Three years ago, five parrots were set free in a wild place of Arizona, thousands of miles from the Channel Islands in Jersey where they had been looked after by zookeepers. No evolutionary strategies informed them how to behave in this new landscape of mountainous pine forest unoccupied by their kind for 50 years. To the researchers' surprise, they failed to make contact with a group of wild parrots imported from Mexico and set free at the same time. Within 24 hours the reintroducing ended in failure, and the poor birds were back in cages, on their way to the safety of the Arizona reintroduction programme. Ever since then, the programme has enjoyed great success, mainly because the birds now being set free are Mexican birds illegally caught in the wild, confiscated   on arrival north of the border, and raised by their parents in the safety of the programme. The experience shows how little we know about the behaviour and psychology   of parrots, as Peter Bennett, a bird researcher, points out: "Reintroducing species of high intelligence like parrots is a lot more difficult. People like parrots, always treating them as nothing more than pets or valuable 'collectables'." Now that many species of parrot are in immediate danger of dying out, biologists are working together to study the natural history and the behaviour of this family of birds. Last year was an important turning point: conservationists founded the World Parrot Trust, based at Hayle in Cornwall, to support research into both wild and caged birds. Research on parrots is vital for two reasons. First, as the Arizona programme showed, when reintroducing parrots to the wild, we need to be aware of what the birds must know if they are to survive in their natural home. We also need to learn more about the needs of parrots kept as pets, particularly as the Trust's campaign does not attempt to discourage the practice, but rather urges people who buy parrots as pets to choose birds raised by humans. According to the passage, people are advised   _  .
to treat wild and caged parrots equally to set up comfortable homes for parrots not to keep wild parrots as pets not to let more parrots go to the wild