My Science School

Whenever we talk of the navigational skills of explorers, we wonder: How did these seafarers find their way about the sea with no navigational aids like sat-nav? The answer is always the same. Sailors of olden days followed the stars. They understood star formation and aligned their route to how the stars appeared in the night sky. But man is not only the creature that “followed the stars.” Sea creatures and birds are known to have looked up to the heavens for guidance. Recent studies in this field show that dung beetles too use the stars for navigation! And they have a brain the size of a grain of wheat!

Dung beetles are African insects. During the day, the beetles walk in a straight line rolling the dung. The beetles survive because of the dung. The dun provides them with food and drink, and during the hot African noon, the beetles simply climb on the dung to keep themselves cool. So the beetle fights for the smallest bit of dung, and carries it away even during the night.

At night, moonlight is their guide. On the days the moon is not visible, dung beetles follow the Milky Way. Human, birds and sea creatures follow just the lodestar. Just one star is enough for them. But the eyes of the dung beetle are not that sharp. The Milky Way has a straight band that is easy for the beetles to follow. For the Milky Way to be seen, the sky has to be clear. So, should we not keep the sky clear, without pollution, so the poor beetles trying to cart their food do not lose their way?

 

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Natural phenomenon

Wildfires or forest fires are a common natural occurrence. They start during the summer months when vegetation dries out. Lighting striking a dried tree is enough to start a blaze. Fanned by the wind, the fire spreads quickly, consuming vast areas of forest. Forest departments and firefighters have a tough job containing the fires and millions are spent and lives lost in extinguishing them.

Animals that live in regions that see frequent forest fires have evolved and adapted to live with it. Animals caught in a forest fire obviously try to escape the flames and break over. Predators seize this golden opportunity to grab a snack. Bears, raccoons, and raptors have been observed hunting down the fleeing animals.

Different species use different strategies to avoid being instantly barbecued. Birds fly away. Mammals run. Amphibians and other small creatures burrow into the ground, hide out in logs, or take cover under rocks. Other animals, including large ones like deer, or take refuge in water bodies.

Bush firefighters in Australia have frequently spotted waves of creepy crawlies rushing ahead of the fire, desperately attempting to outrun the licking tongues of flame.

Smoked out

Some animals die of smoke suffocation or are charred. These are the ones that can’t run fast enough or find suitable shelter. Not all of those creepy crawlies may escape. Young and small animals are particularly at risk and some of their strategies for escape might literally backfire. For example, a koala’s natural instinct is to crawl up into a tree and it ends up trapped.

Deep down

The heat can kill even organisms buried deep in the ground, such as fungi. Jane Smith, a mycologist with the U.S. Forest Service in Corvallis, Oregon, has measured temperatures as high as 700°C beneath in a wildfire, and 100°C a full 5 cm below the surface.

Scientists don’t know the exact number of animals that die in wildfires each year. However, there are also no documented cases of wildfires – even the really bad ones – wiping out entire populations or species.

Rising from the ashes

Landscapes burned in a wildfire don’t die. They just transform into a new habitat. This can also mean new opportunities. In some places, woodpeckers will fly in and feast on bark beetles in dead and dying trees. Black fire beetles lay their eggs only to burned-out trees since there is no sap or resin to trap the larvae when they emerge.

A disturbance like a wildfire lets an old forest be reborn. A fire sparks many changes, as plants, microbes, fungi, and other organisms re-colonize the burned land.

Water bodies in a burned area can also change. Fish may temporarily move away. There can be a short-term dying out among aquatic invertebrates, which can affect the land animals that eat them.

Woodland and grassland animals (and plants) have lived with a cycle of fire and re-growth for ages. Many species actually require fire to regenerate. Heat from the flames can stimulate some fungi, like morel mushrooms, to release spores. Certain plants will produce seeds only after a blaze.

Good or bad?

Over the past century, wildfires have often been put out quickly or prevented because they damage human habitation.

That’s led to fewer species of those trees and plants that grow only in the years after a fire. It’s also caused a fall in some animal species that depend on post-fire habitat. The Kirtland’s warbler is a small American songbird that nests only in young jack pine forests. The pine comes only release their seeds in a fire. Without fire, much of the bird’s nesting habitat has disappeared.

 

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Monkeys go to college

There is an organization in the USA called Helping Hands that trains capuchin monkeys to help people who are paralyzed and confined to a wheelchair

In 1977, a psychologist with Boston’s Tufts University, called Mary Willard wanted to help from who was a quadriplegic. Quadriplegic are paralyzed from the neck down. Her professor suggested she train capuchin monkeys because not only are they highly intelligent, they are also small (they weigh between 3-6 kilos) and live for more than 30 years. Their natural curiosity and tiny hands make them ideal for performing delicate tasks.

With a grant of $2000, Willard begins training capuchins. Her first trained monkey Hellion was placed with 25-year-old Robert Foster in 1979. She was with him for more than 20 years. Willard begins Helping Hands, affectionately known as Monkey College, in 1982. In the last 25 years, it has placed over 100 capuchin monkeys with needy patients. The monkeys live with foster families when they are very young for 3-5 years till they are get used to people. Then they go to the college where they are trained for a further 2-3 years to become full-fledged ‘helping hands’.

Each monkey is trained to do everyday tasks such as turning switches on and off, changing DVD’s and CD’s, picking up dropped items such as keys, pens or phones, heating food in a microwave, turning the pages of a book, fetching food and drink and even scratching a troublesome itch! Their owners either use a laser pointer to show them what to do or give verbal commands.

The capuchins are bred at the local Southwick’s Zoo. The organization spends $35,000 to train and care for each monkey. The money is raised through donations and grants. The patients receive them free of charge. After the monkeys grow old, foster families look after them.

Not only do the monkeys enable their owners to lead more independent lives, they also help these people overcome depression and loneliness.

Clever Capuchins

Capuchins are the most intelligent species of South American or New World monkeys. They are adept at observing people and imitating their actions, especially in handling objects and using tools. They are named after the order of Catholic friars called Capuchins because their cap of dark hair resembles the friar’s headgear.

Other animal helpers

Dogs are widely used as guides for the blind. Some dogs are trained to alert the deaf to fire alarms and other warning devices that use sound. Miniature horses are now popular as guides for the blind because they live longer. These guide ponies are about the size of large dogs and can be trained just as well.

 

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Snapping shrimps are also known as pistol shrimps. They have a deadly weapon to catch their prey. According to the BBC, their enlarged claw can emit a shock wave that stuns the prey. This is how it works: [a] They shut their “super claw” in a rapid action. [b] A jet of water shoots out. [c] This action creates a bubble. [d] The bubble implodes. [e] A flash of light is emitted, which has been described as “shrimpoluminescence”. [f] This luminescence is indication of the extreme pressure and temperature reached inside the bubble at the point of collapse. [g] If you hear the sound of snapping from a shrimp, you can be sure it is from this bubble blast collapsing.

 

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Glow-worms (they are larvae) live in dark and damp environments where they can make use of their bioluminescent body to catch food. In large clusters, the glow-worms present a beautiful sight – as in the Waitomo Caves in New Zealand – but for a flying insect, bioluminescent glow-worm larvae are deadly. Insects fly towards the blue light of the glow-worm larvae, but become stuck in the sticky hanging threads woven by the creatures to ensnare prey. Once an insect is stuck, the glow-worms draw up the hanging line and suck their prey dry. The larvae stage is the only time the Arachnocampa luminosa eats, because the adult gnats don’t have mouths. Larvae occasionally turn cannibalistic, and eat the adult gnats trapped in their sticky snare. Glow-worms live for about nine months.

 

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Velvet worms are called Onychophora, meaning “claw-bearers”. They are caterpillar-like creatures and wear a coat of delicate scales which gives them their velvety appearance.

Velvet worms are found in forests around the southern hemisphere and the equator. They are closely related to arthropods (the phylum that includes spiders, crustaceans and insects).

Velvet worms trap their prey by squirting a sticky slime secretion from up to 30 cm away. The secretion is made in glands on either side of their gut. The worms then eat the immobilized prey, softening it with their digestive saliva.

 

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Frog-fishers are bizarre-looking creatures. They hook their prey with an extended part of their own body that acts as bait. The strange extension of their body, known as lure, resembles a small group of dangling worms, which can regenerate if bitten off. When the fish spots its victim, it begins wiggling its lure. The unsuspecting victim, taking the lure for a meal, comes close to the mouth of the fish. Once the prey – usually a crustacean or fish – is within range, it stands little chance of survival. The frog-fish sucks in its live meal by opening its huge mouth and pulling in the prey in milliseconds. In fact, the fish has possibly the quickest movement in the world. For additional help, the fish has camouflage pattern and fin-feet to move on the sea floor. With all these “weapons”, the frog-fish can be seen as the most formidable predator.

 

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The bolas spider constructs an ingenious “bolas”. A bolas is a type of ancient south-American throwing weapon made of weights on the ends of interconnected cords. It was used to capture animals by entangling their legs. The bolas spider spins its bolas with a sticky glob of silk at the end of another silken thread. At night, it holds its weapon with one of its legs, ready to fling. Female bolas spiders use a different trick. They mimic the chemical signal of a female moth, and lure male moth suitors. When the predator senses the wing vibrations of an approaching moth, it produces a bolas, and throws its “lasso” to capture its meal.

 

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The beautifully-marked margay is a small wild cat native to Central and South America. It lives in primary, deciduous evergreen forest and hunts alone at night. Until the 1990s, margays were hunted illegally for their skin, which resulted in their population decreasing drastically. Margay reportedly uses an incredible mimicry tactic to attract prey in the Amazon jungle. Because the cat is so elusive, scientists have not been able to photograph the creature snaring its prey. So far, what scientists know comes from the stories told by locals. A group of researchers working in Brazil reported that a margay (Leopardus wiedii) makes calls to resemble the sound of a pied tamarind (monkey) baby. The margay would pounce on the parents when they come down looking for the baby.

 

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Net-casting spiders have long legs and large eyes. They use their silk to weave a stamp-sized net, with which they enclose victims with a lightning-quick movement. The spider sets its trap meticulously: first it leaves white-faeces on the ground as target points. Then with its net held between its front legs; it hangs on a thread, lying in wait. When an unsuspecting creature crosses its trap, the spider stretches its net quickly and traps the victim. It then bits the trapped prey and wraps it up ready to eat. The spiders’ huge eyes help them to see well in low light, and have earned them the alternative name “ogre-faced spiders”.

 

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Birds, fish and mammals are food; people rear them in farms for mass production and sell them packaged as meat.

Sadly, animals are not killed for food alone. The Indonesian government brought alarming news to the Convention on International trade in endangered species (CITES) held in Johannesburg, South Africa. They said the colourful helmeted hornbill is being hunted non-stop for its casque (the hard part on its beak) and a sudden explosion in demand for the hornbill casque is driving the bird to extinction very fast.

The casque is usually spongy, but in the helmeted hornbill it is solid keratin (protein). It is like soft ivory. Its colour is golden yellow, but the bird rubs it’s casque (horn on top of the beak) on its preen gland, whose oily secretion gives the surface of the casque a bright red colour.

The bird species seen in Malaysia, Sumatra and Borneo has suddenly been discovered by the world and is heading to extinction. It is in the category of “critically endangered “. For thousands of years, tribals of the Indonesian rainforests have carved various objects out of the ivory of the helmeted hornbill . In 2011, the Chinese begins to buy the carved ivory products in large numbers. From 2012 onwards, the birds have been hunted mercilessly and their heads are now being smuggled to ports in Sumatra and Java and then on to Hong Kong and Taiwan. Bird protection groups estimate that nearly 6,000 birds are killed every year.

The male helmeted hornbill has the ivory. And it is the male bird with the casque that feels the female when she has her chicks and stays in the nest. Killing off the male will starve the female and wipe out the bird population altogether. It may be a good idea not to buy products made of ivory.

Hippopotamus

The hippopotamus, or river horse, spends up to 16 hours a day submerged. Threat to their lives comes from people hunting them for their meat and ivory (teeth in the case of hippos). Strangely,  these herbivores spend most of their time in water with only their face sticking out so they can breathe. The hippo is still a target for hunters who get paid thousands of dollars to kill them.

Great White Shark

The Great white shark is hunted for its fins. Shark fin soup is a delicacy and people believe it will cure certain ailments . Fishermen across the global catch a million of these sharks, cut off their fins and then throw the sharks back into the water. This inhumane practice is a death warrant for these beautiful creatures. Unable to swim, they starve, drown or are eaten by other marine animals. The white shark is also hunted for sport which is also illegal.

African Lion

The African Lion is fast on its way to becoming an endangered species. Their populations have dwindled to half since the 1950s, but it is legal to hunt them for prices in sport competitions. The lines are hunted in two ways.  One, they are hunted in the wild, in forests. Two, the lions are caught and are let loose in game reserves so people can hunt them for pleasures. This is called “canned hunting”. For canned hunting sometimes cubs are reared by humans and are eventually released in an enclosed area. In confined area, the “customer” is guaranteed a kill.

Tiger

Only about 4000 tigers may be left in the wild. Tigers are poached for almost all their body parts - skin, meat, nails, teeth. Tiger skins, bones, teeth and claws are used in traditional medicine. They are believed to cure toothaches and protect against malicious curses, among other problems. Some countries allow tiger farming, but poaching continues since tiger parts fetch huge amounts of money in the market.

Asian & African Elephant

Elephants everywhere are being slaughtered by poachers and hunters for their tasks. Trade of elephant tusks continues to grow as the demand for ivory increases, though stiff penalties have been in place since the 1990s. Hunters go on a safari and helped by professional trackers locate and kill the animals at close range with high calibre weapons.

Black Rhino

Between 1970 and 1992, 96 percent of the black rhino population was killed for their horns, making their numbers critically endangered. The Vietnamese and the Chinese believe the horns can cure a multitude of health problems. Cruelly, their horns are hacked off and the rhinos are often left to die.

Hawksbill Sea Turtle

Although Hawksbill sea turtles are found from the Caribbean Sea to the Indonesian archipelago, their numbers have dwindled so much that they have been listed as almost extinct. Poachers hunt hawksbill for their shells, which are made into ornaments and decorative items and are sold worldwide as travel souvenirs. Hawksbills are killed for their oil, which is used in traditional medicine.

Mush Deer

Thousands of male musk deer have been killed for their musk pods, a gland that produces the musk. This musk, a brown, waxy substance, can be extracted from live animals, but “musk gatherers,” who get big money for the secretion find it easier to kill the deer. Today synthetic alternatives to musk are available, but the hunting hasn’t stopped. Musk is used in traditional medicines for treating cardiac, circulatory and respiratory problems.

 

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The black-footed ferret is a long, slender animal. Nature has made these mammals that way to enable them to easily slip through prairie dog burrows. You may wonder why they haunt these burrows – it’s because their main diet is the prairie dog! Also, they make the burrows their cosy home. They weigh between 1.5 and 2.5 pounds and can grow up to 24 inches long. A strip of dark fur across their eyes gives them the appearance of wearing a mask – rather like bandits!

This member of the weasel family once roamed the prairies from southern Canada to Texas but is now one of the most endangered mammals in North America. In the early 1900s, the United States was perhaps home to over 5 million ferrets. Early in the 20th Century, when agricultural development took place in the U.S., rodent poisons practically wiped out prairie dog populations and in turn the ferrets. Thirteen years after they were listed as endangered in 1967, the last captive ferret died, and the animals were thought to be extinct in North America. Then in 1981 a small population was discovered in a Wyoming prairie dog colony. Between 1991 and 1999, some of these ferrets were released in Wyoming, Montana, South Dakota, Arizona and along the Utah/Colorado border. And that’s how they were brought back from the brink of extinction. Biologists estimate that are now well over a 1000 black-footed ferrets living in the wild. The average life span of a ferret in the wild is 1-3 years, and 4-6 years for ferrets in captivity.

There are only three ferret species on Earth: the European polecat, the Siberian polecat, and the black-footed ferret. The black-footed ferret (Mustela nigripes) is the only ferret species native to North America. Female ferrets are called “jills”, males are called “hobs” and the young ones are called “kits”. The slender animal has buff or tan fur, with black feet, tail tip, nose and face mask. It has triangular ears, hardly any whiskers, a short muzzle, and sharp claws.

While their main diet is the prairie dog, in regions where prairie dogs hibernate in winter, ferrets feed on mice, voles, ground squirrels, rabbits, and birds. Black-footed ferrets get water by consuming their prey. Ferrets are preyed upon by eagles, owls, hawks, rattlesnakes, coyotes, badgers, and bobcats.

Except when mating or raising their offspring, black-footed ferrets are solitary, nocturnal hunters. They use prairie dog burrows to sleep, catch their food, and raise their young. They are vocal animals their sounds ranging from hisses, whimpers to loud chattering. Like domestic ferrets, they perform the “weasel war dance”, consisting of a series of hops, often accompanied by a clucking sound (dooking), arched back, and frizzed tail. In the wild, the ferrets may dance to distract prey as well as to show they are enjoying life.

 

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