Frontyard Sense/Backyard Science II

FRONTYARD SENSE/BACKYARD SCIENCE II

Thank Ya Kindly:

I must confess that I’m partially overwhelmed. Due to the large response from the ‘Frontyard Sense/Backyard Science’ original article, I am now so compelled to crunching out a second one.

The paper quickly shot up to number one in the most page views, doubling the number two spot currently held by ‘Land of the Circus People.’

I do appreciate all the readers and in particular Germany, the Philippines and India’s viewers. These three countries by far outranked all others in viewing this article.

So now, I give you number two.

At the tip of m’hat, thank ya’ll kindly…

Earthen Brown:

Generally, unless there is geological, biological or a combination of localized contaminant, the Earth’s surface soils are a descriptive tone of brown. Pretty much anywhere you tread and eyeball the ground in plains, forests, hills, deserts and permafrost, the surface is a hue of browns. Why is that?

Primarily there are three factors in play here, being…plants, microbes/earthworms and carbon. This is how it works.

Grains of soils are deposited mineral components from parent rock that was weathered down. Originally, the color would have been whatever constituted minerals were laid down. Iron ore deposits give off reds, while sulfur bearing materials would be more yellowish beige. Gypsum, along with its crystalline form known as selenite would be white, as is the case in White Sands National Monument.

Once these minerals are laid out, plants began to grow then drop leaves and also die. This introduced organic material layered on the surface of the minerals was then broken down and mixed by earthworms. Further, it was decomposed by soil microbes, such as bacteria and roundworms. This creates alkaline organic material that is further still, turned over and mixed with loosened minerals by the earthworms to an overall averaged depth of 20 cm. or 7.9 in. This mixed material is known as humus.

Topsoil & base soil layers

The microbes with specialized enzymes break down the chemical bonds in the humus, freeing the carbon and assimilating a lot of the element into their cell. When the microbes die they in turn release the carbon they once had consumed with the rest of the carbon they had once freed into the soil.

Now, with a lot of liberated carbon mixed in the soil, the element’s darker color comes into play. Carbon absorbs most of the color wavelengths in white light except for tinges of primary red, yellow and black. Red and yellow make orange and orange with a dash of black make brown.

You might feel deserts may not support enough plant life and earthworms to give its brown surface color, but remember, in geological times past climate events were once conducive in supporting these scenarios. Where now, there is nothing but desert sands, once upon a time stood grand forests.

Sedimentary rock Coyote Buttes Az.

There is sedimentary rock that was once soils and still retains the color brown.

With a little effort, if one digs beyond the soil zone, they will hit the originally deposited mineral zone or even bedrock and note the varying color or colors.

Skies of Blue; Sunsets of Orange:

On cloudless sunny days, why is the sky naturally eternally blue? On partially cloudy sunrises and sunsets, why is the horizon’s sky naturally colored and splattered in arrays of oranges, reds, yellows and pinks? I do include ‘naturally,’ for manmade smog and pollutants have changed the color in industrialized areas to a haze light gray. In fact, during the 1970s until great effort was put forth to clean-up air pollution, here in the states one did not see a true blue sky east of the Mississippi River.

Earth’s sky is naturally blue due to not only the make-up of its atmosphere, but also at what percent of the factors are at play. The atmosphere is composed of a number of gases.

There are elemental constituents that remain constant over time and location and compounds that show variability at any given time and location.

For the constant atmospheric components, there are the gases:

Nitrogen (N₂) at 78.08%

Oxygen (O₂) at 20.955%

Argon (Ar₂) at 0.93%

Neon (Ne₂), Helium (He₂) and Krypton (Kr₂) are all three at trace amounts

For the variable components, there are the compounds:

Carbon dioxide (CO₂) at up to 0.40%

Water Vapor (H₂O) ranging from 0.00-4.00%

Ozone (O₃) an isotope of oxygen, Methane (CH₄), Sulfur Dioxide (SO₂), and Nitrogen Oxides (NO, NO₂, N₂O) are all in trace amounts

In addition, there is also particulate matter in the forms of dust, soot, volcanic ash, condensed forms of water such as rain, snow, hail, sleet, etc. and pollutants.

We’ll note here that trace amounts are less than ~ 1.00 % and the fluctuations in concentrations of carbon dioxide are caused naturally by the seasons of plant life and superficially by manmade industrialization activities, while fluctuations in relative humidity (the measure of moisture in the air) is determined by climate.

Now, for the second factor and that is of course light. Light is vibrating electric and magnetic fields that radiate outwards in straight lines as waves just as sound waves do. As long as the paired oscillatory waves are not disturbed they will continue their universal journey in straightforward fashion.

These electromagnetic waves travel through space as unimpeded at 299,792 km/sec or 186,282 mi/sec. This of course is what we call the speed of light. The energy produced by these electromagnetic light waves is dependent on the wave’s length and frequency.

A wave length cycles through with crests and troughs at a particular frequency, which is the measured amount of waves that pass by each second. Again, just as in sound waves, the longer the wavelength of light, the lower the frequency and energy of its electromagnetic energy. In the color spectrum, each color has its own unique wavelength.   

White light is the total combination of the wavelengths in the color spectrum that are continuously blending in together, where blackness of course is the total absence of all light’s wavelengths.

To prove this, just when it’s dark enough, go to your closet and look at your brightest red hanging garment. You may see the outline of the red dress or shirt, but you will not see any form of its color; it will appear simply as a dark object. 

  

Also, go to your corner novelty shop and purchase a prism. As white light travels through the prism, the light splits up into its primary colors. The same thing is happening in a rainbow. But instead of incoming white light traveling into then split up by the prism’s optics exiting as its color components, it is split by moisture contained in the air. This moisture could be in the form of rain drops, mist or spray.

A rainbow arc

All this splitting going on is refraction. Rainbows, in order to be luminous must too have a darkened backdrop, such as a rain cloud and is always opposite the sun. Also, a true rainbow is circular, but when viewing a rainbow, it appears as an arc due to the horizon blocking out the other half of the circle. When in an airplane, the horizon zone is eliminated so the full circle of a rainbow may be viewed.

The prism and water droplets in a rainbow first refract the traveling white light bending its path by slowing down its light speed. Then it reflects the new refracted straight path by angling its trajectory. Finally, it again refracts it as it exits the medium exposing essentially, white light’s guts…the individual colors.      

 

With the total atmospheric constituents in the mixture of gas molecules and percentages as listed above, as light travels through our atmosphere it bumps into the gaseous molecules. Believe it or not, but the individual gas molecules that make up our atmosphere are smaller than the overall wavelength of white light. This allows the longer wavelengths to pass right through, but the shorter wavelengths do get absorbed by the molecules. The absorption process is quick and the short wavelengths are then released and sent off in different directions from the original point of incidence as it first entered the molecule as a component of white light.

All the shorter wavelengths get absorbed then released in all different directions, but of the shorter wavelengths with higher frequencies, they are absorbed much more often than the shorter frequencies by Earth’s atmospheric gas molecules. Guess which color has a short wavelength with a higher frequency than the rest of the short wavelength colors? That’s right…blue.

The absorbed blue light is radiated in all directions and gets scattered throughout the sky. This scattering process is called the Rayleigh effect. No matter in what direction you look upwards, the scattered blue light wavelength reaches your eyes.

On the horizon though, the sky gives a much paler blue. This is due to the fact that in order to reach you, the horizon scattered blue light must first travel through more atmospheric gases. Thus, some of it is further scattered away in different directions losing its color intensity.

The scattering of the blue is also why our sun appears yellow. Out in space with no atmospheric content to view through, the sun is white. Here though on Earth, our atmosphere scatters the blue and lesser violets leaving only one other short wavelength of light left and that is the spectral yellow.

On sunrise and sunset scenes other colors come into play and it again has to do with the horizon event. As the sun rises or sets, white light along the horizon travels farther through the atmosphere than it ordinarily would higher up in the sky so, much more of the light’s wavelengths are scattered. First, the sun itself appears to change from normal yellow to golden to orange then to red. This is due to the intense scattering of the shorter wavelengths, leaving only the longest, which happens to be oranges and reds to directly beam towards your eye sockets.

The sky itself in sunrises and sunsets may also take on a host of colors. At this angle of light incidence and in particular if there is the right amount of water vapor and dust in the air, these particles further reflect light out in all directions. As light travels toward you, much more of the scattering effect takes place in the shorter wavelengths, sending longer wavelength beams of reds, oranges and even pinks for your viewing pleasure.

In addition to allowing us to see color, due to the reflecting and refracting of white light, Earth’s atmosphere also is one of the main components, along with the sun, that controls weather and climate. Though life is dependent on nitrogen and oxygen which make-up the major constants of Earth’s current atmosphere, it is the lesser amounts of the variable components that affect our weather, such as water vapor and carbon dioxide. Water vapor, carbon dioxide, methane and nitrous oxide (N₂O) absorb heat emitted by Earth causing warming, whereas sulfur dioxide and clouds (condensing water vapor) blocks sun rays from even reaching the earth’s surface creating an opposite cooling effect.

The earth’s atmosphere serves as a shield deflecting harmful cosmic rays and burning up any falling objects such as smaller meteors, asteroids and comets. One only needs to view pictures of the moon’s pocked surface to attest to the protective measures our atmosphere affords us from solar debris impacts. The moon’s much weaker atmosphere has allowed many impacts to occur in testimonial to all the craters on its surface.

The atmosphere is able to burn up falling celestial debris due to specific pressure it possesses in creating friction. This friction is a form of energy that creates heat on an object hurling through it. Once that heat reaches the object’s melting and ignition points, it will begin to melt and burn up. With traces of the atmosphere up to 500 km (310.685 mi) from Earth’s surface, that’s a lot of atmosphere to travel through before making impact.

Solar System Small Parts:

Meteoroids, meteors and meteorites I’m quite sure are words we’ve all heard of, but do we know the distinction between them?

A meteoroid is a rock or bit of debris that is precariously orbiting the solar system. Size ranges from dust particles to rocky and metallic material up to 10 meters or 33 feet in diameter.

Perseides meteor over the Rockies

A meteor is essentially a meteoroid burning up as it passes through a planet’s atmosphere at speeds up to 17km/sec (10.56 mi/sec). A meteor is what we call falling stars.

A meteorite is essentially a meteor that made it through the atmosphere and impacted the surface, whether it is on land or water.

Interpretation of meteorite impact

Whoever decided to label the same object with three names that are determined by where it is located at a certain point, I’ll never know why, but it stuck and that is what we have to deal with.

To make things even more confusing, the difference between a meteoroid and an asteroid is nothing. An asteroid is simply a big meteoroid, for any meteoroid over ten meters is called an asteroid and which further, a larger asteroid is considered a small planetoid. Some physicists do indeed refer to planetoids as asteroids, but are technically wrong.

The asteroid Gaspra

Still further, a planetoid is not to be confused with a planetesimal, which is more than just a rock, but a protoplanet disk with aggregated material that collects gravitationally after reaching over a kilometer or a little over a half mile at 0.62 miles in diameter. Finally, a protoplanet is considered a planetoid that has developed internal melting creating differentiated layers.

The comet Hale-Bopp over Ohio 

If this isn’t perplexing enough, in going back to asteroids, a comet is considered an asteroid, but with an additional frozen water layer that displays a visible coma or tail once solar radiation and solar winds strike the nucleus of the comet.

      

Now how’s that for mass bewilderment…

Arachnid:

Spiders! You either despise them or have a fascination for them, but either way you normally don’t go around catching them. The ones that do seek out our eight legged friends are far and few in between. There are a myriad of facets we could expound on in discussing the fanged little critters, but primarily we’ll discourse a bit on a few interesting facts and on a couple or three oddball species.

In speaking of fangs, in spiders they are specialized hollow chelicerae that are mouthparts and also act as mandibles that are found on most other arthropods.

Irridescent green chelicerae parts

We usually envision large spiders, like tarantulas, when we think of or have nightmares of them. Perhaps there is a reason, for the giant Goliath birdeating tarantula of the northern South American rainforests, has a full 8.89cm (3.50in) girth, a leg span of 30cm/11.8in and can weigh over 170g/6oz. This spider is in possession of fangs an averaged 2.86cm/1.125in long and though its main appetite is a quest for invertebrates, it has been known to take small rodents, bats, and venomous snakes and yes, birds. The Goliath birdeating tarantula’s toxin effects are only as bad as an hornet’s sting to humans, but its urticating hairs that are ejected into the air is what’s most harmful to humans. By rubbing their abdomen briskly with their hind legs, the airborne spider belly hairs act as a severe irritant to skin, eyes and mucous membranes.

Goliath birdeating spider

But just as impressive is how small spiders can be. The Patu digua male of Colombia has a body the size of a pinhead at 0.37mm/.015in. There are a few spider species where the female is about the same size as the male patu where no males have yet been found. Since males are normally smaller than females in the spider world, perhaps these species will have males even smaller.

Spiders always keep four legs on the surface when walking. For the most part, along with four pairs of legs totaling eight, most spiders also have four pairs of eyes situated along the front of the cephalothorax or rather the head area. The two main eyes are pigmented-cup ocelli and are capable of forming images. The other eyes only detect lightness from darkness and at what direction light is coming from.

Spiders aren’t known for excellent eyesight, but the typical jumping spider has acute eyesight ten times that of a dragonfly, in which has the best insect vision. For better perspective, jumping spiders’ telephoto sight due to a four layered retina and ability to swivel their eyes, are only five times less sharp than human sight.

These sets of secondary eyes detect light by a reflective layer of tissue over the eye called a tapetum lucidum. The reflecting tapetum lucidum is the same tissue found in vertebrate eyes that cause the varying colored eye shines when a flashlight’s beam hits an animal’s eyes. Therefore, so too will a spider’s secondary eyes emit a glow.      

The spider cuticula or exoskeleton is composed of the same material as cuticles are in human fingernails and toenails which contain insoluble proteins cemented with highly cross-linked collagens. This exoskeleton would totally block out information received from the spider’s outside environment if not for the fact that spiders have modified exoskeletons that hosts an array of sensors. The cuticula is penetrated by these sensors that set up networks between the outside world and the nervous system.

Going back 420 million years ago, (190 million years before the first dinosaur roamed the earth) the spider-like arachnid, trigonotarbid lurked, but had no spinnerets for silk making.  For the most part, all spiders today have the ability to spin silk which is a proteinaceous material, but not all spiders spin webs.

Trigonotabida Temporal Range ~ Early Permian

A sensor known as a slit sensillae found in the limb joints, aid in detecting force and pressure differentials. Where eyesight is more important to spiders that actively hunt or ambush prey, slit sensillae are more important to the web makers.

There are many types of weaving in web making such as orb, flat and funnel webs, but members of the spider family Theriidae, or house spiders weave the tangle web. This irregular webbing is what we call cobwebs once the web has collected dust. The word, cobweb comes from the old English disused coppe, which at one time meant spider.

In the spider family Deinopidae, net casting spiders do exactly what their name implies. Primarily nocturnal, they have excellent night vision. These spiders spin a rectangular net reinforcing it with extra silk. They then will suspend themselves just above the ground holding the folded net with their front legs. When an unsuspecting insect walks by, the spider widens the netting up to three times its size from when it was folded, then casts it over the prey.

In the spider family Scytodidae, known as spitting spiders, these guys have taken spider silk and spider toxin to a new realm. Spitting spiders are the only spiders to manufacture silk from their head. They still possess silk glands in the abdomen, but in addition, silk glands in the head are connected to its venom glands.

When an invertebrate prey is chanced upon, the spider will size up the prey from around a distance of 10mm/.39in. Then in measured amounts, will emit two streams of the mixed silk-venom fluid from the small fangs with wide openings in the tip of its chelicerae. The ejection has been clocked at 1/600 of a second. The instantly drying concoction envelops the prey, immobilizing and entrapping it.

Other odd features of the spitting spider from its other spider cousins, is that its head is larger than its abdomen, it only has three pairs of eyes and has specialized long hearing hairs in its legs to locate prey.      

Though there is current research going on in detecting new pigmentation, as yet there are only three classes of pigmentation that have been found for spider coloration. They are…bilins, guanine and ommochromes. Ommochromes are visual pigments giving spiders their characteristic darker eye coloring. Bilins are for shades of green, while guanine displays whites and silver. Guanine is normally an end-product in protein metablosim, but spiders have the ability to block its excretion and store it for color usage. The common melanins, carotenoids and pterins found in most animals are absent in spiders. Spiders also utilize a tanning process to coat their exoskeleton in browns.

In the jumping spider genus, Portia, members are araneophagic meaning that what is on their main menu are other spiders. Portia stalking skills in capturing spider prey up to 200 percent bigger in size, indeed shows intellectual skills. They are capable of learning and problem solving.

A Portia jumping spider species

The favorite prey is web spiders and with the appearance of looking like a wilted leaf, Portia will act as a leaf caught on the web. When the poor eye-sighted web spider comes to investigate to remove the leaf debris or repair the web, the Portia attacks.

If this mode of operandi doesn’t work, the Portia spider will send out vibrations typical of a trapped insect through the web to arouse and then fool the web spider into thinking he has caught a meal.

Again if this fails, the Portia will time his assault with a light breeze that further hinders the web spider’s already poor vision by making images appear blurred.

In the Philippines, a local Portia will ambush and attack spitting spiders (that themselves stalk jumping spiders) from the rear, but in using instinct as a base, through trial and error tactics, they learn that a female spitting spider laden with eggs will not spit, so attack her head-on.

Against other jumping spiders that also possess excellent spider vision, once sighted, Portia will lie in wait appearing as leaf debris and when the unsuspecting jumping spider is in biting range, it quickly pounces and attacks.

The tactic used for any harmless insect is to simply rush and succumb the prey.     

Mimicry, just as camouflage coloration are two defense mechanisms used by a lot of animals, including spiders, but some twelve families of  spiders have taken mimicry not only to an art form, but to a technical science level as well in mimicking ants.

This is a spider mimicking an ant

In Batesian mimicry, where an harmless organism mimics a much more dangerous one, if you came across a certain species of spider conducting this mimic form, you would swear to the heavens you were looking at an ant. Most species of spider that perform Batesian mimicry do it to disguise themselves from their natural predators, while a few do it to stalk and prey on ants. They will even use chemical mimicry to give off the same scent as ant pheromones in fooling the true ant and predators.

A real weaver ant

Female Myrrnarachne spider

In Southeastern Asia, the spider, Myrmarachne plataleoides mimics a very aggressive weaver ant species. The jumping spider is even equipped with black dots located on the sides of the head exactly where the weaver ants’ dark eyes are located on their heads. The male spider of the species even goes further by not only in mimicking the weaver ant, but with its extended and disguised chelicerae, it appears as if the ant mimic spider is carrying a fellow ant, as weaver ants commonly do.

Male Myrmarachne spider

Spiders have eight legs where insects, as ants all have six. Also, insects have antennae where spiders have none. The ant mimic spiders ingeniously get around this obstacle by rendering their two front legs useless for walking. Instead, opting out their front legs for mobility, the spiders have incorporated them into apparent looking antennae, while waving them around in the air as insects do in inspecting their environment.

Spiders of course are predatory and carnivorous. But as in all things there is an exception to every rule, or a subscript to every script; so too is there an exception in spiders. First discovered with a withered dead species in 1896, then recently rediscovered in 2001 and fully analyzed in 2008, a jumping spider from Central America and southeastern Mexico, was found to be mostly herbivorous, a diet consisting almost solely of vegetation. The new found spider is called Bagheera kiplingli.

Do not picture an herbivorous animal grazing the fields, for this jumping spider appears to have adapted its ancestral hunting skills into thievery of delectable veggie meals. The spider dines on the protein rich leaf tips of thorny bullhorn acacia trees or shrubs (Acacia conigera), but it doesn’t collect and eat the buds on its own; it steals them.

There is a symbiotic relationship between the acacia tree and the ant species, Pseudomyrmex ferruginea. The acacia also emits a nutritious sap. The aggressive ants fiercely protect the tree from intruding animals in returning the favor for the tree’s lodging and nutritious rewards.

In utilizing their skilled ancient hunting techniques, the jumping spiders have evolved those tactics into methods for stealing the tree’s nutrients from the ant’s mouths as they are transporting leaf tips and sap. In order to be a thief of fierce stinging and biting ants, the spider has to be very clever and agile. With a sudden hydraulic increase of blood pressure into their legs, the legs are rapidly thrown downwards propelling the body skywards up to fifty times its body length. This is the spider’s mode of hit and run. Before the ant even knows what happened, the spider has taken the meal and in another bound, suddenly disappears as swiftly as he came.

Though on occasion, the spider thief will also swipe an egg or larva being transported by an ant, over 90% of their diet consists of vegetation as corroborated by tissue culture research on the spider. The tissue exhibits isotopic signatures that are only evident in herbivores.

A further oddity about this spider is that unlike all other spiders that expel enzymes in their saliva to externally predigest their food into a liquid, this veggie spider eats his food raw and digests it internally as any respectable herbivore would.

Serpentine Font:

(Belly Crawl)

Ah the snake! Doesn’t thinking of snakes crawling all about bring pure joy to your soul? Most likely not! For some reason, primates (man, ape or monkey) appear to have an innate fear of snakes. Somewhere down the evolutionary line primate and snake encounters must have not gone over too well.

Snakes really are interesting animals. Just imagine foregoing limbs to opt for belly crawl mobility. In all osteological, or skeletal snake structures, except for the most latest evolved viperidae family, there are vestigial remnants of at least hind thigh bones. In the more primitive snakes such as the boas, the vestigial limbs even protrude outside the body, though more pronounced and obvious in the males. This external protuberance known as an anal spur is located at the base near the cloacal opening, a vent tied into the intestinal, urinary and reproductive tracts.

In the blind snake families of Typhlopidae from the tropical regions of Africa, Asia and the Americas and Leptotyphlopidae from the Americas, there are even remnants of a pelvic girdle. In fact the first snakes to appear on the scene as far back as 125 million years ago or so, possessed minute hind limbs in the extinct genera Coniophis and Lapparentophis.

We’ve been speaking of the hind limbs exclusively, for no snake has any structure (functional or vestigial body part) that would be considered a front limb. This is due to their evolution of Hox gene expressions controlling limb morphogenesis. The thorax of animals is a division of the body that lies between the head and abdomen. In humans, the chest area is the thorax. During the fetal stage, the dominant Hox gene expressed itself upon the developing axial skeleton of the evolving snake lineage, incorporating developing limb buds onto the cervical and into the thoracic identity. The dominance of the Hox gene was expressed from the cervical (neck) through the lumbar (lower back) all the way to the caudal (tail). So essentially, a snake’s skeleton is an extremely long exaggerated thorax.      

We pretty much typically recognize the common snake mode of transportation as they slither across. This form of snake ‘S’ wave mobility is called lateral undulation and while it is the main form of terrestrial locomotion it is the only aquatic form. But there are four other forms on how snakes move about as well.

Sidewinding movement

For mobility, snakes utilize the coordinated efforts of ribs, muscle and abdomen scales. In lateral undulation, a firm surface with friction is required to obtain grip for the snake’s belly scales conveniently called the ventral scales. Ribs also help push off anything from rocks and twigs to leaf litter. On a flat surface where grip is not so obtainable, snakes will resort to sidewinding or crotaline locomotion, such as on loose grained sand or in slick mud, where the series of loops leave J-shaped tracks as imprints in the loose surface. In the static nature of sidewinding a very low cost in caloric output is realized.

Elaphe obsoleta quadrivittata

For vertical ascension or tunnel-side restraints, most snakes will resort to concertina locomotion. In this mode of movement the posterior portion of the body is first braced against the tree bark or tunnel wall allowing the anterior portion to extend and straighten. The anterior is then flexed and anchored allowing the snake to straighten its posterior end and pull it forward. The steps are repeated in sequence utilizing vertebrate muscles and belly scales for grip until the snake arrives at his destination.

In horizontal undulation or rectilinear motion, which means movement one way in a straight line, the snake does not bend its body laterally. Incorporating this mode, the ventral scales are lifted then pulled forward before contacting the surface while the body is being pulled over the ventral scales. This generates waves of movement and stasis that pass over the posterior body resulting in a series of skin ripples pushing the snake forward. This method is employed mostly by the heavier boas and pythons and is used for stalking prey since it generates very little movement and is a very slow process, thus a lesser chance in being detected.

Chrysopelea caught in flight mode

Gliding is taken advantage of by the snake genus, Chrysopelea, the flying or gliding snakes of Southeast Asia. Up in trees or any elevation, to elude predators or simply want to go to more accommodating environs, this snake will lean forward to determine a level of inclination, advance a thrust propelling itself from the launching pad, extend its rib cage from back of the head to the anal vent and suck in its belly, thus becoming airborne in a controlled glide. These body assimilations create a concave wing effect, quite like the bottom of a Frisbee and along with a continuous lateral undulation motion parallel to the ground this snake enjoys a long lasting flight (up to a 100 meters/330 feet) and a safe predetermined landing.

The generation of the body’s concave winging cause air pressure to increase underneath the snake creating lift and flight control, where the initial ballistics during lift-off controls the destination point. The lateral undulation stabilizes the flight pattern where the tail may perform as a rudder.

Another glider found in South America, is the short distance aerialist Baron's green racer (Philodryas baroni), which flattens its body to glide from one tree to another.

I should note a sixth form of snake locomotion that deals with heavier boas and pythons that are primarily arboreal. They will grip a branch with the posterior end to act as an anchor, then elongate the anterior head end, reach for another branch, anchor to that one, pull the back half of the body onto the new branch and then repeat the process. This repetitious form of moving through trees can be accomplished by snakes up to 6.1 meters or 20 feet in length quite handedly, or should I say rather ‘un-handedly.’

(Sound)

Snakes have no ears externally or internally to detect sound vibrations from the air, but they do hear you. The ‘ear’ of a snake, for lack of a better word, is within the skull frame itself, where the skull bones sense varying vibrations that travel through the ground. So in effect, as you are merrily enjoying a walk through the field, the snake ‘hears’ your approaching footsteps long before you hear its hiss during the encounter. Snakes may also detect air vibrations through a complex system of internal resonances in distinguishing air vibrations through their scales.

Speaking of hissing, snakes have no larynx or voice box, but even though they can’t hear it, still produce hissing sounds. They do this by expelling air in a forcible manner. Snakes have a small slit known as the glottis just behind the anchored portion of the tongue. The glottis is the opening into the windpipe or trachea. Just behind the glottis is a thin membrane tissue. When air is forcibly expelled from the lungs, the exhaled air rushing past the membrane through the constricted passageway causes the membrane to vibrate producing the familiar snake hiss.    

(Shedding)

Snakes shed their skin up to four times in their first year of life, down to twice or only once a year in older age brackets. Unlike spiders and insects molting out of an old tight exoskeleton, snakes do not shed to grow.  They shed just like humans do to replace worn skin and also to get rid of ectoparasites. Instead of doing it in piecemeal fashion as humans do in flaking, snakes do it all in one sloughing.

The skin of a snake is of course covered in scales (some call scales scutes), which are simply an extension of the skin so are also shed. In this process of molting skin and scales, we call it ecdysis. Ecdysis begins when the connection between the old outer skin and new inner skin liquefies separating then casting off the old outer skin and scale layer.  During ecdysis, the snake is at its grumpiest. For apparent reasons it is obviously an uncomfortable condition and also, the ocular or brille scale that covers the eye is normally transparent, but clouds over once shedding begins making it very difficult to see.

In fact all scales, composed of hard beta keratin, are clear just like the ocular scale. What gives the snake color is not due to pigmentation in the scales but of the diffraction of light through the scales to the pigmented skin and back out to the viewer’s vision perception.

(Scalar)

Since snakes have no eyelids, the ocular smooth scale mentioned above is called a brille covering and protecting the eye.

There are two basic types of scales…smooth and keeled. In smooth scaled snakes, the scales are more reflective appearing shiny. There is a rougher image in keeled scales with a ridge running down the central axis.

Under a microscope, smooth scales appear as densely packed parallel fibers, where keeled scales are widely spaced ridges cross connected by fibers running at right angles.

The family, Hydrophiidae makes up the sea snakes containing around fifty species. Sea snakes left the land for the sea eons ago and are now so equipped for a marine existence that they are very sluggish and awkward on land due to a third of their posterior being rudder shaped. Only one genus of sea snake comes to shore to lay eggs, the rest give birth to live young in water.

The reason I’m bringing sea snakes up here is that in addition to having very potent venom to ensure fleeing fish victims don’t get too far away in swimming, they also possess the roughest keeled scales to wrap around and hold slippery prey.  

Sidewinder (Cerastes cerastes)

To end the scale discussion, there is one genus of snakes that do not shed their tail scales, but instead retain them. Do you know just what snake genus that is? It is the Crotalus genus…the rattlesnakes. A rattlesnake rattle is the loose layers of unshed scales that vibrate against each other in creating the characteristic snake rattle.

(Smell)

To track prey, snakes use scent. Along with some lizards such as monitors, snakes flicker a forked tongue to pick-up odor molecules as air particles and take them into the mouth. There, the molecule odors are recorded by a chemo-receptor located in the roof of the mouth known as Jacobson’s organ.

Jacobson’s organ is an olfactory sense organ and for the snake, is used primarily for understanding its ambient environment by letting it know what is in it. But this organ has a very peculiar and interesting evolution in animals. Jacobson’s organ in the snake is a modified vomeronasal organ.

In most animals that still retain a functioning vomeronasal organ, use it for picking up pheromone scents, chemical messages that are sent by individuals to individuals of the same species.

It was once at one point important in human evolution, for the human embryo retains a vomeronasal organ during the early stages of development, but as the fetus grows, the vomeronasal becomes non-functional. It may though have some effect, for chemical communication does appear to occur in humans.

(Vision)

Snakes do not have the best of eyesight. Most fossorial or burrowing species have vestigial eyes and can only detect light and dark tones, but for the most part snake vision is adequate enough to detect objects and their movements. Keenest eyesight is possessed by the arboreal or tree dwelling snakes.

Snakes with elliptical pupils are primarily nocturnal, while rounded pupils suggest being diurnal. The twig snake has a horizontal elliptical pupil for binocular vision.

(Size)

Snake size varies tremendously in extant snake species with the smallest having to go to Leptotyphlops carlae, known colloquially as the Barbados blindsnake or threadsnake. An adult measures a mere length of 10cm/3.9in. To illustrate a visual comparison, this snake could comfortably curl around an American quarter coin.

The largest is an ongoing debate, but the common anaconda (Eunectes murinus) of South America has a documented length of 7.5m/24.75ft. Though this may not be the longest snake, as that documented title goes to the reticulated python (Python reticulatus) of Southeast Asia at 9m/29.7ft, if they were weighed, the anaconda, which is a boa species, would be the heaviest weighing in at 97.5/214.95lbs.

Vertebrae: Anaconda vs. Titanoboa

Paleontologists found fossilized snake vertebrae from 28 specimens of an extinct species that is by far the largest, longest and heaviest snake we know of so far. Slithering or lumbering around in the rain forests of Columbia 60-58 million years ago was a behemoth of a snake called Titanoboa cerrejonensis. This aptly named titan of a snake grew between 12.75-15m/42-50ft and weighed an estimated 1134kg/2500lbs. The diameter of its girth was a full meter across or 3.3 feet. Titanoboa totally blows away the last known largest snake, the extinct Gigantophis garstini that measured from 9.3-10.7m/31-35ft.

Gigantophis & an average woman

Titanoboa compared to an average man

(Organ Arrangement)

Due to the elongation of the snake body, snakes are either losing one of a paired organ, or are rearranging them. The left lung has become vestigial or totally absent in some species, while the right one is elongating. Paired organs such as the kidneys and reproductive organs are staggered within the body with one located ahead of the other.

The snake’s heart is encased in a sac called the pericardium, but is able to move around due to the lack of a diaphragm. The heart is located right at the fork of the bronchial tubes. The cardiovascular system as a whole is a bit unique in that there is a renal portal system in which blood from the tail must first pass through the kidneys before returning to the heart.

(Venom)

It is incorrect to call a snake poisonous; even for those that inject venom into you. Poison is inhaled, ingested or absorbed; venom is injected. Pert near any snake venom of choice could be swallowed without any ill-effect as long as there is no route to enter the bloodstream as an open mouth sore. Digestion breaks the venom down. So snakes aptly are venomous and not poisonous…except for two species.

Tetrodotoxin

Isolated pockets of the otherwise harmless garter snake, Thamnophis sirtalis of western Oregon preys on the highly toxic rough skinned newt, Taricha granulose. The newt carries a very potent neurotoxin known as tetrodotoxin. If ingested, one newt is more than enough to kill a human causing the dissociation in the exchange of sodium ions between nerves. Acute effects are total paralysis while still maintaining full consciousness until death occurs through cardiac arrest. The newt acquires the toxin from the build-up of the bacterial acquired vibrio species and secretes it over its entire body.

The reason certain garter snakes are not affected, is that they possess a mutant point in the gene that codes for the sodium ion channels. This mutation is resistant to the toxin’s effects maintaining the functionality of the nerve ion exchanges.

After ingesting the poisonous newts, the snake stores this nerve poison in its liver and if any bird or mammal happens to prey on the snake, death soon occurs. Species that prey on snakes quickly learn to avoid this garter snake.

In the Rhabdophis genus found primarily in Southeast Asia, these snakes are both poisonous and venomous. They sequester bufotoxins from toads they prey on and store them in paired nuchal glands located on both sides on the nape of the neck.

Bufotoxin, a poisonous steroid is composed mainly of two compounds, one being bufagin (a digitalis) and the other being bufotenin that affects the central nerves. Most toads manufacture bufotoxin and store and secrete it from the paired parotoid or parotid glands, which are the prominently raised areas just behind each eye. Humans also possess these glands as the largest salivary glands in our anatomy.

When Rhabdophis is threatened, it will arch its neck towards the attacker and release the bufotoxin content from the nuchal glands. Bufotoxin is an irritant to mucous membranes, but can be lethal if it is able to enter the bloodstream.

In addition as mentioned earlier, Rhabdophis is venomous. Snake teeth are fixed and recurved backwards. Rear-fanged snakes have enlarged teeth at the back and top of the mouth. These teeth are recurved as well and though not hollow, are similar to front fixed fangs. Rhabdophis is a rear-fanged snake and can inject a lethal dose to a human. The venom is composed of procoagulants as well as anticoagulants that both play havoc on normal blood coagulation. The venom also possesses the capability of producing spontaneous hemorrhaging due to the possible presence of haemorrhagins.

Snakes we consider venomous are the latest edition of snakes in serpent evolution and the vipers are the latest addition of venomous snakes. It is beginning to appear though that all snakes contain some form of venom. The ones that can do harm to man in possessing fangs for injection of lethal concentrations of venom, are the ones we entail as venomous.

This would suggest that all snakes evolved from an original animal line that manufactured mild venom. The venomous snakes today are the results of species that expounded upon the venomous system in their evolutionary trend.

Snake venom is simply slightly modified to highly modified saliva. In fact the manufacture and secretion of snake venom is from the modified parotid salivary glands. Venom is stored in the alveolus, Latin for little cavity, which is an anatomically biological hollow cavity. From there when put to use, it is transported to ducts via muscle contraction situated around the alveolus and exits out either into the mouth or fangs that are connected to the duct works, then lastly, injected into the wound.

Venom chemistry is a complex mix of proteins, enzymes and proteinic peptides. Traditionally, snake venom was categorized under two headings as either neurotoxic (affects nerves) or hemotoxic (affects blood). Hemotoxin may also be spelled in two other ways…haemotoxin and hematotoxin. Later through advancing research, we realized there is a third major element that merits recognition and that is cytotoxic (affects cells). In fact some have replaced hemotoxin outright with cytotoxin. I myself though, prefer to enlist venom components under all three headings.

Dependent on species, snake venom can be more specifically pronounced in one species, or a species can contain components related to all three types. If surviving a primarily neurotoxic bite, there is complete recovery, whereas in surviving a primarily hemotoxic snake injection, there may be permanent tissue damage.

Following is further description of snake venom types.

Neurotoxin: contains dendrotoxins which inhibit neurotransmissions by blocking the exchanges of positive⁽⁺⁾ and negative^(-) ions across the neuronal membrane, thus no nerve impulse can pass. This creates paralysis and can lead to death. Neurotoxic snake examples are the coral snakes, cobras, mambas, sea snakes and kraits.

Hemotoxin: contains enzymes, in particular nucleotidase and proteins such as serine proteinase that act as coagulents or anticoagulents. Hemotoxins also break down protein surrounding the site of the wound. Hemotoxic snake examples are the vipers, boomslang and certain cobras which contain a lower ratio of hemotoxins.

Cytotoxin: contains the enzyme phospholipase which converts phospholipid molecules into lysophospholipids that are essentially a soap. This soap combines with fat tissue creating cellular mayhem by disrupting cell membranes in breaking down the cement that binds them together. Consequently, body fluid flows into the cell and destroys molecules, a symptom known as necrosis. Cytotoxins also are cardiotoxic that bind to particular muscle cell sites of the heart causing depolarization of the cell to contract, thus quit beating. Cytotoxic dominant snake venom examples are Japanese Habu snakes and the king cobra.

Cytotoxins are more localized where neurotoxins are fast spreaders throughout the animal inflicted, while hemotoxins are localized but slowly spread with survivors exhibiting permanent damage to the affected areas.          

I would like to add another minor venom heading and that is myotoxic. Myotoxins are peptides that are fast acting in causing severe muscle necrosis that leads to instant paralysis. Myotoxins are found in certain rattlesnake species venom.

(Venom Apparatus)

As pointed out earlier, all snakes to a degree possess venom in their salivary system. Also, snakes with the most advanced fang mechanism are the vipers. The introduction of snake venom into a wound is accomplished by the arrangement of four teeth types of teeth structure. They are:

Aglyph: Typical recurved teeth arrangement with no apparent fangs. The vast majority of snakes has this arrangement and relies on chewing to allow normally very mild venom to soak into a wound site. Most aglyphous snakes are considered non-venomous.

Enlarged grooved tooth vs. normal enlarged tooth

Opistoglyph: Snakes with grooved enlarged rear teeth attached to the upper maxilla bones, commonly called rear-fanged. Most snakes with this arrangement have a little more venom potency than any aglyphous snake possesses, but for the most part are still too mild to be considered dangerous to man. These snakes also have to rely on chewing and direct the wound area to the enlarged and grooved teeth. The main exceptions where the bite is lethal in rear-fangs are the boomslang, the twig snake and the rhadbophis snake. Opistoglyphous snakes exhibit the first forms in evolving fangs with their grooving in the enlarged teeth.

Proteroglyph: These are the snakes that displayed the first true fangs that had been fashioned and fixed in place on the upper maxilla at the top and front of the mouth. In the evolution of proteroglyphous snakes the groove in the enlarged tooth began to etch deeper into the tooth until eventually reaching the center. Calcification ensued, encasing the groove forming a hollow fang that was affixed to the venom network. The fangs may still be recurved or slightly curved. These snakes are considered very dangerous.

Solenoglyph: Solenoglyphous snakes are considered to be the most advanced of snakes and primarily are in the viper family. Their apparatus furthered the proteroglyph arrangement with an additional hinging mechanism where the recurved fangs could be folded up against the roof of the mouth and rotate into a striking position when the mouth is opened. Solenoglyphous snakes don’t bite or chew, but rather strike then back off. This eliminates any possibilities of injury due to struggles.

Another solenoglyphous snake is found in the genus, Atractaspis representing fifteen species in Africa and the Middle East. It’s commonly called the burrowing viper, mole viper, burrowing adder and along with a host of others, the side-stabbing snake. These snake species are normally burrowing underground, but when flushed from the subsurface onto the surface say by rain, they appear as a harmless little snake. Don’t fool yourself; they are dangerous and virtually impossible to hold without being envenomated.

Atractaspis

Unlike their solenoglyphous viper relatives, these snakes do not have to open the mouth and thrust forward to strike. Atractaspis not only has the capability to perform a traditional forward strike, they can also perform a lethal injection from either side of the mouth. The maxillary bones where the fangs are based are so designed that the bones have the ability to unhinge sideways allowing the snake to swing its fang into striking position on either side of the mouth. This may occur in repetitive fashion and without opening the mouth; just slinging the fang back and forth from out of the mouth onto the sides until hopefully getting a strike. You can see why there is no way to hold this snake.

(Reproduction)

A male snake hemipenis

Snake reproduction can be a harrowing experience for the female, due to the fact that the male has two penis’ known as a hemipenis or as plural hemipenes. Males alternate hemipenes from copulation to copulation. Hemipenes are held inverted by the male when not in use and are everted when in reproductive use as erectile, much like the human male penis. The big difference here though is that the male snake’s hemipenis is covered in backward curving barbs and hooks that grip the walls of the female’s cloaca. Once the hemipenis is inserted into the female, she has no say in when to end the loving embrace or she would be ripped and must rely on the male when he finishes relaxing the erected hemipenis and pulls out.

Once internal fertilization of the female has taken place, there are three functions female snake species perform in producing young. They are:

Oviparous (egg laying) ~ Most snakes lay eggs and once laid in a fairly safe picked out environment, leave the site totally allowing the hatchlings to defend for themselves from the get go. However, some snake species such as the king cobra female will construct a nest and incubate the eggs and watch after the hatchlings. Most female pythons will not leave her clutch of eggs until hatching except to drink water and will shiver (known as thermogenesis) to generate heat in the incubation of the eggs during cooler weather.

Ovoviviparous (internal hatching) ~ Eggs are retained and hatch inside the female, whereupon the hatchlings exit the female appearing as a live birth. Vipers, grass snakes and most water snakes are ovoviviparous.

Viviparous (placental live birth) ~ Although an egg sac is retained in the Boa constrictor and the common anaconda, Eunectes murinus, both nourish their fetus’ with a placenta giving live birth. This is highly unusual among any reptile species.

(To End Snakes)

In ending the snake section, I’m going to leave you with some personal accounts.

As you may already surmise, herpetology (the study of amphibians and reptiles) is one of my cups of tea. My professional travels allowed me the opportunity to seriously study snakes first hand. I remember in Nigeria holding for the first time a green mamba. In realizing what a potential deadly animal I had caught, I was so nervous that the arm holding the mamba was uncontrollably shaking. In western Africa I remember seeing for the first time a ball python that indeed balled up for easy capture and the pair of spitting cobras that have holes on the sides of the fangs rather than on the tips and can accurately aim for the eyes within 3.6 m/12ft.

Totally oblivious to the cobra pair, I kept walking towards them not realizing they were there, for they were simply perceived as vines with the blending jungle background. Fortunately, my laborer was more astute and halted me while pointing them out. The serpent pair both had half the body extended up in the air swaying ever so slightly to and fro in watching our approach. In fact my chief line cutter was hit by spitting cobra venom and was temporarily blinded. He had to forego two weeks of hospital care.

I also recall the time in Nigeria’s Enugu State hearing then watching monkeys become very stressed, excited and emotional as a python was attempting to snare one of them up in the treetops. There was raucous.  

In what was once central Sudan and now officially the Republic of South Sudan, we had a campsite with large tents for housing. I’d collect various snakes I encountered and put them in burlap bags hanging them from the main tent poles. Even though the tents were big enough for twelve people, I, for some reason, was the only one who would sleep in my tent. I was known as the Snake Man/Captain Texas.

Each night I would lay a tarp out near our camp and every morning would check to see what slivered underneath. There would normally be three to five snakes of the same species I had never seen before or resourced. Taking a couple of specimens back with me to the University of Khartoum’s zoology department, it turned out that these were snake species that had never been nomenclated or described before. They were a small rear-fanged snake with elliptical eyes. I left them with the department, but after shortly leaving the country, I never was able to follow up on the species description. They may be an uncommon snake overall, but where our camp was situated, all you needed was some night ground cover and there they were next morning on a common occurrence.

In the Scandinavian countryside, observing the viper, Vipera berus for the first and only time and in being used to encountering American ill-tempered rattlesnakes and water moccasins, I was taken by its mild nature for a viper.

Back home, without a doubt, my favorite snake of choice is the eastern hognose, Platyrhinos heterodon. This guy’s natural range is wide, covering the eastern half of the U.S. from southern New Hampshire down to Florida and west to eastern Texas up to western Kansas. This snake reaches lengths of 115.6cm/45.5in.

E hognose  standard color phase

E hognose black phase

E hognose variable color phase

Normally a blotched snake of yellow, brown, orangish-red and black, there are common individuals as well colored plain grayish-olive and melanistic jet black specimens.   

The snake displays a host of anatomical features and habit peculiarities. For starters, he has an upturned nose that ends in a tip and is utilized as a spade for digging and plowing about in loamy soils.

Note the upturned nose

When first encountered and disturbed in his habitat, the snake will perform every imaginable aggressive display one could think of in what an honorary snake would do, with the one exception of biting.

With the ability of extending his neck vertebrae, he spreads his neck just like a cobra. While doing his cobra routine, he then fills the rest of his body with air, making him appear almost a third larger. With a deflated neck and bloated body, he then commences to acting as a bad-boy by hissing out all the swallowed air and throwing false strikes. Once he realizes this bluff is not working he’ll proceed to bluff number two.

Bluffing in hissing & spreading neck

If you have stuck around to enjoy the performance, he realizes you’re not going anywhere, so he reckons further measures must be taken. Abandoning the bad-boy routine he immediately rolls over on his back, opens and keeps the mouth agape allowing the limp tongue to dangle out, gives a few quivers and body jerks, and finally remains stolidly still. In other words, as known in Texan jargon, he’s ‘playin-possum;’ ya know, acting as if he just died.

If you pick him up and hold him, he will continue to feign death. Put him back down as right-side up though, he will quickly roll back over onto his back to continue his death performance. Stick your finger down his open mouth and throat and he will not bite.

I have not come across anyone familiar or unfamiliar with snakes, nor read in any literature of this snake biting anyone. The hognose is completely a harmless snake.

"Playin' 'possum"

Unfortunately, when humans cross paths with the hognose and are unaware of his true temper, will either run away in fright flight, or outright kill the snake. Another unfortunate here…if you keep the snake because you get a kick from his entertaining antics, once he is accustomed to you, he readily tames down ceasing the performances.

Another curiosity of the hognose is the first choice taken on the menu. As mentioned earlier, toads have parotoid glands filled with bufotoxin that most predators avoid like the plague, but the ol’ hognose relishes them. He will take frogs, but when given the choice will proceed to the toad aisle every time. Toads will inflate their body with air to avoid being swallowed. Hognoses have enlarged rear teeth on the upper jaw that punctures the bloated toad, then injects a mild venom into the puncture wounds that acts as a sedative. With markedly enlarged adrenal glands it is suspected the glands play a role in neutralizing bufotoxins.  

Snakes are strictly carnivorous predators and will only eat what they freshly capture or kill. Even a starving snake will not accept previously killed food. Road kill is strictly off their menu; except for perhaps the hognose.

I once fed some thawing toads that I had stored in the freezer in hopes of feeding a captive eastern hognose that was still active during the winter months due to being indoors in a warm environment. Not only did he accept them, he greedily took them. Yes, this is one snake to get to know.

In ending where I started, in man, there appears to be an innate fear of snakes. A small child will stick her finger into a candle’s flickering flame until she learns it burns. This same child’s curiosity will even attract her to a spider skirting across the floor until her mother says no. But when that same child sees a snake slither across the lawn for the first time, she cringes in fear on her own accord.

As far as primates go, squirrel monkeys for instance who’ve never seen a snake, being reared as pets their whole lives, will rivet in abject fear if they even see an object remotely similar to a snake, such as a dangling rope.

Ever heard of the old phrase, “The only good snake is a dead snake?” We’ve vilified the snake in our cultures and religions; referred it to evil. Perhaps we depreciate this reptile due to a legless body, his unblinking stare, its emotionless facial features and its slithering mobility.

Invoking fears towards snakes petitions a hostility that evokes an everlasting apprehension. This enhances a dangerous regard for snakes and is imprinted into our own internal reasoning. The ones who truly fear snakes can give no valid reason, they just do. You see, it’s just in us.

Snakes are no more evil than the next animal. They’re very efficient in what they do and perform a myriad of services in culling diseased vermin, keeping control checks on their prey populations and filling a niche in ecosystems that if they vanished from, no other animal could fill the void.

Baby ribbon snakes with one baby rough green (USA)

In the process of niche filling, snakes have conquered land, sea and air. You don’t have to put snakes on your next Valentines list, but to scoot a bit further from just respecting, understand them in learning about them. Snakes are deserving of at least a hint of appreciation.

Nailed:

You may not realize this but your toenails grow slower than your fingernails. Toenails grow on average about 1mm/.04in per month while fingernails grow 3mm/.12in per month. At that rate it takes toenails 12 to 18 months to fully grow while the fingernail takes only 3 to 6 months. Apparently when it comes to growth rates, all nails are not equal even though they’re composed of the same keratin material. Now why is that…

As Scientifically Pronounced,

BJA

08/16/2011