A. Parrots are found across the tropic and in all southern hemisphere continents except Antarctica, but nowhere do the display such a richness of diversity and form as in Australia. One- sixth of the world's 345 parrot species are found there, and Australia has long been renowned for the number and variety of its parrots.

B. In the 16th century, the German cartographer Mercator made a world map that included a place, somewhere near present-day Australia, that he named Terra Psittacorum ‐ the Land of Parrots ‐ and the first European settlers in Australia often referred to the country as Parrot Land. In 1865, the celebrated British naturalist and wildlife artist John Gould said: "No group of birds gives Australia so tropical and benign an air as the numerous species of this great family by which it is tenanted."

C. Parrots are descendants of an ancient line. Due to their great diversity, and since most species inhabit Africa, Australia and South America, it seems almost certain that parrots originated millions of years ago on the ancient southern continent of Gondwana, before it broke up into the separate southern hemisphere continents we know today. Much of Gondwana comprised vast rainforests intersected by huge slow-flowing rivers and expansive lakes, but by eight million years ago, great changes were underway. The center of the continent of Australia had begun to dry out, and the rainforests that once covered it gradually contracted to the continental margins, where, to a limited extent, they still exist today.

D. The creatures that remained in those shrinking rainforests had to adapt to the drier conditions or face extinction. Reacting to these desperate circumstances, the parrot family, typically found in jungles in other parts of the world, has populated some of Australia's harshest environments. The parrots spread from ancestral forests through eucalypt woodlands to colonies the central deserts of Australia, and as a consequence they diversified into a wide range of species with adaptations that reflect the many changes animals and plants had to make to survive in these areas.

E. These evolutionary pressures helped mould keratin, the substance from which breaks are made into a range of tools capable of gathering the new food types favored by various species of parrot. The size of a parrot's short, blunt beak and the length of that beak's do curved upper section are related to the type of food each species eats. Some have comparatively long beaks that are perfect for extracting seeds from fruit; others have broader and stronger beaks that are designed for cracking hard seeds.

F. Differently shaped beaks are not the only adaptations that have been made during the developing relationship between parrots and their food plants. Like all of Australia's many honey eating birds, the rainbow-coloured lorikeets and the flowers on which they feed have long co-evolved with features such as the shape and colour of the flowers adapted to the bird's particular needs, and physical a example, red is the most I attractive colour to birds, and thus flowers which depend on birds for pollination are more often red, and lorikeets' tongues have bristles which help them to collect as much pollen as possible.

G. Today, most of Australia's parrots inhabit woodland and open forest, and their numbers decline towards both deserts and wetter areas. The majority are nomadic to some degree, moving around to take advantage of feeding and breeding places. Two of the dry country parrots, the pink and grey galah and the pink, white and yellow corella have expanded their ranges in recent years. They are among the species that have adapted well to the changes brought about by European settlement forest telling created grasslands where galahs and corellas thrive.

H. But other parrot species did not fare so well when their environments were altered. The clearing of large areas of rainforest is probably responsible for the disappearance of the double-eyed fig parrot, and numbers of ground parrots declined when a great part of their habitat was destroyed by the draining of coastal swamps. Even some parrot species that benefited from forest clearing at first are now comforted by a shortage of nesting sites due to further man-made changes.

I. New conditions also sometimes favour an incoming species over one that originally inhabited the area. For example after farmers cleared large areas of forest on Kangaroo Island off the coast of South Australia, the island was colonised by galahs. They were soon going down holes and destroying black cockatoo eggs in order to take the hole for their own use. Their success precipitated a partial collapse in the black cockatoo population when the later lost the struggle for scarce nesting hollows.

J. There may be no final answer to ensuring an equitable balance between parrot species. Nest box programmers help ease the shortage of nesting sites in some places, but there are not enough, they are expensive and they are not an adequate substitute by large, old trees, such as the habitat they represent and nectar, pollen and seeds they provide. Competition between parrots for nest sites is a result of the changes we humans have made to the Earth. We are the most widespread and dangerous competitors that parrots have ever had to face, but we also have the knowledge and skill to maintain the wonderfully rich diversity of Australia's parrots. All we need is the wild to do so.

Some years ago, Professor Robert Havighurst of the University of Chicago, USA, proposed that stages in human development can best be thought of in terms of the developmental 'tasks' that are part of the normal transition. He identified ten developmental tasks associated with the adolescent transition. Each of the Havighurst tasks can also be seen as elements of the overall sense of self that adolescents carry with them as they move towards and into young adulthood. Adolescents do not progress through these multiple developmental tasks separately; at any given time they may be dealing with several.

The adolescent must adjust to a new physical sense of self. At no other time since birth does an individual undergo such profound physical changes as during early adolescence. Puberty is marked by sudden rapid growth in height and weight. Also, the young person experiences the emergence and accentuation of those physical traits that make the person a boy or a girl. The young person looks less like a child and more like a physically mature adult. The effect of this rapid change is that mid-adolescents are body-conscious, and their concerns are directed towards their opposite-sexed peers.

The adolescent must adjust to new intellectual abilities. In addition to a sudden spurt in physical growth, adolescents experience a sudden increase in their ability to think about their world. As a normal part of maturity, they are able to think more things. However, they are also able to conceive of their world with awareness. Before adolescence, children's thinking is dominated by a concrete example for any problem that they solve; their thinking is constrained to what is real and physical. During adolescence, young people begin to recognise and understand abstractions. The growth in ability to deal with abstractions accelerates during the middle stages of adolescence.

The adolescent must adjust to increased cognitive demands at school. Adults see high school in part as a place where adolescents prepare for adult roles and responsibilities and in part as preparatory for further education. School curricula are frequently dominated by the inclusion of more abstract, demanding material, regardless of whether the adolescents have achieved formal thought. Since not all adolescents make the intellectual transition at the same rate, demands for abstract thinking prior to the achievement of that ability may be frustrating.

The adolescent must adopt a personal value system. During adolescence, as teens develop increasingly complex knowledge systems, they also adopt an integrated set of values and morals. During the early stages of moral development, parents provide their child with a structured set of rules of what is right and wrong, what is acceptable and unacceptable. Eventually the adolescent must assess the parent's values as they come into conflict with values expressed by peers and other segments of society. To reconcile differences, the adolescent restructures those beliefs into a personal ideology.

The adolescent must develop expanded verbal skills to accommodate more complex concepts and tasks. Their limited language of childhood is no longer adequate. As their conceptual development may outstrip their verbal development, adolescents may appear less competent than they really are.

The adolescent must establish adult vocational goals. As part of the process of establishing a personal identity, the adolescent must also begin the process of focusing on the question, "What do you plan to be when you grow up?" Mid-adolescents must identify, at least at a preliminary level, what their adult vocational goals are and how they intend to achieve them.

The adolescent must develop a personal sense of identity. Prior to adolescence, one's identity is an extension of one's parents' identity. During the early adolescent years a young person begins to recognise their uniqueness and to establish themselves as separate individuals, independent of their parents. As such, one must reconsider the answer to the question, ‘what does it mean to be me?’ or "who am l?"

The adolescent must establish emotional and psychological independence from his or her parents, childhood is marked by strong dependence on one's parents. Adolescents may yearn to keep that safe, secure, supportive, dependent relationship. Yet, to be an adult implies a sense of independence, of autonomy, of being one's own person. In an attempt to assert their need for independence and individuality, adolescents may respond with what appears to be hostility and lack of cooperation.

The adolescent must develop stable and productive peer relationships. Although peer interaction is not unique to adolescence, it seems to hit a peak of importance during early adolescence. Certainly by late adolescence or early adulthood the need for peer approval has diminished. This degree to which an adolescent is able to make friends and have an accepting peer group, though, is a major indicator of how well the adolescent will adjust in other areas of social and psychological development. Early adolescence is also a period of intense conformity to peers. Fitting in' not being different, and being accepted seem somehow pressing to this age group. The worst possibility, from the view of the young teen, is to be seen by peers as different.

The adolescent must develop increased impulse control and behavioural maturity. In their shift to adulthood, most young people engage in one or more behaviours that place them at physical, social, or educational risk. Risky behaviours are sufficiently pervasive among adolescents to suggest that risk-taking may be a normal developmental process of middle adolescence. Gradually adolescents develop a set of behavioural self-controls through which they assess which behaviours are acceptable and adult-like.

The many tiny islands of the Pacific Ocean had no human population until ancestors of today's islanders sailed from Southeast Asia in ocean-going canoes approximately 2,000 years ago. At the present time, the debate continues about exactly how they migrated such vast distances across the ocean, without any of the modern technologies we take for granted.

Although the romantic vision of some early twentieth-century writers of fleets of heroic navigators simultaneously setting sail had come to be considered by later investigators to be exaggerated, no considered assessment of Pacific voyaging was forthcoming until 1956 when the American historian Andrew Sharp published his research. Sharp challenged the "heroic vision" by asserting that the expertise of the navigators was limited, and that the settlement of the islands was not systematic, being more dependent on good fortune by drifting canoes. Sharp's theory was widely challenged, and deservedly so. If nothing else, however, it did spark renewed interest in the topic and precipitated valuable new research.

Since the 1960s a wealth of investigations has been conducted, and most of them, thankfully, have been of the "non-armchair" variety. While it would be wrong to denigrate all "armchair" research - that based on an examination of available published materials ‐ it has turned out that so little progress had been made in the area of Pacific voyaging because most writers relied on the same old sources - travelers' journals or missionary narratives compiled by unskilled observers. After Sharp, this began to change, and researchers conducted most of their investigations not in libraries, but in the field.

In 1965, David Lewis, a physician and experienced yachtsman, set to work using his own unique philosophy: he took the yacht he had owned for many years and navigated through the islands in order to contact those men who still find their way at sea using traditional methods. He then accompanied these men, in their traditional canoes, on test voyages from which all modern instruments were banished from sight, though Lewis secretly used them to confirm the navigator's calculations. His most famous such voyage was a return trip of around 1,000 nautical miles between two islands in mid-ocean. Far from drifting, as proposed by Sharp, Lewis found that ancient navigators would have known which course to steer by memorizing which stars rose and set in certain positions along the horizon and this gave them fixed directions by which to steer their boats.

The geographer Edwin Doran followed a quite different approach. He was interested in obtaining exact data on canoe sailing performance, and to that end employed the latest electronic instrumentation. Doran traveled on board traditional sailing canoes in some of the most remote parts of the Pacific, all the while using his instruments to record canoe speeds in different wind strengths ‐ from gales to calms ‐ the angle canoes could sail relative to the wind. In the process, he provided the first really precise attributes of traditional sailing canoes.

A further contribution was made by Steven Horvath. As a physiologist, Horvath's interest was not in navigation techniques or in canoes, but in the physical capabilities of the men themselves. By adapting standard physiological techniques, Horvath was able to calculate the energy expenditure required to paddle canoes of this sort at times when there was no wind to fill the sails, or when the wind was contrary. He concluded that paddles, or perhaps long oars, could indeed have propelled for long distances what were primarily sailing vessels.

Finally, a team led by Wall Garrard conducted important research, in this case by making investigations while remaining safely in the laboratory. Wall Garrard's unusual method was to use the findings of linguists who had studied the languages of the Pacific islands, many of which are remarkably similar although the islands where they are spoken are sometimes thousands of kilometres apart. Clever adaptation of computer simulation techniques pioneered in other disciplines allowed him to produce convincing models suggesting the migrations were indeed systematic, but not simultaneous. Wall Garrard proposed the migrations should be seen not as a single journey made by a massed fleet of canoes, but as a series of ever more ambitious voyages, each pushing further into the unknown ocean.

What do we learn about Pacific navigation and voyaging from this research? Quite correctly, none of the researchers tried to use their findings to prove one theory or another; experiments such as these cannot categorically confirm or negate a hypothesis. The strength of this research lay in the range of methodologies employed. When we splice together these findings we can propose that traditional navigators used a variety of canoe types, sources of water and navigation techniques, and it was this adaptability which was their greatest accomplishment. These navigators observed the conditions prevailing at sea at the time a voyage was made and altered their techniques accordingly. Furthermore, the canoes of the navigators were not drifting helplessly at sea but were most likely part of a systematic migration; as such, the Pacific peoples were able to view the ocean as an avenue, not a barrier, to communication before any other race on Earth. Finally, one unexpected but most welcome consequence of this research has been a renaissance in the practice of traditional voyaging. In some groups of islands in the Pacific today young people are resurrecting the skills of their ancestors, when a few decades ago it seemed they would be lost forever.