Sunday, 28 February 2010

Longest flight migratory birds in the world

65 % of the bird species migrate. The ancients, like Aristotle for example, thought that during the winter birds go inside the mud of the bottom of the swamps or in caves, where they pass the winter, and reemerge in the spring. In the 13th century, the German emperor Frederick the Second, passionate hunter, was the first to suppose they effectuate journeys to the warmer southern lands during the winter.

Some species make very short displacements during winter. For example, the Finnish rooks spend the winter in Northern Germany, displacing themselves with just 50 km (30 mi) daily. These birds are not real migrants, but vagrants. Migration is an instinct that even captive birds can not escape.

It is believed that geographic and clime changes during the Tertiary and Quaternary led to the development of the migration behavior. But migrations do not characterize just birds in temperate and cold areas, but also in the tropics.

Changes in the environment (like shorter days) trigger endocrine reactions, influencing the hypophyse. Offspring of migratory birds grown in captivity manifest a strange behavior during the migration periods: they refuse food and are restless during the time their species is on the way to the wintering places.

Birds do not migrate because of the cold, as you might think, but because they do not find food in winter. Those that can are sedentary. Many species of migratory birds accumulate fat before the journey. The journey is so instinctual that even warm autumns will not stop the birds' journey. Some species are forced to migrate due to the lack of food (like warblers) or by the snow and ice (like many duck species).

 

Nor do cold springs for their return, when many birds perish in cold waves.The
way birds migrate varies a lot: some will do it alone (like the cuckoo), others in pairs, while others in large flocks. In chaffinch (Fringilla coelebs), the males are sedentary while the females migrate.

Some birds migrate in well defined formations, the individual from the front of the line "splitting" the air and after a while passing in the rear for rest of the journey.
The little song birds usually form swarms.
The longest migration made by any bird is that effectuated by the Arctic tern (Sterna paradisaea), which nests on the Arctic zone, in the tundra region, and winters in the Antarctica (when there is the Austral summer). This 19,000 km (12,000 mi) journey ensures that this bird sees two summers per year and more daylight than any other creature on the planet.

One individual ringed on the Farne Islands, Northumberland, UK, in the summer of 1982 was found three months later, in October 1982 in Melbourne, Australia. The bird has made a sea journey of over 22,000 km (14,000 mi).
The American golden plover (Pluvialis dominica) nests in Alaska and winters in the Argentinean pampas, thus making a journey of 16,000 km (10,000 mi).

But even common birds in the temperate zones effectuate large migrations.
The barn swallow (Hirundo rustica) flies from Europe to South Africa about 8-10,000 km (5-6,000 mi) and the common cuckoo (Cuculus canorus) migrates till south Africa or Australia some 7,000 km (4,000 mi). Birds orientate during the migration using the position of sun, stars and Earth's electromagnetism.

Birds usually fly at 30-88 km (18- 52 mi)/h during the migration, making from 250 km (150 mi) to over 500 km (300 mi) daily.

But there are some exceptions. The northern lapwing (Vanellus vanellus) can fly continuously at 150 km/h (90 mi/h), crossing the Atlantic in 24 h.

Some gulls and sand martins can reach during the migration 200 km/h (125 mi/h) under favorable wind. This is amazing for sand martins (Riparia riparia), small birds, as they only use active flight (peregrine falcons can reach 390 km or 242 mi/h, but in dive). The spring migration is faster than the autumn migration, and adults migrate more rapidly than the young birds.

Over the sea, birds fly at hundreds of meters, using sea currents. That's why the heart in case of these little birds counts for 10 % of their weight! But the small song birds also get tired often and need rest, that's why they avoid deserts, oceans or mountains during their migration.

Larger birds do not get tired easily, and the record of the highest migratory flight is detained by cranes and geese.

In 1931 a bar headed geese (Anser indicus) flock was photographed at an altitude of 9,500 m (29,000 ft) over the Himalayas.

Some birds migrate during the daylight, like herons, storks, birds of prey, while others, like owls, cuckoo, woodcocks migrate during the night. Birds of prey and storks use thermal currents formed over the warm ground in their migratory flight.

As these currents form only during the daylight, they are forced to migrate only during this period and cannot cross large sea surface. That's why birds using thermal currents during migrations and others that cannot cross seas use specific corridors for crossing seas, concentrating there during their migration, like Gibraltar, Bosporus and Falsterbo (southern Sweden). Water birds prefer shores. Geese, ducks and cranes migrate both during the day and night.

Birds that eat grains or other vegetable items, eat during their migratory halts, but those that eat animal stuff (like pelicans, insectivorous, birds of prey, storks) usually do not, which means they accumulate fat before the great journey. They usually lose 25 % of their weight during the migration.

Researchers found that - besides their sight - birds also use the Earth's electromagnetism to navigate during their migration. This is how we can explained their ability to maintain their course over large distances, on no matter what weather.

Still, from place to place, the lines of the magnetic field vary and they do not always point the real north. The birds still do not deviate from their route because they adjust their "compass" with precision depending on the place where the Sun sets every evening. This is not influenced by latitude or season.

A petrel transported by plane from England to US turned back to its capture place in 12 days, after crossing 6,000 km (3,800 mi) over the ocean. The Pacific golden plover (Pluvialis fulva) flies tens of hours over the monotonous waters of the Pacific, from Alaska to Hawaii.

The slightest navigational error would mean death in the ocean's waves. But the birds always reach the right place, without any land mark. And even birds migrating over the land fly many times at 4-5,000 m over the ground, too high to use the landscape for orientation.

Even stranger, there are birds that do not migrate by flight but by walking! Crakes (Crex crex) travel their way almost exclusively on foot, flying only when they have to cross waters. Quails (Coturnix coturnix) mix aerial and terrestrial "paths": they can walk tens of kilometers during their migration.




Thursday, 25 February 2010

The oldest tree in the world-- 9550 years Old -- Discovered in Sweden

The world's oldest recorded tree is a 9,550 year old spruce in the Dalarna province of Sweden. The spruce tree has shown to be a tenacious survivor that has endured by growing between erect trees and smaller bushes in pace with the dramatic climate changes over time.

For many years the spruce tree has been regarded as a relative newcomer in the Swedish mountain region. "Our results have shown the complete opposite, that the spruce is one of the oldest known trees in the mountain range," says Leif Kullman, Professor of Physical Geography at Umeå University.

A fascinating discovery was made under the crown of a spruce in Fulu Mountain in Dalarna. Scientists found four "generations" of spruce remains in the form of cones and wood produced from the highest grounds.

The discovery showed trees of 375, 5,660, 9,000 and 9,550 years old and everything displayed clear signs that they have the same genetic makeup as the trees above them. Since spruce trees can multiply with root penetrating braches, they can produce exact copies, or clones.

The tree now growing above the finding place and the wood pieces dating 9,550 years have the same genetic material. The actual has been tested by carbon-14 dating at a laboratory in Miami, Florida, USA.

Previously, pine trees in North America have been cited as the oldest at 4,000 to 5,000 years old.

In the Swedish mountains, from Lapland in the North to Dalarna in the South, scientists have found a cluster of around 20 spruces that are over 8,000 years old.

Although summers have been colder over the past 10,000 years, these trees have survived harsh weather conditions due to their ability to push out another trunk as the other one died. "The average increase in temperature during the summers over the past hundred years has risen one degree in the mountain areas," explains Leif Kullman.

Therefore, we can now see that these spruces have begun to straighten themselves out. There is also evidence that spruces are the species that can best give us insight about climate change.

The ability of spruces to survive harsh conditions also presents other questions for researchers.

Have the spruces actually migrated here during the Ice Age as seeds from the east 1,000 kilometres over the inland ice that that then covered Scandinavia? Do they really originate from the east, as taught in schools? "My research indicates that spruces have spent winters in places west or southwest of Norway where the climate was not as harsh in order to later quickly spread northerly along the ice-free coastal strip," says Leif Kullman.

"In some way they have also successfully found their way to the Swedish mountains."

The study has been carried out in cooperation with the County Administrative Boards in Jämtland and Dalarna.



Meet hungry Alligator And Python

An alligator in the Everglades eats a python. ''Alligators are going to chew them up 99 percent of the time,'' a reptile expert says.
The fight rages on in the Florida Everglades. So far, the first three rounds have gone to the alligator, with documented film footage of the struggle between these two reptiles and with the snake being eaten at the end of the fray. Not so, with the most recent struggle, in which a 13 foot python swallowed a 6 foot alligator. The end result was the death of both predators, when the snake split open after swallowing the alligator whole.

There are currently two conflicting theories of what occured during this most recent episode, since no one actually witnessed the encounter. One theory is that the alligator somehow managed to claw or bite its way through the side of the snake after being swallowed. This seems unlikely as the alligator was most certainly dead prior to being swallowed. Thepython is a constrictor which suffocates it's prey prior to eating it.

Theory number two is that the snake, after swallowing it's large meal, was lethargic and easy prey for a second gator to come along and take a bite out of the snake, thus releasing it's fellow reptile from being digested. The snake was found with the gator's hindquarters protruding from its midsection (see attached photo).

What's troubling about these encounters is that the Burmese pythons invoved, were relatively small, only in the range of 10 to 13 feet. The Burmesepython has been known to grow up to 30 feet in length, in it's native Southeast Asia and is a documented man eater at this size, as well. In addition, it is now verified that there is a sizeable breeding population of these formidable snakes in the everglades. It is literally, only a matter of time before larger pythons are encountered. They are destined to become the top of the food chain in the everglades, to the detriment of the native species, including, American alligators, American crocodiles, panthers and skunk apes.
Not only do these gigantic snakes pose a threat to Florida's natural wildlife, but to humans as well. There is evidence of these snakes moving into suburban Miami, as well as north into other areas of Florida. They are basically able to thrive in any area which supports alligators, climatewise. It is now estimated that there is a population of over 30,000 Burmese pythons in the everglades alone.
Research has shown that other exotic species, such as boa constrictors and yellow anacondas are also showing-up in the everglades, thanks to the exotic pet trade and individuals releasing their pet snakes into the South Florida wilds.



Friday, 19 February 2010

Extrem natural places in the world

magine living in a place so remote the mail only comes once a year. Or reaching the summit of the highest place on earth…which isn’t Mt. Everest. Read on to learn about some of the most extreme places on the planet.


Highest Point on Earth…Sort of

At 29,029 feet (8848 meters), Mt. Everest is famed as the highest peak on earth. And that’s true. It’s also not true. It all depends on how one looks at it. Technically, Mt. Everest’s rocky peak is the highest bit of land from sea level. But because the earth isn’t a perfect sphere, certain lower points are in effect “higher” in space. Mt. Everest is less close to the moon and stars than another mountain which is relatively unknown. And that is Mt. Chimborazo in Ecuador. It’s just over 20,000 feet high, so while it’s not as tall as Mt. Everest, it is actually closer to outer space due to the shape of the earth.
Highest Point Accessible by Vehicle
In Tibet, the stark Semo La road is over 20,000 feet high and takes you through hauntingly beautiful vistas and a treacherous mountain pass. Word has it that Marsimik La is the highest road on earth; but it all comes down to what one might consider an accessible road. Semo La can be used by vehicles. Authorities believe there may be other, higher roads, even more remote, but so far they have not been documented.
Tristan de Cunha: Most Remote Island on Earth

The most remote inhabited island group in the world, Tristan de Cunha in the southern Atlantic Ocean, is so tiny its main island has no airstrip. Home to 272 people sharing just 8 surnames, inhabitants suffer from hereditary complaints like asthma and glaucoma. Annexed by the United Kingdom in the 1800s, the island’s inhabitants have a British postal code and, while they can order things online, it takes a very long time for their orders to arrive. But then, that’s the trade off for having your own island settlement some 2,000 miles from the nearest contine
Deepest Point in the Ocean

The Marianas Trench, off of Guam in the Pacific Ocean, is the deepest point in the world’s oceans. It it over 7 miles - more than 36,000 feet - deep. If Mt. Everest were placed in the trench the summit would be more than a mile under the surface. The pressure at the bottom of the trench is more than 1,000 times stronger than at sea level. The United States Navy sent two naval officers to the bottom in a vessel called the Trieste in 1960. They observed fish, shrimp and other creatures living on the bottom of the sea floor.
Lowest Point on Earth

The Dead Sea is the lowest place on land that’s below sea level, at 1,378 feet. On the border of Jordan and Israel, the road around the Dead Sea also happens to be the lowest road on earth. Famous for its salinity (over ten times that of the Mediterranean Sea), the Dead Sea is said to be home of the first health retreat. Because of the extreme salt content, no life can survive in the sea, hence the name.
Coldest Place on Earth - and Driest, and Wettest…Huh?

Antarctica is a land of extremes. It’s not inhabited year round by humans because it’s simply too freezing cold. In 1983 scientists recorded extreme cold temperatures as low as -129 Fahrenheit. It’s also the wettest place on earth, but simultaneously the driest. The reason it’s the “wettest” is not because of rainfall; since Antarctica is covered by 98% ice, it’s technically very wet. However since it’s also the aforementioned coldest place in the world, it gets very little precipitation - less than 2 inches a year. Which makes Antarctica a desert. A brutally cold ice desert with a massive trench full of even more…ice. Three for the price of one!
Biggest Pure Vertical Drop on Earth


Mount Thor, in Auyuittuq National Park on Baffin Island, Nunavut, Canada, presents a 4,100 foot pure vertical drop. Mt. Thor is Canada’s most famous peak, and it’s made of pure granite. It’s a favorite of thrill seekers and climbers. There have been a few recent rappel expeditions, with one fatality in 2006.
Deepest Ice on Earth

The Bentley Subglacial Trench in Antarctica is phenomenally thick ice, going 8,383 feet deep. It’s the lowest point on earth that isn’t covered by ocean, but the honor still goes to the Dead Sea for lowest point, as the Dead Sea is technically “on” land and the Bentley Trench is technically covered with water (ice). The trench is the same size as Mexico.
Hottest Place on Earth


Death Valley is famously blistering hot, but the hottest place ever officially recorded to outdo Death Valley’s amazing heat is El Azizia in Libya. In 1922 the temperature reached 136 degrees. Death Valley’s hottest temperature on record is 134 degrees. When it’s that hot, what’s another two degrees really


Interesting Evolution Of The Elephant Fish in River Congo

The Congo's freshwater elephant fish, such as the one seen above, use their long snouts to sift through river bottom sediments for food--another example of the Congo as a hotbed of evolution.The fast currents and raucous rapids of the lower river create physical barriers that smaller fish cannot cross, said fish biologist Melanie Stiassny, who led a 2008 expedition on the Congo.
At some points, the river flows more than a million cubic feet (28,000 cubic meters) a second--enough to fill more than 800 Olympic-size swimming pools every minute.
Such barriers isolate fish populations, and over time they become more and more distinct from one another, eventually evolving into new species.
During a survey of Congo fish, Stiassny found seemingly different species just a few hundred meters apart. Some had developed flatter bodies to avoid being pulled by the current, for example. Likewise, living in a low-visibility, sediment-filled stretch of the river, the African electric catfish had evolved the ability to stun nearby prey with up to 350 volts of electricity.
Stiassny and her colleagues took DNA samples, which should allow them to determine how many new and different species they have found in the Congo River.


Interesting Evolution of Tiger Fish in the River Congo

February 13, 2009--Goliath tiger fish, such as the one seen above, are among the uniquely adapted "monster fish" of the Congo River, which winds through several African countries.
A recent, unprecedented river run on the Congo yielded a raft of new discoveries, including different species--some potentially new--in nearly every nook and cranny, scientists announced this week.
The river was also found to be possibly the world's deepest, and its extraordinary changes in depths and currents help explain why it's such a hotbed of fish diversity.
"What we're seeing here is kind of evolution on steroids," said team leader Melanie Stiassny, a fish biologist at the American Museum of Natural History. Stiassny, a member of the National Geographic Society's Conservation Trust, was among the marine and evolutionary biologists, hydrologists, and kayakers who conducted the exhaustive research in summer 2008.







Tuesday, 2 February 2010

THIS IS WHERE THINGS GET SCARY . . .

March 4, 1985 was when Shirley Ann Durdin, a 33-year-old with four children, lost her life to a GW in Peake Bay, Australia. She had been snorkeling in water about 7 feet deep - equivalent to the deep end of a residential swimming pool - when she was fatally attacked by a GW estimated by witnesses to be 20 feet long. The first hit was a gory strike, the fish biting her in half. By the time Mrs. Durdin's would-be rescuers could get to the site of the attack, all that could be seen was the victim's headless torso. After a moment, the GW returned and took it as well. It was the first fatal GW attack in South Australian waters in over 10 years and the first time ever that an Australian victim was known to be eaten.
To be eaten - think about it for more than a moment and you're likely to push the thought from your rational mind and back into the depths of your subconscious, a dark pit that contains all of the other fears of death that are too awful to comprehend - the fear of falling, the fear of burning, the fear of being buried alive . . .
Unfortunately, it is this pit where most first thoughts and impressions of the GW reside. It is only with a bit of academic smoke and mirrors that scientists and researchers can cover up what remains the primary fascination that humans have with the GW, the fact that it is one of a handful of animals alive today that can actually eat one of us alive - and sometimes does.
To date the GW has been responsible for 65 deaths, worldwide since 1876! With 242 recorded non fatal attacks worldwide!





THE JERSEY MAN-EATER (or the 'Jersey Person-Eater' for those more politically correct than I)




Although 'Jaws' is completely fictional, its account of what might happen if a big GW decided to camp offshore of a beach resort community faintly echoes the occurrences of a 12-day period in New Jersey during July of 1916. During this short span, five men were attacked by sharks with four of them being fatal. The first, a young man named Charles Vansant, was about 50 feet from shore when he was bitten on his left thigh. He died of massive blood loss less than two hours later.

Five days later, about 45 miles north of the first attack, Charles Bruder was hit by a shark that took both his feet. Although a lifeboat was launched at the moment he began to scream, he was about 400 feet from shore - too far to help. He perished within minutes of his arrival at shore.

Six days passed before the next incident. In what would be the worst of the Jersey attacks, a young boy named Lester Stillwell was pulled under while swimming with friends in Matawan Creek, some 30 miles north of the second attack. Several men dived into the creek to attempt a rescue only to have one of them, the ironically-named Stanley Fisher, bitten on his right thigh. A large amount of flesh was taken in the attack and although Fisher made it to the operating table, the damage was too great and he, too, fell victim to a shark.

The final victim was on his way to shore as word spread of the Stillwater-Fisher attacks but was too late. He was lucky, receiving only a laceration that managed to miss any major arteries.

The Jersey attacks are not noteworthy for being GW attacks. Although it is likely that a GW or a close relative like the mako shark was responsible for the first two attacks, no GW has ever demonstrated a propensity towards venturing into a freshwater (as opposed to seawater) area. The only shark noteworthy of this behavior is the bull shark and this was the likely suspect of the final three attacks. However, the media frenzy surrounding the attacks and the fears that they spread are indicative of the public's continuing fascination with shark attacks.

Monday, 1 February 2010

The Deadliest Snakes in the World

                      And an alarming number are found in Australia!
1) Fierce Snake or Inland Taipan (Oxyuranus microlepidotus ), Australia. The most toxic venom of any snake. Maximum yield recorded (for one bite) is 110mg. That would porbably be enough to kill over 100 people or 250,000 mice. With an LD50 of 0.01 mg/kg, it is about 10 times as venomous as a Mojave rattlesnake and 750 times as venomous as a common cobra. The Fierce Snake is native to the arid regions of central Australia, extending from the southeast part of the Northern Territory, and into west Queensland. The Fierce Snake can also be found north of Lake Eyre and to the west of the split of the Murray River, Darling River and Murrumbidgee River. Fierce Snakes are known to live in holes, and feed on small rodents such as mice and rats. Despite its name, Fierce Snakes are not known to be particularly aggressive, but docile. They will strike if provoked, however, injecting their incomparably toxic venom.No fatalities have been attributed to this species, and all known bites have been to people who keep them in captivity or actively seek them out in the wild.



2) Australian Brown Snake (Pseudonaja textilis ), Australia. One 1/14,000 of an ounce of this vemon is enough to kill a person. The Eastern Brown Snake (Pseudonaja textilis) – sometimes referred to as the Common Eastern Brown Snake is the world’s second most venomous land snake, native to Australia and may also be found on the peninsulas of Papua New Guinea and Indonesia. Eastern Brown Snakes are very fast moving and highly aggressive. When agitated, they will hold their necks high, appearing in a somewhat upright S-shape. The snake will occasionally chase an aggressor and strike at it repeatedly.


3) Malayan or Blue Krait (Bungarus candidus ), Southeast Asia and Indonesia. 50% of the bites from this snake are fatal even with the use of antivenin treatment.

Kraits are ophiophagous, preying primarily upon other snakes (including venomous varieties) and are cannibalistic, feeding on other kraits. They will also eat small lizards.

All kraits are nocturnal. The snake is more docile during the daylight hours, becoming more aggressive during the night. However, they are rather timid and will often hide their heads within their coiled bodies for protection. When in this posture, they will sometimes whip their tail around as a type of distraction.

4) Taipan (Oxyuranus scutellatus ), Australia. The venom delivered in a single Taipan bite is enough to kill up to 12,000 guinea pigs. The common taipan is the third-most venomous snake on Earth and arguably the second-largest venomous snake in Australia (the first arguably being the mulga, or king brown, snake, Pseudechis australis). The danger posed by the coastal taipan was brought to Australian public awareness in 1950, when young herpetologist Kevin Budden was fatally bitten in capturing the first specimen available for antivenom research.


Hunting with Nature’s Most Extreme Camouflage Artist

Its keen brown eyes and coal black nose could be stones in the snow-white landscape to those unaware they are the points of a triangle formed by its characteristic snout. Merging imperceptibly with its colourless environment, and able to withstand some of the most frigid extremes on the planet, this super-adapted animal trots nimbly on the icy surface, using its acutely sensitive hearing to home in precisely on its next meal under the snow. Then, it pounces.

Mid-air attack: Arctic fox pouncing on prey beneath the snow
The Arctic fox leaps with the energy of a released coiled spring, punching through the snow with its front paws and catching its victim. Lemmings are a favourite food source – a family of foxes can consume dozens of the little rodents a day – but the Arctic fox will also prey on tundra voles, Arctic hare, ground squirrels, sea birds, seal cubs, eggs, carrion and fish under the ice – pretty much any meat it can locate in its harsh frozen habitat. Any leftovers are buried for later, left in cold-storage.

Noo-nee-noo-nee-noo: Arctic fox on the prowl in Nunavut, Canada
The coat of the Arctic fox is perhaps it most amazing adaptation. The fur changes colour with the seasons, turning from brown to white with the advancing winter and soon rendering it invisible to all but the most eagle-eyed. A master of camouflage, the Arctic fox is also unmatched at keeping out the cold: its deep, dense fur helps it stay warm, thickly furred paws provide insulation, and stocky body, short legs and rounded ears expose minimal surface area through which heat might escape.

If anything could look snug in the snow: Arctic fox curled up resting

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