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Category Animal World

What is special about koalas?

They may look like soft, cuddly teddy bears with their big ears and black button eyes, but koalas are not even remotely related to bears and they are certainly not soft! Their silver-grey fur is similar to the coarse wool of sheep.

Koalas are marsupials, animals that carry their young in a pouch. Marsupials are native to both Australia and the Americas, but the largest number of species is found in Australia, New Guinea and nearly islands.

Found in southeastern and eastern Australia, mainly in Victoria and Queensland, koalas live in eucalyptus forests. Their sole diet consists of leaves from a handful of eucalyptus species. They also live high in the branches of eucalyptus trees, safe from predators who would otherwise find them easy prey because they move so slowly and sleep so much.

Koalas need time to digest their meal. Eucalyptus leaves are poisonous to most animals but koalas have special bacteria in their gut that break down the toxic compounds. They have cheek teeth to help grind the tough leaves. Digestion takes along time since all the nutrients and water have to be extracted from leaves which hardly contain any! This is why koalas sleep almost 20 hours a day and move only if they have to.

Even their bodies are adapted to living in the crooks of branches. They have a barely-there tail, a cushiony, rounded rear end and and a curved spine. Their hands and feet are ideal for clinging to branches, with two opposing thumbs that make for a tight grip. The hands are tipped with sharp claws to dig into the bark. The feet have a long grooming toe and a clawless toe as well that behaves like a thumb!

When a koala baby (called a joey) is born, it is the size of a jelly bean and can’t see or hear. It crawls into the mother’s backward-facing puch and drinks milk from one of two teats. There it remains, warm and safe for six months. The mother also feeds it with her own faeces to give it more immunity.

The joey rides on its mother’s belly and when full-grown, on her back. It becomes independent when a year old.

The male koala’s scent glands are located in a bare patch on his chest. He rubs it on a tree trunk to leave his smell. The scent is made up of 35 different chemicals. The male is smelliest in spring, the mating season!

Today, the koals is listed as vulnerable. It is threatened not only by dogs and being run over by cars, but by habitat loss and disease. There are an estimated 40,000 to 100,000 of these cute animals left in the wild.

 

Picture Credit : Google

How animals stay clean and make themselves presentable?

Grooming (also called preening) among animals is the art of cleaning and maintaining parts of the body. It is a species-typical behaviour.

Animals groom themselves in many ways – rats lick their bodies, zebras take dust baths, birds preen their feathers, monkeys pick lice from their fur and insects rub their antennae to keep them clean and functional.

Individual animals regularly clean themselves and put their fur, feathers or other skin coverings in good order. This activity is known as personal grooming, a form of hygiene.

Extracting foreign objects such as insects, leaves, dirt, twigs and parasites are all forms of grooming. Among animals, birds spend considerable time preening their feathers. This is done to remove ectoparasites, keep the feathers in good aerodynamic condition, and waterproof them. To do that, they use the preen oil secreted by the uropygial gland, the dust of down feathers, or other means such as dust-bathing or anting. During oil spills, animal conservationists that rescue penguins sometimes dress the in knitted sweaters to stop them from preening and thereby ingesting the mineral oil, which is poisonous.

Cats are well known for their extensive grooming. Cats groom so often that they often produce hairballs from the fur they ingest.

Animals also groom other members of their species (social grooming). The manner of grooming is so typical of a species that it can be used to distinguish it from a closely related one.

Grooming is pre-wired in the brain. If a mouse that is grooming its face with its paw is interrupted in the act, it ‘automatically’ begins to rub the air in front of its face with the other paw! Animals use their head, paws, claws, beak, tongue, etc. for grooming.

Some animals like the starfish have special, pincer-shaped organs called pedicillariae to remove debris from the body surface.

It was earlier believed that animals groomed themselves to maintain hygiene but now it is known that grooming serves many purposes – signaling, courtship, coalition-building and appeasement.

When two mountain rams fight for dominance, the one who loses licks the neck and shoulders of the victor to appease him. The winner may even kneel down to receive he apparent salute.

In a beehive it is essential for all the worker bees to recognize the queen bee’s scent, which assures them of her presence and vitality. A few worker bees pick up the queen’s scent when they groom her by licking her. The workers then move through the nest and contact other workers with their legs, tongues and antennae. Bee-to-bee grooming spreads the queen’s scent quickly and thoroughly.

Many social animals adapt preening and grooming behaviours for other social purposes such as bonding and the strengthening of social structures. Grooming plays a particularly important role in forming social bonds in many primate species, such as chacma baboons and wedge-capped capuchins. Among primates such as chimps, close relations groom one another loyally. This is called allogrooming. On the other hand, outsiders tend to groom members higher up on the social structure.

Grooming apparently gives an animal an advantage that helps in obtaining privileges at a later date.

 

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What are the different species of beetles?

Beetle Abodes

Beetles are found almost everywhere except in the oceans, seas and Antarctica. They live in all kinds of habitats including scorching deserts, freshwater lakes and freezing polar ice caps, but are most abundant in tropical rain forests.

They make their homes in diverse places. Some burrow underground or in wood or even in the carcasses of animals. Others prefer ant and termite nests where they have a symbiotic relationship with their hosts.

Just Move It!

Most beetle species have thick, hard front wings called elytra and protective back wings. Desert species trap moisture under their wings while water beetles trap air so they can live underwater. Most beetles can fly, though they move in a slow, lugubrious fashion.

Antennae Alerts

The long, flexible antennae on a beetle’s head are feelers that help it find a mate, food, and a place to lay its eggs. They also catch vibrations in the air to warn it of predators. The body and legs of a beetle are covered with tiny hairs that are hyper sensitive to touch, sound, smell, light and taste.

Some beetles have extensions on their head that resemble horns or antlers.

“Eye” See You!

Most beetles have compound eyes and colour vision. Ground beetles that depend on vision for hunting or breeding (like fireflies) have larger eyes. Whirligig beetles swim on the surface of ponds and use their divided eyes for seeing both above and under water at the same time!

Legging It

Beetles sport all kinds of legs, ranging from long and slender for the speedy ground beetles; the dung beetle’s broad and ridged legs for digging; curved and shaped like a paddle for swimming in water beetles and large hind legs for hopping such as in the flea beetles. A sticky pad on the bottom of each foot on some beetles helps them walk on glass for instance. All species have a pair of claws on each foot.

Dining Etiquette

Beetles eat plants, other insects, carcasses, pollen, and dung. Beetles living in water eat small fish, tadpoles and even snails. Rove beetles catch flying insects with a long, sticky tongue. Some beetles feed on nectar.

Bug-bears

Many beetles are also considered pests (the potato beetle and the boll weevil for example), that infest and destroy crops, vegetables and fruits.

Beetle Benefits

Beetles are great recyclers because they feed on anything including animal carcasses and dung. Some like ladybirds eat aphids which are pests.

Largest and Smallest

The Titan beetle is the world’s largest and can grow up to 17cm long. It lives in the South American rainforest. It has both jaws and claws strong enough to tear into animal and human flesh, but is doesn’t attack unless provoked.

On the other end of the scale is the feather-winged beetle which measures around 0.325mm, the smallest free-living insect (as opposed to parasitic insects which are smaller).

 

Picture Credit : Google

Who is the closest relative of dodo bird?

Pigeons are here, there, everywhere, and are generally considered a nuisance. But, there’s one pigeon that draws gasps of admiration – and that’s the Nicobar pigeon (Caloenas nicobarica). It’s colourful plumage is what makes it so attractive. It also happens to be one of the largest pigeons and is the member of its genes. Also known as vulturine pigeon, hackled pigeon, or white-tailed pigeon, its bright plumage is a contrast to its close relative the dodo which is a dull grey. Nicobar pigeons birds are found only in some parts of the world – the Andaman and Nicobar islands in Southeast Asia. They usually avoid human contact and other predators, hence not much is known about the bird. Though one can spot them, they tend to breed on remote and uninhabited islands. Their behaviour is quite different from the other pigeons and doves.

Striking appearance

It has a sturdy body with a small head, long legs and wings, and a small white tail. Adults grow up to 16 inches and weigh about 1 pound. Females are heavier. The feathers on the head and the neck are blue-grey. The mane is covered with iridescent long purple hackles. The legs are purplish red in colour with long yellow claws. Their bills are black and hooked and have a black knob near the base. Body feathers are iridescent in shades of green, blue, hints of copper and gold. Males and females both have the same plumage, but the male is larger than the female and has brown iris, while the female has a white iris. Also, he females have a smaller knob on their bills.

Habitat

These pigeons are found mainly in South East Asia and the Pacific – from the Nicobar Islands to Thailand, Malaysia, Indonesia, the Philippines, and Papua New Guinea, the Solomon Islands, Palau, Myanmar, and the islands near Cambodia and Vietnam. They make their homes in forests and mangroves as they need a constant supply of food. They are nomadic by nature and fly from place to place within their range.

Food

Fruits, seeds, and small insects make up their meal. Their strong gizzard with its gizzard stone helps them feed on nuts with tough shells. The stone helps them grind up hard food items.

Raising the family

In the wild, these birds breed year-round, but in places where there is no human intervention. They are monogamous, and hence, mate for life. The male selects the nesting site and gathers all the required materials. The female then arranges them. Nests are pretty untidy and consist of twigs and dried leaves perched up in the trees. Sometimes there are several nests in a tree built by different members of a flock. The female lays only one egg per clutch, which hatches after a three-four weeks. The adults regurgitate their food and feed the chick crop milk. The fledglings get independent only after a month, but choose to stay in the nest for some more time. The young ones are dark coloured for around two years, and then they get the adult white tail. Nicobar pigeons live till they are 8 – 12 years in the wild and longer in captivity.

Conservation status

The species has been listed as “Near Threatened” by the IUCN because of dwindling forests, and because they are prey for cats and rats. Hunting of the birds by humans for food, the pet trade, and for their gizzard stones which are used as jewellery has also caused their numbers to decline.

Fascinating facts

  • These pigeons travel in large flocks of around 80-85 birds. During the day, they don’t mind the presence of humans, but at night, they prefer flying to uninhabited islands.
  • The birds’ white tail can be seen in flight. It guides other birds while flying at night or in the dark. Each bird follows the other’s tail while flying in a flock.
  • All pigeons suck up water similar to using a straw.
  • Some keep their neck plumage erect, during courtship or while displaying aggressive behaviour.
  • Nicobar pigeons are not very vocal, they normally coo. Only when they are scaring away predators do they make a sound that resembles a grunt.

 

Picture Credit : Google

What do sea pens do?

True to their names, sea pens resemble old-time quill writing pens. These colonial marine cnidarians (a large group of aquatic invertebrate animals) belong to the order Pennatulacea. Although the group is named for its supposed resemblance to antique quill pens, not all sea pen species live up to the comparison. Colours range from dark orange to yellow to white.

These underwater animals are actually a type of octocoral (soft coral), named for the eight stinging tentacles that they use to capture plankton (tiny floating plants and animals) to feed themselves. In fact, a single sea pen is both an individual and a colony. The basic unit of a sea pen, like all other corals, is a polyp, which consists of a sac-like body cavity enclosed by a mouth and surrounded by a ring of tentacles. The larva usually settles down in sand, mud, rubble or, sometimes, solid rock and this becomes the primary ployp. It buds into daughter polyps, and the sea pen grows. It is supported on a stem-like structure. While the larvae of some species settle close to their parents, others are carried great distances by ocean currents.

Some polyps feed by using nematocysts (a specialized cell in the tentacles of a jellyfish, corals and sea anemones, containing a barbed or venomous coiled thread that can be projected in self-defence or to capture prey) to catch plankton; some force polyps reproduce; and some force water in and out of canals that ventilate the colony.

Sea pens inhabit shallow and deep waters from the polar seas to the tropics. Some sea pens use a bulb inflated with water to anchor them to the sea floor. All have hard, internal skeletons, and at least some of them can glow in the dark.

Although many species live in shallow water, others have been found as deep as 20,013 feet (6,100 metres) below the surface. One species of Umbellula has been discovered living in cold, dark waters near Antarctica. It grows to about 10 feet (3 metres) long with a big, flat head of polyps at its end, the tentacles picking food out of the water as the head is pushed along by the current. Most sea pens, however, grow to between 2 inches and 6 feet, 7 inches (5 cm to 2 metres) in height.

 

Picture Credit : Google

How birds are affected by habitat loss?

There are birds like the piping plovers (Charadrius melodus) that lay their eggs directly on the sand of a beach in a shallow depression. When sea-levels rise, beaches are washed away. When temperatures rise, and wetlands dry out, ducks that live and lay eggs on them will have nowhere to go.

Same is the fate of birds that depend on coral reefs. About one third of the carbon dioxide in the atmosphere is absorbed by the ocean. When CO2 increases and the weather gets warm, more CO2 is absorbed and water becomes more acidic. Increased acidity reduces the ability of the corals to secrete calcium carbonate, which forms the structure of the reef. As a result, they become brittle and break easily. The reef structures shrink (something that happened to the Great Barrier Reef). For many birds in the tropics, corals reefs provide an important food source and are critical habitats for survival.

In Hawaii, mosquitoes that carry malaria breed in lower attitudes. Mountaintops provide protection for birds from mosquitoes since they cannot reach the area. Increasing temperatures have led mosquitoes to move further up the mountain slopes, threatening the birds that live at the top of the mountain. Avian malaria is a major reason for the decline of Hawaiian birds.

When birds move out of their habitats in search of new places to occupy, they over-exploit prey sources, leading to destruction of the entire ecosystem. Ospreys have been seen hunting other birds, so they may pose a threat to birds in the area, particularly if fish become scarce.

Recently, peafowl were found across Kerala, surprising bird-watchers. Why did they move from their habitat? Obviously in search of food and shelter. Studies also show that some species of birds are developing shorter wing spans and have less density in their bones.

 

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What should we do to protect birds from climate change?

[1] Stop climate change. Even if we end releasing greenhouse gases now, there will be continued warming by the gases released earlier. Birds will have to face a warmer planet in the coming years.

[2] Preserve bird habitats. Restore them where they have been lost. Build artificial nesting sites (simple cages for sparrows to bring them back).

[3] Continues to observe and collect data on when birds arrive at certain spots, when their numbers decline, and the connection between their numbers and the year’s temperature patterns.

[4] Grow more trees. They help to balance climate changes, keep CO2 level low and give the birds a chance to nest and survive.

[5] Keep your cat indoors. Each year, outdoor cats kill more than a billion birds in the U.S. and Canada; keeping cats inside is safer for them and better for birds.

[6] Make the spaces around your house friendly for birds. Gardens, trees, and native flowers are good for people and birds.

[7] In a factory outside Chennai, migratory birds hit the glass windows often and crashed to the ground. The management built large nets under every window to save the birds.

[8] Wherever you find a place and time, talk about birds and the need to protect them. More than 30% of our breeding birds are already declining and are in need of conservation action.

 

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How do global warming and climate change affect birds?

A good example is the study of great tits (Parus major) in Europe. These birds reproduce when caterpillars come out in spring when the buds burst out. The caterpillars gorge on the new leaves, great tits pick up the caterpillars to feed the nestlings. This maintains the bird’s survival rates.

Bird reproduction takes place just when the caterpillars are in abundance before they form their cocoons. Warmer temperatures have led to caterpillars emerging sooner. The birds lay eggs too late, and the caterpillars are gone. The cues the birds use to reproduce are not matching up with the peak prey availability. This can reduce the number of eggs they lay.

Pied flycatchers (Ficedula hypoleuca) spend the winter in tropical Africa before migrating to Europe in the spring to breed, They use day-length change in their wintering grounds as a cue for migration. But prey availability is based on temperature, and due to climate change, it starts earlier in the year. The birds do not arrive at breeding grounds in time to take advantage of peak prey. See the mismatch? The fly-catcher population has declined more than 90% in some areas.

The snow bunting is adapted to very specific mountain habitats. When climate changes, they cannot find food. The ranges of boreal birds in Northern Europe are predicted to decrease by more than 73% over the next century.

 

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Who are the smallest subspecies of elephant in the world?

The Borneo elephant also known as the Borneo pygmy elephant (Elephas maximus borneensis) is unique to the forests of northeastern Borneo, Malaysia and Indonesia.

Rotund appearance

As its name implies, it is the smallest subspecies of the Asian elephant. Just under 8 foot tall, these elephants have large ears round belies, and long tails, so long that they could even brush the ground as they walk. The females are smaller than the males and either have tiny tusks or none at all. At the end of their long trunk is a single, prehensile finger, which it uses to collect grasses, leaves, fruits and other plants. Reaching down for a drink of water is easy too. One adult can eat up to 150 kg of vegetation per day. Favourite food? Of course, it’s durian and wild bananas which are common in its habitat.

Gentle nature

Borneo elephants are gentler compared to Asian and African elephants. In fact, there are very tame and quite passive, which has led some to believe that they once belonged to a domesticated herd. The story goes that in the 17th Century, the Sultan of Sulu was given a collection of captive elephants, and these were released into the jungles of Borneo. Scientific evidence by way of DNA studies shows that Borneo elephants are local to the region. Their lifespan is anywhere between 50 and 70 years.

Matriarchal system

Borneo elephants are sociable animals and live in matriarchal hierarchy. They form small groups of 8 individuals on average, which are dominated by females. Families typically comprise mothers, daughters, sisters and immature males (occasionally – an adult male). Mature males tend to be solitary or form temporary bull herd.

Behaviour

Family units occasionally gather together. This association is highly beneficial for them, helping keep genetic diversity, which, in turn, is vital for their survival. These active elephants are known to wander throughout their habitat, travelling up to 25-30 miles a day. Borneo elephants are migratory animals. Seasonal migration helps them keep themselves in good physical shape. They are good swimmers too.

Breeding

Calves are born after a gestation of 19-22 months. Only one calf is born. Elephants give birth about every 4-6 years, although this period may be extended when conditions are unfavourable for survival, such as during drought. The little one is fed by its mother till the age of three or four. It is the centre of attention among a herd.

Endangered

Pygmy elephants are an endangered species with barely around 1,500 individuals left in the wild, mostly found in Sabah in Malaysian Borneo. The primary threat to these elephants is habitat loss. As human encroachment wipes out forests, the herds are no longer able to travel along their traditional migration routes and sources of food. These homeless elephants also get killed in conflicts when they enter farmland and trample on crops are eat them up. Some get caught in snares erected by humans to trap other animals.

Hence, conserving forests and maintaining elephant corridors is essential if these elephants are to be saved from becoming extinct.

Quick facts

  • Borneo Pygmy elephants are native to Borneo Island.
  • They are smaller than African elephants.
  • They belong to Elephantidae family.
  • Their average life expectancy is in the range of 60-75 years.
  • They are cute and baby-faced.
  • The female can grow to a height of around 4 to 7 feet.
  • Males grow up to a height of around 7 to 8.2 feet.
  • They weight between 3000 – 5000kg.
  • They are usually grey, but occasionally the colour varies from brownish to blackish grey.

 

Picture Credit : Google

Can half of your brain be asleep?

Birds such as swifts, songbirds, seabirds, and sandpipers also sleep unihemispherically, with half of their brain shut. This helps them during long flights.

Keeping one half of the brain at rest, called unihemispheric slow-wave sleep, is in direct contrast to the typical situation where sleep and wakefulness are mutually exclusive states of the whole brain, the scientists say. “We have found that birds can detect approaching predators during unihemispheric slow-wave sleep, and that they can increase the use of unihemispheric sleep as the risk of predation increases,” they report.

The scientists studied groups of mallard ducks while they rested side by side and found that those at the edge of the group were significantly more likely to keep one eye open, with the closed eye being on the side of its nearest neighbour.

“We have found that birds sleeping under risky situations spend more time with one eye open and half the brain awake, and choose to direct the open eye towards a perceived threat,” added Dr Rattenborg.

 

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