True parrots have a beak with a characteristic curved shape, the jaw with a mobility slightly higher than where it connects with the skull, and a generally upright position. They also have a large cranial capacity and are one of the most intelligent bird groups. They are good fliers and skillful climbers on branches of trees.
Some species can imitate the human voice and other sounds, although they do not have vocal cords — instead possessing a vocal organ at the base of the trachea known as the syrinx.[1]
Like most parrots, the Psittacidae are primarily seed eaters. Some variation is seen in the diet of individual species, with fruits, nuts, leaves, and even insects and other animal prey being taken on occasion by some species. The lorikeets are predominantly nectar feeders; many other parrots drink nectar, as well. Most Psittacidae are cavity-nesting birds which form monogamous pair bonds.
Many species are classified as threatened by the International Union for Conservation of Nature (see IUCN Red List of birds), as well as national and nongovernmental organizations. Trade in birds and other wild animals is governed by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Nearly all parrots are listed on CITES appendices, trade limited or prohibited. Trapping wild parrots for the pet trade, hunting, habitat loss, and competition from invasive species have diminished wild populations, with parrots being subjected to more exploitation than any other group of birds.[2] Of the animals removed from the wild to be sold, very few survive during capture and transport, and those that do often die from poor conditions of captivity, poor diet, and stress. 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.[3]
The parrot family Psittacidae (along with the family Cacatuidae comprising the order Psittaciformes) was traditionally considered to contain two subfamilies, the Psittacinae (typical parrots and allies) and the Loriinae (lories and lorikeets).[5] However, the tree of the parrot family now has been reorganized under the superfamily Psittacoidea: family Psittacidae has been split into three families, tribes Strigopini and Nestorini split out and placed under superfamily Strigopoidea and a new monotypic superfamily Cacatuoidea created containing family Cacatuidae.[4]
The following classification is based on the most recent proposal, which in turn is based on all the relevant recent findings.[4][6][7][8][9][10][11]
^Leo Joseph; Alicia Toon; Erin E. Schirtzinger; Timothy F. Wright (2011). "Molecular systematics of two enigmatic genera Psittacella and Pezoporus illuminate the ecological radiation of Australo-Papuan parrots (Aves: Psittaciformes)". Molecular Phylogenetics and Evolution. 59 (3): 675–684. doi:10.1016/j.ympev.2011.03.017. PMID21453777.
^Schweizer, M.; Seehausen O; Güntert M; Hertwig ST (2009). "The evolutionary diversification of parrots supports a taxon pulse model with multiple trans-oceanic dispersal events and local radiations". Molecular Phylogenetics and Evolution. 54 (3): 984–94. doi:10.1016/j.ympev.2009.08.021. PMID19699808.
^de Kloet, RS; de Kloet SR (2005). "The evolution of the spindlin gene in birds: Sequence analysis of an intron of the spindlin W and Z gene reveals four major divisions of the Psittaciformes". Molecular Phylogenetics and Evolution. 36 (3): 706–721. doi:10.1016/j.ympev.2005.03.013. PMID16099384.
