Nature is made possible by the Corporation for Public Broadcasting and by annual financial support from viewers like you. And by Canon, providing the power of imaging to express your visions at home and work. And by Ford, maker of the Ford Explorer. Sometimes where the pavement ends is where the world begins. Ford Explorer, the world's too big to be left unexplored. Light. Camera. Action. Parrots have fascinated people for a very long time. But what's so special about a parrot? To answer that, you need to examine their lives as pets and in the wild. This is an investigation into the power of parrots. For evidence, we'll call on science, pet owners and parrots themselves. More than 8 million parrots share their lives with humans. Why are they so appealing? The owner will have his or her own answer, but on one thing they'd have to agree. Parrots add color to their lives. We're dropping it all. Disgusting bird. I like parrots especially because they're the most spectacular birds on Earth. I like their curiosity, intelligence and color. Parrots come in a dazzling array of vivid hues, all the colors of the rainbow. These are wild birds, appropriately named Rainbow Lorikeets. They fly in each morning for a free breakfast. The spectacle of these dazzling birds attracts over half a million visitors each year to the Curranbin Sanctuary in Australia. This is not an isolated event. Wherever parrots and people meet, these resplendent birds delight our senses and charm their way into our hearts. But their colors are not designed for our eyes. There are over 300 species of parrots in the world. The majority come in one basic color, green. In the wild, this acts as camouflage, helping them blend into the leaky tree tops. Their vivid green plumage makes parrots nearly invisible in the forest. These budgerigars are budgies in the outback of Australia. Their color is also green, but their pattern is one of fine lines. This helps disguise them in their habitat among the grass stems where they feed on fallen seeds. And they need camouflage, for there are more than a dozen kinds of hungry hawks and falcons on the lookout for something to eat. Traveling in such large flocks is another protective measure. An individual can hide inside the flurry of green. The kea lives in New Zealand, where green is also the best color for blending in. But it has other colors in reserve. The flash of bright underwings acts as a signal, keeping the birds together as they fly over their vast domain. This is color for communication. Both male and female keas have the same plumage, but that's not always the case. The female eclectus parrot is one of the most colorful of all. The male looks so different that it was once thought to belong to another species, but the birds know exactly what to look for in a mate. When the males and females began to court and spark, scientists knew they were really two of a kind. These magnificent macaws of the South American rainforests use color in yet another way. Unlike the eclectus pair, both male and female look alike. These blue and gold macaws are certainly not camouflaged against the forest, but they are dull in comparison to this magnificent bird. Scarlet macaws seem to define the very opposite of the word camouflage. All these large macaws appear to be using color as a way of emphasizing their health. Vibrant plumage indicates that a bird is in good shape, one that would make a good mate. The older the birds are, the more intense the colors become. Plumage therefore can be a sign of experience, a quality which is important when choosing a partner. This is color as advertising. The world's largest and possibly the most sensationally colored of all parrots, the hyacinth macaw. These beautiful and rare birds live in the wooded grasslands of Brazil. We don't really know why they're so brilliantly colored, but if you're this big, you don't have many predators, so there's no reason you can't be as bold and bright as you want to be. White cockatoos aren't hiding themselves either. They may not be bright blue or red, but they are quite striking in their own way. Make them a cause, they have no camouflage, but they are concealed by other means. They live in enormous flocks, a confusing mass for any predator. For your color, you have to keep your plumage clean. In the web of life, their Bronze Colour is only one reason we love parrots. Another, of course, is that they love us. I love you! Come and give me a milk kiss. They're very affectionate creatures. They're like a lot of loving. And he gives me so much love. And I think he thinks I'm a budgie, like him. And I think he's a human being, like me. And he wants to come in. It's like having another person in the house, except it has feathers. Listen here, you put yours back there. I'm strafing. Drinking mine. Parrots form strong bonds with their owners and treat them as honorary members of their own kind. What's that? If you keep a parrot without another mate, they will just latch onto you as their own mate. And it's that closeness, that intimacy and that loyalty which is so wonderful about these birds. He talks to me a lot and I think he throws all his love out to me now. I think it's because he loves me so much. I think that's why I like him so much really, because he likes me. When Harry met Janet, he fell out of love with Kathleen. I don't like Harry. I don't like Harry at all. For a simple reason, he doesn't like me. Watch. See, I can't even get near him, look. This is what I get as soon as I go near him. See? Parrots live a long time. Some species can survive for 70 years or more. And they tend to mate for life, though they may have an affair or two on the side. It's this ability to form long-lasting relationships which makes them so endearing to us, because their love life seems to mirror our own. The bond between male and female is strong. Grooming each other and snuggling together help to reinforce the relationship. As an added bonus, those feathers that are so impossible to reach finally get cleaned. I think what she's really after is she's after preening. And as you see, I wear a beard, and I suppose beards and feathers are not that dissimilar to a parrot. And she will spend a long time just going over me and just checking everything's, all the feathers are lying the right way, I suppose, that's what she's after. In most parrot species, the pair preen each other. But in this case, a rival is trying to win over this female with his grooming techniques. Her mate quickly sends him on his way. Most socializing takes place in the evening. Some pairs sort out the day's disputes. Others reaffirm their allegiance. After a pair has bonded, they begin the difficult process of raising a family. Here, many parrots face a problem. They nest in tree cavities, but these are often in short supply. This is especially true for the larger species, like this Hyacinth macaw, because big holes are even harder to find. Even if they're not ready to nest yet, once they found a cavity large enough to raise the next generation, they'll return every day throughout the year to make sure that no one else has moved in. Palm cockatoos defend their precious hole from envious neighbors by displays, calls, and by tapping on a hollow tree stump. It's a proclamation of ownership. But the cockatoos have taken their displays one step further. They've invented a means of amplifying their claims. These ingenious birds manufacture and then beat their own drumsticks. The message for other cockatoos is loud and clear. The cockatoos are not afraid to make a move. They just want to keep their own place. Most parrots nest in tree hollows, but some prefer a more unorthodox location. This Jariboo stork has worked hard to build its huge nest, and these monk parakeets take full advantage of this spacious real estate. They've become tenants in the Jariboo's towering nest. They've built their own basement apartment. The stork's nest is a great place to lay their eggs because the presence of the large stork deters predators. But this story is an exception to the rule. The birthplace of most parrots is in a tree hollow. The chicks inside this nest are remarkably safe and well taken care of. Galahs are very attentive parents. This faithful nature of parrots is what makes them loving companions for people, but there's much more to their appeal. Let's face it, parrots are simply fun to look at. It's not just the colors, but the whole package. Big round heads, beautiful eyes, soft feathers, and their amazing claw and eye coordination. The bill is an incredible tool designed for cracking open seeds. The upper part holds the seed while the lower part chisels away at the hard shell. The hyacinth has the most powerful bill of any bird. If there's a tough nut to crack, this is one of the few birds that can do the job. The force behind this huge bill comes from powerful jaw muscles, which require a massive skull for support. This macaw is a specialized feeder, eating nuts from just two kinds of palms, but these are some of the hardest nuts in the world. The bill is the essence of a bird. It dictates what it can eat and where it can live. While the hyacinth can feed on one type of palm nut by itself, it depends on a surprising ally to eat the other, cattle. It shares the Pantanal region of Brazil with herds of cattle which were introduced about 400 years ago. The cattle eat nuts, but their bodies can only use the outer coating. The seeds pass through their systems undigested. After the herds move out of an area, the hyacinths move in, picking out the seeds from the cattle's droppings. At least it saves them the trouble of having to crack the nuts. This is a lazy bird's way of gathering seeds. Rainbow lorikeets have a bill which is really just a container to hold a remarkable tongue. They use this long tongue to sip nectar and scrape pollen from flowers. The herds are also known as the herdsmen. The herdsmen are the most powerful and most powerful species of the world. The herdsmen are the most powerful species of the world. They use this long tongue to sip nectar and scrape pollen from flowers. Because of this specialized tongue, their diet is limited to flowers that can be sipped or slurred. In complete contrast, these macaws are true generalists. They feed on hundreds of different trees. Their problem is finding food, because many trees in the rainforest do not produce fruit in any predictable pattern. The macaws have to search far and wide to find their next meal. Once found, the huge bill quickly gets the job done, aided by a foot that acts more like a hand. Macaws have to solve a variety of problems in their complex forest world. They are highly intelligent birds. That much is obvious to even the casual observer. But just how intelligent are they? For that answer, it helps to look at them in another environment. Ask any parrot owner and they'll tell you that their birds can certainly understand English. Does the brain of an Einstein lurk inside this feathered head? For 17 years, Alex on the left and Dr. Irene Pepperberg have been working on the mental powers of parrots. Their efforts at the University of Arizona have produced some remarkable results. What shape? That's right, three-corner. That's a good boy. Well, tell me what color. Green, okay. And what toy? What toy? Truck. You're a good boy. Okay. All right, let's do something a little bit more difficult. Hey, tell me, how many? Two. You're right. Good parrot. Yes, you can have enough. All right, now look. Tell me what's different. Good parrot. You're right. Different color. All right, now look. Tell me, what color bigger? Green. Good boy. Green bigger. Good parrot. Oh, you're a good boy today. Yes, three different questions on the same objects. Good parrot. Yes, you're a good boy. What we've found out is that a bird with a brain that is so different from mammals and primates can perform at the same level as chimpanzees and dolphins on all the tasks that we've used and performs at about the level of a young, say, kindergarten-age child. So whoever coined the term bird brain certainly never met a parrot. But how do they use this prodigious intellect? The rainforest is a hard place to make a living. Just as birds have evolved with adaptations for eating plants, plants have evolved with ways to stop them. Many plants have laced their seeds with poison. But some parrots have found a way to have their plants and eat them too. Each morning, thousands of blue-headed and Amazon parrots and small macaws congregate at a few remote cliffs of clay. They're not here to socialize. It's too dangerous to be on the ground. The birds have come to eat the clay. No one really knows exactly why the parrots do this, but it's possible that the clay contains chemicals that neutralize the toxins in the seeds they eat. This is an ingenious solution to a very irritating problem. The small parrots always come first to the cliff. After they've fed for an hour or so, the big macaws arrive. Then they just take over the cliff by force if necessary. The small parrots are very careful. They're not afraid of the big macaws. If parrots were not smart enough to solve the tricky problems posed by the Amazon rainforest, they would have been able to get away with it.