AUSTRALIA'S BIRDS

Australia is home to some of the world's most remarkable birds. They range from rainforest dwellers to birds of the arid inland, monsoon wetlands, woodlands and grassy plains.

The distant ancestors of these birds lived in the southern super-continent Gondwana. Eventually the land mass which was to become Autsralia separated from Antarctica and drifted northwards, its climate gradually becoming drier. The rainforests which had covered the continent shrank, and plants which could endure arid conditions took their place. Some birds stayed in the remaining area of wet forest, while others adapted to drier environments and to the eucalypts, acacias, spinifex and other drought-tolerant plants which grew in them. Enterprising species such as honeyeaters formed special relationships with these plants. A number of bird species were split into eastern and western forms by the growth of a vast central Australian desert.

The arrival of humans changed Australia's birdscapes once again. Use of fire, clearing trees, hunting, and the introduction of overseas plants and animals contributed to the decline of some species. Other species flourished as new habitat was opened up for them.

Read the text and match the two words in bold with their definitions given below.

A) Chicks which can not move about independently nor feed themselves for some time after hatching.

B) Young birds which can move about independently and feed themselves shortly after hatching.

THE EGGS — A LIVING MASTERPIECE

A bird's egg is one of nature's most beautiful and marvelous structures. If incubated for 36 days, this egg will hatch into a chick which, after another 50 days of parental care, will fly from the nest.

Soon after hatching, the down-covered young of some groups of birds can leave the nest, eat if they are shown food and follow a parent. These precocious chicks are called precocialyoung. The young of other groups of birds, especially the passerines, fed by adults, until their feathers are grown, and are referred to as altricial young.

Incubation of eggs may not begin until the clutch is complete, ensuring the eggs hatch together. Where several females lay in one nest, the first – laid eggs take longer to hatch than the last – laid. Chirping from inside the eggs may help chicks synchronise their entry into the world

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THE LONG HISTORY OF BIRDS	\|	Read the text, fill in the gaps with the words from the box and explain the underlined word.

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