They were probably generalised arboreal birds, and did not have the specialised crushing bills of modern species. It is generally assumed that the Psittaciformes were present during the Cretaceous–Paleogene extinction event (K-Pg extinction), 66 mya. However, other studies suggest that this fossil is not from a bird, but from a caenagnathid oviraptorosaur (a non-avian dinosaur with a birdlike beak), as several details of the fossil used to support its identity as a parrot are not actually exclusive to parrots, and it is dissimilar to the earliest-known unequivocal parrot fossils. Ī single 15 mm (0.6 in) fragment from a large lower bill ( UCMP 143274), found in deposits from the Lance Creek Formation in Niobrara County, Wyoming, had been thought to be the oldest parrot fossil and is presumed to have originated from the Late Cretaceous period, which makes it about 70 million years old. The three major clades of Neotropical parrots originated about 50 Mya (range 57–41 Mya). Molecular studies suggest that parrots evolved approximately 59 million years ago (Mya) (range 66–51 Mya) in Gondwana. There is currently a higher number of fossil remains from the northern hemisphere in the early Cenozoic. The scarcity of parrots in the fossil record, however, presents difficulties in confirming the hypothesis. Psittaciform diversity in South America and Australasia suggests that the order may have evolved in Gondwana, centred in Australasia. Taxonomy Origins and evolutionįossil dentary specimen UCMP 143274 restored as a parrot (left) or an oviraptorosaur They can travel with cyclical tripedal gaits when climbing. Parrots are the only creatures that display true tripedalism, using their necks and beaks as limbs with propulsive forces equal to or greater than those forces generated by the forelimbs of primates when climbing vertical surfaces. Measures taken to conserve the habitats of some high-profile charismatic species have also protected many of the less charismatic species living in the same ecosystems. As of 2021, about 50 million parrots (half of all parrots) live in captivity, with the vast majority of these living as pets in people's homes. Trapping wild parrots for the pet trade, as well as hunting, habitat loss, and competition from invasive species, has diminished wild populations, with parrots being subjected to more exploitation than any other group of birds. Parrots, along with ravens, crows, jays, and magpies, are among the most intelligent birds, and the ability of some species to imitate human speech enhances their popularity as pets. Almost all parrots nest in tree hollows (or nest boxes in captivity), and lay white eggs from which hatch altricial (helpless) young. A few species sometimes eat animals and carrion, while the lories and lorikeets are specialised for feeding on floral nectar and soft fruits. The most important components of most parrots' diets are seeds, nuts, fruit, buds, and other plant material. They form the most variably sized bird order in terms of length.
Most parrots exhibit little or no sexual dimorphism in the visual spectrum.
Many parrots are vividly coloured, and some are multi-coloured. Ĭharacteristic features of parrots include a strong, curved bill, an upright stance, strong legs, and clawed zygodactyl feet. The greatest diversity of parrots is in South America and Australasia. Parrots have a generally pantropical distribution with several species inhabiting temperate regions in the Southern Hemisphere, as well. One-third of all parrot species are threatened by extinction, with higher aggregate extinction risk ( IUCN Red List Index) than any other comparable bird group. The order is subdivided into three superfamilies: the Psittacoidea ("true" parrots), the Cacatuoidea (cockatoos), and the Strigopoidea (New Zealand parrots).
Parrots, also known as psittacines ( / ˈ s ɪ t ə s aɪ n z/), are birds of the roughly 398 species in 92 genera comprising the order Psittaciformes ( / ˈ s ɪ t ə s ɪ f ɔːr m iː z/), found mostly in tropical and subtropical regions.
0 kommentar(er)
