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Summary: Common Myna Acridotheres tristis is considered to be among the world's most damaging invasive species through disturbance, predation, competition pathogen introduction to native birds and other taxa. Claimed impacts on native birds have often been based on anecdotal reports. More substantive evidence of interference with small-island endemic birds has been reported, but impacts have rarely been quantified or subjected to experimental manipulation. On Denis Island (Seychelles), up to 10% of Seychelles Warblers Acrocephalus sechellensis, and small numbers of Seychelles Fodies Foudia sechellesis and Seychelles Paradise Flycatchers Terpsiphone corvina had head injuries following myna attacks, stimulating an eradication of the mynas. Populations of four species of Seychelles' endemic birds, introduced to the island to establish insurance populations, were estimated before, during and after the completion of the eradication, permitting assessment of the impact of myna removal on populations of the endemics. Numbers of all four endemics increased following introduction, but increases in the numbers of Seychelles Magpie Robins Copsychus sechellensis and Seychelles Paradise Flycatchers accelerated after >90% of the mynas had been removed. All endemic populations continued to increase during and after completion of the eradication in 2015, and injuries to Seychelles Warblers, Seychelles Fodies, and Seychelles Paradise Flycatchers ceased. Habitat management within a designated conservation zone on the island, into which the endemics were released and subsequently spread to occupy most of the island, also contributed to the endemic birds' global populations and to their improved conservation status. This study confirms that mynas negatively impact small island populations of endemic birds and suggests that their potential impact has been underestimated. Myna eradication should be considered vital before endangered endemic birds and other taxa susceptible to their negative impacts are translocated to small islands for conservation reasons. [ABSTRACT FROM AUTHOR]

Humans prey on animals with often dramatic effects on abundances, but also alterations to the phenotypical composition of prey populations. Instances of lethal management provide an opportunity to explore proximate mechanisms of phenotypical change. While there is evidence from exploitative predation (e.g. fisheries) that prey can change via evolutionary mechanisms, we present one of the first studies to explore this effect in an invasive vertebrate species that is being lethally controlled. Using an avian species that is known to be changing its behaviour in areas where it is heavily trapped, this study explored whether trapping of specific behavioural phenotypes might underpin observed changes. The behaviour of common mynas, Acridotheres tristis , captured using a large walk-in baited trap was compared with that of mynas captured using a cryptic whoosh net. All tests revealed significant inter-individual variation in ecologically meaningful aspects of myna temperament. Contrary to our predictions, however, we found no evidence that mynas captured in traps were more exploratory, more sociable, less fearful or better problem-solvers than those captured with the cryptic net. We present various interpretations of this finding, including the possibility learning might underpin behavioural changes in free-ranging mynas from heavily trapped populations, complemented by some selection against sociability and low fearfulness. As such, our findings and their interpretation will serve to guide future research on prey responses to human predation and inform animal management practices. • Animal populations change when predated upon by humans. • Invasive common mynas are known to change behaviour where they are trapped. • There was no evidence that trapping only captures more exploratory and social birds. • Trapping may not exert a selective evolutionary pressure on myna behaviour. [ABSTRACT FROM AUTHOR]

Endemic island species are of conservation interest as unique taxa, often with restricted populations, but many are data poor. The Mangaia kingfisher Todiramphus ruficollaris, known locally as the tanga'eo, is endemic to the island of Mangaia in the Cook Islands, and categorized as Vulnerable on the IUCN Red List. The population size has not been estimated since 1996, despite concerns over habitat loss and competition with an invasive species, the common myna Acridotheres tristis. We provide new population estimates for both the tanga'eo and the common myna, using the same methodology as previous estimates. During December 2018–February 2019 we surveyed with distance sampling along 73 line transects walked across the six habitat types on Mangaia. We estimate there are 4,106 tanga'eo on Mangaia (95% CI 3,191–5,283), a dramatic 7–8 fold increase compared to the previous estimate of 393–764. We estimate there are 13,350 common myna (95% CI 10,998–16,206), a slight increase, although densities in the two most favoured habitats for myna have declined. There is no evidence that the common myna poses a threat to the viability of the tanga'eo population, as the latter has increased despite a much larger population of common myna. Presumed declines in the tanga'eo population in the past were probably a result of habitat loss as a result of the cultivation of pineapples Ananas comosus for export, an industry that collapsed in the 1980s. We recommend a review of the IUCN Red List status of the tanga'eo. [ABSTRACT FROM AUTHOR]

The common myna is an invasive species in Florida, Hawaii, and in numerous other locations around the world. It is native to southern and south-east Asia. Common mynas are considered pests to fruit crops in many locales, and they are predators on eggs of other birds. Since their introduction to American Samoa in the 1980s, mynas have become the most frequently observed avifauna in developed areas in the country. The American Samoa Department of Marine and Wildlife Resources (DMWR) is concerned that expanding myna populations will exert competitive pressures on native species such as the Samoan starling and white-collared kingfisher. Additionally, the mynas are increasingly becoming social nuisances through nesting, foraging, and vocalization behaviors. The government and general population of American Samoa would like to eradicate these birds before populations are too large to control. In partnership with DMWR, we conducted trials with captive mynas to determine sensitivity to the avian toxicant DRC-1339, and to evaluate a potential baiting strategy for applying this toxicant on American Samoa to reduce myna populations.

Animals emit predator-elicited calls in response to potential predation threats. These vocalizations induce a variety of anti-predator behaviors in conspecific receivers ranging from moving away from predators (alarm calls) to rallying conspecifics to fend them off (mobbing calls). While much is known about the immediate response to alarm calls, less is known about how mobbing calls influence subsequent antipredator decisions. Mobbing calls stimulate harassment of a potential predator. Therefore we predicted that hearing a mobbing call would make animals less likely to immediately flee an approaching threat. To study the potential effect of mobbing vocalizations on risk assessment, we primed common mynas (Acridotheres tristis) with a series of different stimuli and studied the variation in their subsequent decisions to flee an approaching human by quantifying flight initiation distance (FID). We found that although mynas increased their rate of locomotion after hearing mobbing calls, their subsequent decision to flee was not influenced. We also found that an individual's propensity to move and look explained some variation in FID. This suggests that while mobbing calls do not influence subsequent decisions to flee, they do affect subsequent behavior. [ABSTRACT FROM AUTHOR]

Interaction networks among native and invasive species in a community can inform both invasion impacts and applied management of invasive species. The intensity of aggressive interactions may be related to the overlap in species' ecological niche and functional traits, especially in cavity‐breeding species, that often compete for limited nesting sites. Australia is home to over 100 native and introduced cavity‐nesting species, including several invasive species that are widespread globally, such as the common myna Acridotheres tristis. Here, we aimed to test the extent to which shared functional traits inform the intensity of aggression between cavity‐nesting birds.We quantified the outcomes of aggressive interactions between birds in large hollow‐bearing trees in SE Queensland, Australia. We examined whether more similarly sized birds interacted more frequently, whether larger species won aggressive interactions more often, and whether cavity‐breeding species with similar preferences for nesting sites (breeding‐niche space) interacted more frequently.We recorded a total of 410 aggressive interactions and 48 interacting bird species around tree hollows, including 20 cavity‐nesting bird species. These interactions were dominated by the invasive common myna, the native noisy miner (a non‐cavity‐breeder) and the native rainbow lorikeet Trichoglossus moluccanus, but the common myna won the largest total number of interspecific interactions. On average, larger birds won aggressive interactions more frequently, yet there were some important exceptions to this finding; the common myna (113 ± 30 g) won 26 of the 29 interactions against the larger native rainbow lorikeet (126 ± 44 g). Importantly, species with more similar nest‐site preferences were observed aggressively interacting more frequently.Synthesis and applications. The impact of the invasive common myna was higher‐site preferences. Control efforts for the myna should focus on birds that nest in natural tree hollows. An analysis of shared traits by managers could be used to help identify how many local species would benefit from common myna control in a given area and test if further behavioural studies of common myna are warranted. [ABSTRACT FROM AUTHOR]

Acridotheres tristis, or common myna or Indian myna is a bird species that can mimic human words and sounds around them. Local trainers used to teach the common myna in the State of Kelantan to mimic the words taught using several training procedures. This study aims to determine whether the training procedures used by local trainers have helped in the training process, and the factors that affect the mimicry process for this species are also highlighted. Interview sessions were conducted in nine districts in the State of Kelantan to collect data from local trainers from November 2021 until May 2022. This study utilised the Kruskal-Wallis test to analyse the significant difference in training time among different training procedures and different types of food and water for common myna. The results indicated that the training procedures used by local trainers have affected the training time of this species (p ≤ 0.05). The mean value of training time for other scrape techniques is the lowest, which is considered the best training method in training common myna to mimic the words. The second highest mean value is none scraping methods, followed by scraping tongue using Lalang, which has the highest mean value. In addition, the types of food and water given to common myna by the local trainers during the training procedure did not show a significant difference in training time. [ABSTRACT FROM AUTHOR]

A common myna (Acridotheres tristis) was presented to Veterinary Teaching Hospital, School of Veterinary Medicine, Tehran University after swallowing a needle. Radiography and physical examination revealed a metal foreign body within the body with its distal end in the ventriculus. Surgical removal by ventriculotomy under general anesthesia was attempted. Six months of follow up study revealed no complications.

BACKGROUND In Seychelles, the common myna has been shown to have a negative impact on endangered endemic birds on Denis Island, interfering with breeding attempts and attacking adult endemic birds at their nests. This stimulated an attempt to eradicate the island's mynas. RESULTS The eradication was undertaken in three phases, overall killing 1186 mynas and lasting 5 years. Decoy trapping was the most effective method for catching mynas, but the last birds were shot. Decoy trapping was compromised by catches of non-target species. Data collection from killed birds indicated that trapping did not favour either sex, and that most breeding occurred during the wetter season, November to March. CONCLUSIONS Eradication of mynas from small tropical islands is feasible. The Denis Island eradication was prolonged by difficulties in management and staffing. Using volunteers, the cost of the eradication was similar to that of eradicating rodents from the island. In future eradication attempts in Seychelles, possible food stress during the drier season (May to September) might facilitate trapping at this time. Habitat management, especially the removal of short mown grass, could enhance eradication progress. Continued monitoring is needed to confirm eradication and detect any immigration, and also to record responses in the endemic birds. © 2016 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The dynamic, multi-season occupancy model framework has become a popular tool for modeling open populations with occupancies that change over time through local colonizations and extinctions. However, few versions of the model relate these probabilities to the occupancies of neighboring sites or patches. We present a modeling framework that incorporates this information and is capable of describing a wide variety of spatiotemporal colonization and extinction processes. A key feature of the model is that it is based on a simple set of small-scale rules describing how the process evolves. The result is a dynamic process that can account for complicated large-scale features. In our model, a site is more likely to be colonized if more of its neighbors were previously occupied and if it provides more appealing environmental characteristics than its neighboring sites. Additionally, a site without occupied neighbors may also become colonized through the inclusion of a long-distance dispersal process. Although similar model specifications have been developed for epidemiological applications, ours formally accounts for detectability using the well-known occupancy modeling framework. After demonstrating the viability and potential of this new form of dynamic occupancy model in a simulation study, we use it to obtain inference for the ongoing Common Myna ( Acridotheres tristis) invasion in South Africa. Our results suggest that the Common Myna continues to enlarge its distribution and its spread via short distance movement, rather than long-distance dispersal. Overall, this new modeling framework provides a powerful tool for managers examining the drivers of colonization including short- vs. long-distance dispersal, habitat quality, and distance from source populations. [ABSTRACT FROM AUTHOR]

Foraging innovations are increasingly viewed as a key source of phenotypic plasticity and evolutionary change. Often thought to be associated with increased cognitive abilities, innovative foraging behaviour could potentially emerge as a simple consequence of being able to use a greater variety of motor actions in the foraging context. Here, we explored the role of motor diversity in the innovative problem-solving abilities of a highly successful ecological invader, the Indian myna, Sturnus tristis, using an extractive foraging task with multiple compartments. Consistent with findings from several other species, persistence predicted the latency to solve the first compartment. However, motor diversity was the strongest predictor of both solving latency of all further compartments and number of compartments solved. We suggest that motor diversity may facilitate innovation by increasing the ways in which objects can be handled, which in turn would allow for associative learning processes to enhance the expression of successful foraging behaviours. [Copyright &y& Elsevier]

We used a next generation sequencing (NGS) approach to screen for genome-wide nuclear microsatellite loci in the common (Indian) myna, Acridotheres tristis. In addition, markers previously developed for other Sturnidae species were tested for cross-amplification in A. tristis. In total, we identified 20 loci from NGS data and tested 26 loci for cross-amplification. Out of all loci (NGS developed and cross-amplified), 16 unlinked loci showed polymorphism, ranging from 2 to 9 alleles per locus. Test individuals were obtained from the invasive ranges of common myna in South Africa. Overall, expected and observed heterozygosities ranged from 0.089 to 0.802 and from 0.094 to 0.906, respectively. These markers will be used to shed light on invasion genetics and landscape-scale dynamics of invasive A. tristis in South Africa. [ABSTRACT FROM AUTHOR]

In Australia, the introduced Common Myna ( Acridotheres tristis) is commonly believed to aggressively displace native birds and outcompete them for food and nest resources. However, the current paucity of scientific evidence makes it difficult to devise appropriate management strategies for protection of urban bird populations. This study investigates the way in which the Common Myna uses the urban environment and interacts with other species while foraging and nesting in Sydney, Australia. The bird community varied between habitat types along an urbanisation gradient, and the abundance of the Common Myna increased significantly with the degree of habitat modification. Surveys of the frequency of interspecific interactions revealed that the Common Myna did not initiate a significantly greater number of aggressive encounters than did other species. Focal observations of two potential native competitors showed that despite foraging in close proximity, the Common Myna rarely interfered with feeding activity. Assessment of natural tree hollow occupancy found that Common Mynas used significantly fewer tree hollows than did native species. Analysis of nest site selection indicated that Common Mynas chose to nest in more highly modified habitats, and in artificial structures rather than in vegetation. These findings suggest that, in this study area, Common Mynas have little competitive impact on resource use by native bird species in the urban matrix. The logical conclusion of these results is that the substantial efforts currently directed towards culling of Common Mynas in heavily urbanised environments is misdirected, and resources would be better directed to improvement of natural habitat quality in these areas if the purpose of control is to enhance urban bird diversity. [ABSTRACT FROM AUTHOR]

It is widely established that social alarm signals trigger learning about discrete stimuli present at the same time. Such learning facilitates, for example, acquisition of responses to novel predators and has the functional advantage that individuals avoid exposing themselves to a potentially risky situation. Avoidance of potential danger might equally apply to learning about risky places, but would require social alarm signals to trigger learning about contextual cues, rather than discrete stimuli. Here, we tested this hypothesis by analysing the behaviour of experimental observer Indian mynahs, Acridotheres tristis, both before and after they had watched demonstrator mynahs showing alarm behaviour at a foraging site where observers were accustomed to feeding. To isolate changes specifically attributable to the behaviour of demonstrators, we compared this group''s post-training behaviour with that of a control group, which watched social companions foraging at the feeding site. Unexpectedly, we found no evidence that experimental observers became more wary of the feeding site after observational training relative to control observers, suggesting that social alarm signals do not trigger learning about the location in which an alarmed individual is observed. In light of previous work in our laboratory showing that Indian mynahs become more wary in a place in which they have observed a predator attack on a social companion, we suggest that social learning about places may require observation of both social alarm and its cause. [Copyright &y& Elsevier]

Abstract: Similar to the process seen in invasion biology, urbanized environments lead to biotic homogenization with a few species, often alien, dominating the urban habitat. We investigated avian communities across an urban gradient in Pretoria (South Africa). We defined three urbanization zones: urban, suburban and semi-natural, based on land-cover. We conducted point counts of all species at each of 13 sites in these zones over a 4-month period. We found significantly more species in the semi-natural zone than the urban zone but abundance was significantly lower in semi-natural than urban. The increase in abundance was mainly as a result of alien species with the three most abundant species in the urban zone being all alien. Semi-natural contained fewer alien species than urban and significantly fewer than suburban. The Common Myna Acridotheres tristis was the only alien species that was observed in all three urbanization zones and was the second most abundant species in the suburban and urban zones. Our study supports the process of biotic homogenization, where an increase in alien species occurs in the urban compared to semi-natural zone. Although the suburban zone made an important contribution towards native bird abundance in a larger city environment, this environment was also an important environment for alien species, especially for the Common Myna. [Copyright &y& Elsevier]

Studies of learning have consistently shown that animals form strong associations between aversive events, such as a predatory attack, and the environments in which those events are experienced. Place learning through direct exposure to threat puts the individual at a risk that may be avoided, however, by remembering the location in which encounters between conspecifics and dangerous events are observed. Despite much theoretical work predicting that individuals should rely less on private information and more on public information as the risk of individual assessment increases, there have been no tests of observational spatial memory for potentially dangerous places. We investigated whether Indian mynahs learn about an area in which they observe another individual experience an aversive event, namely capture by a human. Experimental observers watched a human chase, catch and remove a conspecific from a feeding site in which observers were accustomed to feeding. A control group watched a human perform the same capture gestures, but with no mynah present. Analysis of observer behaviour at the feeding site both before and after observational training revealed that experimental observers locomoted more after training than before, relative to control observers, suggesting that mynahs acquired a fear response after watching a predatory attack on a conspecific. It appears that, in addition to learning about the location in which aversive events are experienced directly, animals learn about an environment in which they observe others encounter dangerous events. [Copyright &y& Elsevier]