Category Animal World

            No, not all birds fly. The ostrich, the largest bird on Earth is the best example of a bird that cannot fly. The ostrich is found in the African savannah. Though it cannot fly, it can run very fast, at a speed up to 72 kilometres per hour. An ostrich may be as much as 2.5 metres tall and weigh about 135 kilogrammes. Ostriches produce the largest egg of any living bird. One egg may weigh about 1500 grammes and have the same volume as 25 hen eggs.

            Ostriches, penguins, cassowaries, rheas, emus and liwis are the most well-known flightless birds.

            The penguin, found in Antarctica, has wings modified into flippers to aid it in swimming.

            The cassowary is a large, flightless bird from Australia and New Guinea. It is the biggest bird in Australia, and the second biggest bird in the world, after ostrich. Cassowaries grow to be about 2 metres tall and weigh about 60 kilogrammes. The largest known cassowary was 83 kilogrammes. The cassowary’s life span is about 40 to 50 years.

            Cassowaries have powerful legs and a helmet like crest on the head. They protect themselves by kicking. Cassowaries can run at a speed of upto 50 kilometres per hour.

            Rheas are found only in South America. They are also called South America ostriches. These birds have a height of about 1.5 metres and weigh more than 25 kilogrammes. Rheas are brown in colour.

            Kiwis are small flightless birds. They are the size of a hen, and weigh from 1.5 to 4 kilogrammes. There are three types of kiwis – the common kiwi, spotted kiwi and the little gray kiwi. All are found in New Zealand.

            An important difference between flying and flightless birds is the fact that flightless birds have smaller wing bones. Another distinction is the absent (or greatly reduced, or flat) keel on the breastbone of flightless birds. Flying birds have a keel on their breastbone. The keel anchors the strong muscles that move a bird’s wings during flight. Flightless birds also have more feathers than flying birds. These feathers weigh more.

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            The fastest known bird in level flight is the white throated spine tailed swift. It has been recorded as flying at speeds of over 170 kmph.

            Common eiders, or coastal ducks, can fly nearly 75 kmph. Dunlins (shorebirds) once caught up with, and passed a plane flying at 160 kmph! Swifts, as their name indicates, are among the fastest of all flying birds.

            Peregrine falcons can chase their prey in level flight at 60 kmph, but when stooping or diving to catch it, they reach much higher speeds.

            Other high-speed birds include buzzards, which can glide between 110 and 130 kilometres per hour. Swallows are believed to be able to reach 160 kilometres per hour when migrating, but normally, they do not fly faster than about 50 kilometres per hour.

            The Andean condor, with a wingspan of up to 2.9 metres, is the largest flying bird! This bird lives in the Andes Mountains of South America. Both the Andean condor, and its slightly smaller cousin, the California condor, have unusual wings which allow them to soar only when there is an upward rising air current, and when the weather is dry. When it rains, condors cannot fly, so they must stretch out their wings and allow them to dry before they can once again take to the air. California condors are an endangered species.

            The wandering albatross is also a large flying bird. From one wing tip to another, it’s as long as a family car!

            To escape winter, the whooper swan flies nonstop from Iceland to Scotland – a 1125 km flight. This is the longest flight made by any species of swan. Whoopers are very shy birds, who got their name from the whooping calls they make. They are usually found in fresh water, though at times, they can be seen on sheltered inlets. There are only 1,00,000 Whoopers in the entire world, but their future is very secure, because it is against the law to kill them.

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               Colours in the feather of a bird are formed in two different ways. Pigments, and the physical structure of the feather. Many feathers are coloured by a combination of these features.

               Pigments are chemical compounds that absorb certain wavelengths of light while reflecting others. The colours you see are those reflected back. Feathers coloured by pigments range from crow black to canary Yellow and cardinal red.

               Many colours, such as blue, are a result of feather structure. When light hits these feathers, it hits microscopic structures on the feather that act as prisms to reflect a colour. No blue pigment is known in birds. If you crush a blue scrub jay feather, or dunk it in water it will appear gray.

               Shimmering iridescent colours such as those found in hummingbirds and peacocks are caused by special structures, air bubbles, or films in feather surfaces. These modifications interfere with the bending and scattering of light to strengthen some wavelengths, and cancel out others.

            Bird feathers, which evolved from the scales of reptiles, perform the same function that reptile scales do – they protect a bird in a variety of ways – from the harmful rays of the Sun, from rain, and from injury to their delicate skin.

            They also have the remarkable ability to trap air, thus insulating birds from the cold. There are also feathers on the wings of a bird, which help it to fly. Some birds also use their own feathers to line their nests. Ptarmigans, birds that live in the snow, have feathers on their feet that act like snowshoes!

            These special feathers help the birds from falling through deep snow. This bird changes its feathers three times a year, to help it to camouflage itself as the seasons change.

            The sand grouse, a desert bird, dips its feathers into water and then flies to its chicks, who suck the water off the feathers when they are thirsty!

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                     Yes, indeed! It is not wings, or beaks, or the ability to lay eggs that make a bird a bird. Some mammals lay eggs, and have beaks (like the duck-billed platypus), and some others can fly (like the bat). Reptiles like snakes and crocodiles also lay eggs.

                       However, it is feathers that differentiate a bird from other creatures. Birds are the only creatures that possess feathers.