My Science School

Did you know that the invention of the kerosene lamp may have prevented the extinction of the sperm whale? There was a time when these leviathans of the deep were hunted for the white, waxy substance found in their heads, called spermaceti.

People in the 18th century found that this substance could fuel lamps, power streetlights and even light up lighthouses! Consequently the sperm whale was nearly hunted off the face of the globe. It was only the invention of alternative fuel sources like the kerosene lamp that saved these creatures from total annihilation!

The sperm whale is easily recognizable for its prominent block-shaped forehead. It has the largest brain of any animal on earth. It can grow to a length of 60 feet and weigh around 40 metric tons. The female is smaller than the male but eats up to three times more!

Their favourite food is squid, the bigger the better! In fact the giant squid is their favourite snack. To find the giant squid though, the sperm whale has to dive deep into the ocean depths. It is one of the deepest divers of the whale world, capable of 2000-metre dives. This whale can also hold its breath longest of any mammal - 90 minutes! Some scientists think that the spermaceti in the sperm whale’s brain may help them to withstand high pressures on their dives. Their diet also consists of other deep-water prey like sharks, skates and fish.

They are the largest of the toothed whales, but have teeth only on the lower jaw. They have corresponding holes on their toothless upper jaw into which the lower jaw teeth fit into.

Although sperm whales are protected across the world today and spermaceti is no longer used as fuel, they are still hunted for ambergris. This is a substance which forms around squid beaks in a whale’s stomach. It is used in perfumes and is very valuable.

These iconic behemoths are listed under ‘Vulnerable’  in the IUCN Red List.

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The bowhead whale, just as the name suggests, has a bow-shaped head. Just like the Greenland shark, the bowhead whale also lives in the icy-cold waters within the Arctic Circle. Maybe there is a connection between swimming around in the freezing Arctic waters and living very long because both the Greenland shark and the bowhead whale live well beyond 200 years!

The bowhead whale is the fifth largest mammal on earth, growing up to 60 feet and weighing up to 100 tons! The bowhead whale’s head is one-third of its total length. It has baleen plates in its mouth instead of teeth. It eats by swimming with its mouth open and taking in huge amounts of water along with plankton and tiny crustaceans like krill. It then pushes the water out through the baleen plates which act like filters, retaining only the minute plant and animal life. It eats up to 2 tonnes of food in this fashion every day.

Apart from eating, it also uses its enormous head to break through thick layers of sea ice to create breathing holes. Despite its mighty size, this fun-loving whale loves to jump out of the water (a phenomenon called breaching), splash around and sing! It has a repertoire of more than 60 songs and vocalizations. You might say that it likes to have a ‘whale’ of a time!

It is threatened by habitat loss, water pollution and climate change and is listed under ‘Least Concern’ on the IUCN Red List.

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Did you know that the right whale is called the right whale for the wrong reasons? This whale was historically considered the ‘right whale’ to hunt as it is composed of 40 percent blubber (whale fat). This fat was traditionally used to make essential items like soap, margarine and oil for lamps.

Today it is the rarest of all large whales found in the ocean. This is so, because from as early as the 10th century onwards, it has been hunted almost to the brink of extinction. Whale hunters targeted these whales for many reasons. For one they are slow - moving at the rate of 8 km/h. They often swim close to the shore and are friendly. They are easy to spot as they have two blowholes and the blow of a right whale is V-shaped, which can be seen miles away. They float after they are killed, instead of sinking like other whales, making it easier for the whalers to harvest their bodies.

This whale grows to 55 feet and weighs as much as 70 tons! It has a very large head (almost one-quarter of its body length) and roughened patches of skin called callosities on the top of its head. It has baleen plates instead of teeth in its mouth, which it uses to filter-feed on its favourite food - zooplankton, crustaceans and krill.

Rampant and unchecked hunting through the centuries led the right whale to the verge of extinction. Fortunately international sanctions were put in place by the 1970s to protect them and this whale species was saved. However, they are still commercially hunted by Japan, Finland and Iceland.

Other than humans the right whale is also hunted by orcas. It is listed as ‘Critically Endangered’ in the IUCN Red List.

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If there was an award for survival of an animal in an extreme environment, it would certainly go to the emperor penguin. These birds spend their entire life in the Antarctic, facing chill winds as cold as minus 60 degree centigrade and blizzards blowing at 200 km/h!

The emperor penguin is a distinctive bird. It has a black head and back, pale yellow breast and ear patches and a white belly. Considered the tallest and heaviest of all penguin species, an adult bird is about 4 feet tall and weighs between 23 and 45 kg.

Emperor penguins are very social and live in large groups. These groups are cohesive and supportive and individuals help each other to stay warm in the brutal Antarctic winters. The whole group will huddle in a big circle, with the outer members of the circle moving inwards periodically to ensure that no penguin is exposed to the cold for too long. How’s that for teamwork?

Emperor penguins trek 50-120 km over the open ice to breeding colonies which can contain up to several thousand individuals. Penguins stay with the same partner for life. Females lay a single egg, which is handed over to the male. The mother then goes to the sea to feed. The father will incubate the egg in a special ‘brood pouch’ near his feet for 65 days. He will lose about 40 percent of his body weight during this time. The mother returns just before the chick hatches and feeds it with regurgitated fish from the sea. The father then goes to the sea to feed. In this way the parents take turns foraging at sea and caring for their chick. The lifespan of an emperor penguin is typically around 20 years in the wild.

The emperor penguin is severely affected by climate change and is listed under ‘Near Threatened’ on the IUCN’s Red List.

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The emu is a large, flightless bird that is native to Australia. It is the second tallest bird in the world, growing to a height of about 7 feet and weighing around 56 kg. It is grey in colour with a bluish head and gentle-looking eyes. Did you know that the emu is the only bird in the world with calf muscles in its legs? Even though it cannot fly, its sturdy legs help it run at a top speed of 48 km/h and jump 7 feet vertically up!

The emu has three toes on its feet, one of which is a long dagger like claw that is potentially dangerous. The emu however, is not known to kill humans, though it will defend itself if provoked.

The emu eats plants and insects and can store food as fat for times when supplies run low. It also has a sixth sense for finding water and travels many miles on foot to find it.

Emu fathers are very devoted. The female emu lays a clutch of eggs and then leaves the parenting to the male. The male emu bird incubates the eggs over a period of 50 days, during which it does not eat or drink! It loses up to a third of its body weight during this time and then looks after the hatched chicks for 2 years till they become independent.

Did you know that in 1932, Australia waged a war against emus? And lost? Soldiers were called in to help eradicate a group of 20,000 emus who were eating up wheat fields in Western Australia. After making several attempts to kill the emus, the soldier accepted defeat and returned home! Even machine gun fire proved ineffective against these highly intelligent and strategic birds who evaded every tactic employed against them!

The International Union for the Conservation of Nature and Natural Resources (IUCN) lists the resourceful and resilient emu as a species of ‘Least Concern’, as its populations are stable across Australia.

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If you like dinosaurs, the cassowary will blow your mind! Considered a descendent of the extinct velociraptor, this bird has 12.7 centimetres long dagger like toes on its feet and a kick that would flatten Bruce Lee!

Native to Australia like the kangaroo and the koala, the cassowary is a striking specimen. It has a bright blue head with a fibrous hollow helmet-like casque and a long blue neck with colourful wattles. It is covered with rough black feathers that look like hair from a distance. It has long, thick and powerful legs that are covered with armour-like scutes. Each of its feet has three toes, with the innermost toe sporting a long dagger-like nail capable of disembowelling an unwary intruder with a single slash. Up close, it looks more suited to the world of Jurassic Park than normal life! Not for nothing is this bird called the most dangerous bird on earth!

It is the third tallest bird in the world after the ostrich and the emu, and the second heaviest bird after the ostrich. It can grow to a height of 5 feet 6 inches and weigh about 60 kg. Although it cannot fly, it runs pretty fast, reaching a speed of 50 km/h.

This bird is solitary in nature and loves to eat fruits. So much that some fruits are named after it - such as the cassowary plum. It likes to toss fruits in the air and swallow them whole. It will also eat plants, fungi, insects and small invertebrates when available.

Female cassowaries are larger than the males and make very carefree mothers. For instance, they will lay about 4 eggs and then leave the entire burden of parenting on the male! The male cassowary incubates the dark green eggs for 50 days and then looks after the chicks for nine months till they learn to become independent.

This incredible bird is listed as ‘Endangered’ and suffers from a loss of habitat and human encroachment.

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Two surviving species of bison are found in America and Europe. They are called the American bison and the European bison. The American bison, also known as the buffalo or the plains buffalo, is native to North America. The European bison, also called ‘wisent’, is native to Europe.

The American bison lives in the Great Plains (USA) and can weigh between 400 and 1,270 kg. The wisent lives in woodlands and is taller than the American bison but less heavily built. It can weigh between 800 and 1000 kg.

Before settlers took over the land, millions of bison roamed free in North America. By the late 1800’s bison were hunted almost to the edge of extinction. Today, due to conservation efforts, the bison population is slowly showing signs of recovery in North America.

The European bison became extinct in most parts of Europe during the Middle ages. A small population existed in the Caucasus Mountains and over the years, due to captive breeding programmes, was reintroduced into the wild. Today, the European bison is found in Poland, Germany, France, Lithuania and Switzerland. The largest population is found in Poland.

Bison are nomadic grazers that feed on grass, herbs, twigs and leaves. Even though they look heavy, they are agile and fast, and can reach speeds of 65 km/h. They spend the warmer part of the day resting or rolling in mud and taking dust baths! Bison calves are red in colour and are sometimes called ‘red dogs’ in America due to this. Bison are unpredictable and can stampede upon the least provocation. It is best to give them space and respect their boundaries.

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In the wild, the hippopotamus is the proverbial bully. These out-sized waddlers may look cute and cuddly, but are in fact the most ferocious, unpredictable creatures you could ever encounter! Weighing between 1,210 and 3,000 kg and growing to around 1.52 metres tall and 5 metres long, they have very few natural predators, except humans.

Hippos are native to Africa and spend most of their time in muddy rivers, lakes and mangrove swamps. They do this to escape the hot African sun and to keep their skin moist. In fact, the word hippopotamus means ‘river horse’ in Greek. They are mainly herbivores who eat grass, leaves, fruits and aquatic plants.

Hippos have the dubious distinction of being the world’s deadliest large land animal. They are fiercely territorial in the water and will attack anyone who invades their space, including apex water predators like the crocodile. Did you know that hippos are responsible for nearly 500 deaths in Africa every year! Even elephants and lions steer clear of hippos when they are in the water.

Their main defence is their deadly chomp! With one of the strongest bite forces of all land animals 1825 psi (pounds per square inch), the hippo is certainly an adversary to beware of. Together with its impressive jaw which opens nearly 180 degrees and giant canines that grow to a length of 46 centimetres, the hippo can easily break a man in two if it wants to.

Did you know that hippos are the only animals in nature to produce their own sunscreen! They sweat an oily, red pigment that protects their skin from the UV rays and also prevents bacterial infection.

Hippos are threatened by humans and habitat loss. They are classified as ‘Vulnerable’ in the IUCN Red List.

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The gaur, also called the Indian bison, is the largest bovine species in the world and the tallest species of wild cattle.

It is native to South and Southeast Asia. It is a strong and massively built animal that grows to a height of 1.50 to 2.20 metres and weighs up to 1500 kg.

The gaur is found mostly in India in the Western Ghats in evergreen, tropical and subtropical moist broadleaf forests.

Its horns grow laterally from its face and form a wide hollow on the top of its head. Males or bulls are larger than females or cows, with an intimidating dorsal ridge and a heavy dewlap (loose fold of skin below the neck). The slightly raised back gives it a somewhat belligerent appearance! Adults are blue-eyed and dark brown in colour and the lower halves of their legs are pristine white.

The gaur eats leaves, stems, grass, seeds and flowers of various plants. They also like to eat the barks of certain trees. Peak feeding occurs between 6 am and 8 am, while afternoons are spent resting in the shade of trees.

This intimidating and magnificent animal is bold and fearless. It does not fear any animal or human. The adult gaur bull has very few natural predators. Even the mighty tiger is known to give this animal a wide berth! There are many instances of gaur chasing away tigers by charging towards them. In case of an attack, bigger gaur will surround weaker calves and face off with the predator. When the gaur assumes this battle position, very few tigers will continue the attack.

It is an endangered species protected under the Indian Wildlife Protection Act of 1972. Major threats are bovine diseases from domesticated cattle who often share grazing grounds with the gaur due to encroachment by humans.

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The wild water buffalo, also called Asian buffalo and Asiatic buffalo, is found in India, Bhutan, Cambodia, Myanmar, Nepal, Thailand and Vietnam. Around 3400 Asian buffalo remain in the world, of which 3100 live in India - mostly in the state of Assam.

Wild water buffalo are the largest members of the bovine tribe of cattle which include the bison, yak and the African buffalo. The wild water buffalo is almost as big as the gaur. It grows to a length of about 7 to 10 feet and weighs about 600 to 1200 kg. This species of buffalo has large sweeping horns and is larger and heavier than the domestic water buffalo. It is most likely the progenitor or ancestor of the domestic species.

Wild water buffalo are herbivorous grazers and will eat crops, grass, leaves, herbs and grass. They are found in tropical and subtropical forests and spend most of the day submerged in muddy water to keep cool. The mud, which covers their bodies, serves as a barrier to keep pests and insects away. Since they are almost always near or in water, they also eat aquatic vegetation growing in marshy areas, along the banks of rivers and even growing underwater!

The population of these buffalo is declining and they are listed as ‘Endangered’ by the IUCN. They face threats from hunting - both from humans and tigers, habitat loss, and diseases such as rinder-pest - which they get from domestic cattle that share their grazing land.

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A charging rhino is one of the most impressive sights in nature. With its formidable thick-set horns, armour-like skin and tank- like body, the rhino looks like a top-class predator. In reality it is a shy, reclusive herbivore that prefers to graze in peace and wallow in muddy puddles.

The word rhinoceros is a combination of the Greek words ‘rhino’ (for nose) and ‘ceros’ (for horn).There are 5 species of rhino left in the world, of which 2 are found in Africa and 3 in southern Asia. Of the 3 Asian species, the great Indian horned rhino is the biggest. It is about 2 metres high at the shoulder and 3.5 metres long. An adult male weighs between 1,800 and 2,700 kg.

The rhino eats fruits, leaves and grass. It prefers to graze near water and is active during the early hours of the day. In the afternoons it will avoid the midday heat by lying in muddy water. The rhino is an excellent swimmer but has relatively poor eyesight. This sometimes leads it to charge at objects irrespective of actual threat. That is why it is always best to steer clear of rhinos. It moves at a top speed of 55 km/h and despite its bulk is nimble and can jump or change direction quickly.

 Did you know that rhinos are supposed to be attracted to fires? If it sees a fire it will charge towards it and stamp it out with its feet! How's that for an animal firefighter?

Found exclusively in India and Nepal, the Indian rhino's saga is one of the few environmental success stories of the world. From a meagre 75 in 1905, their numbers have grown to 3500 in 2022. Today, the Indian rhino is the most populous of the three Asian species of rhino found on Earth. This majestic and priceless animal has hardly any predators except for humans who hunt it for its horns. Over the years, countless rhinos across the world have been mercilessly hacked to death for their horns, which are used in traditional medicines and as a mindless display of wealth. They are currently listed under ‘Vulnerable’ in the IUCN Red List.

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The Asian elephant is the largest land animal in Asia and among the heaviest land animals in the world, out-weighed only by African bush elephants. Adult male Asian elephants can weigh between 2400 kg and 5000 kg. They are found in 13 countries in Asia including India, Bangladesh, Nepal, Bhutan, Cambodia, Sri Lanka, Thailand, Vietnam and China.

They inhabit grasslands, tropical evergreen and semi-evergreen forests, moist deciduous forests, dry deciduous and dry thorn forests and secondary forests and scrublands.

They are highly intelligent, form strong family bonds and are capable of feeling emotions such as grief as well as compassion. Their trunks function as a nose, upper lip, a limb for pushing and picking up things, as well as like a straw to pull up water for grooming and to drink. And did you know that the elephant's trunk is more sensitive than a bloodhound’s nose and can smell water from several miles away? They also use the trunk to cuddle their young and display affection to one another. Most amazingly, it is also used as a snorkel while crossing deep water bodies!

Even scientists are waking up to what an extraordinary tool an elephant's trunk is. Biomechanical engineers are studying the elephant’s trunk to find out how its complex operation can help them improve structural designs of many devices.

These extraordinary creatures are threatened by ivory poachers and loss of habitat, as well as elephant-human conflict. They are listed as ‘Endangered’ on the IUCN Red List.

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Did you know that a group of rhinos is called a ‘crash’? A good collective noun for a creature only second to the elephant in size and weight. At 5.9 feet and 2,500 kg the white Rhino tops the list of heavy-weights in the animal world.

In all there are 5 distinct species of rhino, of which the white rhino, which is found in Africa, is the largest and heaviest. The white rhino’s name comes from a misrepresentation of the Afrikaans word ‘wijd’ which means ‘wide’ (and not ‘white’) and refers to the animal’s mouth.

White rhinos, also known as the square-lipped rhino, sport square, hairless upper lips.

The white rhino has two genetically different subspecies - the northern white rhino and the southern white rhino. Sadly, due to the immense rate of poaching of this species, as of March 2018, there are only two northern white rhinos left in the world, both of which are female. They live in the Ol Pejeta Conservancy in Kenya and are protected by armed guards day and night. Their near extinction is due to many years of brutal poaching for rhino horn for use in traditional medicine and as a status symbol in countries like Vietnam and China.

This rarest of rare animal is found in grassland and savannah habitat. They eat grass and drink twice a day when water is available. However, the rhino can live for 4 or 5 days without water if necessary. Rhinos love squelching about in mud holes. This keeps their bodies cool in the brutal African heat and also keeps pests and bugs at bay. The white rhinoceros is considered a keystone species in the savanna grasslands. It is listed as ‘Critically Endangered possibly extinct in the Wild’ in the IUCN Red List.

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The Greenland shark seems more suited to the pages of a fantasy novel than real life. It is the longest living vertebrate and the slowest swimming shark in the world. It can live up to 400 years and beyond and reaches maturity only at the age of 150! In fact, some scientists believe that there could be specimens living in the oceans that are 6 centuries old! Imagine a Greenland shark that may have been alive during the time of Christopher Columbus, swimming about today!

This living fossil is also called sleeper shark and swims at a slow and ponderous speed of 1.2 km per hour. Weighing between 400 and 1400 kg, this shark can grow up to 7.31 metres long! It produces more than 700 pups (young ones) during its lifetime.

It is found deep down in the icy cold waters of the Arctic Ocean around the continental shelves of Greenland, Canada and Iceland, at a depth of 2,200 metres. This grey-green, stealthy predator is known to creep up on its prey and swallow it whole. Although apex predators, this shark will eat any flesh dead or alive and are believed to be primarily scavengers by some scientists.

Large proportions of these sharks are affected by parasitic attacks on their eyes and are partially blind. However this does not affect them much, as there is very little light deep down in the oceans and they are used to hunting in complete darkness.

The flesh of the Greenland shark is poisonous. It contains a chemical called Trimethylamine oxide, which can cause intestinal distress and even death if ingested. However, the early settlers in Greenland found a way to prepare the flesh so that it can be eaten safely. They do this by a long process of fermentation and the resultant product, although safe to eat, has been described as very strong smelling and foul tasting by some well-known chefs!

The Greenland shark is listed as ‘Near Threatened’ by the IUCN due to overhunting, parasitic attacks and climate change.

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If an award was given for the most easy-going and placid animal in the water, it would definitely go to the manatee. Manatees look like giant, elongated lumps of dough with large paddle-shaped tails and wrinkled heads.

They have whiskers growing from their chins and rectangular, nail-tipped flippers. Usually grey or brown in colour, the manatee is one of the most friendly and curious creatures you can encounter underwater.

These plant-eating herbivores graze on sea grasses and other aquatic plants. These gentle giants are also called ‘sea cows’ because of their docile dispositions. They can grow to a length of up to 13 feet and weigh about 590 kg.

They can hold their breath for up to 20 minutes underwater, but usually come up every 2 to 3 minutes to breathe. They spend their time resting for up to 12 hours suspended near the surface of the water or lying on the bottom of shallow, slow-moving rivers, saltwater bays and canals. However, they are capable of reaching speeds of up to 25 km/h, in short bursts, when required.

These marine mammals look like oversized otters or seals but are actually more related to elephants! They are so friendly that it sometimes gets them into trouble! Manatees will swim over to any curious looking object (like a passing boat) and try to examine it. Consequently, many of them get cut by propeller blades and bear the scars on their backs.

They are found in the shallow, marshy coastal areas and rivers of the Caribbean Sea, the Gulf of Mexico, the Amazon basin and West Africa. They cannot survive in temperatures below 60 degrees, which is why they migrate from the open waters of the Gulf of Mexico to natural springs in Florida during the winter months.

The main challenges for manatees are human-related issues, such as habitat destruction and manmade objects such as boats and ships. Other threats include adverse temperatures, predation by crocodiles on their young and diseases. Their numbers are declining and they are listed as ‘Threatened’ in the IUCN List.

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