung on the butt, and the principle reason for that is that I was always wearing heavy work pants, and the principle reason for that is that, well…um…I used to be a logger.

People are surprised when I tell them that, because I’m now such an unabashed tree-hugger and militant environmentalist, but I sort of got here the long way around, and when I yell and wave my arms at the public hearings in defense of our forests, I actually know whereof I speak—the truth is that I have slain a lot of trees, and I have seen the timber industry propaganda from its back side.  I have a two-year degree in forestry, which is another word for logging, and I worked for two seasons in the woods before several things including the intellectual vacuum of small logging towns drove me on to other things.  For one summer while I was in college, I worked on a crew doing something the Forest Service calls tree thinning.  When you thin a stand of trees, you cut every small tree in about a twelve foot radius around the biggest and best looking one, to open up light and nutrients for the Chosen Ones so that they’ll shoot up and become lumber more quickly.  It’s a god-like job, deciding who lives and who dies.  You do this to an entire forest, finally leaving a bunch of perfectly-spaced trees sticking out of a five foot layer of slashed-up trunks and branches where the forest floor used to be.  And of course, you’re only supposed to spare the commercially valuable timber species.  So if, say, a tall, beautiful western black oak (Quercus kellogii) is within twelve feet of a pine seedling, you’re supposed to fell the oak.  (Black oaks are beautiful trees, and I didn’t follow directions well at times.)

In the course of all this, you step on pretty much every square foot of every acre of that forest, or if you don’t you drop a tree on it, so if there’s a yellow jacket nest anywhere, you will get mixed up with it.  And toward the fall, there are a lot of them.  Several per acre.  There are plenty of ways to get injured or killed when you spend your days surrounded by roaring chainsaws and falling trees, but this was by far the one that bedeviled us the most.

And I’ll tell you another difference between the two insects:  When a honey bee stings you, she leaves her stinger and a handful of abdominal organs imbedded in your flesh, and then quickly dies.  Yellow jackets don’t have barbed stingers, which means they can sting you repeatedly and fly away smiling and attack again tomorrow.  One time one of them danced down the side of my face, stinging me five or six times in a crescent running from my right ear all the way across my upper lip.  The little sucker got away clean, too, even though I risked life and limb by removing one hand from my chainsaw to slap at her.  Another time I walked up to a crew mate, and he was standing thirty feet away from his chainsaw just looking at it, where it was sitting there on the forest floor.  Puzzled, I looked at it with him, wondering what was up.  Then I noticed that the saw seemed to be oddly in motion.  Then I realized it was covered with yellow jackets.  He’d set it down on a nest.  He’d only gotten a couple of stings.  They were attacking the saw.  But that was going to have to change.  We contemplated the thing.

“Well…you can’t just leave it there,” I said.

“I know…” he said.  We looked at it some more.

“You gonna go get it?” I said.

“I thought you might.”

We looked at it some more.  “I already have a saw,” I said.

“Mm-hmm,” he said.

Finally he let out a rebel yell and charged in at full flight speed, snagged the saw with one gloved hand without even slowing down and disappeared whooping and hollering into the woods.  I stood looking after him.  He didn’t quiet down for some time.

They have marauding personalities.  They are inquisitive, opportunistic, tenacious and ravenous.  When they check you out they have a sinister way of feinting back and forth just above your skin, like a boxer about to throw a punch.  Even people who study wasps for a living call them “extraordinarily aggressive.”  Almost every other wasp in the world is strictly predatory and hardly ever comes into contact with us, but yellow jackets are very unusual in that they have a scavenging behavior on board, and the sense of curiosity that always accompanies that, so they mix it up with human beings all the time.  They get thick around picnic tables.  Wave one away and she’ll immediately return.  Swat her and she’ll get mad.  They’re well-respected in the woods, both by us and other insects.  Flys, moths, beetles and even other, non-stinging wasps mimic their markings protectively (it’s called Batesian mimicry), but the yellow jackets do have their own predators, including other wasps.  We once hooted and cheered like kids as we watched a yellow jacket and a bald-faced hornet (Dolichovespula maculata), which is a larger, black and white wasp, roll around on the stump that was our lunch table, locked in a predatory battle to the death.  The yellow jacket finally succumbed, and the bald-faced hornet flew away with her prize—right into a large, orb-shaped spider web twenty feet above us.  Nature in action.  A bad day for both of them.

2919baldf.w
Bald Faced Hornet (Dolichovespula maculata)
By Beatriz Moisset [GFDL]

Like bees, they have a potent venom but in a tiny quantity, and most people suffer no serious effects from a sting or three.  But if you’re allergic or  you get swarmed, you can quickly end up in anaphylaxic shock, which is a deadly condition in which your throat swells shut, among other things.  Everyone who works in the woods is asked whether they have an allergy, but of course not everyone knows whether they do or not, and besides, allergies can come and go.  There was a folk legend going around the Forest Service office I worked out of, about a foreman who was supervising a crew in the woods when a worker stepped where he shouldn’t have and picked up several stings.  The foreman asked if he was okay.  Yeah, the guy said.  The foreman asked if he was sure.  Yeah, no problem! he said.  The foreman looked at him.

Later the foreman couldn’t explain why he did this, but he grabbed the guy, heaved him into the pickup and peeled out for town.  By the time they got to the hospital he was comatose.  He’d had his life saved by a man willing to trust his instincts.

Well, that’s the story on yellow jacket wasps, but it’s not the whole story.  I wrote this article entirely from our perspective.  In the next post, I’ll tell the tale through their eyes, and I’ll take you inside a nest, and introduce you to the queen.

Stay tuned.

 

 

 
Copyright © 2013 Randy Fry

By |2017-05-24T00:03:07-05:00October 12th, 2013|Nature Essays|1 Comment

Black Wingtips and Electric Breasts

I told Byron’s fiancé Roni, on a nice hike we went on the day after Thanksgiving, that large birds have black wingtips because black feathers are stronger.  I was pretty proud of myself—I thought this was a pretty cool factoid—but she came back with that feared and revered question, that eternal one-word query that so haunts parents and scientists alike:  Why, she said.  Why are black feathers stronger?

I considered making something up, but she’s getting where she knows me too well, so I took another dive into this subject.  Here’s what I found, and I promise not to go off on any tangents this time.

So if you were a bird of paradise and you wanted to show off for a pretty girl, how would you make your chest blink back and forth between two colors?

Okay, call it a tangent, but it’s where you’re about to end up.

First, just to demonstrate that I do have some focus, I’ll answer Roni’s question:  Black feathers are stronger because they contain the pigment melanin.  Melanin occurs in granules, and any structure containing granules is, not stronger really, but more resistant to abrasion.  It doesn’t dent or scratch as easily.  And scientists have been able to prove that for cracks to propagate in the keratin of a bird feather, there first has to be damage to its hard surface.  Without the initial surface damage, you don’t get cracks developing into what the FAA calls “catastrophic structural failure.”  You find it in high-performing flyers like hawks and gulls, out toward the wingtips where the stresses of flight are the worst, but you also find it on small birds in desert areas, because they contend with a lot of abrasion from blowing sand.  Unkind scientists spent some time denting the beaks of starlings (yeah, I know…), which are also made of keratin (so are fingernails, hooves and the baleen of whales), and they found that beaks with lots of melanin resist damage 39% better than those without, which means that you can be a large bird without black wingtips (the great egret comes to mind), but your flight feathers will have to be about 39% beefier to put up with the abuse.

GreatEgret
Great Egret (Ardea alba)
By Ardea_alba_-San_Francisco_Bay,_California,_USA_-flying-8.jpg: Don DeBold derivative work: Snowmanradio
[CC BY 2.0], via Wikimedia Commons

Feathers are the most complex external structure found on any vertebrate.  They are amazing pieces of evolutionary engineering, but what blew me away about them on this read is what goes on microscopically on their surfaces, creating their structural colors.  As I talked about in the last article, birds have two ways of achieving color:  pigment, and iridescence, but actually it’s not always iridescence, which is rainbowing, so scientists just call it structural color.  The easiest kind of structural color to describe is an oil slick on water.  You end up with two reflective surfaces separated by a teensy distance.  Half the light reflects off  the first surface, and the other half reflects off the second.  The two waveforms return to your eye together but they’ve traveled different distances and they’re out of sync, and they interact, interfere, reinforce, and generally have a good time all over the spectrum, creating new colors depending on the viewer’s angle.  That’s iridescence.  Scientists know how to overfly an oil spill and measure the film’s thickness by studying its color.

Thin_film_interference
Thin-film Iridescence
By Chanli44 at English Wikipedia [Public domain], via Wikimedia Commons

Birds, though, have taken all this to a whole new level.  They have total control over what colors get created when, and from what angle, and I mean, it’s sophisticated.  They use, just to toss out a few terms that ornithologists think in, reflective films, diffraction gratings, selective mirrors, photonic crystals, crystal fibers and deformed matrices.  They are highly precision structures, and when I call them microscopic, I mean really small, like, as small or smaller than the wavelength of light they work with (which renders ordinary light microscopes useless for studying them).  And the color doesn’t always look reflective.  The deep, rich green of many parrots is created by selective mirrors, which are micron-sized bowls which, because of their size and shape, are able to reflect exactly two wavelengths of light—yellow is able to reflect straight off the bottom of the tiny bowl, and blue is able to do a two-step and ricochet from one wall to the other and then back out.  Nothing else reflects.  The result is a perfect green, but it gets better:  The angles of the bowls are carefully randomized so that you see the color from any angle, and you’d swear you’re looking at a pigment.  But you’re not.  Grind the feather up in a mortar and pestle and you’ll have a gray powder.  Many species do use the rainbowing of iridescence but, again, angle the mechanisms carefully in all directions so that it works from any angle and there is a single vibrant iridescent color that hardly varies with viewpoint.  Beetles do this.  The colors of the blue and yellow macaw (Ara ararauna) are structural, and though very striking, they do not come and go, because the structures (deformed matrices, in their case) are oriented in all directions.

BlueAndYellowMacaw
Blue and Yellow Macaw (Ara ararauna) — No pigment in those colors!
By Luc Viatour [GFDL] [CC BY 2.0] [CC BY-SA 3.0], via Wikimedia Commons

Birds mix and match the tricks of color.  They arrange these structures in concert to create combinations of effects, and they mix pigment color with structural color.  The green parakeets in pet shops are a combination of a yellow pigment and a structural blue.  An albino parakeet is blue and white.  In olive-colored songbirds like vireos you’re seeing a structural yellow, plus melanin.

When they do decide to use the angle of view to get an effect, it can be pretty stunning.  It’s why the throats of the hummingbirds in your yard flash as they slalom through the air.  Western bluebirds look drab from most perspectives but now and then they’ll catch the sunlight right and break your heart.  But my favorite is the bird of paradise called Lawes’s parotia (Parotia lawesii), whose breast plate has structural thin-film iridescence, but arranged into V-shaped ridges, so that it reflects only two colors from only two directions, electric blue-green from one direction, and electric yellow-orange from the other.  When he dances for his girl, he shifts his breast back and forth and it blinks from one color to the other.

Pretty amazing stuff, but then birds have had forty million years to work this out, which is about 39.8 million years longer than we’ve existed as a species.

AlbinoParakeet3
Albino parakeet (left)
By Iaminfo [CC BY-SA 3.0] [GFDL], via Wikimedia Commons

And to add one more wrinkle to this, birds can see in the ultra-violet spectrum.  They have a fourth cone in their retinas that we don’t have.  A scarlet ibis isn’t scarlet if you’re an ibis.  He’s deep purple, reflecting a strong structural ultra-violet that we can’t see.  Many species of birds appear to us as if the males and females have identical plumage, but they don’t.  Not to each other.  The western bluebirds I mentioned would be much more stunning birds if we could see in UV.  Scientists actually figured this out years ago because the hawks weren’t stopping in a forest in Bavaria.  Bear with me.  They would always stop over on their migration to hunt voles, and people noticed that when the voles were having a bad year, the hawks wouldn’t even stop.  Wouldn’t even drop down and give it a try.  They’d just pass on over.  How did they know?  It turns out that vole pee reflects ultra-violet light.  To the eyes of a hawk, those little vole trails light up the forest floor like strings of fairy lights.

Now you know.

 

 

 
Copyright © 2012 Randy Fry

By |2017-05-24T00:03:07-05:00December 1st, 2012|Nature Essays|1 Comment

Pink Flamingos and Snowball Earth

Happy Thanksgiving, everyone, and to all my Indian friends, happy Diwali!  This year’s Ranger Randy research assignment from the Thanksgiving gathering of family and friends involved flamingos, and the Zen question of why pink flamingos are pink. A scientist at the Monterey Bay Aquarium once told me that if you grind up a blue jay feather in a mortar and pestle, you get a neutral gray powder, and I’ve always promised myself that someday I’d do that and see if it’s true, just to keep the scientific community honest.  There’s no pigment behind many of the colors you see in bird feathers.  The colors, especially the vibrant colors in something like the red throat of a hummingbird, are accomplished through refraction, like the rainbowing on an oil slick.  This is an extremely clever evolutionary trick, because refraction only works in direct sunlight, which means that if you’re a bird who needs to both show off and worry about predators, you can fly up into the sunlight and make a great, showy spectacle of yourself, but as soon as you drop into the shade of a bush you blink out like a light.

What’s unusual about pink flamingos is that they do have pigment in their feathers.  It comes from the brine shrimp they eat.  Actually, it comes from the blue-green algae that the brine shrimp eat, which contain carotenoids, an organic pigment which gives carrots and apricots their color, and also underlies a ton of biological processes including photosynthesis.  The flamingos who eat more blue-green algae directly are a deeper pink than those who get the carotenoids only through the shrimp.  The babies are born gray, and even an adult flamingo who does not eat the shrimp or algae will gradually turn almost completely white with only a faint pinkish blush.  In zoos, they have to put pigments in their food, to keep the visitors from being extremely disappointed.

Carotenoids are also the reason that fall leaves turn the wonderful red and orange colors they do.  The other pigments like chlorophyll fade first as winter approaches, leaving the carotenoids.

But here’s what really took me off on a tangent on this one.  And what the hey, tangents are what I do in these articles, and that’s as it should be when you’re writing about nature.  John Muir put it well: “Tug on any one thing in nature and you find it connected to everything else.” So here we go: If I understand this correctly, blue-green algae is not exactly an algae, it’s a photosynthesizing bacteria, and here’s the tangent:  it’s the reason we have our atmosphere.  I’m not making this up.  These ancient little one-celled creatures are the reason we can breathe, and the reason our skies are blue.  When their numbers in the oceans started to boom, it was 2.4 billion years ago, and there was no oxygen in our atmosphere at the time.   But photosynthesis generates oxygen (which is why we will all die when we finally manage to kill all our forests), and at first the oxygen molecules they generated just combined with iron molecules in the water and sank like little molecular pebbles to the ocean floor and were never heard from again, except that they created a layer of reddish strata on the ocean floors that is still there today and provides a chronological benchmark for every geologist in the world.  This went on for two hundred million years.

Then, finally, 2.4 billion years ago, the seas ran out of iron.  It had all been swept up and sent to the bottom, and there was no more, and oxygen started to rise into the atmosphere.

What happened next is sometimes called the Great Oxygenation Event—and  sometimes the Great Oxygen Catastrophe.  To all of us, it sounds like a wonderful and blessed event, but it sort of depends on your viewpoint.  Just about every anaerobic organism on Planet Earth perished as this cloud of toxic oxygen swept over the landscape killing everything in its path.  It was one of the biggest extinction events in the history of our world, and it dramatically changed the trajectory of the evolution of life on this rock of ours.  And the mayhem and tragedy that it caused did not end there!  It also oxidized the methane in our upper atmosphere, with the result that it was no longer a greenhouse gas, and the planet was plunged into one of the most dramatic ice ages in our history, sometimes called Snowball Earth, in which some think that even the equatorial waters froze over.  There’s still argument about Snowball Earth, though.  Some argue that such a condition would not have had an exit door—that is, it couldn’t have happened because it couldn’t have un-happened.  With that much reflectivity on the surface of the earth, our planet could never have warmed again.

But smile—we don’t have to worry about Snowball Earth.  Nope, the opposite fate is staring us in the face.

And on that cheery note, I’ll leave you to enjoy your leftover Thanksgiving turkey and Diwali sweets.

Now you know.

 

 

 
Copyright © 2012 Randy Fry
By |2017-11-12T11:31:17-05:00November 25th, 2012|Nature Essays|2 Comments

Hurricanes and Flying Palapas

When Hurricane Wilma hit Dave and Nancy’s Yucatan house in 2005, it hit it so squarely that afterwards all the phone poles north of town were on the ground pointing west, and all the phone poles south of town were on the ground pointing east.  Dave picked us up at the airport and driving back you could look right through the jungle—not a leaf anywhere.  It had been completely defoliated.  One billboard after another was flat on the ground, and Dave had been wandering the neighborhood looking for the palapa that had been on his rooftop terrace.  Palapas are thatched structures used for shade in the Yucatan.  They’re made of logs.

palapa
Palapa
By Thelmadatter
[CC BY-SA 3.0], via Wikimedia Commons

We all know what a hurricane can do to a city, but a friend of ours who regularly visits Dave and Nancy with us asked me recently what hurricanes do to ecosystems.  It was an interesting question that I had never asked myself.  What is the natural effect, and the natural response, to an insanely violent event like a hurricane?  If we remove human beings from the picture for a moment—our cities, our hotels, all our other misdeeds and miscalculations—then what goes on in coastal ecosystems during a hurricane?  Chatting with Susan about the question that night over cocktails, I made a prediction:  I predicted that when I looked into this I would find that the organisms in tropical coastal ecosystems not only can handle hurricanes, but need them.  It wasn’t the most brilliant or daring prediction, but anyway it looks like I was right.

A hurricane is not only a violent event, it is a chaotic one, and when I say that, I’m not using hyperbole, I’m using mathematics.  Chaos mathematics was invented by a guy named Edward Lorenz, and he was a meteorologist—he was trying to write a computer program to model world weather patterns.  Hurricanes in particular and weather systems in general are so complex that predictability itself is defeated, and chaos theory is what Lorenz developed in order to analyze the stuff.  Inherent in chaos theory is what Lorenz called the “butterfly effect,” the idea that a tiny change in initial conditions, like the flap of a butterfly wing, can have a huge effect down the line—like a hurricane.

Which is one reason no two hurricanes are the same.  You might experience anything from lashing winds to rising sea levels to the breaching of barrier islands and sudden exposure to the open ocean, or it may just park above you and dump torrential rain for several days.   A large hurricane can have a storm surge at its center where the sea level is thirty or forty feet higher than normal, and that’s in deep water—before it hits the coast and the ocean floor runs up under it and everything stands up into breaking waves.  It can redraw coastlines by 100 meters or more.  Katrina and Rita alone sent over seventy square miles of our fair land into the deep blue sea, but hurricanes also deposit huge amounts of sediment and nutrients and raise the soil level in coastal marshes and keep them from subsiding and becoming open water.  Estuarine channels and waterways may protect the coast against the storm surge, and you may feel fortunate to live at the end of one, but they can also focus and funnel the surge, depending on their shape, with the result that, hours after the battering, when you’re looking at clear skies and  thinking you’ve survived it, a wall of water suddenly flattens you and everything around you.  The National Hurricane Center used to offer up storm surge measurements along with its one-through-five Saffir-Simpson category rating, but they finally threw up their hands and gave up on it.  The whole thing was just too localized, and their credibility was going to hell.  What happens to you in a hurricane depends on where you are, what you’re up to, and how the gods of chaos mathematics are feeling that day.  Only one thing’s for certain:  it will change your life.  Right underfoot, or paw, or flipper, things will change.  Your world will be different in the morning.

And nature just loves that.  It loves it to death.  I’ve said this in more than one article:  the balance of nature may be a balance, but it’s not a stasis.  Things out there are constantly in motion, and organisms have evolved accordingly.  The idea of a permanent community that never goes anywhere and would be devastating to lose, is a peculiarly human notion.  What the natural world is full of is opportunists, and change is their medium, chaos is their opportunity generator.  Mind you, they don’t have to like it, and any one organism in a hurricane may live or may die, but according to my reading, the communities tend to do just fine in the long term, and in fact need what the hurricanes bring them.

DSC00338
Mangrove forest in the Yucatan. The red water is from the tannin of the mangrove trees.
Photo by Susan Fry

Mangrove forests are a delightfully unlikely plant community.  They occur all over the tropics in shallow coastal waters and fine, depository soils, but the word “mangrove” actually doesn’t have a taxonomical meaning.  These trees and shrubs are all a case of convergent evolution—innovative desperados from a wide variety of family backgrounds who have all figured out a way to live with their roots submerged in saltwater,  which is really a pretty impressive trick when you think about it.  Heck, most trees will suffocate if you submerge their roots even in fresh water.  Roots simply have to have free oxygen, it’s that simple, and also, salt levels that high are in opposition to every osmotic process in their bodies.  Mangrove species each employ a different array of tricks, but they all pull it off—they send things called pneumatophores up into the air like little breathing straws, or they get oxygen through special organs in their bark called lenticels and send it down from there; they have subcellular mechanisms in their roots that admit water but exclude salt, or they dump the salt they ingest into their older leaves and then drop them in the drink like little garbage bags.  They stand absurdly on spindly, stilt-like roots, and the dense network of roots slows tidal actions and causes the deposition of the fine silt they need, creating their own soil exactly the way they like it.  Red mangroves (Rhizophora spp.) produce seedpods that look a lot like large string beans, but what’s different about them is that the seeds germinate right inside the pod before it drops into the salt water and floats away.  After it has drifted awhile, it redistributes its weight and goes from floating horizontally to vertically, so that its bottom end nudges up against the silt and it can establish itself.  And this is even cuter:  if it fails to establish itself, it will redistribute its weight again and float away horizontally to try somewhere else.  Mangrove ecosystems are just bizarre—if you were a working god in a design room somewhere with the other working gods and you proposed a mangrove forest, you would be laughed out of the place.  Yet they cover three quarters of tropical coastlines, and the habitat is rich, home to all manner of crustaceans and mollusks and sessile (attached) organisms, and a tremendously important nursery for small fishes.   And they do protect the coastline from the worst ravages of the hurricane, but not from all of it, and also, they themselves are changed by it, and they adapt.  After the storm there may be several inches added to the underwater soil among all those stilt roots, and they immediately start sending out rootlets horizontally in the new layer, stabilizing it and soaking up the windfall of new nutrients.

Forests may get completely defoliated by the wind, but the only knock-downs are usually at the edges.  (As human development fragments the forests, there is much more of this edge habitat, and much more damage.)  After the storm an entire forest’s worth of leaves starts decaying in the inland bodies of water, depleting oxygen and causing huge fish kills.  Arboreal lizards are suddenly completely exposed to airborne predators in the leafless forest, and may try to drop down to the lower branches for protection, but will be competing there with better-adapted creatures designed for the job.

Migratory birds cross the Gulf of Mexico toward the end of hurricane season, and if a hurricane is threatening, they’re smart enough to wait for better weather before taking off.  They have enough fat to power the 600-plus-mile crossing, but only in reasonable conditions, and in the end they’re as imperfect as we are at predicting the weather, and they can get caught out.  Bird migrations are not as hard-wired as people think, though, and if they land in their usual location and the place has been stripped of all fruit, leaves and insects, they’ll continue on, looking for better stuff.  If they get blown hundreds of miles off-course, they will look around for a stopover that works, and regroup.  (Human developments are making these stopover habitats harder to find for exhausted birds.)   Thousands of birds can perish in a hurricane, or starve in its aftermath if they don’t know how to deal with something like a leafless forest.  Cavity nesters get hit particularly hard following a hurricane, because trees with cavities are by nature weak or already dead, and go down in the wind a lot, often snapping right at the cavity.  When Hugo hit the Carolinas in 1989, one forest lost 87% of its nesting trees and 67% of its red-cockaded woodpeckers (Picoides borealis).  The bird populations can rebound in four or five years if they’re otherwise healthy, but of course it’s the species that are already in trouble that get hammered.  The Puerto Rican parrot (Amazona vittata ) got its numbers halved by Hurricane Hugo in 1989—from 47 birds down to 23.  But even as all these creatures are enduring huge death tolls, they are also taking advantage of the shifting patchwork of habitats.  Edge habitats and transitional habitats are rich places.  Opportunity abounds.

USGS_HurricaneCharleyBreachCaptivaIsland
North Captiva Island, before and after Hurricane Charley
By United States Geological Survey [Public domain], via Wikimedia Commons

Barrier islands are skinny spits of sand running parallel to coastlines, and they are created by—and reshaped by, and destroyed by—natural oceanographic forces, mostly wave dynamics.  Scientists have been proposing theories about their formation since 1845, but to this day you could walk into any oceanography symposium and assert any theory, and you’d more than likely end the evening with a black eye.  The islands  may have vegetation on them, even groves of trees, but make no mistake, at the end of the day they are sand spits, and they are quite fragile.  There’s a whole rank of them along the U.S. Gulf Coast, and in the shallow sounds between them and the mainland are great beds of sea grass, rich incubators and nurseries, full to bursting with shrimp and other crustaceans, young bony fishes and turtles.  Hurricanes overtop the islands and open up new channels through them, suddenly exposing the mainland to direct waves from the storm.  Whole sand dunes get washed into the sound and bury the sea grass beds, but the beds recover quickly, and even the channels blown through the islands heal themselves in following years.  Hurricane Charley, in 2004, opened a new channel fully a quarter mile wide through North Captiva Island, a barrier island off  Florida (fully developed and inhabited, of course).  By 2010 the gap had closed again through natural processes.

Coral reefs are notoriously fragile, but really only because they live in a human-infested world.  They don’t actually mind hurricanes that much, and branching coral like staghorn coral (Acropora cervicornis) even relies on strong storms to distribute itself.  It does reproduce sexually once a year through broadcast spawning (that’s the practice of throwing sperm and eggs into the water and hoping for the best), but its dominant mode of reproduction is through fragmenting.  Storms break off branches and sweep them away, and they are able to reattach to the substrate and start new colonies.  It’s classic opportunism:  after a hurricane staghorn coral leaps to life and recolonizes explosively, turning the most destructive storms on the planet to their advantage—but there’s a problem with it, too.  The problem is that it is asexual reproduction, and doesn’t generate a lot of genetic diversity, and staghorn coral consequently hasn’t handled a changing world very well.  Disease and changes in temperature or salinity give it real trouble, and staghorn coral is currently classified as critically endangered.

Well, to wrap up the story of the first organisms mentioned in this yarn, Dave and Nancy are both okay.  They’ve evolved their own survival mechanisms, and one of them is a sense of humor.  The two of them actually survive about one of these things per year on average, and they’ve gotten pretty good at it.  Once they had just received and installed thousands of dollars worth of new windows when they found themselves in the sights of a hurricane.  Dave raced through the house uninstalling them all again, so the storm could blow through the structure.  It worked.

It’s all about handling change.

Now you know.

 

 

 
Copyright © 2012 Randy Fry

By |2017-05-24T00:03:07-05:00September 17th, 2012|Nature Essays|2 Comments

The Wisdom of the Hive

When a column of marching army ants in Africa attacks a termite mound, remarkable things happen.  The termite queen, who is a helpless, blob-like egg-laying machine, is rolled and pulled into a special chamber by her tenders and walled in.  Soldier termites swarm out of the nest to engage the enemy, and worker termites seal off the entrances behind them.  They will not be able to return.  Win or lose, every one of them will die.  They fight fearlessly, unquestioning, protecting a civilization they have built that might include wells that go down to the water table, ventilation shafts, galleries, fungus gardens and a royal chamber for the queen.  The termite soldiers are several times bigger than the ants, with huge mandibles, but the ants swarm, and attack the extremities, grabbing the hind legs and the antennae, and holding them down for the hoard to kill.

The march of the army ants is a scorched-earth rampage.  Scouts out ahead of the column paint any prey animal they find with a pheromone that triggers attack by the rest of the swarm.  They kill and eat mostly other small invertebrates but can bring down bigger animals including rodents and even human beings.  When they attack a termite colony their goal is to kill the queen so they can abscond with all the eggs.  They cross watercourses and gaps in the landscape by creating swinging bridges with their interlinked bodies, which Susan and I have witnessed in the Yucatan Peninsula in Mexico.  When the army rests, they create “bivouacs” with their bodies, sheltering the queen.

And what’s remarkable about all this?  It’s that any one of these creatures only has a neural junction box for a brain.  Each individual only follows a small set of rules and cues.  Where does the intelligence come from?  Is it even intelligence?  Do we need to redefine the term?

In the scientific community the phenomenon goes by several names:  collective intelligence, emergence, agent-based models, stigmergy.  Each “agent” leaves a trace of its action in the environment, and that triggers a further action by another agent, and what emerges is a whole that is greater—more complex and more intelligent—than the sum of its parts.

Ants
Leaf cutter ants in the Yucatan
Photo by Susan Fry

The leafcutter ants in Central America (Acromyrmex and Atta spp) are thought to be the most complex societies on earth next to humankind.  Susan and I shot this photo of them in the Yucatan.  The columns march for hundreds of yards, threading through all the trees in the forest.  Susan was asking a good question:  Look around you, she said—there are trees everywhere!  Why are they marching all over the place for their leaves?

What leafcutter ants do with those leaves is grow fungus gardens.  The fungus they grow is in the Lepiotaceae family, and it’s a complete, two-way symbiosis—neither ant nor fungus can survive without the other.  If there’s a leaf in the mix that messes up the fungus growth, they detect it and stop gathering it, and they range far afield to collect just the right mix of leaves.  The plants, in turn, detect the attack and start producing “volatile organic chemicals” which are among other things fungicidal, and the ants are selective as they forage and avoid these leaves.  Their fungus gardens include a “nursery” where they experiment with different mixes of leaves, and when they find a leaf that grows the fungus well, from a tree which has not yet mustered its chemical defenses, they remember exactly which tree those leaves came from, and columns of ants seize the moment and maraud that way, stripping it of all the leaves they can before it wises up.

But their astonishing “intelligence” does not stop there.  A mold called Escovopsis is constantly threatening their crop, and the ants have a bacteria growing on their exoskeletons called Actinobacteria which secretes an antibiotic which fights it.  I’m not making this up—these ants invented antibiotics twelve million years ago.  Not only that, but throughout that time, they have somehow prevented Escovopsis from becoming resistant to the antibiotic, a feat medical science has not been able to pull off yet.

Their nest mounds can be 100 feet across and extend 18 feet into the ground, and the colonies can contain eight million individuals, so as with any urbanized civilization, waste management is a problem.   They maintain a garbage heap, constantly working and shuffling it to keep it decomposing (this is done by the older, less useful worker ants—the young ones in their prime are indoors, at work in the fungus gardens).  They place the heap above ground at a location which is equidistant from all hive entrances, to prevent contamination, and that constitutes solving a geometric problem.  They can find the shortest route to a source of leaves, which constitutes solving a geographic problem.  And they routinely shore up walls and colony entrances so that they don’t collapse, which constitutes solving an engineering problem.

            It’s not just naturalists who study this stuff.  Computer scientists and industrial engineers look at it:  How can you create a complex system with a simple set of instructions?  Experts in crowd handling look at ant behavior, and so do traffic flow experts.  Two-way traffic lanes can be observed in ant trails, and people who have to devise the crowd handling at concerts so that stampedes are prevented, study the ants.  A systems analyst at Southwest Airlines named Douglas Lawson modeled ant behavior to figure out how most efficiently to get people onto an airplane.  He knew that ants are the experts at doing complex things by following simple instructions.  (The answer:  Open seating.  It’s why Southwest uses it.)  Research by humankind’s brightest minds is going on every day, but the ants, it seems, have it figured out.  And they have figured it out without anything you could call a brain.

What is intelligence, anyway?

Just looking at my own species—and my own life—I have to say that I feel a connection to these societies of insects.  The wisdom of the hive is, I think, very real for us as well.  I have spent a fair amount of my life looking for wise men and gurus, and I have decided that there are none.  The wisdom, I think, lives in the spaces between us.  It is not individual, it is synergistic.  It is the back side of our human tapestry, binding us together in ways that we do not see.

I am just dying to know:  What is the big problem we are solving, which our brains are not even capable of understanding?

By |2017-05-24T00:03:08-05:00June 30th, 2012|Nature Essays|5 Comments

Queenmakers

My nephew Ryan has my blood in his veins.  He’s an obsessed nature lover with a sense of curiosity that won’t leave him alone.  He captured this photograph near Bonny Doon, in central California, where he was working for an environmental landscaping outfit restoring an old quarry which, they say, largely rebuilt the city of San Francisco after the 1906 quake.  He did what any of my relatives do when they see something weird in the natural world:  He emailed it to me.

I knew immediately what it was, because it’s a childhood memory for me.  My friend and I were scuffing around in my backyard one day when I was maybe ten, and I remember that the fence with our neighbor in one place seemed like it was about twenty feet tall, and it was completely covered with honeysuckle vines,  just a wall of lush foliage and fragrant blossoms several feet thick, and at one point my buddy said, “Hey, come look!”

BeesRyan1.jpg
Ryan’s swarm could easily be forty thousand bees.
Photo by Ryan Fry

I can’t even remember which childhood friend this was, but I vividly remember what he showed me:  He parted the vines before our faces, and we were looking at a solid wall of honeybees.

It’s a behavior called swarming, and it’s how hives make new hives.  The queen bee defects with maybe sixty percent of the whole hive, and heads out to establish a new republic.  It’s pretty much on a timer:  After two years of non-stop effort laying worker bee eggs, she lays a few eggs in some of the larger queen bee honeycomb cells and then blows town with half the troops.  It’s interesting to me that it’s the existing, proven queen that ventures out with the swarm, not one of the new ones.  It puts both hives at risk in the end.

The swarm only moves a little way at first, sometimes only a few yards.  (That’s worth remembering—when you see a swarm, there’s a hive nearby, and though the swarm is not aggressive because they have no young to protect, that’s not true of the hive.)  In their new, nearby location, the swarm aggregates in a mob around the queen, protecting her and staging themselves for the move.

The next thing that happens is that somewhere between twenty and fifty scout bees fly out looking for a new nest site.  They are from the ranks of the experienced forager bees, and they know the landscape.  They need to find a new site pretty quickly and get a hive working—they’re running on nothing but the food in their bellies, and the queen was starved by her nurse bees prior to the move so that she’d be able to fly.  The site must meet many criteria—it must be a cavity protected from the elements, big enough for the hive, warmed by the sun but not too much, and free of ants.  They’ll fly as far as a kilometer or two looking for something that works.  When they come back, they dance about it.

No, really, that’s what they do.  There’s a saying that talking about art is like dancing about architecture, but bees actually do dance about architecture.  It’s called a “waggle dance,” and it’s how bees describe to each other the location of something like a food source.  They run up the wall of the hive waggling their posterior back and forth.  The length in time of the waggle run indicates the distance, and the direction of the run indicates the direction of the thing relative to the sun.  A Nobel Laureate named Karl von Frisch figured this out.  Straight up the vertical honeycombed wall means straight toward the sun, twenty degrees to the right of vertical means twenty degrees to the right of the sun.  And if it’s been a couple of hours since she returned to the hive, she corrects for the intervening movement of the sun.  I’m not making this up.

Bee_dance.svg
The Waggle Dance
By Own work
[CC BY-SA 2.5], via Wikimedia Commons

In the case of a swarm, though, they add another dimension to the choreography:  The more excitedly the bee dances, the better the site met the criteria.

So they all come back, and everyone dances, and then some of the scouts will go back out and check out a couple of the sites promoted by the most excited dancers, and when they come back, they might start promoting that site as well, and others will go out and take a look.  It is only when complete consensus is reached that the swarm flies off and moves into the new hive.

This process by which the swarm collectively decides on the site for a new hive is quite fascinating.  Each bee follows only a fairly simple set of rules and cues, but the the problem that gets solved is a very complex one (an optimization problem).  They are deciding between multiple options, and condidering multiple datapoints for each, and the problem gets solved very intelligently.  It is what scientists call collective intelligence, and it’s studied by more than just naturalists.  The whole becomes greater than the sum of its parts—it’s studied by computer scientists, industrial engineers, and anyone who has to make large numbers of people do something complex with only a few instructions.  It might be the subject of my next article.

Meanwhile, back in the old hive, things might be a little rough.  They’ve only got half the woman-power they used to have (worker bees are all female), and also, the newly-hatched queen bees are called “virgin queens,” and that’s exactly what they are—they are not capable of making babies and replenishing the workforce until they have sex, which takes place hundreds of feet aloft in an elaborate mating flight where she could easily get nailed by a predator and then the hive would collapse, because there is no backup queen.  Though the departing queen laid several eggs in queen cells, queen bees do have stingers, and they’re used exclusively to kill rival queens as they pupate in their honeycomb cells.  The sex is not particularly modest—the virgin queen will mate with from twelve to fifteen different drones, returning to the flights for several days, storing the sperm in an organ called a spermatheca, from which she will use it at will for the rest of her life, which can be from four to five years.  She chooses which eggs to fertilize.  Unfertilized eggs become drones, the only males in the hive.  The fertilized ones all come out female and will be workers unless the worker bees pack the cell with a substance they manufacture called royal jelly, which will alter the way she develops and create a queen.  So it’s actually the workers who are the queenmakers.  They decide when a swarm is called for, or when the existing queen is weakening and needs to be replaced.  They detect this because her pheromones start to get weak, and they will raise some new queens, and then kill her.

Worker bees don’t live as long, only a couple of months.  But in that time they live a full life, going through several different careers, starting out doing menial cleaning work or tending to the young, then venturing out with experienced foragers on orientation flights, learning the landscape and becoming valuable breadwinners, bringing pollen and nectar back to feed the hive.  In their sunset weeks, they are put to work guarding the hive, and are the ones who will attack and sting an intruder, leaving their barbed stinger and a handful of abdominal organs in the adversary and dying themselves.  They have become expendable warriors.

BeeOnDaisy
A Foraging European Honey Bee (Apis mellifera)
Photo By Susan Fry

Well, to take us back to the nineteen-sixties and finish the childhood story, my folks called a beekeeper out, and when he got the swarm into a hive box I asked if I could keep it.  My parents, being my parents, said, “Sure!”  They were always very supportive of my natural obsessions, so for a year or so I became a beekeeper.  It put everyone in the family to some trouble.  My mom at one point got swarmed and was laid up in bed for several days.  Bees actually have a very powerful venom, and if you get enough stings it can be pretty brutal.  Foraging honeybees seldom sting unless roughly handled, and it will be the only sting you get.  (My first bee sting—a traumatic, earlier childhood memory—was when one got tangled in my hair and I reached up to see what was going on.)  But if you get stung near the hive you’ll find out that when they sting they also release a pheromone that sets off any other bees nearby, and you can get swarmed.  They’ve got an extremely accute olfactory, and the pheromone is persistent, and even if you’re lucky enough to be near some water you can dive into, when you come back up they’ll resume the attack.

My beekeeper career was not terribly successful.  The hive lost its queen somehow, and Gary, always the supportive and helpful brother, would assist me in taking the top off the bee box and lifting out the vertical racks of honeycomb (massed with bees) one after another, looking hopefully for queen bee cells that might hold a pupating new queen.  Our folks didn’t have a ton of money and had only sprung for one beekeeper hood, so Gary would wear a pair of toy aviator goggles from a dime store, and one time a bee managed to get up underneath one of the lenses and was frantically buzzing around right in front of his eyeball.  I can’t remember whether he actually got stung (Gary, do you recall?), but the dance he did as he ripped the goggles from his head transcended the boundary between self-preservation and art.

In the end, the hive perished, and my family set out on the path toward physical and emotional recovery.

Now you know.

By |2017-05-24T00:03:08-05:00June 19th, 2012|Nature Essays|2 Comments

Fort Ord National Monument

Something good happened this week.  With the stroke of a pen, President Obama, using the National Antiquities Act, turned the former Fort Ord, in Monterey, California, into a National Monument.

It may not mean a lot to folks who don’t live in the Monterey Bay Area, but it means a hell of a lot to Susan and I, because we pretty much spent our courtship there.

It was 1994, and the fort had just been closed as part of base realignment, and nobody really had a firm handle on the place for a while, and the public hadn’t really discovered it yet.  It was a land of falling-down barbed wire fences, rusty signs warning of unexploded ordnance, derelict tanks and troop carriers left on the firing ranges for target practice getting gradually taken over by riotous vines and wildflowers as nature took possession again—and miles and miles of trails and closed roads through chaparral and oak woodlands.  Hundreds of our happiest miles were spent in that place, training for marathons and wildlife watching at the same time.

We weren’t supposed to go on the firing ranges themselves, of course, but we couldn’t resist because they were such fabulous wildlife refuges.  Military bases have been called the best-kept conservation secret in America.  Usually when we say “wildlife refuge,” we mean somewhere human beings get to tromp around and look at wildlife, or even hook it or shoot it.  Not so on those firing ranges.  They truly did belong exclusively to the wildlife, and the only prints we saw were of animals.  After a light rain the prints would be preserved in amazing detail, and we once stood on a sandy knoll and reconstructed almost completely a pretty dire struggle between a mountain lion and a deer.  We couldn’t figure out who prevailed in the end, but we didn’t see a carcass around.  On those runs we saw bobcats, foxes, coyotes and golden eagles, and on night runs we would see skunks, raccoons and great horned owls.  We once chased a great horned owl fully two miles down a road one phone pole at a time, which kept us amused for a good twenty minutes (okay, for some runners it would have been more like fourteen, but a ten-minute mile isn’t bad when you’re wildlife watching).  As we approached him each time we could almost hear him mutter something as he lumbered into the air again and flew ahead of us to the top of the next phone pole.  He never figured out that all he needed to do was fly one phone pole back the other way.  Owls, our favorite symbol of wisdom, are actually one of the stupider birds, it turns out, at least by the human yardstick that we always measure these things with.  (Jays and crows are the smartest.)

Well, the firing range days finally came to an end and we began sticking to the legal roads and trails, because my brother Gary is a federal prosecutor up in San Jose, and trespassing on those firing ranges is a federal crime, and I found out that once a week he was driving down to Monterey to prosecute such things.  So we cleaned up our act, rather than make Gary stand in front of a judge and say something like, “Your honor, I must recuse myself because the breathtakingly stupid defendant is my brother.”

When the fort first closed, there was no shortage of bad ideas about what to do with the place.  Someone even suggested a huge amusement park (now there’s someone who should be sentenced to six months in Anaheim).  It was largely our congressman, Sam Farr, who kept the worst from happening.  The buildings on the developed part of the fort became California State University, Monterey Bay, and the city of Marina did get permission to build a thousand or so houses, but they only got as far as bulldozing and road-building before the project stalled.  As for the open space, it’s been under the stewardship of the Bureau of Land Management until now, and they’ve done an okay job I guess, and I like the BLM’s more relaxed approach to rules and regulations, but at the end of the day I don’t trust those folks.  They’re the ones who brought us Glen Canyon Dam and broke Ed Abbey’s heart and made him who he was, and besides, they’re very fond of selling mineral rights to oil and gas companies.  So Susan and I are happy people this week.  National Monument is good.

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Maritime Chaparral

But what makes the open space in Fort Ord so special is that it is largely made up of a plant community called maritime chaparral, and maritime chaparral is an extremely special ecosystem, and a pretty rare one, and it is also pretty transient.  And to understand maritime chaparral, you have to start at the beach.

 

There, grains of sand are swept past your ankles and up the beach by the sea breeze, and if you put something in their path—say, a stick of driftwood, or an empty soda pop can—the grains are carried over it, and then hit the dead air behind the object, and drop.  Soon you have a small mound of sand hunkering against the back side of the object, but the process doesn’t stop.  Your new dune continues to grow, and as it becomes more mountainous, sand continues to run up its face, over its razor ridge top, and drop onto is back.  The dune is marching.

The first rampart of dunes facing the beach are called the foredunes, and they are pretty devoid of vegetation.  But as you walk back into the next ones, called the backdunes, you will start to see pioneering plants like sand verbena (Abronia latifolia) and silver beachweed (Ambrosia chamissonis) which are salt-tolerant and able to get much of their water from the sea mist.  Their hold is a tenuous one, and if you wipe them out in a small area at the ridge top of a dune, say by running an ATV over it, the sand will begin to get blown inland through the naked channel you have opened, and a great parabolic bowl will form on the seaward face of the dune as the entire dune empties itself out through the new passage, and buries the next area inland.  This is called a blow-out, and it is why dune habitats are so fragile.  A lot of this is normal, of course.  Marching is what dunes do, just ask any city worker—they will march right over your freeways, roads and yards if you let them.

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Wildflowers are spare in the chaparral, but they can be found

As you walk still farther inland, the woody plants start to get a foothold, and by the time you get a mile or so from the beach, you’re standing in an unbroken sea of chest-high brush.  This is maritime chaparral.  It doesn’t look like much from the top, but all the action is underneath.  There, creatures live who know no other universe and never come out into open spaces.  The rodents, lizards and rabbits are the base of the predatory food pyramid, and support populations of road runners, foxes, bobcats and raccoons.  The songbirds all have stubby wings and near-sighted vision, and there is question whether some of them are even able to fly across something like a road, because they can’t see across it.  Tiny game trails honeycomb the ground level like little tunnels, and you’ll see a place where a fox habitually comes out of one and leaves his scat beside your trail, and there will be several piles of it, increasingly decomposed, the oldest nothing more than a wisp of fur and some toenails.   And these creatures like for the sea of brush to be unbroken.  If you plant a tree or erect a phone pole, hawks, crows and jays will hang out on top of it and watch, figuring out where the nests are.

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The keystone plants are manzanita and ceonothus

Here and there you’ll see the waist-high, dome-shaped hutch built by a dusky-footed wood rat.  He constructs the exterior with thorny branches if he can so the foxes and coyotes can’t tear it down, and he and his family occupy the ground floor, but the remainder of it becomes a condominium for every small rodent imaginable.

 

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Oak Woodland

The keystone plant species are various species of manzanita (Arctostaphylos spp.) and some species of ceonothus commonly called California lilac (ceonothus spp.) but there are myriad others, including salvia, monkeyflower, coastal sage and coyotebrush.  Most of them including the manzanita are pyrescent, meaning that the seeds require fire to germinate in big numbers.  It is fire that sustains the ecosystem and keeps it chaparral.  When it runs through it kills absolutely everything, and then decades of seeds stored up in the soil leap to life and the chaparral is rejuvenated.  It is a transitional community.  Suppress all your fires and the oaks will begin to shade out the brush, and the area will start to transition into oak woodland.  In fact, just keep walking and oak woodland is what you will end up in.  And that’s the climax community, the end of our walk through the stages of natural succession.

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Walking on Ancient Beaches

And throughout it all, you were walking on fossil sand dunes.  They have marched back miles from the sea to become the perfectly ordinary-looking hills bordering the Salinas Valley, but if your trail has worn into it at all, you’ll find yourself looking down, because you suddenly feel like you’re walking on a beach—and indeed you are.  An ancient one.  The stuff underfoot is loose, tractionless, and unmistakably sand.  Finally, our grains of sand wander into a watercourse, then into the Salinas River, then back out to sea where the waves wash them up onto the beach to begin the whole circuit again.  Some grains of sand have made this trip many times, taking from three to five hundred years for each trip, and they’ve become discolored in their old age, which is why our beaches here on the Monterey Bay are yellow instead of white.

Now you know.

 

 

 
Copyright © 2012 Randy Fry
By |2017-05-24T00:03:08-05:00April 29th, 2012|Nature Essays|Comments Off on Fort Ord National Monument

Poets and Astrophysicists

“But a thighbone or so,” was how poet Robinson Jeffers put it.  That’s what he expected to be left of our great civilization a few thousand years from now.  Ed Abbey pictures us surviving, but differently—he sees a day when blue-eyed Bedouins will herd their sheep past the great and mysterious ruins of concrete dams.

Carl Sagan, on the other hand, tried to look into our future by looking out, at the stars.

We all know and love—and make fun of—Carl Sagan as the popularizer of science, but he was actually a very interesting man.  He was an advisor to NASA from the nineteen fifties onward, and we all remember him as the face of space exploration on our TV sets.  Every comic in the world has had some amount of fun with his phrase, “billions and billions,” and he always took it with great humor (though he never said exactly that—the closest he came in his TV series “Cosmos” was “billions upon billions”).  What people tend to forget, though, was that he was also a brilliant scientist and social thinker, and with an impressive conscience on board.

He would tell you that two opposing forces guided his life:  a sense of wonder about the universe, and a skeptical thought process when investigating it.  One of them, he felt, was no good to you without the other, and that is the paradox that made the man:  The scientist willing to go out on a limb and turn the search for extraterrestrial creatures into a mainstream science, also held skepticism to be a personal ethic.  It used to be thought, for instance, that the planet Venus had a balmy, paradise-like climate until Carl Sagan ran the numbers.  He came up with a surface temperature of 900 degrees Fahrenheit, and was later proven right by the Mariner spacecraft.  It was Venus that got him interested in global warming—he realized that that planet is one giant case of runaway greenhouse warming.

But his epiphany regarding the future of the human race came via a mathematical equation called the Drake Equation.  The Drake Equation looks like this:

N = R* ∙ fp ∙ ne ∙ fl ∙ fi ∙ fc ∙ L

where:

N = the number of civilizations in our galaxy with which communication might be possible;

and

R* = the average rate of star formation per year in our galaxy

fp = the fraction of those stars that have planets

ne = the average number of planets that can potentially support life per star that has planets

fℓ = the fraction of the above that actually go on to develop life at some point

fi = the fraction of the above that actually go on to develop intelligent life

fc = the fraction of civilizations that develop a technology that releases detectable signs of their existence into space

L = the length of time for which such civilizations release detectable signals into space

 

It is an interesting equation with an interesting mission:  It attempts to calculate the number of detectable technological civilizations that should exist in our Milky Way galaxy.  And when Carl Sagan ran those numbers he was astonished.  No matter what reasonable numbers he plugged into that equation, the conclusion was the same:  We should be awash in intelligent radio signals.  And we’re not.  We’re all alone.  His conclusion?

Civilizations don’t last long.

He spent the last half of his career working to prevent the same fate from befalling this civilization.  He was the one who realized that a nuclear exchange would be even more hideous than we were already assuming.  It would put enough fine particulate matter into the upper atmosphere to create what he called a nuclear winter, lasting years, or decades.  It was such a winter that killed the dinosaurs in the Cretaceous-Tertiary Extinction, caused not by nuclear explosions but by an asteroid impact where the Yucatan Peninsula is now.  He also worked on that problem, advocating an organized search for near-earth objects that could impact our planet.  When someone suggested creating nuclear devices capable of deflecting them away from the Earth, he pointed out that to be able to deflect it away from us was to be able to  deflect it toward us, and then you have a doomsday weapon, which, in his opinion, we already had way too many of.

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Carl Sagan was central to adding a plaque to the Pioneer spacecraft as a greeting to other civilizations

He tirelessly promoted an organized search for extraterrestrial intelligence, and finally got it some respect when he got seventy scientists, including seven Nobel laureates, to sign a petition published in the journal Science.  That was the birth of his project SETI, which was among the first projects to develop “distributed computing”, using volunteer home computers across the world-wide web to do the prodigious number crunching necessary.  It was one of the key projects that ushered in the era of “citizen science,” which can now be found everywhere.  Now you can even enter your bird sightings into the website of the Cornell Laboratory of Ornithology, where they become part of an amazingly detailed database of bird distribution and movements.

He became an anti-nuclear activist.  He considered Ronald Reagan’s Strategic Defense Initiative to be absolute madness, and was arrested twice climbing a cyclone fence with other demonstrators to attempt to occupy a nuclear test site in Nevada.

He considered the idea of a male, human-like god to be silliness, but did not distain the religiously minded, and hated to be called an atheist.  Skeptical even about atheism, he pointed out that an atheist knows that there is no god.  “An atheist,” he said, “has to know a lot more than I know.”  He wrote the popular novel, “Contact,” where he works a lot with the interplay between science and religion.  I will always remember the scene in that book, set after hours in a natural history museum, involving a physicist, a priest and a Foucault pendulum.  The scientist volunteered to put her nose exactly where she knew the laws of physics would cause the great ball to stop, if the priest would put his a foot closer and pray for divine intervention.  (The priest took her up on it, but then flinched, and was very disappointed in his own lack of faith.)

Carl Sagan died at only 62 years of age, after a long fight with myelodysplasia, and never saw that book become the Jodie Foster movie.  The kid from Brooklyn who started going to the library because none of his friends could tell him what a star was, touched all our lives, even those of people who have not heard of him.  He received many awards and accolades in his life, including the Public Welfare Medal from the National Academy of Sciences.  (Mind you, that academy never awarded him a membership, considering his well-publicized media activities to be a bit unseemly.)  Isaac Asimov said that he was one of only two people whose intellect surpassed his own, and to get a concession like that out of Isaac Asimov is indeed an accomplishment.  My personal favorite, though, is that his fellow astrophysicists have named a unit of measurement after him.  A Sagan of something is four billion or more of it—the word billions by definition being two billion or more, making billions and billions at least four.

So I am raising a glass to Carl Sagan tonight—a very interesting man who lived in very interesting times.  To grow up in the space exploration age was to grow up with Carl Sagan.  I will remember his goofy face imparting his sense of wonder to us all over the TV set as the data and footage started to stream in from each new space mission.  And I will remember him for his conscience, his activism, and his work to make this civilization a success.

But to be perfectly honest, for myself I might prefer Robinson Jeffers’ vision of our future.  A world without us might, I think, be a better place.  So that’s the image I’ll leave you with:  A thigh bone or so…here and there a rust stain on a mound of plaster.

 

 

 
Copyright © 2012 Randy Fry
By |2017-05-24T00:03:08-05:00March 4th, 2012|Nature Essays|Comments Off on Poets and Astrophysicists