My Science School

The largest bird on the planet is, rather ironically, the flightless ostrich. It also lays the largest eggs among any living land animal. Ostriches are also the fastest birds on land with an ability to run at 70 kilometres per hour. They are found in the African savanna and desert lands, where they meet most of their water requirements from the plants they eat.

Unlike other birds, ostriches use their wings as "rudders" to help them change direction while running. Their powerful and long legs cover about 3 to 5 metres in a single stride. These legs are also rather formidable weapons. An ostrich kick can kill a human or a potential predator such as a lion! Their feet have long, sharp claws too. Ostriches live in small herds with less than a dozen birds in one herd. They mostly eat plants, roots, and seeds but also consume insects, lizards, and other creatures that are found in this harsh habitat.

Although there is a popular belief that ostriches bury their heads in the sand, this is not true. Perhaps the saying would have originated because of the bird's defensive behaviour. When faced with trouble, ostriches lie low and press their long necks to the ground as a means to become less visible. Since their plumage blends well with sandy soil, from a distance, it gives the impression that they have buried their heads in the sand.

Picture Credit : Google

Did you know that bowerbirds are famous for building elaborate structures and even decorating them? Read on to know fascinating facts about the species.

The early European explorers to Australia and New Guinea thought that the elaborate structures they sometimes came across in the forests were built by Aborigines, so artistic and skilled were they. Imagine their surprise when they found that a species of bird was responsible!

The bird is called a bowerbird because of its habit of making complicated 'bowers' or places of courtship to attract and impress the females. The males spend weeks setting up and decorating their bowers. A young male may take several years to perfect the technique.

There are 20 species of bowerbirds of which the satin bowerbird of Australia builds the most elaborate bower. The remarkable structure it builds may reach up to 2.7 m in height. It may consist of a tower of twigs arranged around a central sapling or resemble a miniature house, complete with a door and thatched roof!

Other species clear an area in the forest and set up an 'avenue' or domed tunnel of sticks with just enough space for the bird to enter. Some prepare a lek or display area spread with upturned leaves or 'tiled' with rocks.

Several species give their bowers a coat of paint, using charcoal mixed with saliva or the natural pigment contained in the juice of wild berries. A piece of bark fibre or a tuft of leaves held in the beak serves as a 'paintbrush'. Not content with this, a bowerbird may bring coloured stones, feathers, leaves and flowers to add to the decoration. Iridescent insect skeletons, spider webs and snail shells serve as extra adornment.

Modern-day bowerbirds use discarded buttons, toys, empty tins, coloured straws, broken glass, and even CDs for this purpose! The floor of the bower is often strewn with an enticing bed of soft, fresh leaves.

When the male bowerbird is satisfied with his handiwork, he lures the female inside by calling loudly and when she shows interest, with a dance display. Most male bowerbirds play no part in raising the young. The female lays eggs, which she will incubate by herself. She also cares for the brood on her own.

Quick facts

• There are 20 different bowerbird species, and the males come in colours ranging from green, orange, red, yellow and black to white, olive-brown and sooty grey. Some have a brilliant crest or a ruff. Females are comparatively dull
• Bowerbirds live in tropical forests, mangroves, eucalyptus groves and savanna woodlands.
• They can imitate the calls of other species, as also machines like a chain saw.
• Satin bowerbirds may reuse and refurbish the same bower for more than 30 years.
• Different species go for different colours. The striped gardener bowerbird prefers yellow, red, and blue objects, while the fawn-breasted bowerbird favours green
• Bowerbirds may kill insects solely for the purpose of decorating Competition for females is fierce.
• The birds fight for choicest pieces, steal baubles from each other and tear apart their rivals’ bowers.
• Researchers think that they are the only animal species besides humans to have an aesthetic sense.

Picture Credit : Google 

Harpy eagles are America's most powerful birds of prey that live in the tropical rainforest. They are a key bio-indicator, meaning if there are good numbers of harpies in the forest, then it is certain that there is a healthy number of its prey species.

In Greek mythology, the harpy was a terrifying creature with the body of an eagle and the face of a woman. Harpies flew about in flocks and had a foul smell and sharp claws.

The aptly named harpy eagle of Central and South America has a piercing gaze and fan-like crest that give it a fearsome look. It has dark slate-grey plumage. with lighter grey feathers on its head and face. A broad bib of black separates its head and underside. Its belly and legs are a startling white.

Harpies are America's most powerful birds of prey, though not the largest (that title is held by the Andean condor). They live in the tropical rainforest, and unlike eagles that live in the open, they prefer to hunt just beneath the canopy - this in spite of having a wingspan of around 2.5 m! The wings are shorter and broader than those of other eagles to facilitate hunting among the trees. As with most eagle species, female harpies are almost double the size of males.

These fascinating eagles are extremely dexterous fliers and at the top of the food chain wherever they live. Harpies can weave in and out of branches and pluck unlucky sloths and monkeys off like ripe fruit with their wickedly curved, razor sharp talons. The back talons are longer than those of a grizzly bears at 13 cm. Sloths and monkeys are the females' favourite food but the males prefer the smaller opossums, fawns, snakes, iguanas, and even porcupines.

A harpy eagle can perch silently for hours and hours, waiting for a meal. It can fly almost vertically, so it can attack from below as well as drop down from above. It can turn its head upside down to get a look at its prey as it zooms in. Its keen eyes can spot something as small as two cm in size from 200 metres away.

Harpy eagles are elusive and rarely seen, though their range is very wide. They are near-threatened due to logging and agriculture. No one knows how many remain in the wild - scientists believe the number could be between 20,000 and 50,000.

Fact file

• Harpies build huge nests measuring around 1.2 m wide and 1.5 m long, big enough for a person to lie in!
• The birds mate for life, and once a nest is built, an eagle pair may reuse and repair the same nest for many years.
• Harpy eagles are usually quiet but they can wail, croak, whistle, click, and mew.
• Monkeys and sloths may weigh up to eight kg but a harpy's talons can latch on with a pressure of over 50 kg. This is bone-crushing, and the victim dies instantly.
• Chicks are pure white and attain adult colouring at the age of three. The harpy is Panama's national bird.
• The eagle is a key bio-indicator. That is, if there are good numbers of harpies in the forest, then it is certain that there is a healthy number of its prey species.

Picture Credit : Google