Myiopsitta Monachus Research Articles

Effects of a 0.3% cholesterol diet and a 20% fat diet on plasma lipids and lipoproteins in Quaker parrots (Myiopsitta monachus).

Lipid disorders are common in captive psittacine birds, but associated changes in blood lipids and lipoproteins have not been well characterized. The Quaker parrot is prone to dyslipidemia and has been extensively used as an experimental model. We aimed to study the effects of a 0.3% cholesterol diet and a 20% fat diet on plasma lipids and lipoproteins in Quaker parrots. Two crossover studies were performed with each diet. During each study, 12 parrots were divided into two groups fed the treatment or control diet for 2weeks. After a 2-month wash-out period, the groups were reversed. At the end of each period, plasma lipidomics and lipoprotein profiling were performed. Data were analyzed by univariate tests adjusted for false discovery rates, volcano plots, and enrichment analyses. The cholesterol diet induced changes in many plasma lipids and lipoproteins. Total cholesterol and cholesteryl esters were significantly and markedly elevated. Ceramides were the second subclass of lipids that were elevated. Several glycerophosphocholines, sphingomyelins, and one diacylglycerol were also significantly elevated, albeit to a lesser magnitude. All lipoproteins were elevated, with the greatest increase seen in non-HDL. The fat diet mainly resulted in a decrease in plasma glycerolipids and an increase in acylcarnitines. Lipoprotein plasma levels remained unchanged. Quaker parrots fed a 0.3% cholesterol diet showed profound and complex dyslipidemic changes that could be used to further study lipid disorders and their management in psittacine birds. A 20% fat diet higher in n-6 polyunsaturated fatty acids did not lead to dyslipidemia.

Skin microbiota of quaker parrots (Myiopsitta monachus) with normal feathering or feather loss via next-generation sequencing technology

BackgroundFeather damaging behavior (feather picking) is a common malady of captive parrots. Diagnosis is challenging as a primary disadvantage to clinicians faced with diagnosis of parrot skin disease remains the lack of normative data for the healthy parrot epidermal microbiology. The objective of this pilot study was to establish bacterial and fungal cutaneous microbiota baselines for quaker parrots with and without feather loss. MethodsHealthy quaker parrots (Myiopsitta monachus n = 12) with intact feathers were compared to 12 quaker parrots with evidence of feather loss via next-generation DNA sequencing of bacteria and fungus swabbed from skin. ResultsOf 351 bacterial and 97 fungal species identified, no statistical differences occurred in bacteria or fungal alpha-diversity or beta-diversity based on age, sex, or feather loss. However, enclosure affected bacterial beta-diversity. The most abundant bacterial species for fully feathered quaker parrots were Exiguobacterium indicum, Sphingomonas yabuuchiae, and Corynebacterium spp.,. Fragaria/Populus euphratica, S. yabuuchiae, and E. indicum for quaker parrots with feather loss. Lactobacillales, Acinetobacter, Kocuria sp., and Streptococcus epidermidis were significantly enriched in fully feathered quaker parrots, while Streptococcaceae, Methylobacterium, Clostridiales, Nocardioidaceae, Nesterenkonia, and Actinomycetospora were significantly enriched in quaker parrots with feather loss. Both groups had Cladosporium halotolerans/sphaerospermum as the predominant fungus, while Capnodiales was significantly enriched in quaker parrots with feather loss. Conclusions and clinical relevanceUse of next generation microbial sequencing as a preliminary diagnostic tool of bacterial and fungal communities of captive birds allows veterinarians to confirm cytologic diagnoses and circumvent the limitations of culture testing. Diagnostic implications include the potential transmission of pathogenic bacteria and/or fungi and pathogen resistance between cohoused birds.

Foraging diet of the two commonest non-native parakeets (Aves, Psittaciformes) in Italy: assessing their impact on ornamental and commercial plants

Alhough the role as pest of the two most common invasive parakeets (rose-ringed parakeet, Psittacula krameri and monk parakeet, Myiopsitta monachus) has been largely recognized, nevertheless analytical data on foraging diet on cultivated plants are still scanty in non-native countries. Here, we carried out a revision about the impact of these birds on ornamental and commercial plants in Italy, both for urban and rural sites. Reviewing scientific papers, grey literature and personal observations, we obtained two species-specific checklists of edible plants. In this regard, we focused on plants of commercial interest in rural areas, implying a possible economic impact. We obtained evidences for 81 plant taxa belonging to 34 families (Rosaceae: the highest impacted). Almost all the evidences were related to ornamental species in urban parks and only a limited number of records refer to cultivated plants located in rural sites. Rose-ringed parakeet showed a significant higher percentage of foraged species when compared to monk parakeet. Nevertheless, when considering the plants of commercial interest in rural sites, monk parakeet showed a significantly higher number of records. Thanks to large distribution and easy detectability of these species, we obtained a large number of ‘grey’ data (local papers, unpublished reports and personal observations) that, although with a lower reliability, defined a first arrangement at large (national) scale. Future systematic field studies and citizen science actions will be necessary to obtain further quantitative data to support management and control strategies focused on these invasive birds.

Rescue data as an alternative for assessing trends and phenological changes in two invasive parakeet species

Monitoring population trends of alien species is pivotal to design effective management plans to preserve native biodiversity, particularly urban areas, where most populations of alien birds are established. Urban wildlife rescue centers, with personnel trained to record species, age and sex of each individual brought by the public, may represent a reliable citizen-science based method to estimate both local changes in alien species phenology and population trends. In this work, we analysed records of monk and ring-necked parakeets by comparing rescue records in the urban area of Rome from the last 15 years. We also tested whether breeding phenology of alien parakeets showed any changes since the start of the invasion processes.We recorded a strong correlation between the number of rescued parakeets and their population trends, thus confirming the importance of wildlife rescue centers in monitoring populations of alien species in urban areas. We also observed a shift in the breeding phenology of these parakeet species. The hatching peak for ring-necked parakeet occurred in early spring, in line with previous studies on the reproduction of this species, but with a slight increase in the number of months with evidence of breeding in the last years. As to the monk parakeet, our findings support the expansion of its reproductive season between 2006 and 2020 in Rome, with chicks currently being observed for seven months a year. Therefore, data collected through wildlife rescue centers may help improving models of population growth of alien species established in urban areas.

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.

Apparent Lack of Circovirus Transmission from Invasive Parakeets to Native Birds.

The transmission of pathogens to native species has been highlighted as one of the most important impacts of biological invasions. In this study, we evaluated the presence of psittacine beak and feather disease virus (BFDV) and other circoviruses in native bird species cohabiting with invasive populations of wild rose-ringed (Psittacula krameri) and monk parakeets (Myiopsitta monachus) that were found positive for a particular BFDV genotype in Sevilla, southern Spain. None of the 290 individuals from the 18 native bird species captured showed typical signs of disease caused by BFDV. A sample of 79 individuals from 15 native species showed negative results for the presence of the BFDV genotype previously detected in the sympatric invasive parakeets, as well as any other of the circoviruses tested. Although preliminary, this study suggests a lack of circovirus transmission from invasive parakeets to native birds at the study site. Further research is needed to determine if this apparent absence in transmission depends on the BFDV genotype present in the parakeets, which requires additional screening in other invasive and native populations living in sympatry.

Long distance dispersal of monk parakeets

Invasive species threaten biodiversity all around the world and for this reason, identifying the causes and mitigating their effects is a priority in conservation biology. One of the most important factors when dealing with invasive species is dispersal, because the distribution of dispersal distances among members of a population can greatly affect the rate of spread of these invasive populations. Long distance dispersal events have a disproportionately large influence on dispersal kernel estimations, but because of restricted spatial sampling scales they are difficult to detect. Here we use an extensive database of 3,114 monk parakeets ringed in Barcelona city since 2002 as part of an extensive control program across Catalonia where 3,460 birds have been captured since 2013. Our aim was to describe these long–distance movements of monk parakeets. We recorded dispersal distances of over 10 km for a total of eight individuals. Long–distance dispersions were in all directions and both males and females were involved. While some individuals moved in their first year, others delayed dispersal several years. Given that long–distance dispersal events can have a large influence on the rate of range expansion of invasive species this information can be of great utility when modeling the dispersal and spread of the species.

A PCR-Based Retrospective Study for Beak and Feather Disease Virus (BFDV) in Five Wild Populations of Parrots from Australia, Argentina and New Zealand

The beak and feather disease virus (family Circovirdae) is a virus of concern in the conservation of wild Psittaciformes globally. We conducted a PCR screening for the beak and feather disease virus (BFDV) using samples collected during previous field studies (1993–2014) in five populations of parrots of the Southern Hemisphere: Eclectus parrots (Eclectus roratus) and Crimson rosellas (Platycercus elegans) from Australia, Burrowing parrots (Cyanoliseus patagonus) and Monk parakeets from Argentina (Myiopsitta monachus), and Forbes’ parakeet from New Zealand (Cyanoramphus forbesi). A total of 612 samples were screened. BFDV was not detected in any of the sampled birds. Our results provide a retrospective screening, covering three different tribes of Old and New World parrots, including two of the most numerous species, and contributing a large set of negative results. Furthermore, our results suggest that geographical and temporal differences in BFDV distribution may exist and merit further research, as a critical component in the efforts to manage the disease and its epidemiological aspects. The results presented here hold the potential to provide a baseline for future studies investigating the temporal evolution and the spread of BFDV.

Recurrent chromosome reshuffling and the evolution of neo-sex chromosomes in parrots

The karyotype of most birds has remained considerably stable during more than 100 million years’ evolution, except for some groups, such as parrots. The evolutionary processes and underlying genetic mechanism of chromosomal rearrangements in parrots, however, are poorly understood. Here, using chromosome-level assemblies of four parrot genomes, we uncover frequent chromosome fusions and fissions, with most of them occurring independently among lineages. The increased activities of chromosomal rearrangements in parrots are likely associated with parrot-specific loss of two genes, ALC1 and PARP3, that have known functions in the repair of double-strand breaks and maintenance of genome stability. We further find that the fusion of the ZW sex chromosomes and chromosome 11 has created a pair of neo-sex chromosomes in the ancestor of parrots, and the chromosome 25 has been further added to the sex chromosomes in monk parakeet. Together, the combination of our genomic and cytogenetic analyses characterizes the complex evolutionary history of chromosomal rearrangements and sex chromosomes in parrots.

Abundance of White-fronted Parrots and diet of an urban parrot assemblage (Aves: Psittaciformes) in a green Neotropical city

Urban ecosystems are evolutionarily recent novel environments acting as biodiversity filters. Psittacidae birds are considered successful urban adapters mainly due to their generalist feeding and opportunistic behavior, allowing them to occupy environments from cold temperate to dry xeric areas. Therefore, it is important to understand how these species interact in the urban environment. We studied the interannual (2013–2016) abundance of the White-fronted Parrot (Amazona albifrons) in the Neotropical cities of Xalapa and Coatepec, in Central Veracruz, México. Additionally, we studied the feeding ecology during 13 months of 6 parrot species detected in the city of Xalapa. The abundance of the White-fronted Parrot was significantly higher in Xalapa than in Coatepec, and it was homogeneous across years. Non-native plants represented 30–41% of Psittacidae diets in Xalapa, where seeds were the most commonly consumed resource. We recorded the highest Psittacidae species richness and highest diet overlap among species by the end of the dry season (April–May). The White-fronted Parrot had the highest plant richness in its diet, followed by the Monk Parakeet (Myiopsitta monachus) and the Green Parakeet (Psittacara holochlorus); yet, the White-fronted Parrot had a specialized diet dominated by two plant species (Grevillea robusta and Ficus aurea). The diet overlap among the three above-mentioned parrot species was not significantly different to a null model, where the White-fronted Parrot and the Monk Parakeet overlapped during the months of February, April, June, and September. The White-fronted Parrot is an urban adapter that has successfully expanded its geographic range via natural means and by human activities. The invasive Monk Parakeet is currently restricted to one park in Xalapa, and it has remained in that stage for many years (i.e., pre-expansion phase). Exotic plant species in Xalapa represent ∼55% of the woody vegetation, some of which have longer flowering and fruiting periods that may have aided the successful establishment of parrot species in urban environments.

The monk parakeet (Myiopsitta monachus) as a potential pest for agriculture in the Mediterranean basin

The monk parakeet (Myiopsitta monachus) has been introduced in the last decades to many cities in many parts of the world. For most of this time it has been restricted primarily to urban areas, but it is starting to spread to rural habitats. In its native range, the monk parakeet is considered a pest for agriculture, consuming a wide variety of crops such as grains, fruits, and vegetables. However, there is very little information about its potential role as a pest for agriculture in the areas where it is exotic. Here we conducted an experimental survey of the impact of the monk parakeet on corn in SE Spain using camera traps. The monk parakeet was the animal that produced the highest damage, being responsible for 98.6% of the time employed by all animals consuming corn. The percentage of cobs damaged ranged from 36.8 to 100% depending on the cultivar, whereas the crop loss (measured as the length of the cob consumed with respect to the total length of the cob) ranged from 17.7 to 71.1%. The results suggest that the monk parakeet may be a serious pest for agriculture in the Mediterranean basin if their populations continue growing.

Sex and Age Effects on Monk Parakeet Home-Range Variation in the Urban Habitat

Home-range size is a key aspect of space-use, and variation in home-range size and structure may have profound consequences for the potential impact of damage and control strategies for invasive species. However, knowledge on home-range structure of naturalized parrot species is very limited. The aim of this study was to quantify patterns of home-range variation according to sex and age of the monk parakeet Myiopsitta monachus, an invasive parakeet in Europe. Mean kernel home-range size was 12.4 ± 1.22 ha (range 1.7–74.1 ha; N = 73 birds). Juveniles had a larger home-range size than adults, but sexes did not differ in kernel home-range size. The mean maximum distance moved by monk parakeets was 727 ± 37.0 m (range: 150–1581 m), and it was not dependent on either the sex or age of the birds. Having a small home range is one of the conditions for the feasible eradication of an invasive species; hence, the small home range of urban monk parakeets that we report here is good news for pest managers. However, this small home-range size can limit the effectiveness of culling operations with traps or feeders with contraceptives or poison, and other alternatives, such as funnel nets or traps, should be used.

Dietary plasticity in an invasive species and implications for management: the case of the monk parakeet in a Mediterranean city

Behavioural flexibility may play a relevant role during invasion of a new habitat. A typical example of behavioural flexibility favouring invasion success refers to changes in foraging behaviour. Here we provide data on changes in the foraging strategies of monk parakeets Myiopsitta monachus over a period of 17 years (2001–2017) in Barcelona city. During this time, consumption of food on the ground increased by more than 25 % and the consumption of anthropogenic food increased by 8 %. Detailed information about the food consumed is provided. Feeding on the ground and consumption of low plants allow parakeets to reach not only anthropogenic food but also crops, thereby increasing the risk of crop damage as the invasion evolves. Early detection of damage to crops is crucial in order to prevent further harm, and makes the precautionary principle highly relevant.

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.

The diet of Monk Parakeet Myiopsitta monachus nestlings in an urban area: a study using stable isotopes

ABSTRACT Capsule: Previous observations in Barcelona and other cities showed that approximately 40% of the food ingested by adult Monk Parakeets Myiopsitta monachus is of anthropogenic origin. Here we show that this type of food source is also used for feeding nestlings. Aims: To quantify the proportion of anthropogenic food within the diet of nestling Monk Parakeets, a non-native species in Barcelona. Methods: We analysed stable isotopes of 13C and 15N in feathers of Monk Parakeet nestlings collected in the Barcelona city area. We also sampled potential food sources ingested by Monk Parakeets to reconstruct the nestling diet using Bayesian mixing models with MixSIAR. Results: Almost 30% of the nestlings’ diet was composed of anthropogenic food. Conclusions: Since food availability is a major factor regulating population growth, we propose educating the general public to reduce the food supply for the species and ultimately limit its population growth.

A fine-grained analysis of a Monk parakeet (Myiopsitta monachus) nest suggests a nonhomogeneous internal structure

We report first data on the fine-grained structure (branch diameter, length and diversity) in three different sectors [core (central side), buffer (peripheral side), and nest chamber)] of a nest of Monk Parakeets (Myiopsitta monachus) from a non-native breeding site located in an urban park (Rome, central Italy). The central core sector was characterized by longer and thicker branches capable of supporting the nest. The peripheral part (buffer) was characterized by less long and less thick branches with the function of completing the structure. Branches building the nest chamber were shorter and less thick but very diversified in size, because they included both small branches supplied inside the chamber and longer branches covering it. This diversification of the internal chamber (nest chamber) could be functional to maintain stable temperatures of incubator chambers compared to large fluctuations outside the nest. The presence of leaves of herbaceous species (Hordeum leporinum) could play a bactericidal role for the nest plant material.

The Number and Distribution of Introduced and Naturalized Parrots

Parrots have been transported and traded by humans for at least the last 2000 years and this trade continues unabated today. This transport of species has involved the majority of recognized parrot species (300+ of 382 species). Inevitably, some alien species either escape captivity or are released and may establish breeding populations in the novel area. With respect to parrots, established but alien populations are becoming common in many parts of the world. In this review, we attempt to estimate the total number of parrot species introduced into the wild in non-native areas and assess how many of these have self-sustaining breeding populations. Based the public databases GAVIA, eBird, and iNaturalist, 166 species of Psittaciformes have been introduced (seen in the wild) into 120 countries or territories outside of the native range. Of these, 60 species are naturalized, and an additional 11 species are breeding in at least one country outside of their native range (86 countries or territories total). The Rose-ringed Parakeet (Psittacula krameri) and Monk Parakeet (Myiopsitta monachus) are the most widely distributed and successful of the introduced parrots, being naturalized in 47 and 26 countries or territories, respectively. Far and away, the United States and its territories support the greatest number of naturalized parrots, with 28 different species found in either the continental US, or Hawaii or Puerto Rico. Naturalized species as well as urbanized native species of parrots are likely to continue increasing in numbers and geographical range, and detailed studies are needed to both confirm species richness in each area as well mitigate potential ecological impacts and conflicts with humans.

Potential distributions of invasive vertebrates in the Iberian Peninsula under projected changes in climate extreme events

AbstractAimInvasive alien species (IAS) can cause profound impacts on ecosystem function and diversity, human health, well‐being and livelihoods. Climate change is an important driver of biological invasions, so it is critical to develop models and climate‐driven scenarios of IAS range shifts to establish preventive measures. In this study, we analyse how projected changes in the frequency and magnitude of climate extreme events could affect the spread of the six most widely distributed invasive vertebrate species in the Iberian Peninsula.LocationIberian Peninsula.TaxaRed avadavat (Amandava amandava), common waxbill (Estrilda astrild), monk parakeet (Myiopsitta monachus), rose‐ringed parakeet (Psittacula krameri), American mink (Neovison vison) and pond slider (Trachemys scripta).MethodsWe followed best‐practice standards for species distribution models (SDMs) regarding handling of the response and predictor variables, model building and evaluation using metrics that assess different facets of model performance. We used an ensemble approach with four modelling methods of varying complexity, including both regression‐based and tree‐based machine‐learning algorithms. We analysed five regional models for current (1971–2000) and future climate (2021–2050). We used principal components analysis to assess consensus among model outputs and positively weighed predictions from well‐performing models.ResultsSelected models showed high consensus and good predictive capacity on block cross‐validation areas. Generalized Linear Models and Generalized Additive Models scored highest in reliability (calibration), but Bayesian Additive Regression Trees provided the best balance between calibration and discrimination capacity. Forecasts include visible changes in environmental favourability, with losses generally outweighing the gains, but with some areas becoming more favourable for several species.Main conclusionsIncreased frequency and/or intensity of climate extreme events associated with ongoing climate change are projected to reduce overall invasion risk for the species examined although increases in favourability should be expected locally.

Individual vocal signatures show reduced complexity following invasion

The manner in which vocal learning is used for social recognition may be sensitive to the social environment. Biological invaders capable of vocal learning are useful for testing this possibility, as invasion alters population size. Some vocal learning species use frequency modulation patterns of acoustic signals for individual recognition. In such species, frequency modulation patterns should be more complex in larger social groups, reflecting greater selection for individual distinctiveness. We used numbers of nests and nest densities as proxies of local population sizes of native range monk parakeets, Myiopsitta monachus , in Uruguay and invasive range populations in the United States. Flock sizes were obtained to estimate maximum social group sizes per range. Supervised machine learning and frequency contours were employed to compare contact call structure between native and invasive range populations, and the effect of urban habitats on call structure was also assessed. Invasive range populations exhibited fewer nests, lower nest densities and smaller maximum flock sizes, which is consistent with a reduction in population size following invasion. Parakeets at invasive range sites also produced contact calls with simpler frequency modulation patterns. Beecher's statistic (HS) revealed reduced individual identity content and fewer possible unique individual signatures in invasive range calls. Simpler individual signatures are consistent with relaxed selection on the complexity of learned calls likely used for individual vocal recognition in the smaller local populations that we identified post-invasion. Frequency modulation patterns were simpler in urban habitats in both ranges, indicating that urban habitats could also alter the social environment and in turn influence the complexity of learned individual signatures. These findings contribute to a growing literature on the use of vocal learning for individual recognition and indicate that vocal learning can be used to produce individual vocal signatures in a manner sensitive to local population size. • Local population and social group size estimates were smaller in the invasive range. • Invasive range parakeets produced calls with simpler individual signatures. • Urban calls had simpler frequency modulation patterns in the native and invasive ranges. • Monk parakeets may use vocal learning for individual vocal recognition.

The Role of Monk Parakeets as Nest-Site Facilitators in Their Native and Invaded Areas.

Simple SummaryInvasive species can be harmful to native species, although this fact could be more complex when some natives eventually benefit from invaders. Faced with this paradox, we show how the invasive monk parakeet, the only parrot species that builds its nests with sticks, can host other species as tenants, increasing nest-site availability for native but also exotic species. This same pattern is observed in the native range of the species, and when parakeets occupy urban or rural habitats, although the richness of tenants was higher in invaded areas and rural habitats. Tenants participated in the cooperative defense against predators, benefiting parakeets with their presence. As tenants can be both native and invasive species, management plans should consider the complex network of interactions developed with the invader.While most of the knowledge on invasive species focuses on their impacts, little is known about their potential positive effects on other species. Invasive ecosystem engineers can disrupt recipient environments; however, they may also facilitate access to novel resources for native species. The monk parakeet (Myiopsitta monachus) is a worldwide invader and the only parrot that builds its own communal nests, which can be used by other species. However, the ecological effects of these interspecific interactions are barely known. We compared the role of the monk parakeet as a nest-site facilitator in different rural and urban areas, both invaded and native, across three continents and eight breeding seasons. A total of 2690 nests from 42 tenant species, mostly cavity-nesting birds, were recorded in 26% of 2595 monk parakeet nests. Rural and invaded areas showed the highest abundance and richness of tenant species. Multispecies communal nests triggered interspecific aggression between the monk parakeet host and its tenants, but also a cooperative defense against predators. Despite the positive effects for native species, monk parakeets also facilitate nesting opportunities to other non-native species and may also transmit diseases to tenants, highlighting the complexity of biotic interactions in biological invasions.