The parrot is a group of 393 birds in 92 genera that make up the order Nautilus , distributed in most tropical and subtropical regions. The order is subdivided into three superfamilys: nautilus ("true" parrots), cockatoo (cockatoo), and spotted parrots (New Zealand parrots). Parrots are usually distributed in the pantropics, and several species also inhabit temperate regions of the southern hemisphere. Parrots have the greatest diversity in South America and Australia. Parrots are characterized by strong , curved beaks , an upright posture , strong legs , and clawed zygomatic feet. Many parrots are brightly colored, and some are colorful. Most parrots show little or no sex differences in the visual spectrum. In terms of length, they form the most varying bird orders. The most important ingredients in most parrot diets are seeds, nuts, fruits, buds, and other plant materials. A few species sometimes eat animals and carrion, while lorises and lorises feed exclusively on nectar and soft fruits. Almost all parrots build nests (or captive nest boxes) in tree holes and lay white eggs to hatch helpless young birds. Parrots, like crows, crows, jays and magpies, are the most intelligent birds, and the ability of some species to mimic human sounds has increased their popularity as pets. Some parrots are intelligent, talking and comparable to people aged four to five. The killing of wild parrots for pet trade, as well as hunting, habitat loss and competition from exotic species, has reduced wild populations, and parrots are exploited more than any other bird population. Measures taken to protect the habitats of some of the most striking attractive species have also protected many less attractive species living in the same ecosystem.