Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide


Myiopsitta monachus
(monk parakeet)



Myiopsitta monachus (monk parakeet)


  • Last modified
  • 22 November 2019
  • Datasheet Type(s)
  • Invasive Species
  • Preferred Scientific Name
  • Myiopsitta monachus
  • Preferred Common Name
  • monk parakeet
  • Taxonomic Tree
  • Domain: Eukaryota
  •   Kingdom: Metazoa
  •     Phylum: Chordata
  •       Subphylum: Vertebrata
  •         Class: Aves
  • Summary of Invasiveness
  • Myiopsitta monachus (monk parakeets) are popular in the pet trade business. Their distinction as the only nest-building parrot has allowed them to adapt to cold climates and urban areas, thus increasing their range when intentionally or uni...

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Myiopsitta monachus (monk parakeet); adult, feeding in black olive tree (Bucida buceras). Palm Beach County, Florida, USA.
CaptionMyiopsitta monachus (monk parakeet); adult, feeding in black olive tree (Bucida buceras). Palm Beach County, Florida, USA.
Copyright©Stephanie Sanchez/ of Georgia - CC BY-NC 3.0 US
Myiopsitta monachus (monk parakeet); adult, feeding in black olive tree (Bucida buceras). Palm Beach County, Florida, USA.
AdultMyiopsitta monachus (monk parakeet); adult, feeding in black olive tree (Bucida buceras). Palm Beach County, Florida, USA.©Stephanie Sanchez/ of Georgia - CC BY-NC 3.0 US


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Preferred Scientific Name

  • Myiopsitta monachus (Boddaert, 1783)

Preferred Common Name

  • monk parakeet

Other Scientific Names

  • Psittacus monachus (Boddaert, 1783)

International Common Names

  • English: grey-breasted parakeet; grey-headed parakeet; quaker conure; quaker parakeet; quaker parrot
  • Spanish: catita com?n; cotorra argentina
  • French: convue veuve; perruche-souris
  • Portuguese: caturra-da-argentina; matto grasso; papo branco

Local Common Names

  • Finland: munkkiaratti
  • Germany: Mönchssittich
  • Hungary: burátpapagáj
  • Italy: parrocchetto monaco
  • Netherlands: monniksparikiet
  • Poland: mniszka
  • Sweden: munkparakit

Summary of Invasiveness

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Myiopsitta monachus (monk parakeets) are popular in the pet trade business. Their distinction as the only nest-building parrot has allowed them to adapt to cold climates and urban areas, thus increasing their range when intentionally or unintentionally released. In Argentina, where Myipositta monachus is native, it is reported to cause one billion dollars worth of crop damage annually. They have, as yet, not significantly harmed any other invaded region.

Taxonomic Tree

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  • Domain: Eukaryota
  •     Kingdom: Metazoa
  •         Phylum: Chordata
  •             Subphylum: Vertebrata
  •                 Class: Aves
  •                     Order: Psittaciformes
  •                         Family: Psittacidae
  •                             Genus: Myiopsitta
  •                                 Species: Myiopsitta monachus


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Myiopsitta monachus is a small, stocky parrot, measuring approximately 30 cm in total length (Campbell,1998) with a wingspan of 53cm and a mass of 90-120g (Spreyer and Bucher, 1998). M. monachus is mostly green with a gray or off white face, cheeks, throat and breast. They have a bright yellow lower abdomen and vent area. The flight feathers are blue-black, and the tail feathers are long and green. They have a pale orange or dull yellow bill and gray legs (Campbell, 1998) and a dark brown iris (Spreyer and Bucher, 1998). Immature M. monachus are a brighter green with a greenish forehead. (Campbell, 2000) They do not exhibit sexual dimorphism (Spreyer and Bucher, 1998), with males and females having identical plumage. Males are generally slightly larger than females, except during breeding season when the body mass of females increases slightly (Newman et al, 2004). They are usually found in loose flocks of 15-20 birds, although flocks of up to 100 are not uncommon. M. monachus are quite vocal with a wide vocabulary of screeches, squawks and chattering noises (Campbell 2000).


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Native range: Subtropical and temperate South America in lowlands east of the Andes Mountains from Bolivia, Paraguay, Uruguay, southern Brazil south to the Patagonia region of Argentina. (Campbell, 2000)
Known introduced range: Eastern United States, Southern Canada, Spain, Italy, France, Belgium, Germany, Austria, Holland, Czech Republic, Kenya, Japan, Bermuda, Puerto Rico, Bahamas, and England (Campbell, 2000).

Distribution Table

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The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

Last updated: 10 Feb 2022
Continent/Country/Region Distribution Last Reported Origin First Reported Invasive Reference Notes






DenmarkPresentIntroducedFirst reported: 1980s
ItalyPresentPresent based on regional distribution.
-Canary IslandsPresentIntroduced
United KingdomPresentPresent based on regional distribution.

North America

British Virgin IslandsPresentIntroduced2007
CanadaPresentPresent based on regional distribution.
Cayman IslandsPresentIntroduced1987Invasive
Dominican RepublicPresentIntroduced1998
Puerto RicoPresentIntroduced1955
U.S. Virgin IslandsPresentIntroduced1989
United StatesPresentIntroducedInvasiveFirst reported: 1960s
-CaliforniaPresent, LocalizedIntroduced
-New JerseyPresentIntroduced
-New YorkPresentIntroduced
-Rhode IslandPresentIntroduced

South America



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Myiopsitta monachus prefer open habitats. In their native range they populate savannah woodlands, farmland, plantations, orchards and cultivated forests (Campbell, 2000), from low elevations up to 1600m above sea level (Spreyer and Bucher, 1998). They are the only parrot that builds its own nest instead of using existing cavities. They weave sticks and spiny branches together to create a sturdy nest used year round for roosting. The nests are almost always 10 metres or more above the ground, often in tall trees (Spreyer and Bucher, 1998).

Studies of monk parakeet populations at Arroyito and Jesus Maria, Cordoba province, Argentina, showed that monk parakeets preferred Eucalyptus trees (Arroyito) and native trees (Jesus Naria) for breeding nests (Navarro, Martella, & Bucher, 1992). In its introduced range they live almost exclusively in urban areas, preferring open habitats, including parks, planted urban areas, golf courses, farms, gardens and orchards (Campbell, 2000).

Habitat List

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Terrestrial ManagedCultivated / agricultural land Present, no further details
Terrestrial ManagedManaged forests, plantations and orchards Present, no further details
Terrestrial ManagedDisturbed areas Present, no further details
Terrestrial ManagedUrban / peri-urban areas Present, no further details
Terrestrial Natural / Semi-naturalNatural grasslands Present, no further details

Biology and Ecology

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Myiopsitta monachus (monk parakeet) is a CITES-listed species. Please follow this link CITES- Myiopsitta monachus for more details. Roughly 5,000 species of animals and 28,000 species of plants are protected by CITES against over-exploitation through international trade.

Monk parakeets display several types of "helping behaviours" that may have contributed to their success as alien species. Included are communal nest building, delayed breeding, the presence of non-breeding mature adults, nest sentinel systems and reduced natal dispersal. After leaving the nest, young birds often remain close, building their own nests or adding on to an existing nest. Nests can be small, housing a single pair or up to one metre in diameter and weighing 200kg and house multiple pairs. Nests have roofs and entry holes, mainly on the underside and often multiple chambers for nesting pairs and small groups of non-breeding indivduals. (Spreyer and Bucher, 1998). "Once the site of the nest structure is selected, individual monk parakeets construct a nest cavity, affixing it to the main nest structure." (Burger and Gochfeld, 2005). M. monachus are very social birds, having eleven or more different calls that each elicit a different response from others in the colony. (Campbell, 2000).

In their native range, M. monachus are generalist granivores and will eat maize, millet, sorghum, sunflowers and other seeds, as well as some fruits, nuts, berries and insects. Year round favorite foods include thistle (Asteraceae) and grass (Poaceae), and fruits of palm and other native trees, largely tala (Celtis spinosa). (Spreyer and Bucher, 1998). Monk parakeets are highly flexible in their food habits (Pruett-Jones et al, 2007). In their introduced range, they feed on the seeds and fruits of exotic ornamental plants and on bird seed provided year round by humans. (Hyman and Pruett-Jones, 1995). They use their large beak to consume seeds and take bites from large pieces of fruit. They have also been seen cracking pine cones to get to the seeds and snipping the heads off dandelions and eating the seeds. In winter, M. monachus often feeds in large flocks of several hundred while a few sentinels sit on high perches and search for predators. During the breeding season, flocks larger than 4 birds are rare. M. monachus generally feeds 3.2-8km from the nest site and may forage as far as 24km away durning the non-breeding season. (Spreyer and Bucher, 1998).
    In South America, gonadal development begins in August, peaks in November and declines rapidly thereafter. Testes enlarge to fifteen times their normal size and ovaries grow in similar proportion. This pattern supports the idea of a fixed annual cycle driven by a photoperiod. South American monk parakeets copulate in October while North American birds copulate in the spring months as the photoperiod increases. In a study of a Myiopsitta monachus population in Punta Blanca in the Buenos Aires province of Argentina, pairs produced the first eggs in mid-October. The average clutch size was 7 eggs (range 5-12) (Campbell 2000).
      Lifecycle stages
      In the studied Punta Blanca population, Myiopsitta monachus (monk parakeet) eggs hatched asynchronously after 24 days. The hatch rate was just over 50%. The hatchlings are covered with yellow down and are fed by the parents via regurgitation (Spreyer and Bucher, 1998) for approximately 40 days, after which they leave the nest (Campbell, 2000). The nestlings reach a weight of approximately 106 grammes before fledging (Campbell, 2000).

        Means of Movement and Dispersal

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        Introduction pathways to new locations
        Pet/aquarium trade: Nearly 65,000 monk parakeets were imported into the U.S. from 1968 to 1972 (Spreyer and Bucher, 1998).

        Local dispersal methods
        Escape from confinement: Upon import, some monk parakeets escaped from damaged shipping crates. (Spreyer & Bucher, 1998).
        Intentional release: Birds were released by owners tired of them and also intentionally from zoos in U.S. and England. (Spreyer and Bucher, 1998).

          Pathway Causes

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          CauseNotesLong DistanceLocalReferences
          Escape from confinement or garden escape Yes
          Intentional release Yes
          Pet trade Yes Yes

          Impact Summary

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          Crop production Negative
          Cultural/amenity Negative
          Economic/livelihood Negative


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          In its native range, M. monachus is considered a significant agricultural pest, often causing damage to field crops and orchards. There have also been reports of transmission lines short-circuited by nesting birds. In its introduced range, impacts are mainly associated with nesting behaviours. Monk parakeets build large bulky nests on communication towers and electric utiliites such as distribution poles and transmission towers. On communication towers they are simply a maintenance problem and do not affect communications. However nests on electric utilities can cause outages and fires, as the large nests can complete electric circuits. This problem is pronounced in wet weather. Monk parakeet nests can cause significant effects to electric utilities including decrease in electric reliability, equipment damage, and lost revenue from nest and bird caused power outages, increase in operation and maintenance costs associated with nest removal and repair of damaged structures as well as public safety concerns (Newman et al, 2004).Costs associated with monk parakeets can be quite considerable. For example, during a five-month period in 2001 in South Florida 198 outages related to monk parakeets were logged. Lost revenue from electric power sales was $24,000 and the cost for repair of outages was estimated at $221,000 (Newman et al, 2004). However in it's introduced range M. monachus has not caused the agricultural devastation predicted, nor has there been any solid evidence that native fauna are negatively affected by their establishment. There is also the possibility that monk parakeets will spread plant diseases by transporting infected planting material to uninfected trees. For example, in Florida citrus canker is a major concern (Newman et al, 2004). There has also been some speculation that growing urban populations of M. monachus could become source populations for surrounding areas. The birds are widely admired by city dwellers who see little other wildlife (Campbell, 2000). Fitzwater (1988) also states "In addition to being a fruit crop pest in South America, it has great potential for dissemination of Newcastle disease. It also cuts trigs and buds from ornamental trees. They are one of the most raucous of birds."


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          Known for their beauty and intelligence, Myiopsitta monachus (monk parakeets) are a popular pet, especially in North America, since the 1960's (Campbell, 2000).

          Uses List

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          • Pet/aquarium trade

          Similarities to Other Species/Conditions

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          Canary-winged parakeet (Brotogeris versicolurus) is mainly green but has a distinctive yellow wing patch that is especially visble during flight. It is smaller than the monk parakeet Myiopsitta monachus but larger than the budgerigar. (Spreyer and Bucher, 1998).

          Budgerigars Melopsittacus undulatus can be confused with the monk parakeet (Myiopsitta monachus) due to their similar green color, however; M undulatus has a yellow face and throat and is a significantly smaller bird, approximately half as long as the monk parakeet. Budgerigars are native to central Australia. (Campbell, 2006). Unlike M. monachus and Psittacula krameri, Budgerigars feed almost exclusively on seeds found on or near the ground. (Spreyer and Bucher, 1998).

          According to Kibbe and Cutright (1973), "The ring-necked parakeet, a native of India, is 16 inches long, thus larger than the Monk. It is bright green, with a very long blue-green tail, and a large bright red bill. The male has a black throat and a conspicous black ring around its neck. The underwing coverts are yellow." They mainly feed on fruits and grains in their native habitat (Butler, 2003a), and the similarity of their diet to the monk parakeet also make them a potential agricultural threat. (Kibbe and Cutright, 1973).



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            Aramburu, Roxana M.; Pezzoni, M. ; Calvo, Silvina; Arambarri, Ana M., 2009. Presence of thorns in the gizzards of nestling Monk Parakeets (Myiopsitta m. monachus) Ornitologia Neotropical. 20(1). 2009. 93-98.

            Avery, Michael L; Yoder, Christi A.; Tillman, Eric A., 2008. Diazacon inhibits reproduction in invasive monk parakeet populations Journal of Wildlife Management. 72(6). AUG 2008. 1449-1452.

            Bomford, M., 2003. Risk Assessment for the Import and Keeping of Exotic Vertebrates in Australia. Bureau of Rural Sciences, Canberra.

            Buhrman-Deever, Susannah C; Rappaport, Amy R.; Bradbury, Jack W., 2007. Geographic variation in contact calls of feral North American populations of the Monk Parakeet. Condor. 109(2). MAY 2007. 389-398.

            Burger, J.; Gochfeld, M., 2009. Exotic monk parakeets (Myiopsitta monachus) in New Jersey: nest site selection, rebuilding following removal, and their urban wildlife appeal Urban Ecosystems. 12(2). JUN 2009. 185-196.

            Burger, S. & M. Gochfeld. 2005. Nesting Behavior and Nest Site Selection in Monk Parakeets Myiopsitta monachus in the Pantanal of Brazil. Springer Berlin/Heidleberg.

            Butler, Christopher J. 2003. Population Biology of the Introduced Rose-Ringed Parakeet Psittacula krameri in the UK. University of Oxford. Department of Zoology. Edward Grey Institue of Field Ornithology.

            Butler, Christopher J. 2003. Species Status Review: Monk Parakeets in Oregon. Oregon Birds 29(2):97.

            Butler, Christopher J. 2005. Feral Parrots in the Continental United States and United Kingdom: Past, Present and Future. Journal of Avian Medicine and Surgery, 19(2):142-149.

            Campbell, T. S. 2000. The Monk Parakeet, Myiopsitta monachus. Institute for Biological Invasions. Invader of the Month.

            CONABIO. 2008. Sistema de información sobre especies invasoras en México. Especies invasoras - Aves. Comisión Nacional para el Conocimiento y Uso de la Biodiversidad. Fecha de acceso.

            Dangoisse, Gersende., 2009. A Study of the Population of Monk Parakeets (Myiopsitta monachus) in Brussels Aves. 46(2). JUN 2009. 57-69.

            Fitzwater, W.D. 1988. Solutions to Urban Bird Problems. Proceedings of the Thirteenth Vertebrate Press Conference. University of Nebraska, Lincoln.

            Fryer, G. 1960. Concerning the proposed introduction of Nile perch into Lake Victoria. East African Agricultural Journal 25(4): 267-270.

            Hauser, L., Carvalho, G. R., Pitcher, T. J. and Ogutu-Ohwayo, R. 1998. Genetic affinities of an introduced predator: Nile perch in Lake Victoria, East Africa. Molecular Ecology 7: 849-859.

            Herrera, Mauricio; Hennessey, Bennett., 2007. Quantifying the illegal parrot trade in Santa Cruz de la Sierra, Bolivia, with emphasis on threatened species Bird Conservation International. 17(4). DEC 2007. 295-300.

            Hyman J, & S. Pruett-Jones. 1995. Natural History of the Monk Parakeet in Hyde Park, Chicago. Wilson Bulletin [WILLSON BULL.] Vol. 107, No. 3, pp. 510-517.

            Iriarte, A.J., Lobos, G.A., & F.M. Jaksic. 2005. Invasive Vertebrate Species in Chile and Their Control and Monitorings by Governmental Agencies. Revista Chilena de Historia Natural, Vol. 78, No. 1.

            Kazuhiro Eguchi and Hitoha E. Amano: “Spread of exotic birds in Japan”. Ornithological Science, Vol. 3, pp.3-11 (2004).

            Kibbe, D.P., and N.J. Cutright. 1973. The Monk Parakeet in New York. Wildlife Damage Management, Internet Center for Bird Control Seminars Proceedings. University of Nebraska, Lincoln.

            Munoz, Antonio-Roman; Real, Raimundo., 2006. Assessing the potential range expansion of the exotic monk parakeet in Spain Diversity & Distributions. 12(6). NOV 2006. 656-665.

            Navarro, J.L., Martella, M.B., & E.H. Bucher. 1992. Breeding Season and Productivity of Monk Parakeets in Cordoba, Argentina. Wilson Bulletin [WILLSON BULL.]. Vol. 104, No.3, pp. 413-424.

            Newman, J. R., C. M. Newman, J. R. Lindsay, B. Merchant, M. L. Avery, & S. Pruett-Jones., 2004. Monk Parakeets: An Expanding Problem on Power Lines and Other Electrical Utility Structures. Presented at the Environmental Concerns in Rights-of-Way Management 8th International Symposium; Saratoga Springs, NY; September 2004.

            Newman, J.R., Newman, C.M., Lindsay, J.R., Merchant, B., Avery, M.L. Pruett, S. 2004. Monk Parakeets: An Expanding Problem on Power Lines and Other Electrical Utility Structures. Environmental Concerns in Rights-of-Way Management 8th International Symposium; Saratoga Springs, NY.

            Peris, S.T. & R.M. Aramburu. 1995. Reproductive Phenology and Breeding Success of Monk Parakeet Myiopsitta monachus in Argentina. Studies on Neotropical Fauna and Environment Vol.30, No. 2, pp. 115-119.

            Pranty, Bill., 2009. Nesting Substrates of Monk Parakeets (Myiopsitta monachus) in Florida Florida Field Naturalist. 37(2). MAY 2009. 51-57

            Pruett-Jones, S., Newman, J.R., Newman, C.M., Avery, M.L., Lindsay, J.R. 2007. Population viability analysis of monk parakeets in the United States and examination of alternative management strategies. Human-Wildlife Conflicts 1(1): 35-44.

            Pruett-Jones, Stephan., James R. Newman., Christian M. Newman., Michael L. Avery and James R. Lindsay., 2007. Population viability analysis of monk parakeets in the United States and examination of alternative management strategies Human–Wildlife Confl icts 1(1):35–44, Spring 2007

            Pruett-Jones, Stephen; Newman, James R.; Newman, Christian M.; Lindsay, James R., 2005. Population growth of monk parakeets in Florida Florida Field Naturalist. 33(1). February 2005. 1-14.

            Real, Raimundo; Marquez, Ana L.; Estrada, Alba; Munoz, A. Roman; Vargas, J. Mario., 2008. Modelling chorotypes of invasive vertebrates in mainland Spain Diversity & Distributions. 14(2). MAR 2008. 364-373.

            Roll, Uri; Dayan, Tamar; Simberloff, Daniel., 2008. Non-indigenous terrestrial vertebrates in Israel and adjacent areas Biological Invasions. 10(5). JUN 2008. 659-672.

            Russello, M. A; Saranathan, V.; Buhrman-Deever, S.; Eberhard, J.; Caccone, A., 2007. Characterization of polymorphic microsatellite loci for the invasive monk parakeet (Myiopsitta monachus) Molecular Ecology Notes. 7(6). NOV 2007. 990-992.

            Russello, Michael A.; Avery, Michael L.; Wright, Timothy F., 2008. Genetic evidence links invasive monk parakeet populations in the United States to the international pet trade BMC Evolutionary Biology. 8 JUL 24 2008. Article No.: 217

            South, J.M., and S. Pruett-Jones. 2000. Patterns of Flock Size, Diet, and Vigilance of Naturalize Monk Parakeets in Hyde Park, Chicago. The Condor 102:848-854.

            Spreyer, M.F., and E.H. Bucher. 1998. Monk Parakeet Myiopsitta monachus. The Birds of North America, No. 322 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.

            Tillman, E.A., Van Doom, A., & M.L. Avery. 2000. Bird Damage to Tropical Fruit in South Florida. Wildlife Damage Management Conferences Proceedings. University of Nebraska, Lincoln.

            UNEP-WCMC. 18 October, 2006. UNEP-WCMC Species Database: CITES-Listed Species. Myiopsitta monachus

            Varnham, K. 2006. Non-native species in UK Overseas Territories: a review. JNCC Report 372. Peterborough: United Kingdom.

            Witte, F., Van Densen, W. L. T. 1995. Fish stocks and fisheries of Lake Victoria. Samara Publishing Ltd., UK. 404pp.

            Yoder, C.A., Avery, M.L., Keacher, K.L. & Tillman, E.A. 2007. Use of DiazaCon™ as a reproductive inhibitor for monk parakeets (Myiopsitta monachus). Wildlife Research 34: 8–13.

            Yoder, Christi A., Michael L. Avery., Kandy L. Keacher and Eric A. Tillman., 2007. Use of DiazaCon™ as a reproductive inhibitor for monk parakeets (Myiopsitta monachus). Wildlife Research, 2007, 34, 8–13


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              Compiled by: National Biological Information Infrastructure (NBII) & IUCN/SSC Invasive Species Specialist Group (ISSG)Updates with support from the Overseas Territories Environmental Programme (OTEP) project XOT603, a joint project with the Cayman Islands Government - Department of Environment

              Last Modified: Monday, October 04, 2010

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