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Location of the four Regions in Canberra, South East Australia. doi:10.1371/journal.pone.0040622.g001
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There is widespread concern over the impact of introduced species on biodiversity, but the magnitude of these impacts can be variable. Understanding the impact of an introduced species is essential for effective management. However, empirical evidence of the impact of an introduced species can be difficult to obtain, especially when the impact is t...
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Context 1
... determined the abundance of 20 bird species in Canberra over 29 years using data from the COG GBS, comprising seven cavity-nesting (Table 1), eight small species (,25 cm head to tail) ( Table 2) and five large species (.30 cm head to tail)( Table 3). We used ArcGIS 10H [44] to define four geographic regions in Canberra (Figure 1). This enabled grouping of survey sites to ensure continuity of survey effort over each region and year. ...
Context 2
... random model was set to region and time and we used autoregressive models of order one (AR1) and two (AR2), and Wald tests for dropping individual terms from the full fixed model. We sequentially removed the least significant explanatory variable from the model, continuing this process until only significant (,0.05) explanatory variables remained (with the exception of the variables year and years after Common Myna establishment, which were included in all models) (Table 1, 2, 3). We used a table of effects to predict the impact of each significant variable (6SE). ...
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We surveyed the common birds on eight human inhabited islands of the Andaman Island group, and identified 15 species as the most common bird species on the basis of abundance and extent of distribution. Of these, the introduced species – House Sparrow Passer domesticus (19.8% abundance) and Common Myna Acridotheres tristis (9.8% abundance) – were t...
Global anthropogenic changes are occurring at an unprecedented rate; one change, human-facilitated introduction of species outside their native range, has had significant ecological and economic impacts. Surprisingly, what traits facilitate range expansions post-introduction is relatively unknown. This information could help predict future expansio...
Citations
... The negative impact of the Myna on birds include aggressive behaviour at nesting sites, competition for food, or destroying or taking over nests. Its impacts has been recorded on various bird species in other countries, some of which breed in Syria, such as Jackdaw (Corvus monedula) (Handal & Qumsiyeh, 2021), Black-backed Gull (Larus marinus) (Counsilman, 1974), Common Blackbird (Turdus merula) (Grarock et al., 2012), Eurasian Hoopoe (Upupa epops), Syrian Woodpecker (Dendrocopos syriacus), and Rock Dove (Columba livia) (Abd Rabou, 2022). Additionally, it may affect reptiles by devouring the eggs of the Lebanon Lizard (Phoenicolacerta laevis) (Handal & Qumsiyeh, 2021). ...
The widespread occurrence of Common Myna Acridotheres tristis in neighboring countries has led to its introduction and spread to all urban areas in the western part of Syria. The first colony was established in Tartous on the Mediterranean coast in 2016. This study provides the first record and data on the distribution of the Myna in Syria, indicating that further work is needed to study its possible negative effects observed in other countries where the species is not native.
... As elevation increases, there is a general trend of decreasing temperature and increasing precipitation. This altitudinal gradient creates diverse microclimate conditions, which can vary significantly over relatively short distances [18]. Also, the characteristics of the soil and land cover in a given area are important factors that can influence the distribution and habitat suitability for various species [19]. ...
The common myna bird (Acridotheres tristis Linnaeus, 1766) is widely recognized as one of the most formidable invasive avian species globally. The bird poses significant challenges due to its ability to outcompete a variety of native cavity-nesting birds. Additionally, the common myna is a notable agricultural pest and a substantial threat to indigenous biodiversity. The current study is focused on understanding the distribution pattern of the common myna (Acridotheres tristis Linnaeus, 1766) in Egypt and the significant favorable conditions to predict the invasion scale of the bird to the Egyptian fauna. To determine the environmental variables influencing the invasion range of the common myna in Egypt, a Species Distribution Model (SDM) was employed. The current work documented 117 invasion sites of the species from February to December 2023. The predicted habitats are mainly concentrated close to the Nile Delta of Egypt, the Suez Canal region, North and South Sinai, in addition to scattered areas on the Red Sea coast, along the riverbanks of Upper Egypt, in addition to a few northwestern areas of the Western Desert. The most significant environmental factors affecting the establishment were the Minimum Temperature of the Coldest Month, the Mean Temperature of the Coldest Quarter, and Elevation. The current invaded areas comprise about 0.8% of Egypt (8240 km2 out of roughly one million km2). We found that this is significant and of concern due to the expectation of increasingly favourable conditions due to global warming; this will turn this invasive species into a real threat to Egyptian ecosystems due to its aggressive competition with native cavity-nesting birds, its impact as an agricultural pest, and its potential to disrupt local biodiversity.
... The common myna's ecological impacts are particularly pronounced in island ecosystems (Hughes et al. 2017;Feare et al. 2022) and have also been studied within Australia, New Zealand, and South Africa, where their widespread geographic coverage has elicited research interest into their invasion history and impacts (Peacock et al. 2007;Ewart et al. 2019;Beesley et al. 2023). The common myna has been the focus of ecological and conservation research owing to their aggressive territorial behaviour that may exclude native avians from nesting structures and foraging areas (Tindall et al. 2007;Grarock et al. 2012;Rogers et al. 2020), though evidence for this is mixed in some environments (Lowe et al. 2011). In addition to this, there are also concerns about this species regarding nesting nuisance and crop interference, all of which has led them to be categorised as an agricultural pest in most of their introduced ranges (Tracey & Saunders 2003;Koopman & Pitt 2007). ...
In an era of global climate change and massive environmental disturbance, biodiversity conservation is receiving increased attention. Conservation efforts are being greatly aided by genetic tools and approaches, which seek to understand patterns of genetic diversity and how they impact species health and ability to persist under future climate regimes. Invasive species offer vital model systems in which to investigate questions around adaptive potential, with a particular focus on how changes in genetic diversity and effective population size interact with the novel selection regime of the invaded range to drive rapid evolution. The common myna (Acridotheres tristis) is a globally invasive passerine, which has undergone multiple concurrent and sequential bottlenecks across its globally invasive range, and yet has established itself across a diverse array of ecological conditions. It is therefore an excellent model species for research both into the persistence of low-diversity populations and the mechanics of biological invasion. To underpin research on the invasion genetics of this species, we present the genome assembly of the common myna, assembled using a backbone of Oxford Nanopore Technologies long reads, alongside an RNA-seq based transcriptome and genome annotation. To provide genomic context for future studies, we describe the genomic landscape of this species, including genome wide allelic diversity, methylation, repeats, and recombination rate, as well as an examination of gene family expansions and contractions. Finally, we use demographic analysis to identify that some native regions underwent a dramatic population increase between the two most recent periods of glaciation, but also reveal artefactual impacts of genetic bottlenecks on demographic analysis.
... Despite common mynas being listed as being one of the world's worst invasive species, empirical evidence of their negative impacts on native species is lacking (Lowe et al., 2001). Previous studies have shown that the establishment of common mynas is associated with a decline in the abundance of native bird species (Grarock et al., 2012;Colléony and Shwartz, 2020), with competition (for food and nest cavities) and nest interference/predation being the assumed proximate causes (Blanvillain et al., 2003;Grarock et al., 2012). While numerous common myna-predation events (of native bird species) are documented, these normally concern egg and/or chick predation . ...
... Despite common mynas being listed as being one of the world's worst invasive species, empirical evidence of their negative impacts on native species is lacking (Lowe et al., 2001). Previous studies have shown that the establishment of common mynas is associated with a decline in the abundance of native bird species (Grarock et al., 2012;Colléony and Shwartz, 2020), with competition (for food and nest cavities) and nest interference/predation being the assumed proximate causes (Blanvillain et al., 2003;Grarock et al., 2012). While numerous common myna-predation events (of native bird species) are documented, these normally concern egg and/or chick predation . ...
... Additionally, nest boxes such as those in this study likely facilitate native nest predators and the invasive common myna, species that are likely to be successful in urban areas even without the addition of nest boxes. The low occupancy by native birds and high variability in nest box use in our study and other work [18,32,33] highlight the complexity and significant gaps that remain when supplementing the loss of natural tree hollows in urban environments. ...
... Additionally, competitive interactions between common myna and native birds outside the nest boxes [12] and non-direct impacts [27] could occur, making the nest boxes less appealing for native birds. However, a commonly cited impact of the common myna, filling nest boxes with nesting material [33,40], did not deter other native parrot or rosella species from subsequently nesting in those boxes. In addition, many native species, such as the white-throated treecreeper observed in this study, fill nest cavities with material, so other native species may be adapted to cope with such behaviour. ...
... In N.S.W., crimson rosella nesting attempts declined as common myna nesting attempts increased over the season (Figure 2), but more data are needed to test whether this is significant. While spatial segregation in myna and native species nest sites has been observed [11,33,41], temporal shifts in breeding may also allow species to reduce or avoid competition with common mynas. Future work on competition should explore how boxes that exclude mynas influence the timing of breeding by native species. ...
Simple Summary
We aimed to investigate how an invasive cavity-breeding bird, the common (Indian) myna, and a native nest predator, the common brushtail possum, influence urban nest box use by native birds in Queensland and New South Wales, Australia. We quantified nest box use by invasive and native species, assessed nesting success and failure rates, and explored what environmental factors might influence nest box occupancy and nesting success. We found that the native possums were the most common nest box users and that possum occupancy of boxes was associated with higher rates of nesting failures by all bird species. More common myna nesting attempts were observed in areas where mynas have been established longer. We found no evidence of a significant negative impact by the common myna on other birds in our study locations, which may be partly due to the low rates of use of our nest boxes by native birds. Nevertheless, better nest box design and guidelines for setting them up are needed if we aim to provide more nesting opportunities for native birds to replace the decline in big old cavity trees.
Abstract
Many bird species in Australia require tree hollows for breeding. However, assessing the benefits of urban nest boxes to native birds requires frequent monitoring that allows to assess nesting success. To better understand the benefits of nest boxes for native birds, we examined the impact of local habitat characteristics, invasive species (common myna, Acridotheres tristis), and native mammalian predators on urban nest box use and nesting success of native birds. We installed 216 nest boxes across nine locations in southeastern Australia (S.E. Queensland and northern New South Wales) in both long-invaded sites (invaded before 1970) and more recently invaded sites (after 1990). We monitored all boxes weekly over two breeding seasons. We recorded seven bird species and three mammal species using the nest boxes. Weekly box occupancy by all species averaged 8% of all boxes, with the species most frequently recorded in the nest boxes being the common brushtail possum (Trichosurus vulpecula), a native cavity user and nest predator. We recorded 137 nesting attempts in the boxes across all bird species. The most frequent nesting species were the invasive alien common mynas (72 nesting attempts). We recorded an average nesting failure rate of 53.3% for all bird species. We did not record any common mynas evicting other nesting birds, and found that several native species used the same box after the common myna completed its nesting. We recorded native possums in 92% of the boxes, and possum occupancy of boxes per site was negatively correlated with bird nesting success (p = 0.021). These results suggest that when boxes are accessible to invasive species and native predators, they are unlikely to significantly improve nesting opportunities for native birds. To ensure efficient use of limited conservation resources, nest boxes should be designed to target species of high conservation importance and limit other species of both predators and competitors.
... Despite mynas being listed as being one of the world's worst invasive species, empirical evidence of their negative impacts on native species is lacking (Lowe et al., 2001). Previous studies have shown that establishment of mynas is associated with a decline in the abundance of native bird species (Grarock et al., 2012;Colléony and Shwartz, 2020), with competition (for food and nest cavities) and nest interference/predation being the assumed proximate causes (Blanvillain et al., 2003;Grarock et al., 2012). While numerous myna-predation events (of native bird species) are documented, these normally concern egg and/or chick predation (Evans, 2021). ...
... Despite mynas being listed as being one of the world's worst invasive species, empirical evidence of their negative impacts on native species is lacking (Lowe et al., 2001). Previous studies have shown that establishment of mynas is associated with a decline in the abundance of native bird species (Grarock et al., 2012;Colléony and Shwartz, 2020), with competition (for food and nest cavities) and nest interference/predation being the assumed proximate causes (Blanvillain et al., 2003;Grarock et al., 2012). While numerous myna-predation events (of native bird species) are documented, these normally concern egg and/or chick predation (Evans, 2021). ...
Invasive predators are a major driver of extinctions and continue to threaten native populations worldwide. Island eradications of (mostly mammalian) invasive predators have facilitated the (re)establishment of numerous island-endemic populations. Other invasive taxa, such as some predatory birds, could pose a more persistent threat due to their ability to fly and actively re-invade even remote and isolated islands. However, the impact of invasive predatory birds has been largely overlooked. We report on a novel sex-specific impact of an invasive-nest predator, the common myna (Acridotheres tristis), on a reintroduced population of Seychelles warblers (Acrocephalus sechellensis); translocated from Cousin Island to Denis Island in 2004. Regular post-translocation monitoring revealed that female mortality was 20% higher than males, leading to a 60-70% male-biased population sex-ratio between 2005-2015. This was attributed to mynas inflicting severe injuries to incubating female warblers while attempting to prey upon eggs in their nests. These effects likely contributed to the slower-than-expected population growth observed (relative to previous translocations of Seychelles warblers to other islands) over the same period. An eradication programme beginning in 2011 removed all mynas from Denis by 2015. Subsequently, we observed a balancing of sex-specific survival and the population sex-ratio of Seychelles warblers and, consequently, accelerated population growth. This study demonstrates the importance of assessing the threat posed by all invasive taxa (not just mammals) to island conservation. Furthermore, we show how extended monitoring is needed to identify problems, and develop solutions, post-translocation.
... Ring-necked Parakeets have increased dramatically; the Myna at 250% and the two Psittacids by a whopping 843% [21] . In fact, much work has been done to assess the negative impacts of Indian Myna on native wildlife species in several countries across the world [15,16,20,49,[50][51][52][53][54][55][56][57][58][59][60][61] . For this reason and many others, the Indian Myna was declared by the IUCN Species Survival Commission in 2000 to be one of the most invasive species on the planet and one of only three birds to make it into the 100 species that most threaten biodiversity [62] . ...
... Similarly, Hughes et al. [57] found Common Mynas to be a major predator of the eggs of Sooty Tern (Onychoprion fuscatus) on Ascension Island in the South Atlantic. Grarock et al. [53] found a negative relationship between the establishment of the Common Myna and the long-term abundance of three cavity-nesting species and eight small species of Australian birds. In a seemingly contrary study, Lowe et al. [65] revealed that Indian Mynas have little competitive effect on resource use by native bird species in the urban matrix of Sydney, Australia. ...
Abstract
The coastal Gaza Strip, which has an area of 365 km2; equivalent to about 1.5% of the area of Palestine (27,000 km2), is home to a relatively large diversity of bird species, including the invasive Indian Myna (Acridotheres tristis Linnaeus, 1766). The present study aims to address the occurrence, risks and some other ecological aspects of the Indian Myna in the Gaza Strip. This 10-year descriptive and cumulative study from 2013 to 2022 was based on field visits, direct observations, frequent meetings and discussions with stakeholders, follow-up of news and social media, as well as photography for documentary and confirmatory purposes. The results of the current study showed that the emergence of Indian Myna in the Gaza Strip began in 2006, and after 2008, its numbers increased remarkably and significantly. The bird arose in Palestine as a result of cage escapees from zoos or deliberate releases. Indian Mynas are usually abundant throughout the year in urban areas and the outskirts of the Gaza Strip, where feeding sites are available. The main habitats of Indian Minas include urban parks, gardens, agricultural orchards, and other similar environments. Potential local risks of the Indian Myna included its threats to local biodiversity, damage to domestic life and agricultural crops, as well as potential disturbance, noise and disease transmission to Gazans. Nets and sticks coated with glue were the main methods used by Gazans to capture Indian Mynas. The Indian Myna is locally sold at cheap prices of 2-3 USD per pair. A few Gazans claimed to eat the bird. It appears that the Indian Myna poses little threat in the Gaza Strip, and therefore there are no clear methods adopted by the responsible authorities to control the bird. Finally, the study recommends appropriate management strategies to stop or reduce the spread of non-native biota in the Gaza Strip when their numbers increase alarmingly and their risks increase to an intolerable extent.
Keywords: Indian Myna, Acridotheres tristis, occurrence, trapping, risks, invasive species, biodiversity, and Gaza Strip
... This corroborates what farmers and bird hunters in the Gaza Strip have said about Eurasian Hoopoe and other native birds being affected by Rose-ringed Parakeets [7,72,73]. Similar to Rose-ringed Parakeets, invasive Indian or Common Mynas (Acridotheres tristis) were reported to have a negative effect on the abundance of several cavity-nesters in Australia and Israel [38,74]. Mori et al. [75] suggested a possible competition between Rose-ringed Parakeets and Scops Owls (Otus scops) for suitable tree cavities. ...
The invasive Rose-ringed Parakeet (Psittacula kramer Scopoli, 1769) has become an integral part of the Palestine environment and ecology. Large numbers of the species are now being caught and sold at markets and shops selling pets in the Gaza Strip because of its attractive colors and ability to learn and imitate speech. Several dangers have been attributed to this bird in the local environment. As the first locally, the current modest study aims to focus on the trapping and potential risks of the Rose-ringed Parakeet in the Gaza Strip. The study, which lasted one year extended from September 2021 to August 2022, was based on field visits and direct observations, frequent meetings and discussions with stakeholders, follow-up of news and social media sites in addition to photography. The results showed that most of the bird hunters take bird trapping as a “profession” due to poverty, unemployment, scarcity of job opportunities and deteriorating economic conditions in light of the siege imposed by Israel on the Gaza Strip since
2005. Trapping of Rose-ringed Parakeets, which occur annually from early April to October, is concentrated near the eastern and northern borders of the Gaza Strip due to their unique ecological characteristics and proximity to the Gaza Envelope (a complex of
Israeli settlements, located 7 km from the north and eastern borders of the Gaza Strip) which, with its orchards, farms and forest trees, constitutes fertile land for birds and the parakeet in question. Many Gazans have been killed, injured or arrested by the Israeli
army for hunting birds near the border. Netting and glue-coated sticks associated with the use of parakeets of the same species or sound recordings are the two most important methods used locally for trapping the Rose-ringed Parakeet. The price of one pair of trapped parakeets ranges between 12 and 18 USD. Rose-ringed Parakeets pose many potential dangers locally because of their feeding on agricultural crops, especially fruits, their competition with some local wild birds, especially cavity-nesting ones, and their
potential to cause health and noise risks to humans.
... In Australia, common mynas entered aggressive encounters during nesting site selection with alien starlings and two native parrot species, and demonstrated the potential to threaten the parrot population (Pell and Tidemann 1997). Grarock et al. (2012) reported a negative relationship between population trends of several native species and common myna establishment in Canberra. ...
... comm.). Through their agressive behaviour and medium body size (average 23 cm in length) common mynas have the potential to compete with native bird populations on a local scale; birds using tree cavities for nesting that are smaller than common myna can be considered most vulnerable based on experience from Australia (Grarock et al. 2012). Common mynas also could become a nuisance to tourists through their noise and behaviour, such as stealing food from tables. ...
... Up to now, only a little over 20% of the birds sighted were removed by the park rangers. While most of the studies describing the impact of common mynas come from urban environment, their presence has in some places led to population declines of native bird species in those areas, mainly through competition and predation on other birds' eggs (Evans 2021;Evans et al. 2016;Grarock et al. 2012). Therefore, a possibility of similar impact on a local scale in KNP cannot be excluded, although due to the park's large area, common mynas are probably not very likely to have an impact on total population sizes of native bird species. ...
Common myna (Acridotheres tristis) is a passerine bird native to south-east Asia, established as an alien in many parts of the world including South Africa, where it is invasive. Common mynas are synanthropic birds with a strong preference for urban areas that usually do not expand into natural areas. However, as we document here, since the first records in Kruger National Park in 2000 when the birds started to spread from outside the park, the rate of spread has recently dramatically increased, with last three years accounting for 66% of the total number of 128 sightings. Thirty-two birds were observed to be nesting or breeding. This data suggests that the common myna in Kruger National Park is in the initial phase of establishment. Although the impacts on native birds at a population level are unlikely to be severe in a large natural savanna area with little human influence, the species is scored as having moderate impact in the EICAT IUCN scheme. Thus, we suggest that the population of common myna needs to be monitored and controlled to prevent it from further increase and spread.
... Both native and introduced species are represented among this class of highly synanthropic birds (Garden et al., 2006;Jones and Wieneke, 2000;Tait et al., 2005). Some of these species have had direct negative effects on the presence of other native species (e.g., the invasive common myna (Acridotheres tristis) (Grarock et al., 2012), the native noisy miner (Manorina melanocephala) (Maron et al., 2013;Parsons et al., 2006;Piper and Catterall, 2003) and native pied currawong (Strepera graculina) (Bayly and Blumstein, 2001;Major et al., 1996;Parsons et al., 2006). ...
Urban environments are increasingly acknowledged as a priority for biodiversity conservation. Birds in particular are capable of persisting, and sometimes thriving, in cities and towns globally. However, the process of urbanization results in the loss of many bird species due to the resulting changes in habitat conditions. Urban expansion and densification present a threat to both urban bird biodiversity and bird conservation more broadly. Australian urban areas, including suburban and peri-urban areas, currently support moderate bird species richness, but the rapidly changing urban landscape threatens these communities. Unfortunately, many bird species' population trends are not actively studied, resulting in a poor understanding of species persistence in urban environments. Here, we used bird survey data from long-running citizen science databases in a Bayesian List Length Analysis to determine changes in bird species prevalence (the probability of observing a species in a given survey event) over time in Australia's four most populous urban regions. We found that introduced species, historically prominent in Australian urban bird communities, are decreasing in prevalence in all four regions, while a small group of native urban exploiters are becoming more prevalent. Our results also show that many species perceived to be “iconic” or “common” are experiencing declines in prevalence in urban areas, highlighting the importance of monitoring and conservation action in urban areas.