The monk parakeet (Myiopsitta monachus), also known as the monk parrot or Quaker parrot, is a species of true parrot in the family Psittacidae. It is a small, bright-green parrot with a greyish breast and greenish-yellow abdomen. Its average lifespan is 20–30 years. It originates from the temperate to subtropical areas of South America. Self-sustaining feral populations occur in many places, mainly in areas of similar climate in North America and Europe.
The nominate subspecies of this parakeet is 29 cm (11 in) long on average, with a 48-centimetre (19 in) wingspan, and weighs 100 g (3.5 oz). Females tend to be 10–20% smaller, but can only be reliably sexed by DNA or feather testing. It has bright-green upperparts. The forehead and breast are pale gray with darker scalloping and the rest of the underparts are very light-green to yellow. The remiges are dark blue, and the tail is long and tapering. The bill is orange. The call is a loud and throaty chape(-yee) or quak quaki quak-wi quarr, and screeches skveet.
Domestic breeds in colors other than the natural plumage have been produced. These include birds with white, blue, and yellow in place of green. As such coloration provides less camouflage, feral birds are usually of wild-type coloration.
Unusually for a parrot, monk parakeet pairs occasionally have helper individuals, often grown offspring, which assist with feeding the young.
The lifespans of monk parakeets have been given as 20-30 years; the former might refer to typical lifespans in captivity and/or in the wild, while the latter is in the range of maximum lifespans recorded for parakeets.
Monk parakeets probably have individual voice prints that allow them to recognize each other, independently from the used call type.
In its native range, the monk parakeet is very common. In Argentina, Brazil, and Uruguay, monk parakeets are regarded as major agricultural pests (as noted by Charles Darwin, among others). Their population explosion in South American rural areas seems to be associated with the expansion of eucalyptus forestry for paper pulp production, which offers the bird the opportunity to build protected nests in artificial forests where ecological competition from other species is limited.
Self-sustaining feral populations have been recorded in several U.S. states and various regions of Europe (namely Spain, Portugal, Azores, Madeira, Balearic Islands, Gibraltar, France, Corsica, Malta, Cyprus, Sardinia, Italy, Greece, Romania, Channel Islands, Great Britain, Ireland, and Belgium), as well as in British Columbia, Canada, Brazil, Mexico, Chile, Germany,Puerto Rico, Easter Island, South Korea, Singapore, and Japan. As it is an open-woodlands species, it adapts readily to urban areas.
