Parakeet Populations Research Articles

Infectious agents present in monk parakeet (Myiopsitta monachus) and rose-ringed parakeet (Psittacula krameri) invasive species in the parks of Madrid and Seville, Spain.

The introduction of invasive species into an ecosystem could result in biodiversity loss and the spread of infectious agents that could cause re-emergent or emergent zoonotic diseases. Monk parakeets (Myiopsitta monachus) and rose-ringed parakeets (Psittacula krameri) are considered widespread invasive exotic species in urban habitats from the Iberian Peninsula. The aim of this study was to assess the presence of relevant infectious agents in wild parakeets captured in urban parks in Madrid and Seville (Spain). A total of 81 cloacal samples were collected and analysed using molecular techniques. The prevalence of infectious agents varied between parakeet species: 9.5% of monk parakeets and 15% of rose-ringed parakeets were positive for enteropathogenic E. coli (EPEC), 13.3% of rose-ringed parakeets for avian influenza virus (AIV), 3.3% of rose-ringed parakeets for Newcastle disease virus (NDV), and a 23.8% of monk parakeets for Chlamydia psittaci. All C. psittaci-identified isolates were classified as B, E, or E/B genotypes, indicating transmission from wild urban pigeons to parakeets. These results highlight the need for monitoring parakeet populations due to the implications for human and animal health.

A Novel Dependoparvovirus Identified in Cloacal Swabs of Monk Parakeet (Myiopsitta monachus) from Urban Areas of Spain.

The introduction of invasive birds into new ecosystems frequently has negative consequences for the resident populations. Accordingly, the increasing population of monk parakeets (Myiopsitta monachus) in Europe may pose a threat because we have little knowledge of the viruses they can transmit to native naïve species. In this study, we describe a new dependoparvovirus detected by metagenomic analysis of cloacal samples from 28 apparently healthy individuals captured in urban areas of Madrid, Spain. The genomic characterization revealed that the genome encoded the NS and VP proteins typical of parvoviruses and was flanked by inverted terminal repeats. No recombination signal was detected. The phylogenetic analysis showed that it was closely related to a parvovirus isolated in a wild psittacid in China. Both viruses share 80% Rep protein sequence identity and only 64% with other dependoparvoviruses identified in Passeriformes, Anseriformes, and Piciformes and are included in a highly supported clade, which could be considered a new species. The prevalence was very low, and none of the additional 73 individuals tested positive by PCR. These results highlight the importance of exploring the viral genome in invasive species to prevent the emergence of novel viral pathogenic species.

Evaluation of roost culling as a management strategy for reducing invasive rose-ringed parakeet (Psittacula krameri) populations

Rose-ringed parakeets (Psittacula krameri) are one of the most widespread invasive avian species worldwide. This species was introduced to the island of Kaua‘i, Hawai‘i, USA, in the 1960s. The rapidly increasing population has caused substantial economic losses in the agricultural and tourism industries. We evaluated the efficacy of a roost culling program conducted by an independent contractor from March 2020 to March 2021. We estimated island-wide minimum abundance was 10,512 parakeets in January 2020 and 7,372 in April 2021. Over 30 nights of culling at four roost sites, approximately 6,030 parakeets were removed via air rifles with 4,415 (73%) confirmed via carcasses retrieval. An estimated average of 45 parakeets were removed per hour of shooter effort. The proportion of adult females removed in 2020 was 1.9 × greater when culled outside of the estimated nesting season. Of the four roosts where culling occurred, the parakeets fully abandoned three and partially abandoned one site. Of the three fully abandoned roosts, an estimated average of 29.6% of birds were culled prior to roost abandonment. The roost culling effort was conducted during the COVID-19 pandemic, when tourist numbers and foot traffic were greatly reduced. It is unknown how public perception of roost culling in public areas may impact future efforts. Findings suggest roost culling can be utilized for management of nonnative rose-ringed parakeet populations when roost size is small enough and staff size large enough to cull entire roosts in no greater than two consecutive nights (e.g., if two shooters are available for three hours per night, roost culling should only be attempted on a roost with ≤ 540 rose-ringed parakeets).

Annual Censuses and Citizen Science Data Show Rapid Population Increases and Range Expansion of Invasive Rose-Ringed and Monk Parakeets in Seville, Spain.

Simple SummaryMonitoring programs are crucial to understanding and managing invasive species populations. However, they are infrequent and not usually conducted in the long term. In this work, we used population censuses and observational data from citizen science platforms to monitor the growth and expansion of populations of two invasive species established in Seville (Spain): the rose-ringed parakeet and the monk parakeet. During our study period (2013–2021), rose-ringed and monk parakeet populations increased fivefold and twentyfold, respectively. These rapid population growths coincided with the increasing number of observations of both species recorded by volunteer birdwatchers, as well as the increasing expansion of monk parakeets throughout the study area. Citizen science can be useful for roughly knowing the population status of invasive species, but it cannot replace specific monitoring programs to understand their spatiotemporal dynamics.Population changes of invasive species can go unnoticed long before population explosions, so long-term monitoring programs are needed to assess changes in population size. Although invasive populations of rose-ringed (Psittacula krameri) and monk parakeets (Myiopsitta monachus) are present worldwide, their current status and dynamics are mostly poorly known. Here, we provide a long-term population monitoring of both parakeet species established in a Mediterranean urban area. Between 2013 and 2021, we conducted systematic population censuses in the city of Seville and collected their occurrence and spatial distribution data from citizen science platforms. Our censuses showed a rapid population growth of both species: rose-ringed parakeets increased from 1200 to 6300 individuals, while monk parakeets increased from 70 to 1487 individuals. These population trends were weakly reflected by the number of parakeet observations and the number of cells with parakeet observations but not by the number of individuals recorded in citizen science platforms. Moreover, for the monk parakeet, the number of cells with observations was related to the spatial spread of its nests across the study area. Although resource-intensive, long-term monitoring programs are essential to assess population changes and develop effective management actions for invasive species. Thus, contrasting this information with data taken through citizen science platforms can validate the utility of the latter for assessing population status of invasive species.

First record of a population of Rose-ringed parakeet (Psittacula krameri) in Argentina

ABSTRACT The Rose-ringed parakeet (Psittacula krameri), native to India, South Asia, and Sub-Saharan Africa, is considered one of the most invasive bird species. It has been recorded in 37 countries, in some of which it was originally introduced as a pet. It has become an agricultural pest and a threat to native birds in many countries. In South America, populations of this species were only known to exist in Venezuela and the Caribbean Islands. We report the finding of a small reproductive population of Rose-ringed parakeets in the city of Corrientes, in northeastern Argentina. We provide information on its observed feeding patterns and interactions with two other species of birds. We suggest monitoring the species and its population trends, as well as starting an awareness campaign of the dangers to native fauna posed by invasive alien species.

Nesting innovations allow population growth in an invasive population of rose-ringed parakeets.

Certain traits of recipient environments, such as the availability of limiting resources, strongly determine the establishment success and spread of non-native species. These limitations may be overcome through behavioral plasticity, allowing them to exploit alternative resources. Here, we show how a secondary cavity nester bird, the rose-ringed parakeet Psittacula krameri, innovates its nesting behavior as a response to the shortage of tree cavities for nesting in its invasive range in Tenerife (Canary Islands). We observed that some breeding pairs excavated their own nest cavities in palms, thus becoming primary cavity nester, whereas others occupied nests built with wood sticks by another invasive species, the monk parakeet Myiopsitta monachus. The use of these novel nesting strategies increased the number of breeding pairs by up to 52% over 6 years, contributing to a 128.8% increase of the whole population. Innovative nests were located at greater heights above ground and were more aggregated around conspecifics but did not result in greater breeding success than natural cavities. Occupation of monk parakeet colonies by rose-ringed parakeets also benefited the former species through a protective-nesting association against nest predators. Our results show how an invasive species innovate nesting behaviors and increase nest-site availability in the recipient environment, thus facilitating its population growth and invasion process. Potential behavioral innovations in other invasive rose-ringed parakeet populations may be overlooked, and should be considered for effective management plans.

Contact calls of island Brown-throated Parakeets exhibit both character and variance shifts compared to calls of their mainland relatives

Abstract Learned vocalizations play a key role in parrot social dynamics and vocal dialects have been documented for several mainland species, but to date no studies of geographically structured call variation in parrot species have examined the role of isolation on islands. In a study of the Brown-throated Parakeet (Eupsittula pertinax), which inhabits 5 small Caribbean islands as well as the adjacent mainland, we found that the contact calls of island and mainland parakeets show divergence in vocal characters as well as in call variability. We assessed call variation using 3 approaches: frequency measurements, spectrogram cross-correlation (SPCC) analyses, and call duration measurements. Island parakeets’ calls were longer and had lower mean frequencies, and calls from different islands were distinguishable from each other as well as from mainland calls using measures derived from the SPCCs. In addition, we measured call variability at 2 different levels—within-location and within-individual. We found calls to be more variable for island parakeets for SPCC and duration measures, but less variable for frequency measures. The observed call differentiation among locations may be due to drift, whereas the lower frequency of island calls could either be a response to the windy environment on the islands or a consequence of the island subspecies’ larger body sizes. We also hypothesize that the isolation of parakeet populations on small islands may have resulted in reduced selection for local call convergence, allowing island parakeets to produce more variable calls. We suggest that due to poor signal transmission in the windy island environment, selective pressures may favor variability in more easily perceived call features (like call duration) rather than more subtle features, like frequency shifts. Experimental tests are required to determine whether observed call patterns translate into similarly structured patterns in the responses to vocal variants.

Evolution of Beak and Feather Disease Virus across Three Decades of Conservation Intervention for Population Recovery of the Mauritius Parakeet

Emerging infectious diseases (EIDs) are key contributors to the current global biodiversity crisis. Psittaciformes (parrots) are one of the most vulnerable avian taxa and psittacine beak and feather disease (PBFD) is the most common viral disease in wild parrots. PBFD is caused by the beak and feather disease virus (BFDV), which belongs to the Circoviridae family and comprises a circular, single-stranded DNA genome. BFDV is considered to have spread rapidly across the world and, in 2005, an outbreak of PBFD was documented in the recovering population of the Mauritius parakeet (Alexandrinus eques). The Mauritius parakeet was once the world’s rarest parrot and has been successfully recovered through 30 years of intensive conservation management. Molecular surveillance for the prevalence of BFDV was carried out across a 24-year sample archive spanning the period from 1993 to 2017, and DNA sequencing of positive individuals provided an opportunity to assess patterns of phylogenetic and haplotype diversity. Phylogenetic analyses show variation in the extent of viral diversification within the replicase protein (Rep). Timeseries of BFDV prevalence and number of haplotypes reveal that two subsequent waves of infection occurred in 2010/2011 and 2013/2014 following the initial outbreak in 2005. Continued disease surveillance to determine the frequency and intensity of subsequent waves of infection may benefit future translocation/reintroduction planning. The continued growth of the Mauritius parakeet population despite the presence of BFDV bodes well for its long-term persistence.

Investigating people’s perceptions of alien parakeets in urban environments

Biological invasions are widely recognised as a significant threat to biodiversity, a driver of global change and a relevant economic problem. Actions to control or eradicate invasive alien species (IAS) can cause great controversy, especially when targeted species are charismatic. Thus, better understanding people’s perceptions of invasive species is key for ensuring more effective IAS management. The ring-necked parakeet (Psittacula krameri) and the monk parakeet (Myiopsitta monachus) are two of the most successful avian invaders worldwide, causing several ecological and socio-economic impacts in recipient regions. We used image-based questionnaires to assess differences in people’s perceptions of recently established ring-necked and monk parakeet colonies in an urban environment (Porto, Portugal). Most participants recognised both species and had a positive perception of the parakeets, with respondents’ education, gender and age influencing their perception. Potential ecological, economic and social impacts caused by these species do not seem be widely acknowledged yet, likely due to the limited awareness of IAS or the incipiency of their impacts in the area. Our results suggest future actions to manage feral parakeet populations in the area will likely be met with public opposition. While increased public literacy about IAS might help improve risk awareness, complementary tools should be used to promote support for potential interventions. Social assessments are vital to identify, evaluate and address social costs and benefits of IAS. Further research should adopt a multidisciplinary approach to foster communication in IAS management actions, implementing effective and sustainable measures to tackle biological invasions by charismatic vertebrates.

Fine-scale genetic structure reflects limited and coordinated dispersal in the colonial monk parakeet, Myiopsitta monachus.

The genetic structure of animal populations has considerable behavioural, ecological and evolutionary implications and may arise from various demographic traits. Here, we use observational field data and molecular genetics to determine the genetic structure of an invasive population of monk parakeets, Myiopsitta monachus, at a range of spatial scales, and investigate the demographic processes that generate the observed structure. Monk parakeets construct large nests that can house several pairs occupying separate chambers; these nests are often aggregated within nesting trees. We determined patterns of relatedness within compound nests, within nesting trees and between trees. Spatial autocorrelation analyses of pairwise genetic relatedness revealed fine-scale genetic structure with relatives of both sexes spatially clustered within, but not beyond, nesting trees. In addition, males were more related to males sharing their compound nests than to other males occupying the same nesting tree. By contrast, males and females within compound nests were not significantly more closely related than elsewhere in the same tree, and we found no evidence for inbreeding. Adults showed high breeding site fidelity between years despite considerable disturbance of nest sites. Natal dispersal was female-biased, but dispersal distances were relatively short with some natal philopatry observed in both sexes. Sibling coalitions, typically of males, were observed amongst both philopatric and dispersing birds. Our results show significant clustering of kin within compound nests and nesting trees resulting from limited and coordinated natal dispersal, with subsequent breeding site fidelity. The resulting genetic structure has implications for social behaviour in this unusual parrot species.

First record of Ornithonyssus bursa (Berlese, 1888) (Mesostigmata: Macronyssidae) parasitizing invasive monk parakeets in Santiago, Chile.

Myiopsitta monachus is an invasive psittacine with wide distribution due to the pet trade. Its large communal nests and synanthropic nature contribute to its successful colonization of cities, from where it seems to be expanding in range and numbers. This is relevant with regard to pathogens that invasive species may harbor, especially when host populations thrive. We aimed to identify an abundant mite found in invasive monk parakeet chicks that had been collected in Santiago during 2017 and 2018. Through morphological and molecular identification of the 18S ribosomal RNA gene, we confirmed the presence of Ornithonyssus bursa. This was the first report of this mite in Chile. This mite is common in native and invasive monk parakeet populations and may affect other birds, including domestic fowl. Further, this mite bites people and can be a potential vector of pathogens such as bacteria or viruses. We conclude that this parasite was likely introduced with the parakeet and discuss possible ecological, health and economic consequences of this new potential pest.

A framework to evaluate whether to pool or separate behaviors in a multilayer network.

A multilayer network approach combines different network layers, which are connected by interlayer edges, to create a single mathematical object. These networks can contain a variety of information types and represent different aspects of a system. However, the process for selecting which information to include is not always straightforward. Using data on 2 agonistic behaviors in a captive population of monk parakeets (Myiopsitta monachus), we developed a framework for investigating how pooling or splitting behaviors at the scale of dyadic relationships (between 2 individuals) affects individual- and group-level social properties. We designed 2 reference models to test whether randomizing the number of interactions across behavior types results in similar structural patterns as the observed data. Although the behaviors were correlated, the first reference model suggests that the 2 behaviors convey different information about some social properties and should therefore not be pooled. However, once we controlled for data sparsity, we found that the observed measures corresponded with those from the second reference model. Hence, our initial result may have been due to the unequal frequencies of each behavior. Overall, our findings support pooling the 2 behaviors. Awareness of how selected measurements can be affected by data properties is warranted, but nonetheless our framework disentangles these efforts and as a result can be used for myriad types of behaviors and questions. This framework will help researchers make informed and data-driven decisions about which behaviors to pool or separate, prior to using the data in subsequent multilayer network analyses.

Temporary Behavioral Responses to Playbacks by a Pest Parrot and Implications for Management

Human-wildlife interactions continue to increase due to anthropogenic disturbances, with some interactions resulting in conflict. Leveraging a taxa’s bias for a particular sensory cue is a promising management avenue for reducing the potential and realized negative consequences of human-wildlife conflict. For instance, many avian species heavily depend on acoustic communication, and acoustic cues can provide opportunities to reduce conflict with various avian species. The monk parakeet (Myiopsitta monachus) is a gregarious parrot native to South America that has established populations worldwide and is considered an urban and agricultural pest in parts of its native and introduced ranges. We conducted playback experiments with a captive population of monk parakeets to evaluate auditory cues that may be useful for designing management protocols. Our experiment evaluated the efficacy of two stimuli: predator vocalizations as potential repulsion and conspecific vocalizations as potential attraction stimuli for parakeets. We measured two responses: (1) categorical group-level behavioral responses and (2) time to cease vigilance and return to behavior prior to playback. In the repulsion playbacks, monk parakeets were repelled by predator vocalizations in 80% of trials and took longer to cease vigilance and return to baseline behavior compared to attraction playbacks. In the attraction playbacks, monk parakeets exhibited vigilant behavior and weak or no attraction to the stimulus, with attraction only being observed in 10% of trials. Our results demonstrate that predator playbacks may be particularly useful for completing management objectives, such as temporary removal from a location.

Thinking Like a Parrot: A Wide‐Ranging Synthesis of the Current State of Research on Wild Parrot Biology

Thinking Like a Parrot: A Wide‐Ranging Synthesis of the Current State of Research on Wild Parrot Biology

A protective nesting association with native species counteracts biotic resistance for the spread of an invasive parakeet from urban into rural habitats

BackgroundNon-native species are often introduced in cities, where they take advantage of microclimatic conditions, resources provided by humans, and competitor/predator release to establish and proliferate. However, native communities in the surrounding rural or natural areas usually halt their spread through biotic resistance, mainly via top-down regulative processes (predation pressure). Here, we show an unusual commensal interaction between exotic and native bird species that favours the spread of the former from urban to rural habitats.ResultsWe show how Monk parakeets Myiopsitta monachus, an invasive species often introduced in cities worldwide, associated for breeding with a much larger, native species (the white stork Ciconia ciconia) to reduce predation risk in central Spain, thus allowing their colonization of rural areas. Parakeets selected stork nests close to conspecifics and where breeding raptors were less abundant. Parakeets always flushed when raptors approached their nests when breeding alone, but stayed at their nests when breeding in association with storks. Moreover, when storks abandoned a nest, parakeets abandoned it in the following year, suggesting that storks actually confer protection against predators.ConclusionsOur results show how a protective-nesting association between invasive and native species can counteract biotic resistance to allow the spread of an invasive species across non-urban habitats, where they may become crop pests. Monk parakeet populations are now growing exponentially in several cities in several Mediterranean countries, where they coexist with white storks. Therefore, management plans should consider this risk of spread into rural areas and favour native predators as potential biological controllers.

Haemoproteus minutus is highly virulent for Australasian and South American parrots

BackgroundHaemoproteus and Plasmodium species are widespread avian blood parasites. Several Plasmodium species are known for their high virulence and have caused significant declines in naïve bird populations. The impact of closely related Haemoproteus parasites is largely unknown. Recently we reported a lethal disease in two parrot aviaries caused by Haemoproteus parasites.ResultsHere we show that the causative pathogen Haemoproteus minutus is responsible for further 17 lethal outbreaks in parrot aviaries in Denmark, Germany and Great Britain. All affected parrots are endemic to Australasia and South America. We sequenced the cytochrome b gene from megalomeront-infected muscle tissue of 21 parrots and identified the two lineages TUPHI01 and TURDUS2 as causative agents, commonly naturally infecting the common blackbird (Turdus merula) and the song thrush (Turdus philomelos), respectively, in the Palaearctic. No intraerythrocytic parasite stages were found in any of the parrots. We failed to detect H. minutus in invasive Indian ring-necked parakeets (Psittacula krameri) in Germany. Together this suggests that abortive infections with two virulent lineages of H. minutus are lethal for naïve parrot species from Australasia and South America. We asked whether we could detect H. minutus in New Zealand, where its Turdus hosts were introduced in the 1800s. We therefore tested invasive blackbirds and song thrushes, and the co-existing endemic red-fronted parakeet (Cyanoramphus novaezelandiae) population on three New Zealand islands. No Haemoproteus spp. DNA was detected in all blood samples, indicating absence of transmission.ConclusionsThe results of this study show that captive parrots in Europe are threatened by two lineages of an otherwise benign parasite of Turdus spp. Aviary collections of parrots should be protected from Culicoides spp. vectors in Europe. Animal trade and climate changes extending the current vector and parasite distribution have to be considered as potential risk factors for the introduction of the disease in naïve parrot populations.

Sex Determination in Male and Female Melopsittacus undulates using a Morphometric Method

Parakeets (Melopsittacus undulates) are classified parrot order Psittaciformes. Parakeets are monomorphic birds whose sex is difficult to be distinguished. Sex identification is very important for breeding efforts in order to increase the parakeet population. External morphology was determined to identify the sex of the birds. This research was conducted to determine the sex of parakeets (male and female). This study used five male and five female parakeets aged 4 months as the study objects. This study used the quantitative and qualitative method. Results of this study was verified by performing surgery to determine the sex of parakeet based on their reproductive organs. The t-test results of morphometric characteristics showed no significant different in the length of body, upper bill, lower bill, wing, tail, femur, tibial-tarsus, tarsometatarsus and digits as well as the body weight between male and female parakeets. The color of the cere was useful to accurately determine sex in parakeets (blue in males and white in females). This research provided information to the public about the differences between male and female parakeets for the selection of good broodstock in order to increase their population in captivity.

Ectoparasite sharing among native and invasive birds in a metropolitan area.

Parasite-mediated competition has been reported to be one of the most harmful, although overlooked, impacts that alien species have on native ecosystems. Monk parakeets Myiopsitta monachus are successful invaders in Europe, where they have been introduced from South America. Colonial nests of these parrots may also host other species, e.g. the rock pigeon Columba livia forma domestica. In this work, we analysed the ectoparasite composition of monk parakeets in Barcelona (Spain) and we evaluated their potential role as parasite-mediated competitors, by comparing their parasitic load with that of coexisting rock pigeons. Only two arthropod species were observed on monk parakeets, whereas four species were detected on pigeons. Parakeets were rarely infested by pigeon parasites (prevalence = 0.66%), whereas parakeet mites were recorded more often on pigeons (prevalence = 10.00%). The number of total parasites per bird increased with increasing densities of monk parakeets, both for pigeons and for parakeets. Therefore, overcrowding of birds due to the increasing population of monk parakeets in Barcelona may affect the health status of native pigeons, suggesting a potential role for parasite mediated competition by introduced parakeets. Furthermore, spill-over of alien mites (Ornithonyssus bursa) by monk parakeets to rock pigeons should be monitoring as it may affect human health.

Social conformity affects experimental measurement of boldness in male but not female monk parakeets (Myiopsitta monachus)

AbstractThe standard approach for characterizing boldness rarely considers the influence of social environment on the expression of boldness in group-living animals. We studied a wild-caught, captive population of monk parakeets (Myiopsitta monachus) to investigate the impact of conspecific presence on boldness — a personality trait in monk parakeets — in a controlled environment. We quantified seven boldness metrics across three types of behavioural assay: novel object, emergence, and predator exposure tests in the presence of a companion pair of flock mates. Because of the high degree of sociality in this species, we hypothesized that the presence of companion birds would facilitate the focal individuals’ behavioural responses (i.e., increase the average boldness level). We found that behavioural response in a risky foraging context was inversely correlated between solitary and social condition in males, but not in females. Our results have implications for characterizing sex-specific differences of risk-taking behaviour in social animals.

History of nonnative Monk Parakeets in Mexico.

Nonnative Monk Parakeets have been reported in increasing numbers across many cities in Mexico, and were formally classified as an invasive species in Mexico in late 2016. However, there has not been a large-scale attempt to determine how international pet trade and national and international governmental regulations have played a part in colonization, and when the species appeared in different areas. We describe the changes in regulations that led the international pet trade market to shift to Mexico, then used international trade data to determine how many parakeets were commercially imported each year and where those individuals originated. We also quantified the recent increases in Monk Parakeet (Myiopsitta monachus) sightings in Mexico in both the scientific literature and in citizen science reports. We describe the timeline of increased reports to understand the history of nonnative Monk Parakeets in Mexico. As in other areas where the species has colonized, the main mode of transport is through the international pet trade. Over half a million Monk Parakeets were commercially imported to Mexico during 2000–2015, with the majority of importation (90%) occurring in 2008–2014, and almost all (98%) were imported from Uruguay. The earliest record of a free-flying Monk Parakeet was observed during 1994–1995 in Mexico City, but sightings of the parakeets did not become geographically widespread in either the scientific literature or citizen science databases until 2012–2015. By 2015, parakeets had been reported in 97 cities in Mexico. Mexico City has consistently seen steep increases in reporting since this species was first reported in Mexico. Here we find that both national and international legal regulations and health concerns drove a rise and fall in Monk Parakeet pet trade importations, shortly followed by widespread sightings of feral parakeets across Mexico. Further monitoring of introduced Monk Parakeet populations in Mexico is needed to understand the establishment, growth and spread of introduced populations.