Recent Posts
Picture of a bee-eater making sounds
Meet a bird who raises children on high voltage wires
Meet a bird who raises children on high voltage wires
Storks favor a nesting place in a prominent place, such as the top of a tall tree, although they will sometimes make do with a modern-day counterpart, an electrical pole."But for centuries, rooftops, churches, and chimneys throughout Europe have been favorite nesting sites.
Both the male and the female bird patiently build the nest, an extraordinary structure that may well look as if it will topple off its perch at any moment.
But appearances can be deceptive, and the large nests are rarely dislodged even during the most violent storms.
So durable are the nests that the storks on returning each year usually just spend a week or so making minimal repairs to their home.
This repair work, which involves adding twigs and other material, is usually done by both storks as soon as they arrive from their winter quarters.
And eventually, it is this repair work that brings about the nest’s demise—it just collapses under its own weight.
By that time the nest may well be as much as seven feet [2 m] high and three or more feet [a meter or more] in diameter.
Just as the parents return to their nest every spring, so the offspring try to find a site as near as possible to their place of hatching.
Thus, some old buildings become host to a dozen or more enormous nests, all occupied by descendants of one original pair.
Comings and Goings
Some European storks winter in West Africa south of the Sahara, while others travel as far as South Africa.
They start the long journey south in August. As they are not strong fliers, the journey is done in stages.
They prefer to migrate in groups of varying size, and often all the storks in a certain area will join up before departing on their migration.
Being among the earliest migratory birds to return north, they arrive back at their nests in February or March.
Because of their size—they have a wingspan of about six feet [1.8 m]—and their dependability, migrating storks have always attracted attention.
The distance they travel every year—a round-trip of over ten thousand miles [16,000 km] in some cases—is remarkable, all the more so considering that they glide most of the way.
Like the large birds of prey, they rely on thermals, rising bodies of hot air, to gain altitude, after which they take advantage of their broad wings to glide effortlessly for long distances, only rarely beating their wings.
A unique feature of the storks’ migration is their passage across the Mediterranean. They prefer not to travel over water, where thermals are absent.
Thus, every August thousands of storks congregate to make the crossing at the two points where the distance over the water is the shortest (the Strait of Gibraltar and the Bosporus).
Surprisingly, the long journey across the Sahara Desert does not daunt them as much as the nine-mile [14 km] stretch of water separating Spain and Africa, which can take them as much as five hours.
Storks and Babies
Where did the story originate?
Apparently, the idea is based on two legends. Years ago, people noticed that storks appeared seemingly miraculously each year at the same time.
Some thought that they went to Egypt during the winter months and became men, only to revert to being birds in the spring (this explained their attachment to human dwellings).
It was also noticed that storks spent most of the day feeding in marshy areas, which were said to be the dwelling place of the souls of newborn babies.
As storks were birds that were most solicitous parents, it did not require too much imagination for people to link fact and fiction and come up with the notion that babies were brought by storks.
The stork—traditional harbinger of spring, babies, and good fortune—has long held a special place in human’s myths and affections.
Its graceful flight, its affinity for human settlements, and its useful role in controlling agricultural pests have all contributed to its popular image.
But perhaps its most endearing feature is its faithfulness—faithfulness to its nest, to which it returns every year, and loyalty to its mate, with which it forms a lifelong bond.
In fact, its name in Hebrew means “loyal one” or “one of loving-kindness” because, as the Talmud explains, it is a creature distinguished for treating its mate with affection.
Thanks to this popular image, nearly two hundred years ago the stork was a protected species in Holland and, reportedly, tame storks could be seen strutting around the fish market of The Hague.
It was later made the national bird of Germany. And nowadays, in some European towns, platforms are erected on roofs to encourage this friendly bird to nest on them. Storks are welcome neighbors!
Let hope this altitude will persist into the future!
Amazing facts about a whale
Amazing facts about a whale
The ocean surface is smooth and tranquil.
Suddenly, there is an explosion of water and spray!
A 40-ton black beast makes what appears to be an abortive launch into flight.
The animal falters for a moment at the peak of its upward thrust.
Then, with a resounding crash, it disappears below the surface of the water.
For those who witness this, the impression left on them is lasting.
They have privileged to witness one of the largest of earth’s animals, the whale, rear itself above the water to catch a breath of air.
For many hundreds of years humans has marveled at the whale, believing at one time that its appearances near coasts or on shores were portents heralding great events.
While to a great extent superstitions concerning the whale have disappeared, awe and amazement have not.
A closer look at this giant’s form and habits will show why.
What is a whale?
It breathes air, suckles its young and even has some of the external hairs so characteristic of mammals.
However, the only time a whale breaks the water’s surface is to exhale a blast of steamy breath, known as the blow, and to inhale more life-sustaining air.
Unlike other marine mammals, whales cannot lounge around shorelines.
For some of the ‘great whales’ to be beached even temporarily means certain death.
Without water to support such a huge bulk, their ribs collapse and death occurs by suffocation.
Whales are divided into two basic groups, the baleen whales (with whale bones, rather than teeth) and the toothed whales.
Perhaps the best known of the baleen group is the giant blue whale, spanning a length of some 100 feet (30 m) and weighing up to 134 tons.
Says the book Whales, by E. J. Slijper, that weight is equivalent to four brontosaurs or 30 elephants, or 200 cows, or 1,600 men!
Certainly this monarch of the deep is the largest creature, living or dead, ever known to move upon planet Earth.
The baleen or whalebone itself is a horny growth, edged with frayed bristles that hang from the whale’s upper jaw.
It is made of a substance similar to our own hair and nails and is constantly growing and being worn away.
A row of these long tapered baleen plates on each side of the mouth creates a large sieve that separates plankton, a major part of the diet for this type of whale, from tremendous quantities of water.
On the other hand, toothed whales are not equipped to catch the tiny plankton.
Instead, they prey primarily on fish, squid and other seagoing mammals.
Toothed whales range in size from the four-foot (1.2-m) long porpoise through the well-known dolphins and killer whales right up to the 60-foot (18-m) long sperm whale.
Amazing Abilities
How can such a huge creature plow through the ocean at speeds rivaling a nuclear-powered submarine?
Investigations have shown that, unlike the rigid submarine, a whale’s body is flexible.
A layer of blubber thwarts friction and reduces turbulence to a minimum.
Another endowment of the whale is its ability to produce an array of noises ranging from creaks and squeaks to chirps and shrill whistles.
Use of these sounds appear to be twofold: they help to keep the family groups, known as pods, together, and also are a form of sonar, enabling the whale to locate food and “see” in the dark.
The gigantic bodies of whales have long been viewed as enormous bags of “goodies.”
Originally people sought the flesh as food and the blubber for oil.
Nowadays people produce from whale carcasses such things as automatic transmission fluid, candles, fertilizer and, yes, even lipstick.
What will be the whale’s future?
Will it become extinct?
Some efforts have been made to ensure the survival of whales.
The International Whaling Commission (IWC) is a voluntary body made up of representatives of whaling nations.
Since 1946 the Commission has placed bans and quotas on catching various species.
But its effectiveness and true loyalties have come under fire from conservation groups.
Whether efforts to preserve the whale population will succeed remains to be seen.
How a red grouper fish uses color signals like traffic lights?
How a red grouper fish uses color signals like traffic lights?
Sure enough, the red color of a red grouper fish is impressive.
But what many do not realize is that the red grouper fish uses it's red color as signals, somewhat like we use traffic lights.
When the red grouper is hunting rather than merely keeping watch over his territory, his color turns a darker shade of red.
The clown fish, which is preyed upon by the grouper, can tell from the grouper’s color when he is ‘off duty.’
During these safe periods, a clown fish will boldly chase away a grouper who invades his territory.
A beautiful chaffinch
Meet the 'spiderman' frog with human-like fingers and toes
Meet the 'spiderman' frog with human-like fingers and toes
'El coqui' a frog with unusual features
This little frog averages 36 mm (less than an inch and a half) in length. Its body is not much larger than a human’s thumbnail.
The head, with its large, protruding eyes, is wider than the torso.
Those eyes are ever on the alert for any careless insect that might fly close enough to become a tasty morsel.
Unlike other frogs, coquí does not have webbed feet but has long human-like fingers and toes.
Its skin changes from light to dark, to match its surroundings.
Another non-frog like feature is its development from eggs to embryo to frog.
There is no tadpole stage.
The female is a giant compared to the male.
She usually lays about 36 eggs on the leaf of an air plant, just at the surface of the water in the lower part of the leaf.
The eggs form an oval mass six to eight mm (about one-fourth inch) in diameter.
At night coquíes sit about on vegetation, enjoying their own harmonious sounds.
Only the males sing.
Sometimes they begin their melodious song softly, going up the musical scale, “co-qui-qui-qui-qui-qui!” very rapidly.
As the song gets louder, it settles down to the common two-note “ko-kee! ko-kee!”
The residents of Puerto Rico where the frog is usually found find this a most pleasing accompaniment to their evening meals.
They particularly enjoy the nightly songs of this little frog in the bromeliad plant hanging on the porch.
Unfortunately, many times his privacy was often invaded as people pulled down a leaf of the plant to peep in at the small body from which that big voice came.
The frog usually puffs himself up to twice his size, then squeezing out the “ko-kee!” whistles, his body pulsating with each note.
Creating a coqui family
In a small town in Puerto Ricoa woman had the delight of actually witnessing the birth of a coquí family.
One night she saw the female high up on the kitchen wall.
The darker, somewhat warty female is not nearly as good-looking as the male.
In the morning the woman checked the hole that was the male’s living quarters, and found him sitting over a mass of eggs.
The nights were quiet now, for while attending to his duties papa coquí does not sing.
The woman kept close watch on the eggs, and her vigilance paid off.
Finally, she noticed a stream of water going over the eggs.
Again and again the male sprayed them.
Soon one of the eggs seemed to be whirling, but just for a moment.
The membrane broke and out hopped a tiny coquí, about the size of a common ant but with long legs.
The tiny animal disappeared quickly.
Then other eggs began hatching.
Finally, the hole was alive with swirling eggs and tiny coquíes scurrying for cover.
The father kept spraying water at intervals, apparently unconcerned about the flight of his offspring.
When his work was finished, he left.
His voice was not heard for several evenings.
But after a week or so the familiar sound came from the same window perch he formerly used.
And there he sat, his little body pushing out those two welcome notes, “ko-kee! ko-kee!”
Picture of a palette surgeonfish
Amazing facts about a crowned crane
Amazing facts about a crowned crane
The crowned crane is one of the most beautiful birds in the world.
It is a stately bird with subtle colors and an exquisite shape.
Almost four feet [more than a meter] long, it has a huge wingspan and a delicate, long neck, also characteristic of other types of cranes.
Male and female crowned cranes look alike.
The dark back feathers attractively frame the pure white wing feathers that run down both sides of the bird and turn golden near the tail.
Other wing feathers are a rich chestnut brown.
The face of the crowned crane is a delight to see. Its cheeks are ivory and are surrounded by soft, ebony head feathers on the crown and throat.
The eyes are a beautiful light-blue. From the black throat feathers hangs a long, bright-red wattle, which dangles like a scarlet pendant when the crane stretches its neck horizontally.
Most conspicuous of all is the spectacular plume of slender, golden head feathers that form a magnificent symmetrical crown.
These lustrous, thin feathers glow golden when lit by the rays of the sun.
All these striking, contrasting colors are balanced atop two long, slender black legs.
The trumpeting call of the crowned crane is one of the unforgettable sounds: O-wahng! O-wahng! O-wahng!
This loud cry can be heard for great distances.
Often, a pair of cranes will call out together as they fly to or from their roosting trees.
At certain times of the year, crowned cranes congregate and may number up to 30 birds, producing a cacophony of sound that is a delight to the ears.
Parental Care
Crowned cranes evidently mate for life.
They are found in especially in swamps and marshy areas, where they nest and raise their young.
The nest is a large cone-shaped heap of grass and reeds that provides a platform on which the female lays two or three large, greenish-blue eggs.
The male and female take turns sitting on the eggs, and within a month the chicks hatch.
The parents work together to feed and care for their downy offspring, and they will protect their fledglings fearlessly.
The crowned cranes’ main diet consists of insects, frogs, small snakes, and seeds.
Using their long, spindly legs and their large feet, they stamp the ground, making a quick meal of any small creature that is flushed out of the grass.
Bird Ballet
Crowned cranes are enthusiastic and entertaining dancers.
Flapping their large colorful wings, they lift themselves into the air vertically and then float gently back to the earth as if attached to a parachute.
Gracefully bounding about, they run and spring into the air, circling their mates and bobbing their heads with quick, clownish jerks.
Holding their large wings open, they stand erect and display the beautiful colors of their wing feathers.
Sometimes a pair will contort their necks into elegant shapes and look each other in the eye.
Beak-to-beak, they utter a series of low, booming notes as if serenading each other.
Standing upright again, they resume their elaborate bird ballet.
The Fight to Survive
Crowned cranes are rather tolerant of humans and are easily tamed.
Because of their delightful color and shape and their entertaining dancing displays, they are popular in zoos and are sought after to ornament private estates and gardens.
With such a demand, it is not surprising that their numbers are dwindling.
Further pressure on the crowned crane comes from the reclamation of wetlands and the use of poisons and insecticides, which pollute lakes and streams.
Picture of a black swan up close
Meet nudibranch the most beautiful snails in the world.
Meet nudibranch the most beautiful snails in the world.
What do you think of when someone mentions the word “snail” or “slug”?
Most of us think of some slimy, slippery animal that isn’t the least bit pretty, fascinating, or appealing.
Beneath the surface of the sea, however, lives a type of sea slug, a snail like animal, that is so beautiful and colorful that it has been called the butterfly of the seas.
Although most of these creatures are shell-less, they are in the mollusk family, which includes seashells.
What is it? It’s a nudibranch (pronounced nōōdē-brank).
Nudibranch
The nudibranch was given its name because it is a mollusk without a shell and, therefore, its gills are exposed. Its name means, literally, “naked gills.”
Marine biologists are still learning about nudibranchs, but over 3,000 species have been found and most of them identified.
They range in length from 1/8 inch [0.3 cm] to more than 12 inches [30 cm] and are among the most vividly colored animals in the sea, possessing vibrant orange, blue, purple, yellow, and red pigments.
Even the masses of eggs of some of these animals are beautiful in color and design.
Their eggs are laid in ribbons arranged in various shapes, which have an appearance much like the ribbon you might use to decorate a gift.
These “ribbons” are laid on edge and are formed into a large egg mass resembling a beautiful flower.
What keeps such a delicate-looking morsel from being nibbled on and eaten by fish and other predators?
The egg case contains a substance that makes them very distasteful to predators, thereby protecting the eggs until they develop into planktonic larvae.
Adult nudibranchs not only are delicate and highly visible but are slow-moving and soft, a seeming paradox in the often severe, harsh, and hostile environment of the ocean—so much so that one marine biologist said, “They amaze and astound simply because they are.”
Yes, it is amazing that they can continue to exist in their environment—particularly that such an appetizing-to-look-at morsel keeps from being eaten by the fish that are attracted by its bright colors and often fluttering appearance.
Many of the soft-bodied nudibranchs are uniquely designed to graze on sea anemones and their relatives the hydroids.
These organisms upon which they feed have stinging cells in their tentacles to stun their prey and to act as a protection against most predators.
The nudibranch, however, is immune to their sting, and when one of these sea slugs eats the stinging structures responsible for the venomous sting of the anemone or hydroid, its remarkably designed digestive system passes some of these poisonous organisms on to other parts of its body to become a defense against marauders who might like to make a meal of Mr. Nudibranch.
Other nudibranchs protect themselves by secreting mucus that smells unpleasant to man and perhaps makes them unappetizing to fish and other predators.
One species, the sea lemon, has a specialized gland that emits a slimy, sour secretion containing sulfuric acid as a defense against predators.
Fish have been observed to grab a nudibranch, only to spit it out in “disgust.”
Observation of this behavior has led scientists to conclude that the association of bright color and repugnant taste and/or a stung mouth produces a learned response that makes the brightly colored sea slug an invitation to an unpalatable meal.
A powerful defense mechanism indeed!
Some nudibranchs enjoy still another defense mechanism; they can swim and are thus able to get away from possible danger of an obstinate foe.
Others are able to cast off parts of their bodies when under attack and get away. Later, these parts are regenerated.
When observing the delicate beauty of the nudibranch in its ocean environment and learning a little about its means of continued existence,
How gecko's amazing sticky feet really work?
How gecko's amazing sticky feet really work?
Its feet look like hands, but they perform feats no hands can.
It is another case of invention preceding human’s inventions by thousands of years—in this case the Velcro fabric fasteners so widely used today.
Many are amazed to see the little common gecko, Tarentola mauritanica, scurry up walls and across ceilings, and even scamper up glass windows.
Once it was thought that Mr. Gecko did it by suction cups on its feet or maybe even glue.
But nothing so crude as that!
The book The Grand Design says:
“Each of the gecko’s toes has a pad bearing ridge-like scales. Under a microscope it can be seen that each scale bears hundreds of tiny, hairlike protrusions called setae. As if this were not enough, a further magnification shows that the individual setae are tipped by ‘brushes’ of up to 2000 incredibly small branched filaments, bearing saucer-shaped tips. This provides a phenomenal total of about 100 million points of contact.”
Millions of microscopic hooklets fasten into the tiniest irregularities of a surface—even those present on glass.
The mechanism of release and reattachment of the hooks is incredible.
The gecko bends the ends of its toes upward, which draws the hooks out of the irregularities in the surface.
With toes still bent upward, it advances its foot to the next step and then presses its toes down.
The hooklets again interlock with the surface irregularities—somewhat as a cat alternately extends and withdraws its claws when climbing a tree.
Thus, the little gecko performs amazing feats with its amazing feet.
Amazing facts about a dragonfly compound eyes
Amazing facts about a dragonfly compound eyes
A Head Full of Eyes
If the flight of the dragonfly is extraordinary, no less can be said of its eyesight.
Two huge compound eyes almost cover the dragonfly’s head.
Each of these eyes has up to 30,000 hexagonal units that are like tiny eyes within an eye, since each one transmits a separate image to the brain.
That doesn’t mean, however, that a dragonfly sees thousands of different pictures, all at the same time.
Rather than seeing a complete picture, as we do, it senses movement, patterns, contrasts, and shapes.
All those images need analyzing.
Thus, 80 percent of a dragonfly’s brain is dedicated to assessing visual information.
Few optical systems are as sensitive—a dragonfly can spot a mosquito some 60 feet [20 meters] away.
Even at dusk, when the light is so dim that a human observer can barely spot tiny flies, tropical dragonflies easily capture them.
A dragonfly’s rapid, darting flight through riverside vegetation requires hundreds of split-second decisions.
It can handle this formidable task because it can see up to a hundred distinct images a second, over five times more than we can.
Thus, a movie, which projects 24 images a second, would just look like a series of still photos to a dragonfly.
Subscribe to:
Posts (Atom)
