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Friday, November 13 2009 |
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 By Wendy Langhans
Imagine trying to eat corn-on-the-cob without teeth. Or biting into a juicy dill pickle. Or munching on a bag of trail mix. Not so easy, is it? Teeth are a tool we take for granted - until they stop working. And every tool requires maintenance to keep it working properly.
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Friday, October 30 2009 |
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 By Wendy Langhans
At least that's what the field guide says about "Stinking Gourd". The reality is much worse. Imagine a smell that's a cross between dirty gym socks and a skunk. No wonder the botanical name is Cucurbita foetidissima. The Latin root foetidus gives us the English word fetid (TO STINK) and, as any musician knows, issimo means UTMOST. This plant truly "stinks to high heaven".
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Friday, October 23 2009 |
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By Wendy Langhans
What is it about sport cars and speed? For years, automotive engineers have tried to pack the maximum amount of horsepower in the minimum amount of space. Now recent studies suggest a design enhancement that might provide a few more miles per hour - feathers.
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Friday, October 16 2009 |
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By Wendy Langhans
Earlier this week, while making a right turn on to McBean Parkway, the unexpected happened - the rear end of my car hydroplaned. Just a bit. Not unmanageable. But a wake-up call nonetheless. You see, the rain, combined with the oil and grease that had accumulated over the dry summer months, created a thin, slippery film that "pulled the rug out" from under my rear tires.
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Friday, October 09 2009 |
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By Wendy Langhans
I learned a lot by playing in a sandbox when I was a child. I particularly remember pouring buckets of water over the imaginary landscape. It was fascinating to watch the sand change color as it soaked up the water, much like our kitchen sponge turned bright red as it soaked up my spilled cherry Kool-Aid. I discovered that dirt is hole-y.
Notice the subtle color changes between wet and dry soil.
But as I got older, I learned more. Holes are not simply the two-dimensional circles we see at the surface; rather, they are a constantly changing, three-dimensional network of twisting and interconnected passageways. But to keep our discussion brief, we can classify holes into three types, based on their diameter.
- Micropores are 5-30 microns in diameter. (By comparison, the eye of a needle is about 749 microns wide.) They serve as water reservoirs in the soil, because they are small enough to hold water by capillary attraction against the pull of gravity. This is where you will find bacteria and other microorganisms.
- Mesopores are 35-70 microns in diameter. They allow water to move slowly. This is where you will find fungi and root hairs.
- Macropores are greater than 75 microns in diameter. Water drains through these pores by gravity. These pores also allow oxygen to enter the soil. This is where you will find invertebrate animals such as worms and larger plant roots.
Soil is a "mineral/organic framework" in which air and water are distributed through a matrix of holes. In simpler words, soil is made up of stuff, empty space and the surface area where they meet. An English researcher once calculated that the surface area "lining the tiny pores and passageways in a couple of tablespoons of soil added up to a quarter of a million square feet - the area occupied by a city block". (James Nardi, "Life in the Soil"). And just like any city, these passageways are teeming with life.
Who knew that hole-y dirt could be the portal to such a complex and interesting world? Or as Alice said after she went down the rabbit hole, "curiouser and curiouser."
Upcoming Outdoor Events:
Saturday, October 17, 8-10 AM. Bird walk in Towsley Canyon. All year round, the habitats of Towsley Canyon attract a wealth of birdlife. Beginners are welcome. Bring your binoculars. 2 hours, easy walk. For a map, go here.
You can listen to stories like this every Friday morning at 7:10 a.m. on "The Hike Report", brought to you by your hometown radio station KHTS (AM1220) and by the Mountains Recreation and Conservation Authority.
For the complete MRCA hike and activity schedule and for trail maps, click here or go to www.LAMountains.com.
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Friday, October 02 2009 |
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By Wendy Langhans
One morning early last week, I was sitting on the front porch slurping a cup of hot coffee. It was o'dark hundred, way too early for civilized folks to be up and about. With my eyes half open, I watched two dragonflies, darting back and forth, like runway models strutting and holding a pose. Their movements were unpredictably quick and precise. I wondered, "how do they manage to fly like that?
Dragonflies have two pairs of wings, one pair in front and one pair in back.
I assumed it must have something to do with their wings. When observing a dragonfly at rest, it's easy to see that dragonflies have two pairs of wings, a front pair and a back pair. But to truly be able to see these wings in motion, you need a high-speed video camera and the ability to observe their movements in slow motion. (For a slow-motion video of dragonfly flight from David Attenborough's "Life in the Undergrowth", click here.) When observed this way, scientists discovered these two pair of wings stroke in curves - more like a canoe paddle than a rowboat oar. And they don't always stroke in unison.
- Synchronized-stroking. The front and back pairs move in unison. This is used to maximize thrust and lift, especially when accelerating or quickly changing direction.
- Counter-stroking. The front and back pairs move 180 degrees out of phase. So while the front pair are moving down, the back pair are moving up. This stroke is very efficient when hovering, minimizing the amount of power needed to remain in a stationary position.
- Phase-stroking. The front and back pairs move 54-100 degrees out of phase. This is used for forward flight, providing a blend of efficiency and lift.
A four-wing design with independent-control and flexible stroke provides the dragonfly with the power needed for take-off and speed, plus maneuverability and efficiency.
About five hundred years ago, Leonardo da Vinci based his design of an "ornithopter", a wing-flapping flying machine, on his observation of birds. But I wonder - did he ever sit on his balcony watching dragonflies? What would his design have looked like if he had?
Upcoming Outdoor Events:
Saturday, October 3, at Placerita Canyon
Family Nature Walk
October 3, 2009 (11:00 am - 12:00 pm)
An easy, 1-hour walk exploring the area's natural and cultural history.
Animal Presentation
October 3, 2009 (1:00 pm - 2:00 pm)
See, learn and ask questions about live native animals of the area.
Sunday, October 4, Ramona Days at Rancho Cumulos
October 4, 2009 (10:00 am - 4:00 pm)
A great place to take the family for a glimpse of Southern California history.
For more information, go to their website.
You can listen to stories like this every Friday morning at 7:10 a.m. on "The Hike Report", brought to you by your hometown radio station KHTS (AM1220) and by the Mountains Recreation and Conservation Authority.
For the complete MRCA hike and activity schedule and for trail maps, click here or go to www.LAMountains.com.
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Friday, September 25 2009 |
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By Wendy Langhans
The Guiberson fire, which is now burning in Ventura County near Fillmore and Moorpark, was possibly caused by spontaneous combustion in a manure pile. I know it sounds like a bad joke, but could it possibly be true? Can spontaneous combustion actually occur? And if so, how?
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Friday, September 18 2009 |
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By Wendy Langhans
Last week, a friend shared her photos from a trip to the wineries around Santa Barbara. She included a few photos of a tarantula she found in a winery patio. This reminded me of the classic opening line to a joke: a (fill-in-the-blank) walks into a bar... I wonder if any of these jokes would work with a tarantula? They'd have to be both funny and accurate. You be the judge of how funny they are.
A tarantula on the move. (Photo courtesy Sheri Marrs.)
"A tarantula walks into a bar wearing a pearl necklace. He orders a drink. "I've never seen a tarantula wearing a pearl necklace before", says the barkeep. "What do you expect with basic black?", says the tarantula."
Darn - this joke won't work. Not only do tarantulas come in different colors (including pink), the ones you see wandering about during the day are males (in search of females, of course.)
Is this tarantula in search of a free drink or amore?
"A tarantula walks into a bar. OUCH! You would have thought he would have seen it!"
Hmmm - this joke might work. After all, tarantula's are arachnids and, like most spiders, they have eight eyes. However, their eyesight is weak; they can't see very far.
"A tarantula walks into a bar. The bartender says, 'You're quite a celebrity around here. We've even got a tequila named after you.' The tarantula says, 'You've got a drink named Steve?'"
Darn - I don't think this joke will work, especially if I tell it during a meal. Tarantula's don't drink liquids, not even tequila. How they get their nourishment is really quite gruesome (click here for the details).
"A man walks into a bar and sits down next to a lady and a tarantula. The man asks, "Does your tarantula bite?". The lady answers, "Never!" The man reaches out to pet the tarantula and the tarantula bites him. The man says, "I thought you said your tarantula doesn't bite!" The woman replies, "He doesn't. This isn't my tarantula."
Darn - this joke won't work very well either. Yes, tarantulas do have fangs and bite their prey, which consists mostly of insects and lizards. But according to WebMD, the native tarantulas found in North America rarely bite humans. When threatened, tarantulas retreat or if that doesn't work, rub their legs on their abdomen, releasing "urticating hairs" into the air. This hair can irritate the eyes, lungs, and exposed skin of any potential predator. The downside is, of course, that it creates a temporary bald spot on the tarantula, at least until the hair grows back.
All right - I admit it - these jokes are pretty lame. But this last joke has given me a new idea - does anybody know any good jokes about balding?
Upcoming Outdoor Events:
Saturday, September 19, 8-10 AM Bird walk in Towsley Canyon. All year round, the habitats of Towsley Canyon attract a wealth of birdlife. Beginners are welcome. Bring your binoculars. 2 hours, easy walk.
You can listen to stories like this every Friday morning at 7:10 a.m. on "The Hike Report", brought to you by your hometown radio station KHTS (AM1220) and by the Mountains Recreation and Conservation Authority.
For the complete MRCA hike and activity schedule and for trail maps, go to www.LAMountains.com.
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Friday, September 11 2009 |
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By Wendy Langhans
It looked both ominous and somehow familiar - the pyrocumulus clouds that appeared over our Santa Clarita valley almost two weeks ago. It certainly caught my attention, enough so that I went home and grabbed my camera.
It was a pyrocumulus cloud, created by the Station fire. Pyrocumulus clouds get their name from their shape ("cumulus" means "heap" in Latin) and their source ("pyr" means "fire" in Greek). And these clouds DO look like a heap, although I think they sometimes resemble a cauliflower.
Pyrocumulus clouds contain thousands of different kinds of emissions. But I'd like to talk about four major components: water vapor, ash particles, tar particles and soot particles.
- Water vapor comes from two sources, the moisture already in the fuel and the byproduct of combustion. (You may remember that last week, we talked about "live fuel moisture" content, which is the percent by weight of moisture in live plant material.)
- Ash particles are sand-like minerals that remain after combustion. Some of these whitish-colored particles remain on the ground and some are carried aloft and deposited miles away.
- Tar particles result from inefficient combustion of fuel, which is usually due to lack of oxygen.
- Soot particles are clusters of carbon particles that are found inside the flame. When flames are ripped open from the wind turbulence, the not-yet-burned particles of black soot escape into the updraft.
As I take a second look, I now realize why it looks both familiar and ominous. The white, cauliflower-shaped cloud gets it's color and shape from condensing water vapor. It resembles the thunderstorms from my midwestern childhood. And the gray clouds get their color from a combination of black soot, white ash and tar particles. These clouds look ominous because I know where those particles came from - out of the turbulent winds of an uncontained and dangerous wildfire.
Upcoming Outdoor Events:
Saturday, September 19, 8-10 AM Bird walk in Towsley Canyon. All year round, the habitats of Towsley Canyon attract a wealth of birdlife. Beginners are welcome. Bring your binoculars. 2 hours, easy walk. For a map, go here.
You can listen to stories like this every Friday morning at 7:10 a.m. on "The Hike Report", brought to you by your hometown radio station KHTS (AM1220) and by the Mountains Recreation and Conservation Authority.
For the complete MRCA hike and activity schedule and for trail maps, click here or go to www.LAMountains.com. |
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Friday, September 04 2009 |
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By Wendy Langhans
"It hasn't burned in 60 years." My heart sank when I heard that on the news reports, because I knew fire requires fuel and a lot of fuel can accumulate over 60 years. But as anyone who has ever built a campfire can tell you, not all fuel burns equally well. Firefighters refer to three characteristics that affect fuel flammability: moisture level, size of fuel pieces and vertical arrangement.
(1) Moisture level. This is affected by three things - is the fuel live or dead? How much rain did we get last winter? What is the humidity level? When building a campfire, you don't use green, freshly cut wood. You choose dead wood that has sat around for awhile, so that the residual moisture has time to evaporate. The amount of winter rains determines the amount of moisture available at the beginning of summer. The humidity levels determine how fast the moisture evaporates.
In California, firefighters calculate moisture levels using "live fuel" measurements. Samples of a common shrub, Chamise, are weighed, dried, and weighed a second time. A 100% reading means that water comprises half of the weight of the plant. A reading below 60% generally means you are approaching critical level. Here's an example of local readings.
View of Castaic Lake with white-tipped Chamise in foreground.
They also measure "100 hour fuel moisture" levels. This measurement is a sampling of 1-3" diameter dead fuels, which take several days to react to changes in humidity. "It can also be used as a very rough estimate of the average moisture content of the forest floor from three-fourths inch to 4 inches below the surface." Right now it's at 5%.
(2) Size of fuel pieces (as measured by diameter). When you light a campfire, you apply the match to the fuel with the smallest diameter - the tinder. That's because the smaller diameter fuel, with it's larger ratio of surface area to mass, dries out more quickly, is exposed to more oxygen and reaches ignition temperature sooner.
(3) Vertical arrangement. Heat is transferred by conduction (next to), radiation (across and up) and convection (up). When you build a campfire, you create a "teepee" of logs sitting on top of a pile kindling which sits on top of a pile of tinder, in order to take advantage of all three types of heat transfer. Just so, in a wildland fire, the surface fuels (duff and leaf litter) lie below the understory of tall shrubs and small trees (ladder fuels) which lie below the overstory canopy of tall trees (crown). And when you factor in mountainous slopes, you increase this vertical arrangement even more.
Here's an example of the vertical arrangement of fuel on a slope.
So, when I heard that the area hadn't burned in 60 years, I knew the area would contain large amounts of fuel, with significant amounts of dead wood. I also knew that fuel moisture levels were already low because of low winter rainfall and low humidity levels. And I knew it was a mountainous region. So I knew that most of the factors were in place for a large fire, which to date has now burned over 140,000 acres.
Upcoming Outdoor Events:
Many local events have been rescheduled due to unhealthy air quality. Check back next week.
You can listen to stories like this every Friday morning at 7:10 a.m. on "The Hike Report", brought to you by your hometown radio station KHTS (AM1220) and by the Mountains Recreation and Conservation Authority.
For the complete MRCA hike and activity schedule and for trail maps, click here or go to www.LAMountains.com. |
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Friday, August 28 2009 |
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By Wendy Langhans
Our bedtime ritual in Santa Clarita - opening the upstairs bedroom windows and allowing the cool, fresh night air to fill the rooms. Of course, sometimes the rooms are also filled with night noises, like honking geese at 2:00 AM.
Honking geese? At 2:00 AM? Yup. It's that time of year. In the weeks leading up to migration, the Canada geese get restless. The Germans have a word for it, "Zugunruhe" (pronounced zook'-oon-roo-ha). Wildlife biologists refer to it as "migratory restlessness". It "describes a behavior, usually at night, usually in birds, of increased activity, orienting towards the flight destination, practice flights, etc. Since most birds are diurnal (day-active), an increase (or even appearance) of activity during the night is a pretty good behavioral indicator that the animals are experiencing the urge to migrate." And we know that Canada geese migrate at night.
The Canada Geese are getting restless.
So what causes this restlessness in the late summer and fall? Cooler temperatures? Certainly NOT around here, but maybe further north in Canada. Drop in barometric pressure? Perhaps. After a cold front passes through, the winds flows out of the northwest, providing a tail-wind for migrating birds. But, while these conditions may factor into the timing of migration, they are not the primary stimulus.
The most likely stimulus has to do with the amount daylight and it's affect on hormone production and interaction. We know from experiments that removing the pineal gland reduces avian migratory restlessness. We also know that darkness stimulates the pineal gland to produce melatonin and daylight inhibits the production. But the issues are complex and as one site puts it, "the stimulus for autumnal premigratory preparation is not well understood."
So I'd like to propose a theory of my own - I think it has to do with hot flashes. By flying through the air, I hypothesize that the geese create their own personal fan. Perhaps I ought conduct an experiment: get a fan and a long extension cord and see if that keeps them quiet at 2 AM. Can't hurt, right?
Upcoming Outdoor Events:
Saturday, August 29th, 11-Noon. Family Nature walk at
Placerita Canyon. There's also an animal presentation from 1-2 PM.
Saturday, August 29th, 8:30-11:30 AM. SCV Green will host a "Witness to Wildlife" interactive community hike. For more information go here.
Friday, September 4, 7:30-9:30 PM. Full Moon Hike.
Come see Towsley Canyon in a different light. Perhaps we'll even see examples of Zugunruhe. We meet at the front gate. Bring water and wear close-toed shoes. Families welcome.
You can listen to stories like this every Friday morning at 7:10 a.m. on "The Hike Report", brought to you by your hometown radio station KHTS (AM1220) and by the Mountains Recreation and Conservation Authority.
For the complete MRCA hike and activity schedule and for trail maps, click here or go to www.LAMountains.com. |
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Friday, August 21 2009 |
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By Wendy Langhans
Who among us hasn't hit their head? Whether it's a cabinet door left open or a slippery banana peel, we all know what it feels like. IT HURTS!
But woodpeckers are constantly banging their heads against trees. We often hear Acorn woodpeckers and Nuttall's woodpeckers pounding on trees to get at the tasty insects lying beneath the bark.
Acorn Woodpecker
Nuttall's Woodpecker
And in the fall, Acorn woodpeckers also drill holes in trees or fence posts, where they store acorns for consumption later in the winter.
Acorn woodpeckers store acorns in a "Granary Tree"
Each time a woodpecker bangs its beak into a tree - at a speed of 12 mph and a rate of 20-25 times per second - its "head absorbs 1,300 pounds of force." We know that humans often suffer brain damage from head trauma. So why don't woodpeckers get brain damage?
In sorting through the literature, I found five reasons why.
1) The bones in their skull are "spongy" and absorb some of the shock before it reaches the brain.
The next two reasons can be explained by this equation from High School physics: Stress = force/area or (mass x deceleration)/area.
2) Their brains are small, with a large surface/weight ratio. This means that, relatively speaking, the force of impact is spread out over a larger area.
3) The duration of deceleration is small - about .5 millisecond.
The fourth reason is we call the "contre coup" affect, when the skull "bounces back" after impact, causing a secondary hit by the back of the brain against the back of the skull.
4) Woodpeckers have less cerebral-spinal fluid in their brains, so there is less brain movement inside their skull. For a more thorough explanation of this effect, go here and look on page 9.
And the last reason has to do with the rotational force applied to the brain, a shear force that can tear brain neurons apart:
5) Many, but not all woodpeckers, peck in a straight line. This minimizes the rotational force.
So, the next time you have a frustrating day and feel the urge to hit your head against the wall, just remember that your brain is larger and more fragile than a woodpecker's. But if you decided to do it anyway, I recommend that you DON'T take a running start, WEAR a helmet and HIT the wall straight on.
Upcoming Outdoor Events:
Saturday, August 22nd, and every Wednesday, 8:00 AM. Trail Maintenance Volunteers at Towsley Canyon.
Come join our trail maintenance volunteers for camaraderie and a heart-thumping workout. For more information contact Steve Ioerger at 661-291-1565.
Saturday, August 22, 2009. Acorns, Sea and Sage: Chumash Native Americans. Ranch house at William S. Hart Museum.
Discover how the Chumash used their natural resources to survive hundreds of years ago. You even have a chance to grind your own acorns! Activities geared for 3-10 year olds, but all ages welcome. Adults must accompany child. For more information, call 661-254-4584 or visit www.hartmuseum.org.
Friday, September 4, 7:30-9:30 PM. Full Moon Hike.
Come see Towsley Canyon in a different light. We meet at the front gate. Families welcome.
You can listen to stories like this every Friday morning at 7:10 a.m. on "The Hike Report", brought to you by your hometown radio station KHTS (AM1220) and by the Mountains Recreation and Conservation Authority.
For the complete MRCA hike and activity schedule and for trail maps, click here or go to www.LAMountains.com.
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