Difference between revisions of "Parrot" - New World Encyclopedia
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| Yellow-naped Parrot Amazona (ochrocephala) auropalliata Yellow-naped Parrot
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(but see below) Family Cacatuidae (cockatoos)
' - (paraphyletic) |
Parrots or psittacines (pronounced /ˈsɪtəˌsaɪnz/[1][2]) is an order (namely Psittaciformes) of birds that includes about 353 species. They are usually grouped into two families: the Cacatuidae (cockatoo), and the Psittacidae (true parrots), but see below.
All members of the order have a generally erect stance and a characteristic curved beak shape with the upper mandible having slight mobility in the joint with the skull. All parrots are zygodactyl, with two toes at the front of each foot and two at the back.
Parrots can be found in most warm regions of the world, including India, southeast Asia and west Africa. The Carolina Parakeet, now extinct, lived in the United States. By far the greatest number of parrot species come from Australasia, South America, and Central America.
The order is diverse and contains exceptions (notoriously the Eclectus for sexual dimorphism, and the kakapo for flightlessness, diet & digestion, and lek breeding). However, most parrots are cavity nesters, are minimally or not sexually dimorphic, and seem to be highly social. Along with the Corvidae, the Psittaciformes are generally considered the most intelligent of the birds. Parrots are altricial - their young are helpless at birth - and the larger species breed slowly (K-selection). Extant species range in size from the Buff-faced Pygmy-Parrot, at under 10 g and 8 cm (3.2 inches), to the Hyacinth Macaw, at 1.6 kg (3.5 lbs) and 1 meter (3.3 feet).
Evolution and systematics
Origins
In general, an area which has, relative to other areas, a great concentration of different lineages within a particular family is likely to be the original ancestral home of that family. The diversity of Psittaciformes in South America and Australasia suggests that the order has a Gondwanan origin. The parrot family's fossil record, however, is sparse and their origin remains a matter of informed speculation rather than fact.
A single 15 mm fragment from a lower bill (UCMP 143274), found in Lance Creek Formation deposits of Niobrara County, Wyoming, has been suggested as the first parrot fossil. Of Late Cretaceous age, it is about 70 million years old. But subsequent reviews have established that this fossil is almost certainly from a caenagnathid theropod - a group of non-avian dinosaurs with a birdlike beak - and not from a bird.
It is now generally assumed that the Psittaciformes or their common ancestors with a bunch of related bird orders were present somewhere on the world around the K-Pg extinction event, some 65 mya (million years ago). If so, they probably had not evolved their morphological autapomorphies yet, but were generalized arboreal birds, roughly similar (though not necessarily closely related) to today's potoos or frogmouths (see also Palaeopsittacus below).
Europe is the origin of the first generally accepted parrot fossils. They date from the Eocene, starting around 50 mya (million years ago). Several fairly complete skeletons of parrot-like birds have been found in England and Germany. Some uncertainty remains, but on the whole it seems more likely that these are not true ancestors of the modern parrots, but related lineages which evolved in the Northern Hemisphere but have since died out. These are probably not "missing links" between ancestral and modern parrots, but rather psittaciform lineages that evolved parallel to true parrots and cockatoos and had their own peculiar autapomorphies:
- Psittacopes (basal?)
- Serudaptus - pseudasturid or psittacid?
- Pseudasturidae
- Pseudasturides - formerly Pseudastur
- Quercypsittidae
- Quercypsitta (Late Eocene)
The earliest records of modern parrots date to about 23-20 mya and are also from Europe. Subsequently, the fossil record - mainly from Europe, again - consists of bones clearly recognizable as belonging to modern-type parrots. The Southern Hemisphere does not have nearly as rich a fossil record for the period of interest as the Northern, and contains no known parrot-like remains earlier than the early to middle Miocene, around 20 mya. At this point, however, is found the first unambiguous parrot fossil (as opposed to a parrot-like one), an upper jaw which is indistinguishable from that of modern cockatoos. A few modern genera are tentatively dated to a Miocene origin, but their unequivocal record stretches back only some 5 million years (see genus articles for more).
The named fossil genera of parrots are probably all in the Psittacidae or close to its ancestry:
- Archaeopsittacus (Late Oligocene/Early Miocene)
- Xenopsitta (Early Miocene of Czechia)
- Bavaripsitta (Middle Miocene of Steinberg, Germany)
- "Pararallus dispar" (Middle Miocene of France) - includes "Psittacus" lartetianus
Some Paleogene fossils are not unequivocally accepted to be of psittaciforms:
- Palaeopsittacus (Early - Middle Eocene of NW Europe) - caprimulgiform (podargid?) or quercypsittid?
- "Precursor" (Early Eocene of England) - psittaciform (in part - several species? pseudasturid or psittacid?)
- Pulchrapollia - includes "Primobucco" olsoni - psittaciform (pseudasturid or psittacid?)
Phylogeny
The phylogeny of the parrots is still under investigation, and no definite answers are available for entire sections. The classifications as presented reflects the current status, and are subject to change when new studies resolve some of the open questions. For that reason, this classification should be treated as preliminary.
The Psittaciformes are generally considered to consist of two major living lineages of family rank: the true parrots (Psittacidae) and the cockatoos (Cacatuidae). The Cacatuidae are quite distinct, having a movable headcrest, different arrangement of the carotid arteries, a gall bladder, differences in the skull bones, and lack the Dyck texture feathers which, in the Psittacidae, scatters light in such a way as to produce the vibrant colours of so many parrots. However, the actual situation may be more complex (see below).
While understanding of the relationships between subgroups of true parrots - e.g. the one containing the Grey Parrot vs. the relatives of the budgerigar - are rather well resolved and knowledge of relationships between species has much improved in the last years, it is still a matter of dispute whether the distinct lineages of true parrots should be considered subfamilies or tribes. Due to parrot fossils and molecular divergence date estimates providing insufficient data to properly resolve when exactly the major diversification and divergence periods in parrot evolution took place, i.e., how distinct the various lineages are really from each other, or how fast and radically they were changed by evolution.
Lorikeets were previously regarded as a third family Loriidae,[3] though now most often considered a subfamily of the Psittacidae.[4] Others lump all Psittaciformes into one giant family.[citation needed] The present majority view is that they are distinct enough to warrant subfamily status, but some consider the quite pronounced differences not evidence of a uniquely deep evolutionary split but rather not different quantitatively from the differences between more closely related lineages. Biogeography suggests that the lorikeets are best considered a uniquely distinct lineage, not as divergent as cockatoos maybe, but still standing apart from other psittacids.
Recent molecular studies, such as that of mtDNA in 1998,[5] or the sex chromosome spindlin gene in 2005,[6] find the relationships of the main lineages of living parrots to be for the most part unresolvable with any confidence. An unexpected[7] result was that according to the spindlin sequence data, the only major divergence among living parrots that could be reliably positioned in the calculated phylogenies occurred between some New Zealand parrots - Kakapo, Kaka and Kea - and the remaining psittaciformes.
The case for distinctness of at least the nestorines seems to be fairly complete by now. Its position - with or without the kakapo - and ancient age as suggested by the molecular data is at odds with the fossil record though, as it would require an absurdly high degree of homoplasy and a decidedly non-parsimonious character distribution in living parrots. As the study relies upon an obsolete molecular clock model uncalibrated by material evidence, the results are highly spurious. The scenario of Miyaki et al. (1998),[5] while less complete (and excluding the kakapo) agrees better, though not completely, with the material evidence. Again, an unreliable molecular clock model was used.
While the latter two seem indeed to constitute a distinct lineage, placement of the kakapo with these is contradicted by mtDNA cytochrome b sequence data.[5] In any case, the major lineages of psittacines seem indeed to represent distinct clades, but their relationship among them is not well resolvable by the present molecular data. They appear to have radiated throughout a fairly limited timespan, approximately during the Eocene. One finding of major importance is that neither cockatoos nor lories seem to be as distinct from other major parrot lineages as they are usually assumed to be.
Systematics
- A list of all parrots by common name in alphabetical order.
- This list provides the taxonomic sequence of Psittacidae genera and species following a two-subfamily approach (as in the taxobox above).
- Below is a version of the latter in which more subfamilies are recognized. Molecular data (see above) suggests that several subfamilies might indeed be valid and perhaps even be elevated to family rank, but arrangement of tribes in these is not well resolved at present.
Template:Cleanup-list
Family Psittacidae: true parrots, over 300 species
- Subfamily Arinae: Neotropical parrots, about 150 species in some 30 genera. Probably 2 distinct lineages:[5][6]
- Subfamily Loriinae: Around a dozen genera with some 50 species of lorikeets and lories, centered in New Guinea, spreading to Australia, Indonesia, and the islands of the south Pacific.
- Subfamily Micropsittinae: 6 species of pygmy parrot, all in a single genus.
- Subfamily Nestorinae: 1 genus with only 2 living species, the Kea and Kākā of the New Zealand region.
- Subfamily Psittacinae
- Tribe Cyclopsittacini: fig parrots, 3 genera, all from New Guinea or nearby.
- Tribe Polytelini: three genera from Australia and the Wallacea. - may belong to broad-tailed parrots
- Tribe Psittrichadini: A single species, Pesquet's Parrot.
- Tribe Psittacini: Afrotropical parrots, about a dozen species in 3 genera.
- Tribe Psittaculini: Paleotropic psittaculine parrots, nearly 70 living species in 12 genera, distributed from India to Australasia.
- Subfamily Platycercinae: Broad-tailed parrots; nearly 30 species in roughly one dozen genera.
- Tribe Melopsittacini: one genus with one species, the Budgerigar
- Tribe Neophemini: two small genera of parrots.
- Tribe Pezoporini: one genus of parrots with two quite distinct species.
- Tribe Platycercini: Rosellas and relatives; around 20 species in 8 genera.
- Subfamily Strigopinae: The flightless, nearly extinct Kakapo of New Zealand.
Diet
The diet of parrots consists of seeds, fruit, nectar and pollen and to a lesser degree animal prey. Without question the most important of these to most true parrots and cockatoos are seeds. The evolution of the large and powerful bill can be explained primarily as an adaptation to opening and consuming seeds. All true parrots except the Pesquet's Parrot employ the same method to obtain the seed from the husk; the seed is held between the mandibles and the lower mandible crushes the husk, whereupon the seed is rotated in the bill and the remaining husk is removed. A foot is sometimes used in order to help holding large seeds in place. Parrots are seed predators rather than seed dispersers; and in many cases where species are recorded as consuming fruit they are only eating the fruit in order to get at the seed. As seeds often have poisons to protect them parrots will consume clay in order to filter the toxic compounds.[8] - The lorikeets, Swift Parrot and Philippine Hanging parrot are primarily nectar and pollen consumers, and have tongues with brush tips to collect this source of food. Many other species also consume nectar as well when it becomes available.
In addition to feeding on seeds and flowers, some parrot species will prey on animals. Golden-winged Parakeets prey on water snails, and famously the Keas of New Zealand will scavenge on sheep carcases and even kill juvenile petrels. Another New Zealand parrot, the Antipodes Island Parakeet, enters the burrows of nesting Grey-backed Storm-petrels and kills the incubating adults.[9] Some cockatoos and the Kākā will also excavate branches and wood in order to obtain grubs.
Intelligence
Studies with captive birds have given us insight into which birds are the most intelligent. While parrots have the distinction of being able to mimic human speech, studies with the African Grey Parrot have shown that some are able to associate words with their meanings and form simple sentences (see Alex and N'kisi). Along with crows, ravens, and jays (family Corvidae), parrots are considered the most intelligent of birds. The brain-to body size ratio of psittacines and corvines is actually comparable to that of higher primates.[10] One argument against the supposed intelligent capabilities of bird species is that birds have a relatively small cerebral cortex, which is the part of the brain considered to be the main area of intelligence in other animals. However, it seems that birds use a different part of their brain, the medio-rostral neostriatum/hyperstriatum ventrale, as the seat of their intelligence. Not surprisingly, research has shown that these species tend to have the largest hyperstriata, and Dr. Harvey J. Karten, a neuroscientist at UCSD who has studied the physiology of birds, discovered that the lower part of avian brains are similar to ours. In Animal Planet's program "Most Extreme Animals: Smartest", parrots were ranked #1 as the world's smartest animals. Not only have parrots demonstrated intelligence through scientific testing of their language using ability, but some species of parrot such as the Kea are also highly skilled at using tools and solving puzzles.[11]
Sound imitation and speech
Many species can imitate human speech or other sounds, and the results of a study by Irene Pepperberg suggest a high learning ability in an African Grey Parrot named Alex. Alex has been trained to use words to identify objects, describe them, count them, and even answer complex questions such as "How many red squares?" with over 80% accuracy (which is more impressive than it sounds, considering that transcribers only need to be able to recognize Alex speaking a word with 90% accuracy before that word can be used in tests. It's also interesting that he scores higher with unfamiliar objects). A second example is that of N'kisi, another African grey, which has been shown to have a vocabulary of approximately a thousand words and has displayed an ability to invent as well as use words in context and in the correct tense.[12]
Parrots do not have vocal cords, so sound is accomplished by expelling air across the mouth of the bifurcated trachea. Different sounds are produced by changing the depth and shape of trachea. So, talking parrots are really whistling in different variations. Congo African Grey parrots (CAG) are well known for their ability to "talk", which may be caused by more control, or stronger trachea. But that dosen't mean that a cockatiel (cockatiels are not well known for talking ability), could have a greater vocabulary than an African Grey parrot.
Parrots and humans
Parrots as vulnerable or endangered species
The Convention on the International Trade in Endangered Species (CITES) has made trade, import and export of all wild caught parrot and cockatoo species illegal; highly endangered species are protected on the CITES appendix 1 list, and all the other species are protected on the CITES appendix 2 list of vulnerable species. Habitat loss, enviromental changes and illegal trapping remain risks to wild populations.
Parrots as pets
Parrots are kept as pets, particularly conures, macaws, Amazons, cockatoos, African Greys, lovebirds, Cockatiels, Budgerigars, eclectus,and parakeets, because of their varied colouration or their ability to imitate human speech. Sometimes the wings of such birds are clipped, but many people keep flighted pet parrots. Some parrot species, including large cockatoos, Amazon, and macaws, have very long life-spans of up to 80 years.
King Tut, a salmon-crested (aka Moluccan) cockatoo, arrived at the San Diego Zoo on May 25, 1925, and served as the zoo's official greeter from 1951 until his retirement in 1989. In 2004, Britain's Daily Mirror newspaper carried the story of a female macaw supposedly born in 1899, and subsequently a pet of Winston Churchill during World War II; the aged parrot, called Charlie, was reputed to curse the Nazis and Adolf Hitler.[13] Subsequent research strongly suggested that the parrot had never belonged to Winston Churchill,[14][15] although Charlie's great age was not in question.
The popularity of parrots as pets has led to a thriving - and often illegal - trade in the birds, and some species are now threatened with extinction. The scale of the problem can be seen in the Tony Silva case of 1996, in which a parrot expert and former director at Tenerife's Loro Parque (Europe's largest parrot park) was jailed in the United States for 82 months and fined $100,000 for smuggling Hyacinth Macaws.[16] The case led to calls for greater protection and control over trade in the birds. Loro Parque has since become well known for parrot conservation work.[17]
In some wildlife centers, larger parrot species such as macaws are used in bird displays.[citation needed]
Despite their popularity, parrots are difficult pets. While they can be emotionally rewarding, they are also emotionally demanding and many species can be quite loud (Peacocks are often considered loud. Parrots can be much louder, with some cockatoos purportedly peaking at 135 db). Parrots are described as "relentlessly social", and many people buy parrots without understanding them, resulting in many birds being abandoned.
Feral populations
Escaped parrots of several species have proved surprisingly hardy in adapting to conditions in Europe and North America. They sometimes even multiply to the point of becoming a nuisance, or a minor pest and a threat to local ecosystems.
Budgerigar Feral Budgerigars have existed since the 1940s in the St Petersburg, Florida area of the United States, but have decreased since the early 1980s. Colder than normal winter temperatures in some years and increased competition from European Starlings appear to be the main reasons for the declining population.
Rainbow Lorikeet Feral colonies of Rainbow Lorikeet (Trichoglossus haematodus) have been established in Perth, Western Australia[18] and in Auckland, New Zealand.
Eastern Rosella The Eastern Rosella (Platycercus eximius) has become naturalized in the North Island of New Zealand.[19]
Rose-ringed Parakeet A sizeable population of naturalized Rose-ringed Parakeets (Psittacula krameri) exists in and around cities in England, the Netherlands, Belgium and western and southern Germany. They are believed (and in some cases documented[citation needed]) to have descended from escaped or released pets. The largest UK roost of these is thought to be in Esher, Surrey, numbering several thousand. Feral Rose-ringed Parakeets also occur in the United States and South Africa.
Alexandrine Parakeet Often flocking with the naturalized P. krameri populations in Belgium and England are smaller populations of Alexandrine Parakeets (Psittacula eupatria).
Monk Parakeet Populations of the Monk Parakeet (Myiopsitta monachus) have established themselves in many areas of the United States and Spain.
Other In the United States are furthermore found feral Brotogeris spp. (mainly B. versicolurus (Canary-winged Parakeet a.k.a. White-winged Parrot) and/or B. chiriri (Yellow-chevroned Parakeet/Parrot) in a few areas. A population of naturalized Rose-collared aka Peach-faced Lovebirds (Agapornis roseicollis) have naturalized themselves in Tucson, Arizona. Several species, including Red-lored Parrots (Amazona autumnalis), Lilac-crowned Parrots (Amazona finschi), and Yellow-chevroned Parakeets (Brotogeris chiriri), have become well established in Southern California and a population of mainly Red-masked or Cherry-headed Parakeet/Conure, a female Mitred Parakeet/Conure, and hybrids of those species lives in the area of Telegraph Hill in San Francisco. Many states in the U.S. have now enacted laws banning some of the above species from being sold, breed, or kept as pets.
References and footnotes
- ↑ http://www.bartleby.com/61/21/P0632100.html Bartleby.com
- ↑ http://www.merriam-webster.com/dictionary/psittacine Merrian-webster.com
- ↑ Forshaw, Joseph M. & Cooper, William T. (1978): Parrots of the World (2nd ed). Landsdowne Editions, Melbourne Australia ISBN 0-7018-0690-7
- ↑ Forshaw, Joseph M. & Cooper, William T. (2002): Australian Parrots (3rd ed). Press, Willoughby, Australia. ISBN 0-9581212-0-6
- ↑ 5.0 5.1 5.2 5.3 Miyaki, C. Y.; Matioli, S. R.; Burke, T. & Wajntal, A. (1998): Parrot evolution and paleogeographical events: Mitochondrial DNA evidence. Molecular Biology and Evolution 15: 544-551. PDF fulltext
- ↑ 6.0 6.1 de Kloet, R.S. & de Kloet, S.R. (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: 706-721.
- ↑ But not unsurprising, given the amount of early Paleogene [[endemic (biology)|]] bird lineages in New Zealand. See moa, hihi, Acanthisittidae, Callaeidae.
- ↑ Diamond, J (1999). "Evolutionary biology: Dirty eating for healthy living" Nature 400(6740): 120-121
- ↑ Greene, T. (1999) "Aspects of the ecology of Antipodes Island Parakeet ( Cyanoramphus unicolor) and Reischek's Parakeet ( C. novaezelandiae hochstetten) on Antipodes Island, October - November 1995" Notornis 46: 301-310 [1]
- ↑ http://www.nserc.ca/news/features/parrot_e.htm nserc.ca
- ↑ http://www.bbc.co.uk/nature/animals/features/132index.shtml BBC.co.uk
- ↑ Parrot's oratory stuns scientists
- ↑ http://www.google.com/url?sa=t&ct=res&cd=1&url=http%3A//www.mirror.co.uk/news/allnews/content_objectid%3D13832640_method%3Dfull_siteid%3D50143_headline%3D-F----THE-NAZIS—SAYS-CHURCHILL-S-PARROT-name_page.html&ei=qmsHQ8LsJ7-AQueAlcQO
- ↑ http://news.bbc.co.uk/1/hi/england/3414323.stm
- ↑ http://news.bbc.co.uk/1/hi/england/3417353.stm
- ↑ http://www.wwf.org.uk/filelibrary/pdf/crime_and_punishment.pdf 1
- ↑ http://www.loroparque-fundacion.org/
- ↑ Chapman, Tamra. (2006): The status, impact and management of the feral Rainbow Lorikeet (Trichoglossus haematodus moluccanus) in south-west Western Australia. Eclectus 16-17: 17-18.
- ↑ Falla RA, Sibson RB & Turbot EG (1966) A Field guide to the birds of New Zealand. Collins, London (ISBN 0-00-212022-4)
External links
Template:Pet Species
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