My Science School

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).

 

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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

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.

 

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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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[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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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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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.

 

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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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The dolphin sleeps with half its brain and one of its eyes shut at a time to keep a watch on approaching predators and other dolphins. After two hours or so, they shut the other eye and the other half of the brain, so both eyes and brain hemispheres get their due rest.

Dolphins have binocular vision (with their eyes sitting on opposite sides of their head), so the researchers trained one of the dolphins to recognized two shapes, either three horizontal red bars or one vertical green bar. They trained Say with her right eye first.

The scientists thought that because half of the dolphin's brain would be asleep during testing, Say would only recognize the shapes with the eye connected to the conscious half of her brain. But she gave them a surprise: She trained her left eye on the shapes, even though that eye had not seen the shapes before.

Ridgway said this must mean that information is transferred between the two hemispheres of the brain.

The dolphins proved just as sharp with their eyes as they were with their ears: After 120 hours, they still saw the shapes.

 

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Many creatures sleep in a group for protection from predators. Puppies, squirrels, bats and meerkats sleep huddled together for warmth and protection.

Puppies will often sleep on their stomach so that they can get up quickly and not miss any playtime. If a dog sleeps on its back, it is either very comfortable, as it's organs are the most exposed, or it's trying to cool off. If your dog cuddles with you, it's showing you affection and trust.

Many dogs will circle before laying down, which is what their ancestors the wolves would do to trample grass down to make a comfortable bed. Digging is something their ancestors would do to keep them warm in the winter and cool in the summer.

If your dog sleeps during the day, it may be due to boredom. If there's any kind of noise and their ears perk up, it means that they are just waiting for something exciting to happen and weren't in deep sleep.

 

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The large hairy armadillo sleeps for 20 hours a day. It is followed by the brown bat (19 hours), the North American opossum (18 hours), the python (18 hours) and the owl monkey (17 hours).

Armadillos live in temperate and warm habitats, including rain forests, grasslands, and semi-deserts. Because of their low metabolic rate and lack of fat stores, cold is their enemy, and spates of intemperate weather can wipe out whole populations.

Most species dig burrows and sleep prolifically, up to 16 hours per day, foraging in the early morning and evening for beetles, ants, termites, and other insects. They have very poor eyesight, and utilize their keen sense of smell to hunt. Strong legs and huge front claws are used for digging, and long, sticky tongues for extracting ants and termites from their tunnels. In addition to bugs, armadillos eat small vertebrates, plants, and some fruit, as well as the occasional carrion meal.

 

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Prey animals such as deer and sheep sleep for 3 to 4 hours per night, and sheep typically sleep in a herd for added protection. The giraffe sleeps only about 30 to 90 minutes a day. Because getting up from the ground takes them a little time, laying down makes them more vulnerable to predators such as crocodiles and lions. For this reason, they will often sleep standing up and may rest their head on their rumps. Researchers until the 1950s believed that they didn't sleep at all. Many prey animals sleep less than predatory animals. However, this rule does not apply to all species.

Since they are a prey species, they sleep extremely lightly and tend to nap during the day. They’ll sleep within the herd, and some sheep will stay awake whilst others to sleep to act as alarm bells in case of predators.

 

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Did you know some animals sleep through summer? This is called aestivation. The equivalent during the winter months is hibernation, which you may be aware of. But humans neither aestivate nor hibernate. Some molluscs (e.g. Spanish snail), fish species (e.g. African lungfish in picture), reptiles (e.g. North American desert tortoise) and amphibians (e.g. waterholding frog) spend hot or dry period in a prolonged state of torpor or dormancy. They do so to avoid damage from high temperatures. They have to conserve energy, retain water in the body and ration the use of stored energy during aestivation. Animals that aestivate go through almost the same physiological processes as those that hibernate.

For going into hibernation or aestivation, animals go through the pre-preparation stage, where the animals store enough of food and water which may last for the long duration, but generally, the food is stored in the form of fat, which provides energy to survive.

These sleep proceeds gradually, as the metabolic activity, hearts beat and breathing rates also slows down. The electrical activity in the brain though stops, but still, the animals respond to stimuli such as sound, light, and temperature.

 

Picture Credit : Google