Acridotheres Tristis Research Articles

Ecological and ethological features of Acridotheres tristis during reproductive phase

Ecological and ethological features of Acridotheres tristis during reproductive phase

Roosting Behaviour and Population of Indian Mynas; & its Correlation with Sunset (light intensity) and the Time of Arrival

Abstract: Communal roosting behaviour is a very fascinating phenomenon that has been observed in numerous avian species wherein many birds stay together during night or daytime. Size of communal roosts may range from 5-6 individuals (e.g. Peafowl, drongo) to over 10,000 birds (e.g. Indian myna, crow, parakeets). Such birds have tendency to flock on their roost-ward journey. In this research, we observed communal roosting behaviour and population of Indian Myna (Acridotheres tristis). We identified one of the communal roosts of Indian Myna in Vaikunth Crematorium, Navi Peth area Pune and counted their population size at the time of their arrival to the roost during sunset on a fortnightly basis for a year by point count method. Census records were taken at 5 minutes interval on the number of flocks and flock sizes of these birds arriving to the communal roost in the evening. Also, recorded the light intensities over those intervals with the help of photometer. Our objective was to find out their population size and changes in the size at this particular roost and also to find out the correlation between the time of sunset (light intensity) and their time of arrival to the roost. This study illustrates the effect of light intensity on their roosting behaviour and analysis of any seasonal and monthly changes observed during the data collection period from 2 consecutive post breeding periods.

Review of the chewing louse fauna of the invasive common myna (Acridotheres tristis), with new records from Palestine and a redescription of Brueelia chayanh Ansari, 1955 (Phthiraptera, Ischnocera, Brueelia-complex).

Palestine hosts a large diversity of birds, with 393 recorded species, but little data are available on the chewing lice fauna found on these birds. In this study, we surveyed the species of chewing lice found on the common myna, Acridotheres tristis, which is one of the most invasive bird species in the world. Forty-five mynas were examined to collect their ectoparasites, which were preserved and slide mounted. Among the 1004 chewing lice processed, we identified two species: Menacanthus eurysternus (Burmeister, 1838) (prevalence 100%) and Brueelia chayanh Ansari, 1955 (prevalence 82.2%). No other species of chewing louse known from A. tristis in its native range was found, showing a possible sorting event in the founding population of common myna in the region. Prevalence (100%) and abundance (22.3) were high compared to similar studies of the common myna. To contribute to future research on the lice of common mynas, we provide an annotated checklist of the louse species reported from this host globally. Also, we redescribe and illustrate Brueelia chayanh, and place Sturnidoecus tristisae Bughio et al., 2018 as a new junior synonym of Sturnidoecus bannoo Ansari, 1968.

Diversity, Abundance, and Distribution of Avifauna in District Jhang, Pakistan

The present study was conducted from March 2021 to February 2022 in the Thal desert and Trimmu barrage of district Jhang located in the Punjab province of Pakistan to find out the diversity, abundance, and distribution of birds. The point count method was used for the Trimmu barrage, and the line transect method was used for the collection of data in the Thal desert area. We recorded 31,696 individuals belonging to 67 species of birds from two distinct types of habitats (Thal desert and Trimmu barrage) of district Jhang. Among these species, 39 species were residents, 18 species were winter visitors, 9 species were summer breeders, and a single species (Terek sandpiper) was a passage migrant. Highly significant differences ( X 2 = 14979.7 , df = 11 , and P < 0.01 ) were observed in the abundance of birds between both habitats on every month. From the Thal desert area, 12,905 individuals belonging to 45 species were identified while 18,791 individuals from 58 bird species were observed in the Trimmu barrage, with 36 bird species among 67 species being common at both habitats. The most dominant species of the Trimmu barrage were the common pochard, little grebe, common coot, cattle egret, gadwall, little egret, red-wattled lapwing, and common teal. On the other hand, the Indian roller, common quail, cattle egret, common myna, and Indian kite were found to be the most common species in the Thal desert. The most notable feature of the present study is the identification of Xenus cinereus (Terek sandpiper) and Ammomanes phoenicura (rufous-tailed lark) in district Jhang as both species had no previous record in the study area. The Trimmu barrage was the more diverse and abundant site compared to the Thal desert as it provides both terrestrial and aquatic habitats for birds. The study determined that more varieties in the habitat and thermal changes affect the diversity, abundance, and distribution of birds.

Nesting Resource Partitioning of Four Species (Acridotheres tristis, Acridotheres ginginianus, Sturnia pagodarum and Gracupica contra) of Sturnidae Family in Peri-Urban Region of Ajmer City, Rajasthan, India

Aims: The study aims to study the resource partitioning and nesting behaviour in four species namely Common Myna, Bank Myna, Brahminy Starling, and Asian Pied Starling nesting in human settlements.
 Place and Duration of Study: The study was conducted from January 2022 to July 2023 in peri-urban areas of Ajmer city, Rajasthan, India.
 Methodology: Using observations and point-count transects, we examined the nesting preferences, heights, and materials used by these species.
 Results: The findings reveal that all four species demonstrated a remarkable adaptability to urban environments by selecting man-made structures as their preferred nesting sites. Common Mynas, in particular, displayed a preference for a variety of human constructions, such as buildings and building cracks, and utilized materials like twigs, straws, plastic, paper, and cotton.
 Conclusion: This study highlights the importance of considering wildlife adaptation in urban planning and conservation efforts, as these birds thrive in human-altered landscapes. The nesting behaviors and adaptation of these Sturnidae species in urban environments reveal their ability to coexist with human development. Understanding these interactions is crucial for both avian ecology and urban planning, as it sheds light on the intricate relationships between wildlife and changing landscapes.

Survey on the gastrointestinal parasites in Passeriformes and Psittaciformes with a focus on zoonotic parasites

Considering the increase in the keeping of pet birds and the importance of gastrointestinal parasitic infection, especially zoonotic parasites, this study was conducted to determine the prevalence of gastrointestinal parasites in different species of Passeriformes and Psittaciformes. In this study, one hundred and twenty fresh fecal samples were collected from different species of captive pet birds in Ahvaz from Apr 2021 to Aug 2021. The collected samples were analyzed using Clayton-Lane methods, Modified Ziehl–Neelsen, and Trichrome staining. Light microscopic morphometry was used for the identification of helminth eggs and oocysts. The results of this study showed that 37 samples (30.83%) were infected with gastrointestinal parasites. Among the helminthic parasites, three samples (2.5%) were infected with Hymenolepis spp.. Among protozoan parasites, 24 samples (20%) were infected with Eimeria spp., three samples (2.5%) were infected with Isospora spp., two samples (1.66%) were infected with Cryptosporidium spp., and five samples (4.16%) were infected with Giardia spp.. The results of the present study showed that the highest rate of gastrointestinal parasitic infection was in Passeriformes kept in pet shops and the prevalence of gastrointestinal parasitic infection was higher in the zebra finch, common mynah, and canary compared to other pet birds. But the highest rate of zoonotic parasitic infection was in Psittaciformes. According to the results, zoonotic parasites are present in pet birds in the Ahvaz area and should be considered by the owners of these pet birds, breeders, veterinarians, and public health organizations.

Alien vs. Predator: Impacts of Invasive Species and Native Predators on Urban Nest Box Use by Native Birds.

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.

Tracing the introduction of the invasive common myna using population genomics

The common myna (Acridotheres tristis) is one of the most invasive bird species in the world, yet its colonisation history is only partly understood. We identified the introduction history and population structure, and quantified the genetic diversity of myna populations from the native range in India and introduced populations in New Zealand, Australia, Fiji, Hawaii, and South Africa, based on thousands of single nucleotide polymorphism markers in 814 individuals. We were able to identify the source population of mynas in several invasive locations: mynas from Fiji and Melbourne, Australia, were likely founded by individuals from a subpopulation in Maharashtra, India, while mynas in Hawaii and South Africa were likely independently founded by individuals from other localities in India. Our findings suggest that New Zealand mynas were founded by individuals from Melbourne, which, in turn, were founded by individuals from Maharashtra. We identified two genetic clusters among New Zealand mynas, divided by New Zealand’s North Island’s axial mountain ranges, confirming previous observations that mountains and thick forests may form barriers to myna dispersal. Our study provides a foundation for other population and invasion genomic studies and provides useful information for the management of this invasive species.

Drivers of power line collisions and electrocutions of birds in Nepal.

Among the several anthropogenic factors, power lines are increasingly regarded as one of the most significant hazards to bird species, primarily owing to collisions and electrocutions. Nepal has comparatively fewer studies on the impact of power line collisions and electrocution on birds compared with developed nations. From November 2021 to May 2022, we assessed the effect of power line collisions and electrocutions on the mortality of birds in the Putalibazar Municipality of the Syangja district of Nepal. We established 117 circular plots in diverse habitats, including agricultural lands, forests, settlements, and river basins, along a 30.6 km long distribution line. Within 18 plots, we detected 43 fatalities of 11 species (17 individuals of six species due to collision and 26 individuals of eight species due to electrocution). House Swift (Apus nipalensis) and Common Myna (Acridotheres tristis) were the primary victims of the collision, whereas House Crow (Corvus splendens) and Rock Pigeon (Columba livia) were frequently observed electrocuted. We also recorded the electrocution of the critically endangered White-rumped Vulture (Gyps bengalensis). The total rate of bird power line collisions per kilometer was 0.55 birds, while the total electrocution rate per 10 poles was 2.22. The bird abundance, distance to agricultural regions, and proximity to human settlements were found to have a strong relationship with the mortality of birds caused by power lines. In order to reduce power line collisions and electrocution fatalities, we recommend conducting a detailed bird population study prior to determining the route of distribution lines.

DENSITY AND NEST-SITE SELECTION OF INVASIVE MYNAS AND STARLINGS IN URBAN AND SUB-URBAN AREAS IN WESTERN SARAWAK, MALAYSIA

Urban pest bird species, such as the Asian Glossy Starling, Javan Myna, and Common Myna have been a persistent menace to urban properties. This study compares the population densities of each species within urban and sub-urban areas between Kuching and Kota Samarahan. It was found that Javan Myna and Common Myna populations are concentrated in Pending with population densities of 12.9 ind/ha and 13.3 ind/ha, respectively. The Asian Glossy Starling was found to occupy heavily populated areas in Waterfront and the Universiti Malaysia Sarawak campus, with a population density of 15.0 ind/ha at both sites. We also studied the nesting density and habitat requirements of these species. The highest record of nesting density for the Common Myna (0.8 nests/ha) and Javan Myna (0.7 nests/ha) is in Pending, while the Asian Glossy Starling (2.6 nests/ha) is in Waterfront. The following microhabitat variables influenced the birds’ nest site selection: i) nest distance from garbage bins; ii) nest distance from shrubs and grass; and iii) nest distance from trees. Additionally, the data indicated that the birds had a strong preference for nesting in artificial structures. The Common Myna (25%) chose to nest inside air vents, whereas the Javan Myna (29.63%) and Asian Glossy Starling (51.95%) preferred to nest in holes and cavities.

T-PERCHES DETERMINING AVIAN FEEDING GUILDS IN MAIZE

Avian diversity is considered an environmental indicator for measuring ecosystem quality. The availability of food and its diverse types influence bird distribution and their community structure in agricultural landscapes. The current study investigated the role of T-perches as bird attractants in maize at the Punjab Agricultural University, Ludhiana. A total of 39 species were observed belonging to 12 orders and 24 families. Insectivorous birds were observed as the most dominant feeding guild constituting 47.12%. Black drongo, jungle babbler, common myna, house crow, green bee-eater, and red-vented bulbul were noted utilizing t-perches for foraging purposes. The key factor driving the increase in insectivorous bird species seemed to be the additional perching sites available by installing T-perches.

The introduction and distribution history of the common myna (Acridotheres tristis) in New Zealand

ABSTRACT Throughout history, human movements have been a mechanism by which species are introduced to new environments. Although these introductions may sometimes be unintended, they have often occurred through organised effort and led to successful establishment outside a species’ native range. The common myna (Acridotheres tristis) is an invasive bird species that has successfully established globally, including on New Zealand’s North Island. To better understand the establishment of this invasive species, historical records of the myna’s introduction and subsequent distribution were compiled and analysed. We determine that mynas were introduced into New Zealand repeatedly between the 1860s and 1880s, originating from stock acclimatised in Australia with strong links to Melbourne. Additionally, we track the changing distribution of the myna across New Zealand, allowing us to create a detailed timeline. Our findings are discussed in the context of the motivations behind myna introduction, and public response to their introduction and spread.

Community structure, ecology, and conservation issues of avifauna of two human-dominated landscapes in Faridpur district, Bangladesh during Covid-19 pandemic

A study was conducted on community structure, ecology, and conservation issues of the avifauna of two human-dominated landscapes in a lower Ganges Madhukhali Upazila, under the Faridpur district during the COVID-19 pandemic period. Direct field observations were made from April 2020 to March 2021. In total, 109 species of birds belong to 18 orders, and 49 families were observed, with a total count of 5,453 individuals. Resident bird species (93 species, 85.32%) dominant in the study area, whereas the migratory species were only 16 (14.68%). The highest number of bird species (93 species, 85.32%) with the highest number of individuals (n=3171, 58.15%) was observed in Beleswar (rural site) area. Shannon diversity index value (H=3.89, Ds= 0.9724) was higher in the rural site than Madhukhali municipal area (urban site). In the winter season, the highest number of bird species (95 species, 87.15%) with the highest number of individuals (n=2303, 42.23%) was observed. Among micro-habitats, trees, particularly the native tree species, were the preferable sites for bird nesting, foraging, and roosting. Among birds, Acridotheres tristis was the most abundant species (n=316, 5.79%) in the study area, and an uneven distribution of species in the community structure was observed. The abundance of birds shows that 59 (54.12%) species were very common, 8 (7.33%) common, 9 (8.25%) uncommon, and 33 (30.27%) rare. Among the bird species, Ichthyophaga ichthyaetus was categorised as Near Threatened (NT), and the rest are Least Concerned (IUCN Bangladesh 2015). Illegal hunting of birds, especially waterbirds, is the major threat in the rural site. Preparing a proper management plan based on the baseline data is essential for protecting of avian diversity in the study area. J. Asiat. Soc. Bangladesh, Sci. 48(1-2): 53-66, June-December 2022

Radiologic features of radiolucent foreign bodies ingestion in common mynah (Acridotheres tristis).

In mynahs with foreign body ingestion, delayed diagnosis increases the risk of poor outcomes. The aim of this study was to evaluate various radiologic features on plain and contrast radiographs in mynahs for assessing the presence of ingested foreign bodies. In our cross-sectional study, a total of 41 mynahs were included. The diagnosis was made by history, surgery, excision by forceps or excretion in the faeces. Overall, 21 mynahs were considered not to have a foreign body in their gastrointestinal tract. Plain and post-contrast [oral administration of bariumsulphate colloidal suspension of 25% weight/volume (20mg/kg)] lateral and ventrodorsal radiographs from the cervical and coelomic cavity were taken.Different parameters including oesophageal, proventricular, and small intestinal diameters and opacities were assessed. Image evaluation was performed by two national board-certified radiologists blinded to the final diagnoses. The inter- and intra-observer reliabilities of the diagnostic features were significant (p < 0.001). The diagnosis of the foreign body was highly accurate [90.2% (95% CI: 76.9%, 92.3%)] with the sensitivity, specificity, and area under the representative characteristic curve of 90.0%, 90.5%, and 0.93%, respectively for plain radiographs. The size and opacity of the oesophagus, proventriculus, and intestinal loops as well as serosal details were significantly different between mynahs with and without foreign body intake (p < 0.05). Lateral and ventrodorsal plain radiographs are highly reliable for diagnosing the presence of non-opaque obstructing objects in the gastrointestinal tract of mynahs. Attention should be paid to the size and opacity of the oesophagus, extension, and opacity of the proventriculus, segmental opacity of intestinal loops, and decrease in serosal details.

Изменение структуры населения птиц под воздействием антропогенных факторов в долине р. Угам (Западный Тянь-Шань)

The article addresses the issues of changes in the species composition and number of birds in the middle part of the valley of the Ugam River. The valley has been mastered by humans since ancient times, but due to its geographical location, the possibilities for conducting economic activities in it have always been limited, and its intensity has its own characteristics. Here, the location of the only settlement changed, orchards were planted and cut down, cattle were grazed everywhere or in the vicinity of the village, hayfields were mowed or abandoned, and field roads were laid and overgrown. The inclusion of the territory in the Sairam-Ugam National Park has reoriented human activities. The construction of tourist facilities has begun and continues here, which has led to an increase in the number of lovers of outdoor recreation. All this was reflected in the birds of the valley, which are very sensitive to environmental changes. This is especially noticeable in mountainous conditions, where the concentration of nesting species is not high, the main routes of migrants go along the foothills, and wintering conditions are not favorable. The first data on the avifauna of this section of the valley were obtained by M.N. Korelov in the summer and autumn of 1949 and later collected by the author in May 2003, July 2011, and 2022, which made it possible to analyse its species-specific variation. Over 70 years of observations, 127 bird species were encountered here, of which 114 were in 1949, 53 were in 2003, 54 were in 2011, and 44 were in 2022. The structure of the bird population in the valley also changed. This is especially noticeable in July 2003 and 2022, when the studies were carried out on the same days. In the first year, human activity was limited to the outskirts of the village, and in the second year, it was carried out throughout the entire section of the valley. In the first year, 617 individuals were encountered in 4 days; in the second year, 307, i.e., twice as small. In 2003, the main bird populations were Corvus corone (11.4% of the number of birds encountered), Pica pica (11.2%), Emberiza bruniceps (9.4%), Acridotheres tristis (7.3%), Emberiza cia (6.6%), Lanius minor (5.7%) and Carduelis caniceps (5.3%), and in 2022, Chloris chloris (12.4%), Ac. tristis (12.1%), C. caniceps (11.4%), Streptopelia orientalis (6.6%), C. corone (4.5%), P. pica and Em. bruniceps (3.8% each). With the development of the valley by humans, the species ratio of birds also changed. In 1949, species whose life is exclusively associated with humans were not recorded here; in 2003, 2011, and 2022, they included 5 species (Columba livia, Streptopelia senegalensis, Hirundo rustica, H. daurica, and Acridotheres tristis), which accounted for 14.2, 29.0, and 10.3% of the number of individuals encountered, respectively. The number of species indifferent to the place of residence, but preferring natural biotopes, has been stable over the years - 16, 17, 15 and 16, but changed quantitatively (50.0, 31.1 and 45.7% in 2003, 2011 and 2022). During the same period, the diversity of species living in natural biotopes also decreased (32, 27, and 25). All these and other issues are discussed in the analysis of each bird species, and it is shown that the increased anthropotization of the valley leads to a reduction in species diversity, the number of birds living here and to the loss of its uniqueness.

Abdominal Hernia in a Common Mynah (Acridotheres tristis) Associated With Hepatic Lipidosis and Concurrent Respiratory Aspergillosis

Hepatic lipidosis and hernia are problems that can occur in pet birds due to different causes. Aspergillosis is also an important disease of pet birds. This article reports an interesting case which, to our knowledge, is the first one in Iran. A 7-year-old male common mynah was presented to the clinic of avian diseases at the University of Tehran, Tehran City, Iran, with a history of severe dyspnea, anorexia, feeding with a high-energy diet, and recently been in the northern parts of Iran. Unfortunately, the bird died. Necropsy was done to diagnose the cause of death. Tissue samples from abdominal viscera, lungs, and air sacs were collected and fixed in 10% buffered formalin and stained with hematoxylin and eosin. Bacterial cultures from the liver and bone marrow were performed on blood and MacConkey agars. In the external carcass examination, the abdominal swelling, hernia, and yellow discoloration under the skin were obvious. At necropsy, the liver was enlarged with yellowish discoloration. There was also a high amount of fat around the abdominal viscera. Microscopically, fatty change, hepatocellular necrosis, and hemorrhages were seen in the liver. There were also vegetative forms of Aspergillus on the lung’s parenchyma and air sacs. No bacterial growth was observed. Pet birds are usually restricted to a cage by minimal contact with other birds; thus, diseases related to management are common among these birds. So keeping in suitable conditions with an appropriate, balanced diet is important for their health.

Avian Diversity and Its Feeding Guilds in Respect to the Rural Landscape of District Barnala (Punjab)

Avian diversity is a strong indication of the stability and integrity of structure and processes in an ecosystem. Though birds are adapted to almost every habitat and breed on almost all the continents of the earth, the majority of birds are linked to the agro-ecosystem to survive as agriculture offers an extremely predictable and concentrated food source; and birds also play a role in nutrient cycling, soil formation, and energy transfer in the ecosystems. Therefore, from the perspective of environmental monitoring, the assessment of bird assemblages in various ecosystems is prioritized. Due to the intensification of agriculture, Punjab's agro-ecosystem has undergone tremendous changes. The present study on avian diversity in the rural agricultural landscape (RurekeKalan, Sekha, Sanghera, and Cheema) of district Barnala, Punjab has been conducted from March 2022 to May 2022 using a Digital SLR camera (Canon 1300 D) binoculars (Nikon A211 16X50) to observe the birds. Thirty species of birds belonging to twelve orders have been recorded, order Passeriformes being the most dominant one. Common Myna and Blue Rock Pigeon were found to be the most prevalent as compared to other bird species. Omnivory was found to be dominant as compared to other feeding habits. Although the present work is in no way conclusive, it serves to give an approximate understanding of the fauna in the study site and also reveals that agricultural intensification is a major concern for avian diversity conservation. The present study provides baseline data to understand the precise functions that different species of birds play in agro-ecosystems and for future study regarding conservation, habitat preferences, seasonal variations, nest ecology, breeding biology, etc. of the avian species that have been observed in the study region.

Study of human knowledge and attitude toward urban birds in Faisalabad city, Pakistan.

Birds are very valuable indicators of species richness and endemic patterns in a specified ecosystem, which eventually help the scientist to measure the environmental degradation. The aim of present study was to know human knowledge and attitude toward urban birds in Faisalabad city, Pakistan. The study conducted in four consecutive months: November 2019 to February 2020. Population of birds was noted from eight residential towns of Faisalabad city, data were collected through questionnaire. Faisalabad has a reasonably large population of birds and present data show that, there is a significant difference between favorite bird of residential areas and institutions. The pigeon received the most likeness in bird population among residential area residents, while the myna received the least. The most popular bird in Faisalabad institutions was the sparrow, while the least popular bird was the common myna. Bird adaptation percentage of residential areas and institutional areas of Faisalabad was the highest for parrot and sparrow respectively. People in residential areas and institutions, on the other hand, adapted least to common myna. It is concluded that people of the study area like birds and offered food and high population of birds are present in study area.

Breeding status of invasive Rose-ringed Parakeets Psittacula krameri in Durban, South Africa

The Rose-ringed Parakeet Psittacula krameri has established feral populations in South African suburban areas. However, the information on the breeding biology of parakeets remains poorly documented in the country. We assessed parakeets’ breeding status and behaviour by locating their roost and breeding sites in Durban, eThekwini Metropole, KwaZulu-Natal province. We also placed artificial nest boxes to determine the occupancy of parakeets or other bird species. We identified 39 parakeet breeding sites with a total of 72 nests. There were no significant differences between the number of active parakeet nests in the first (n = 53 nests) and second breeding seasons (n = 59). Rose-ringed Parakeets used four tree species for nesting, with the white milkwood Sideroxylon inerme used the most (71%). Only East African lowland honey bees Apis mellifera scutellata and Common Mynas Acridotheres tristis used the artificial nest boxes. Parakeet fledgings recorded ranged between one and three per nest, and their numbers differed significantly between seasons. The number of fledglings was not influenced by any of the tree variables measured and distance or location. The distance between the parakeets’ roosting and breeding sites ranged from 1.43 to 5.0 km. Our study provides essential data for an overall management strategy, including eradication programs for this species in South Africa.

Radiographic Reference Intervals for Cardiac Size in Common Mynahs (Acridotheres tristis).

Cardiovascular diseases in the common mynah (Acridotheres tristis) often go undiagnosed due to limitations with the physical examination and common concurrent illnesses. The aim of this study was to establish accurate reference intervals for cardiac size based on radiographs for this species. All birds were considered healthy based on physical examination. High-quality ventrodorsal radiographic images were obtained from 34 healthy common mynah birds. The cardiac width (CW), thoracic width, distance between third and fourth ribs, synsacral width, coracoid width, and distance between clavicular bones were evaluated on the ventrodorsal radiographic images. Additionally, the ratio between the CW and these anatomical indices were measured. In order to evaluate the correlation between CW and the radiographic indices, a linear regression model was used. The mean ± SD for CW in the 34 birds was 16.1 ± 0.9 mm (95% confidence interval: 14.1-18 mm). Significant moderate correlation was found for CW with thoracic width (R2 = 0.37; P < 0.001), coracoid width (R2 = 0.25; P = 0.002), and the distance between the third and fourth ribs (R2 = 0.34; P < 0.001). The radiographic reference intervals calculated in this study can be used to evaluate cardiac size in the common mynah bird.