Monk Parakeets are very
popular cage birds!
Photo courtesy Kathleen Carr.

Massive importations by the U.S. pet industry in the 1960s followed by intentional releases by bored pet owners and irresponsible importers enabled feral populations of these popular cage birds to become established in a number of urban areas.  These areas have in common numerous species of exotic fruit- and seed- bearing ornamental plants, and/or human populations that regularly supplement bird diets with commercial bird seed.  This provides a year-round source of food that would be otherwise unavailable in cold temperate urban areas like Chicago.  Despite being introduced into Europe and North America over 30 years ago, this species has not spread in waves over our landscape as did the European starling, but  remains isolated in urban enclaves.  Moreover, it has not (yet) wreaked the havoc on North American or European agriculture predicted by its behavior in its native lands.  In the 1970s the USFWS attempted to eliminate feral monk populations before they became unmanageable, but failed despite the small sizes of all the feral populations at the time.  Since then, populations of this attractive, personable, and conspicuous species have grown exponentially, and new populations have become established in many urban centers.  Its endearing qualities and status as a persecuted underdog have brought many local citizens, politicians, birders, and even professional biologists to the defense of this invader.  Further studies are needed to resolve the complex biological and sociological issues surrounding this species!

Of the +330 species of parrots, only monk parakeets construct their own nests of sticks!
Photo courtesy Jason South.



  • Kingdom: Animalia

  • Phylum: Chordata

  • Class: Aves

  • Order: Psittaciformes

  • Family: Psittacidae

  • Subfamily: Arinae

  • Genus: Myiopsitta

  • Species: monachus

  • Subspecies: calita,  cotorra, luchsi, and monachus.

Other names:  Quaker parrot, Quaker parakeet, Quaker conure, gray breasted parakeet, gray headed parakeet, cliff parakeet (M. M. luchsi), catorra or cotorra (M. m. cotorra), conure veuve, papo branco, matto grosso, and perquito do pantanal.  Regarding the species name spelling, in literature arising from Argentina and Uraguay, the feminine form of the species name (monacha) is sometimes used because the genus name (Myiopsitta) is feminine.  However, the specific name originally awarded to this species is monachus, a masculine noun that means "monk" in Latin, so monanchus is the proper species name (Bucher 1988).

In their native lands, monks are considered agricultural pests!
Photo courtesy Jason South.


Similar Species:  

At over 330 species, even a simple list of similar parrots and parakeets would be too extensive for this venue, but three similar sized parakeets introduced to North America and other locations worldwide are worth mentioning.  The budgerigar (Melopsittacus undulatus), from Australia, is also mostly green, but has a yellow face and throat.  The male rose- ringed parakeet (Psittacula krameri), from Africa, Asia, and India, is pale green but has a black chin and rose or pink collar.  The canary- or white- winged parakeet (Brotogeris versicolurus), from South America, is mostly green with a yellow wing patch.  See Long (1981) and Lever (1987) for further descriptions of these and other species.  For a complete list of similar parakeets in North America, visit the American Ornithologists' Union Checklist of North American Birds, the Birds of North America, and any popular North American field guide for plates or pictures.  For parrots introduced outside North America, see Juniper and Parr (1998).

The USFWS attempted to eradicate monks between 1970 and 1975, but to no avail!
Photo courtesy Jason South.


Identification Aids:   

For more photos, visit the sites in my Contacts section below.

For North American paper sources, the popular Petersen's Field Guide has a color plate and the National Geographic Society (1987) field guide has two color plates, one of a monk in flight.

Since 1975, monk populations have grown exponentially in the United States, and they are now likely past the point of efficient and economical control!
Photo courtesy Jason South.


Contacts:  If you need more information, try these sites:

has photos, links to other sites, and  abstracts of research papers.

has photos, links, and even audio files of monk sounds you can download.

Hyde Park Parakeets has photos, links, and a good (albeit 3 year old) bibliography which includes some newspaper articles.

For a really detailed comparison of its biology and distribution in North America and South America, with numerous references, see Spreyer and Bucher (1998), which has been annotated for the Web.

The Cornell Ornithology Lab site has information on exotic birds.

If all else fails, Birdnet will link you to most bird-related web sites.

If you see this species outside its native range, please notify someone at a professional ornithological organization and contact the webmaster of one of the private sites linked above.  If you see monks in Florida, please contact Bill Pranty.  Or, simply contact Todd Campbell at the Institute for Biological Invasions at, who will forward your message to the appropriate persons.

Any monk management plan may be met with fierce opposition by citizen groups and animal rights organizations!
Photo courtesy Jon-Marc Davey.


Please cite this page as:
Campbell, T. S. 2000. The Monk Parakeet, Myiopsitta monachus. Institute for Biological Invasions Invader of the Month.



































































































































































































December 2000
The Monk Parakeet
(Myiopsitta monachus Boddaert 1783)

Todd S. Campbell
The Institute for Biological Invasions

Contents:  Taxonomy - Similar Species - Identification Aids - Contacts - Description - Native Range & Biology - Introduced Range & Biology - Known & Potential Impacts - Management - Literature Cited

Description:  The monk parakeet is a small (about 30 cm in total length), stocky, mostly green parrot with a gray or off-white face, cheeks, and throat, a usually gray breast with white bars, bright yellow lower abdominal and vent areas, blue-black flight feathers, long green tail feathers, a pale orange or yellow bill, and gray legs, while immature birds are bright green with  greenish foreheads (Long 1981, Sick 1993, Beaman and Madge 1998, Juniper and Parr 1998, and Spreyer and Bucher 1998).  Its name originated from its gray face which, if you have a good imagination, seems to be peering out from a hooded robe.

Monks are quite vocal and have a wide vocabulary, with many different screeches and squawks and nearly continuous chatter at communal nests (Juniper and Parr 1998, Spreyer and Bucher 1998, Stanley's Quakerville has two audio files you can download).  Monks usually fly in loose flocks of 15 to 20 birds, but flocks of 100 birds are not uncommon (Long 1981).  However, they are not a migratory species in their native or introduced lands (Spreyer and Bucher 1998).


Native Range & Biology:  Monks are native to subtropical and temperate South America.  They are found exclusively in lowlands east of the Andes from Bolivia, Paraguay, Uruguay and southern Brazil south to the Patagonia region of Argentina (Stevenson and Anderson 1994, Aramburu 1997, Juniper and Parr 1998).  Juniper and Parr (1998) and Spreyer and Bucher (1998) recognize four subspecies: M. m. monachus, from southeastern Brazil, Uruguay, and northeastern Argentina, M. m. calita, from western and southern Argentina, M. m. cotorra, from southeastern Bolivia, Paraguay, northern Argentina, and southern Brazil, and M. m. luchsi, an isolated population of monks in Bolivia which are smaller and exhibit different nesting behaviors, and may be a different species of parakeet.

The native range of monk parakeets (in red).

Of the over 330 species of parrots, monk parakeets are the only species that does not nest in existing cavities (Lever 1987).  Rather, they use their bills to construct a nest of woven sticks and spiny branches.  Nests are usually constructed 10 or more meters above the ground, either against the trunk or out on branches of a variety of trees, but are often found in tall eucalyptus trees (Sick 1993).  They also construct nests on power poles and towers.  In the arid intermountain valleys of south- central Bolivia, M. m. luchsi builds nests on cliffs, rather than in trees (Lanning 1991).  Sometimes, monks adopt abandoned nests of other birds, which they modify to serve as foundations for their own nest (e.g., Eberhard 1996).  The nest may be small, housing a single pair, or a very large, complex structure up to a meter in diameter, weighing up to 200 kg and housing multiple pairs (Sick 1993).  Nest cavities are lined with pulverized branches and leaves and the entrances point obliquely downward (Sick 1993).  These large, robust structures last a long time, are used throughout the year, and are one of the many reasons for the monk's success as aliens in northern temperate latitudes with harsh winters.

The population of monk parakeets in Punta Blanca in Buenos Aires province, central Argentina, (lat 340-56'S, lon 570-39'W) is probably the best studied wild population (e.g., papers by Aramburu, Bucher, and their colleagues).  The first eggs are generally laid around mid-October, with average clutch size of about 7 eggs (range 5-12), asynchronous hatching after about 24 days, and a hatching rate of just over 50 percent (Peris and Aramburu 1995).  Upon hatching, wild monk nestlings are are covered with yellow down, must be fed by their parents, and open their eyes in 8-10 days (Aramburu 1997).  Nestlings reach about 106 g in weight during the ca. 40-day period they remain at the nest (Aramburu 1997).  Navarro et al. (1992) report very similar values from a population at Arroyito and Jesús María, Córdoba Province, Argentina, where they preferred tall eucalyptus trees to native vegetation for nesting and produced more fledglings, possibly a result of lower predation (Navarro et al. 1992).  In Argentina, only 17 percent of all nestlings fledged successfully, the main sources of nest mortality being predation by black rats (Rattus) and opossum (Didelphis), but sibling aggression also played a role (Peris and Aramburu 1995).

Reduced natal dispersal and delayed breeding have been demonstrated in wild monks near Jesús María, Córdoba Province, Argentina (Martin and Bucher 1993).  They dispersed from the nest before the next breeding season, but traveled only short distances from their nest, a behavior not generally reported for parrots.  Despite exhibiting reduced natal dispersal and occasionally feeding their own and other siblings in the colony, they generally did not stay around the nest to help their parents.  Rather, they formed pairs and started constructing their own nests or adding onto the colony at about one year of age.  However, they put off breeding until they were about two years old.  A large stick nest is difficult to make, and Martin and Bucher (1993) suggest it may be easier for inexperienced monk parakeets to add to an existing colony, which serves as a refuge from predators and a sort of training ground for young nest-makers.  Colonial nesting begets close social interaction (or vice versa), and each of the eleven or more different calls made by monks of all ages, including a colony alarm call, elicit specific responses from nest mates and other birds in the colony (Martella and Bucher 1990).

Behaviors such as communal nest building, reduced natal dispersal, delayed breeding, the presence of non-breeding mature adults, and nest sentinel systems (alarm calls) are all indications of "helping" (Brown 1987).  These behaviors have been observed in monk parakeets (Martin and Bucher 1993, Spreyer and Bucher 1998, South and Pruett-Jones 2000).  Although helping might seem noble or altruistic, most colony helpers and defenders are directly related to the colony members they defend (e.g., scrub jays, red- cockaded woodpeckers, prairie dogs, and many other highly social, colonial vertebrates), so these behaviors are actually selfish from a genetic and evolutionary standpoint, collectively known as "kin selection."

Monk parakeets prefer open habitats of native savannah woodlands and human-altered or artificial habitats such as open eucalyptus forests, plantations, farms, orchards, and palm groves (Long 1981, Lever 1987, Bucher 1992, Spreyer and Bucher 1998).  They generally require trees for nesting (but see Lanning 1991), but prefer isolated, tall trees in open landscapes to mature forests and low, dense woodlands (Sick 1993).  Some attribute the recent spread and proliferation of this species in their native Argentina to alteration of forested habitat (e.g., thinning), reduction of predator populations, cultivation of eucalyptus, and easy access to cultivated food crops such as maize (Sick 1993), although monks often travel long distances to feed (Long 1981).

Monks are essentially granivorous, eating seeds of plants in the families Poaceae, Asteraceae, and Cyperacea during all times of the year, and seeds of maize and sunflower between February and September (Aramburu 1995).  They also consume wheat, barley, millet, leaf buds, blossoms, fruits, nut, berries, and insects (Long 1981, Sick 1993).  In areas near maize fields in the state of Rio Grande do Sul, Brazil, monks consumed rice, sorghum, and wild seeds, but at nearly 60 percent, maize was the predominant species in their crop (Fallavena and Silva 1988).

Evidence of crop depredation by monk parakeets dates as far back as the Incas and other pre-European cultures, and Charles Darwin was even made aware of the problem in Uraguay in 1833 (Bucher 1992).  In Buenos Aires Province, Argentina, the monk parakeet has been considered an agricultural pest for over 60 years (Aramburu 1995).  Bucher (1992) reviewed the status of neotropical parrots as agricultural pests, and mentioned monk parakeets often.  In short, Bucher states that many types of parrots, including the monk parakeet, are known to damage agricultural crops, but the damage is generally light and economic impact minor.  The monk parakeet is an important pest of corn and sunflower, but they also inflict damage, albeit minimal, on sorghum and pine tree shoots.  Quite possibly, the massive exportation of monk parakeets from Argentina in the 1980s was justified by their status as pests.  But while parrots possess some of the morphological and behavioral adaptations characteristic of avian pest species (e.g., generalist feeding strategies), most parrots do not fit the overall profile of pest species, and the damage to agricultural crops tends to be exaggerated by farmers worldwide.  Moreover, such damage is usually related to, or entirely explained by, poor agricultural practices of humans, rather than aggressive foraging by monk parakeets, and motivation for eliminating the birds is often political.  Clearly, conflicts between native monk parakeets and humans will continue to escalate as humans continue to expand into forested habitats and bring agriculture along (Bucher and Nores 1988).

Even in their native lands, a suite of difficult issues surround parrots in general, and monk parakeets in particular.  Successful management in native lands will require decision makers to strike a delicate balance between the status of parrots as potentially threatened or endangered species, their popularity as attractive and valuable pets worldwide, and their persecution as agricultural pests.  But the status of parrots as exotic, potentially invasive pest species makes this balancing act even more difficult when taken outside their native lands.


Introduced Range & Biology:  

The main pathways of monk parakeet introductions.

Between the late 1960s and early 1970s, over 64,000 monk parakeets were imported into North America, and their establishment was the result of intentional or unintentional releases of captive individuals (Lever 1987).  Feral monk parakeets were widely established in many major urban areas by the early 1970s, including at least 21 sites in seven states (Niedermeyer and Hickey 1977, Long 1981, Lever 1987, VanBael and Pruett-Jones 1996).  Between 1970 and 1975, the USFWS conducted a "retrieval" program, but although certain populations (e.g. in California) were completely eliminated, reducing its range to seven localities in five states, the overall monk population was reduced by only about 44 percent (Niedermeyer and Hickey 1977).  Van Bael and Pruett-Jones (1996) utilized the Christmas Bird Counts (CBC) between 1971 and 1995 and tallies of personal communications from ornithologists around the country to show that monk parakeet populations grew exponentially after 1975 and that monks occurred at 76 locations in 15 states by 1995.

Information about their current distribution is often conflicting, likely because populations disappear and reappear (Spreyer and Bucher 1998), but stable populations occur in at least Alabama, Connecticut, Delaware, Illinois, Florida, Louisiana, New Jersey, New York, Oregon, Texas, Rhode Island, and Virginia, and possibly in Colorado, Missouri, Ohio, and South Carolina (Hyman and Pruett-Jones 1995, Spreyer and Bucher 1998).  Observations of this species should be documented and brought to the attention of ornithologists regardless of locality (see Contacts).  The following is a more detailed history of colonization, expansion, and eradication efforts at selected sites worldwide.

First recorded in New York in the late 1960s (Lever 1987, Long 1981), they became widespread in the northeast and New England states in the 1970s (Niedermeyer and Hickey 1977), but their range was dramatically reduced by the USFWS control efforts, according to CBC data from the early 1990s (Van Bael and Pruett-Jones 1996).  Although they had been eradicated in New York, Connecticut, and New Jersey (Smith 1988, as cited in Stevenson and Anderson 1994), CBC data from the 1990s reveals large, stable populations of monks in these areas (Van Bael and Pruett-Jones 1996).  Monks were first observed to the north in Montreal, Quebec, Canada in 1980, representing the northernmost known population of monks, and may have taken hold (Gauthier and Aubrey 1996, Spreyer and Bucher 1998).

Although monks reached and colonized numerous locations in midwest and middle Atlantic states (Neidermeyer and Hickey 1977, Long 1981), most of these populations did not exist by 1995 (Van Bael and Pruett-Jones 1996).  The best studied population occurs in Hyde Park in Chicago, Illinois (Hyman and Pruett-Jones 1995, South and Pruett-Jones 2000).  In April 1992, Hyman and Pruett-Jones (1995) counted 64 birds and a total of 26 nests on power poles and one antenna tower in Hyde Park, a suburb west of Chicago.  After the nestlings fledged in July, they counted a total of 143 birds, and in the spring of 1993, counted a total of 95 birds in the same area (Hyman and Pruett-Jones 1995).  The birds foraged on plant buds, weeds, fruits and berries of ornamental plants when available, but fed exclusively on commercial bird seed at bird feeders during the coldest months.  More recently, South and Pruett-Jones (2000) made over 1,400 individual foraging observations from 300 foraging groups in the Hyde Park population.  The birds fed mainly on birdseed (over 25 % of their overall diet).  The plant families Poaceae and Rosaceae were represented in over 10% of the foraging observations, but monks fed on 11 other families of plants as well.  Seasonal differences in diets were dramatic, with flowers and buds comprising over 80% of their diet in spring, fruits comprising over 80% of their diet in summer, and seeds comprising 100% of their diet in winter.  They formed feeding groups usually of less than five birds, and the largest flock observed was 31 birds.

Florida has the largest population of monk parakeets in the United States.  They were first reported there in 1972 (Kale 1972, Ogden 1972), and were widespread by 1992 (Stevenson and Anderson 1994).  Unpublished information indicates the Florida monk population may presently consist of 50,000 to 150,000 birds or more in at least 16 counties, and may be "too large to survey and map completely" ( Pranty 2000).  A mapping effort is underway in Florida, for which volunteers are being recruited to help "survey and map monk parakeet nests in Florida in 1999 and 2000."  Over 3300 monk parakeets were seen in 1999 alone, but unfortunately, access to the data from this survey has been restricted, apparently due to (largely unwarranted) fears of survey volunteers that monk parakeets are slated for control or eradication in Florida.

The urbanization of the eastern coast of Florida, which included removal of native vegetation, plantings of thousands of species of fruit- and nectar-bearing ornamental plants, and the unintentional establishment of numerous fruit-bearing exotic invasive plant species has created an environment conducive to the survival and proliferation of released tropical cage birds (Carleton 1971, Owre 1973, Robertson and Kushlan 1974, Carleton and Owre 1975, Robertson and Fredrick 1994, James 1997).  The huge variety of ornamental plants, the semi-tropical climate, and the fact that citizens regularly supplement bird diets at feeders, virtually guarantees that some type of fruit, nectar, or seed mast is available at all times of the year to exotic bird species (James 1997).

Texas has breeding populations in at least Austin, Dallas, and Ft. Worth (Huebner 1996, Spreyer and Bucher 1998), and may fall just behind Florida in overall monk population size. Widespread in California in the 1970s (Niedermeyer and Hickey 1977), many monk parakeets were captured or shot (Long 1981), hence they are not included in California CBC data between 1990 and 1995 (Van Bael and Pruett-Jones 1996) or any of the popular western bird guides.

Monk parakeets have colonized many mainland and near-shore island locations in the Old World.  In Spain, monks are firmly entrenched in Barcelona (Spano and Truffi 1986, Sol et al. 1997a, 1997b), the Canary Islands and possibly the Balearic Islands (Beaman and Madge 1998).  The factors responsible for their establishment and success in in Barcelona are similar to those in North America, where urban areas have been planted with many species of edible plants and palms.  The largest exotic palms (Phoenix sp.) provide safe harbor for nesting parakeets and are considered the main factor influencing monk parakeet distribution (Sol et al. 1997a).  The Barcelona population is growing exponentially and individuals have also been reported in Andalucia, Madrid, Murica, and Valencia, thus, monk parakeets are expected to expand into rural areas and become agricultural pests (Sol et al. 1997b).

Monks were introduced in England, but may have been extirpated there (Long 1981, Lever 1987).  They are present on the island of Sicily, Italy (Spano and Truffi 1986, Caruso and Scelsi 1994).  Monks are also known from France (Adde 1998), Belgium (Spano and Truffi 1986), Germany and Austria (Sick 1993), Amsterdam, Holland (Bull 1973), and the Czech Republic (Beaman and Madge 1998).  In Africa, they have been recorded in Nyeri, Kenya (Lever 1987), but the status of that population is unknown.

Monk populations have popped up on oceanic islands all over the globe.  In the Pacific, monks have been observed in Hawaii but somehow never became established (Berger 1976, Lever 1987, Long 1981), but are established in Japan (Lever 1987).  In the Atlantic and Caribbean, monks have been found on Bermuda (Wingate 1985, Spreyer and Bucher 1998) and are firmly entrenched in Puerto Rico (Neidermeyer and Hickey 1977, Lever 1987, Lever 1994), but the population known from Eleuthera Island, Bahamas may have been extirpated by recent hurricanes (Spreyer and Bucher 1998).

In Europe and North America, this bird prefers open habitats, including planted urban areas, parks, golf courses, farms, gardens, and orchards.  Monk parakeets occur largely in urbanized or otherwise disturbed areas of North America.  However, the population is apparently doubling every five years (Van Bael and Pruett-Jones 1996).  Introduced species sometimes spend a long period simmering before they reach boiling point.  This lag is often explained by the Allee effect, where initial colonizers are so spread out that many are unable to find mates before they perish.  But whatever the cause for the 30 year lag in monk parakeet population explosion, that phase appears to be over.

In summary, the adaptability, fecundity, and and generalized diet of this species have all contributed to the success of the monk parakeet outside its native range, but external factors have been pivotal as well.  Urbanization decreases the amount of vegetated area of a landscape, but also brings with it a replacement of the few patches of remaining native vegetation with ornamental vegetation, which causes further declines in the diversity and abundance of native flora and fauna, and so on.  Exotic ornamental plant assemblages are the result of both intentional introductions of fruit-bearing ornamentals as well as unintentional establishment of species that happen to bear fruits, seeds, or nectars that are suitable for parakeets and other exotic cage birds.  So, while South American monk populations may be limited by nesting sites, in North America, they may be limited by winter food supply (Spreyer and Bucher 1998).  Replacement of native vegetation with agricultural crops and fruit- or seed- bearing ornamentals, combined with the largely erroneous perception that supplemental feedings will help declining native avian populations rather than naturalized exotics, has in the past and will in the future allow monk parakeet to expand its range in the United States and abroad.  It seems obvious that this species will expand its range significantly and quickly (e.g., Van Bael and Pruett-Jones 1996).


Known & Potential Impacts:  The monk parakeet is a clear example of an exotic species with a positive impact, at least in human sociological or psychological terms.  Sightings of these attractive little birds surely lift the spirits of some city dwellers with few or no opportunities for viewing wildlife, whether of not they have a negative view of exotic invasive species in general, or even this species in particular.  The powerful attraction to this species is obvious in the numerous web sites created by urban parakeet lovers (too many to link in this format).  But what, if any, are the measurable, negative environmental and economic impacts of this species?

Evidence that monk parakeets affect native birds or other vertebrates is sparse.  Long (1981) suggests competition has been documented in New York and New Jersey, but provides no data to support this statement other than anecdotal reports by Davis (no date) that monks had been observed killing a blue jay and a robin.  Sol et al. (1997a, 1997b) suggest that monks could "strongly impact native biota" without providing any supporting evidence or risk analysis.  Ultimately, the laws of thermodynamics dictate that the insertion of a new element (e.g., a species) into a biotic system must have some effect, however small, on that system.  But in the urban areas where the feral populations of monks are most abundant, the small amount of "habitat" present often consists of mowed lawns and European starlings and other exotics are usually the most abundant birds.  On the other hand, native birds may need every advantage they can get in degraded urban habitats, and the addition of yet another exotic species may have a compounding or synergistic effect on the native fauna (Von Holle et al. 2000).  One more straw on the camel's back, so to speak.

While there may be no dramatic negative impacts in urban areas per se, basic population biology predicts that monk populations will continue to increase in size and geographical extent and that urban populations of monks will serve as source populations for surrounding areas.  This is where agricultural and/or environmental problems might begin.  To-date, the demonstrable negative impacts of this species have been largely limited to crop raiding in their native lands in Argentina, as discussed above in Native Range & Biology.  However, monks had to be exterminated from Bedfordshire, Great Britain because of the damage they inflicted on nearby orchards (Yealland 1958 as cited in Long 1981).  Recently, more press and web space has been devoted to the question of whether or not monk parakeets are even capable of becoming pests (e.g., Parrots and Plunder), despite substantial evidence to the contrary for birds in general (Temple 1992) and parrots and monk parakeets in particular (Bucher 1992).  In fact, monk parakeets are agricultural pests in Argentina and at least one other location, and their nests damage transmission lines by causing them to short circuit (Bucher 1992).  At issue is the amount of damage they inflict.

Despite being present in North America since before 1972, the monk parakeet has not exhibited the massive outbreaks and agricultural devastation once predicted (Spreyer and Bucher 1998).  So, although the monk's impacts to North American and European food crop productivity remains to be seen, the potential for at least some negative impacts to agriculture clearly exists.  Their impact on native biota, habitats, and whole ecosystems is much more difficult to predict.  This species is not a major problem now, and probably should fall well below most exotic species on any of the major pest lists.  That said, existing monk parakeet populations should be continuously monitored in North America and Europe to assess range expansion and impacts to native species, native systems, agriculture, and human structures.  Only then can a formal risk assessment be performed and an ethical management plan proposed.


Management:   This is a complex issue involving a charismatic vertebrate species and widely different motives, all of which arise from inherently good intentions, but some of which may be lacking in judgment.  Parrots in general, and monk parakeets in particular, are beautiful birds that generate public sympathy despite their alien status.  Telling are the efforts expended in defending "wild" parrots in San Francisco, in which two prolific web sites, Wild Parrots of Telegraph Hill and The Wild Parrots of San Francisco, rarely mention the fact that the birds are nonindigenous.  Trained scientists even defend exotic monk parakeets in non peer-reviewed formats on the web (e.g., Spreyer 1998).  Politicians have also become involved, sometimes posthumously, as in the Mayor Harold Washington Memorial Trust Fund (South 1997).

Some suggest that the treatment of the monk parakeet as "guilty until proven innocent" (GUPI) has been unfair and unjustified (e.g., Spreyer 1998).  However, the assumption of guilt has been, without any exceptions that I am aware, the proper course of action for nonindigenous species and the basis for the few regulations that have successfully thwarted introductions of exotic invasives (e.g., "weeds lists").  That the monk parakeet has not (yet) become a major pest in over 30 years should not cause us to re-evaluate the GUPI attitude toward this or any other exotic species.  In fact, an "innocent until proven guilty" (IUPG) attitude has resulted in unfortunate introductions, some with dire consequences (e.g., agricultural bio-control efforts like the cane toad, Bufo marinus, a total disaster in Australia).  From a logical standpoint, the IUPG line of reasoning simply cannot be defended for any nonindigenous species.  But whether or not actions can be justified from a practical, economical, or political standpoint, based solely on GUPI reasoning, is another matter indeed.  For biological invasions, as with human and veterinary medicine and endangered species, an ounce of prevention is usually worth a pound of cure.  Trade regulations and a moratorium on trade have been suggested for Spain (Sol et al. 1997a, 1997b), and should be initiated elsewhere, based on recommendations of the Bird Trade Subcommittee of the AOU (1991).  But should the monk parakeet be eradicated from North America or Europe?  The jury has been out for over 30 years and clearly begs a verdict, however late.

Control and eradication programs are generally controversial, labor intensive, and incredibly expensive and should be reserved exclusively for high priority pests and new pests that have real potential of being controlled or eradicated before it is too late.  Eradication may be too controversial and costly to be warranted for this species, which has not (yet) caused substantial harm to native species or industries that we know.  If further studies or risk assessments show monk parakeets to be relatively innocuous to native systems and human industries over the long haul, eradication should be a low priority relative to the thousands of other established exotic species that wreak significant havoc.  But even if such studies show monk parakeets to be a significant threat, local, national and international animal rights organizations are sure to protest any attempts to eradicate or even remotely limit population growth of this charismatic species.  Based on past performances, such protests will be mounted regardless of the level of negative impact this species is found to have on native biota, charismatic or otherwise.  Ultimately, the most intense debates may occur between those wanting to protect feral birds and those wanting to protect their crops.  I propose the latter should be given the benefit of the doubt, however, we must remain focused on causation and not allow monk parakeets to become political scapegoats for the failure of farmers to properly manage their crops.

It is noteworthy that all control methods in Argentina, including the offering of a bounty which resulted in a return of over 400,000 pairs of monk feet in two years (Bump 1971), have been totally ineffective (Spreyer and Bucher 1998).  However, this finding has little applicability to the North American situation, where the birds are largely confined to urban areas.  The rapid extinction of the passenger pigeon at the hand of our immediate ancestors with their crude and cruel methods is a painful reminder that bird eradication is physically possible.  But in this day and age, to be effective, any management program proposed for this species in the U. S. must: 1) employ bird capture and nest removal techniques that are effective and efficient but also humane, 2) include provisions for adoption of captured birds and positive or negative incentives to keep the birds from being re-released, 3) include short-term management of the ornamental plants and crops on which it thrives until bird removals are complete, 4) include short-term controls on winter supplemental feedings in known colony areas until bird removals are complete, 5) utilize long- term, landscape- level prevention initiatives, 6) establish or better enforce laws preventing importation and interstate transport of this species, and most importantly, 7) have significant public support.  Without these elements, we will merely repeat the failures of the 1970s.

Finally, it has been suggested that locations of parakeet colonies and data from Christmas Bird Counts (CBC) be kept secret for fear that the information will be used in parakeet eradication programs (e.g., Bill Pranty in Florida).  Although the eradication program of the 1970s may have worked in a few states, such paranoia may be unfounded, as no control or eradication programs are in operation or proposed for this species in the U. S. or abroad, that I am aware.  More importantly, although the practice of selective data access by certain agencies and natural area inventories has been pivotal in protecting endangered species from exploitation, such practices set a dangerous precedent when used on exotic species, for which information sharing is pivotal for assessing management requirements and risk to native biota.  In fact, the withholding of information by laypersons and scientists will hamper the timely and accurate documentation of monk parakeet range expansion and utilization of natural habitats, and studies of their effects on biotic systems, such that if they are ever found to impact agriculture or native systems, it will likely be too late.

Stories of lost opportunity are common in exotic species lore, and the monk parakeet is a clear example of the phrase "too little, too late."  The failed eradication program in the 1970s and a lack of concern and/or intentional avoidance of the issue since that time may have made the situation irreversible, if only due to growing emotional attachment to these colorful, intelligent birds.  After all, monk parakeets are probably not beyond control from a biological or logistical standpoint, but they are likely beyond control from a public sentiment standpoint.  Good or bad, feral monks may be here to stay.  That said, the study of this interesting species in its native and introduced range will certainly advance the study of biological invasions in general and exotic parrots in particular.  Moreover, studies of public sentiment about the management (or, mismanagement) of this species will augment our understanding of the psychological and sociological ramifications of the myriad ways in which we must attempt to thwart the homogenization of our planet's biota.


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The monk parakeet page was last updated on 10/08/2001