Acridotheres Tristis Research Articles

Identifying the hidden parasitic intruders: Molecular insights into the health of common Myna

Birds are known to act as the parasite reservoir and can transmit them to other organisms through food chains. This study aims to report the molecular prevalence and phylogenetic evaluation of various blood borne pathogens (Toxoplasma gondii, Isospora spp., Plasmodium spp., Haemoproteus spp., Leucocytozoan spp. and Neospora caninum) in blood samples of common Myna (Acridotheres tristis: N = 80) collected from four region (Jhang, Khanewal, Multan and Muzaffargarh) in Punjab Pakistan. Effect of pathogens on the complete blood count of the host was also determined. Results revealed by 2/80 Myna (2.5 %) amplified ITS-1 gene of Toxoplasma (T.) gondii (confirmed by DNA sequencing) while 2/80 (2.5 %) birds amplified 18S rDNA gene and Isospora spp. Phylogenetic analysis of both pathogens showed that Pakistani isolates were clustered together and were closely related to isolates that were reported from worldwide countries.Risk factor analysis revealed that prevalence of both pathogens was not restricted to a particular sampling site or a particular bird sex (P > 0.05). T. gondii infected birds had elevated red cell distribution width while Isospora sp. infected birds had elevated % monocytes and platelet distribution width while decreased mean cell hemoglobin, mean corpuscular hemoglobin concentration and platelets hematocrit than their respective uninfected birds. In conclusion, we are reporting the presence of T. gondii and Isospora sp. among Pakistani common Myna that had disturbed the complete blood count parameters that may have affected their normal physiology.

Survey of gastrointestinal coccidian parasites of pet birds in Tehran

ABSTRACT Birds of various families and genera comprise a notable proportion of veterinary clients in veterinary practice. Regarding the scarcity of information on avian coccidia in pet birds, this study was designed to investigate and identify the diversity of gastrointestinal coccidian protozoa in caged pet birds. Accordingly, droppings samples were collected in 2.5% potassium dichromate and examined for the presence of oocysts by wet smear and by flotation with the saturated salt solution. Detected oocysts were further morphologically specified. Special Modified Ziehl-Neelsen stain was used for the detection of Cryptosporidium spp. oocysts. Out of the 145 droppings that were collected for parasitological investigations, it was discovered that a Japanese quail (Coturnix japonica) had a Cryptosporidium sp. infection (1/145: 0.7%). Additionally, Isospora spp. was found in a common mynah and a canary (2/145: 1.4%), while Eimeria sp. was detected in a canary (1/145: 0.7%). Studied birds were clinically normal and no signs of intestinal infection were observed. The oocysts are described morphologically in detail and compared with the available data. Periodic faecal examination should be recommended for monitoring intestinal parasites in pet birds both from a public health perspective for Cryptosporidium and for avian host health in the case of non-zoonotic parasites. Additionally, the identification of parasite/host species composition will enhance our understanding of species diversity and the variety of hosts that coccidian parasites are capable of infecting.

Bio-inspired machine-learning aided geo-magnetic field based AUV navigation system

The navigational accuracy of sea animals and trans-ocean birds provides inspiration in using geo-magnetic field (GMF) for realizing strategic truly autonomous underwater vehicles (AUV) capable of determining their absolute position on earth, without the aid of ship-referenced acoustic baseline systems. Supervised Machine Learning algorithms are applied on the GMF intensity data obtained from NOAA World Magnetic Model for a 900 km2 within the Indian mineral exploratory area in the Central Indian Ocean, with a resolution of 50 m, considering the sensitivity of commercially available magnetometers. It is identified that, for AUVs equipped with magnetometers with a detection sensitivity of 0.1 nT, the supervisory random forest regression and decision tree algorithm trained with priori GMF data, could provide trajectory guidance to AUVs with an absolute mean position accuracy in 2D plane, with reference to the last known position from Integrated Navigation system aided initially with GPS and with acoustic positioning in underwater. Circular Error Probable (CEP 50) of 53 m and 56 m, respectively. The scalar GMF anomaly navigation demonstrated to be a viable GPS-alternative navigation system could be extended to larger areas with inclination and declination vectors, as unique identifiers.

Predicting the Invasion Range of the Common Myna, Acridotheres tristis Linnaeus, 1766 in Egypt under Climate Change

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.

Range expansion and habitat preferences of an introduced bird in the northwestern Arabian Peninsula: The case of the common myna Acridotheres tristis

Introduced species can have harmful impacts on native species and ecosystems. Certain species can benefit from anthropogenic activities and habitat modification, even outside of their native ranges. Introduced species in Saudi Arabia have received little attention, which has resulted in limited knowledge on this topic, especially regarding the northwestern region of Saudi Arabia. One bird species introduced to Saudi Arabia is the common myna (Acridotheres tristis), which appears to be invading vast areas of the country. For the first time, the distribution and habitat preferences of the common myna have been investigated across different habitats in Tabuk Province, northwestern Saudi Arabia. Notably, common mynas were detected in habitats with different conditions, including urban, suburban, and agricultural habitats. Overall, the common myna appears to be a flexible species that has adapted to this arid environment and effectively uses available resources in foraging and nest site selection. Common mynas were observed in both urban and suburban environments of Tabuk City with their presence being noticeably higher in urban and suburban than in agricultural habitats. This suggests that the centers of human activity and urban/suburban development seem to be preferable sites for this species, as shown by analyzing the human influence index. Based on observations from fieldwork, the common myna population is expected to increase since breeding appears to be escalating with no major threats. The current ecological status of the common myna and its range expansion to different habitats in northwestern Saudi Arabia is worrying and thus warrants further monitoring and investigation.

Scavengers in the human-dominated landscape: an experimental study.

Rapid urbanization is a major cause of habitat and biodiversity loss and human-animal conflict. While urbanization is inevitable, we need to develop a good understanding of the urban ecosystem and the urban-adapted species, in order to ensure sustainable cities for our future. Scavengers play a major role in urban ecosystems, and often, urban adaptation involves a shift towards scavenging behaviour in wild animals. We experimented at different sites in the state of West Bengal, India, to identify the scavenging guild within urban habitats, in response to human-provided food. Our study found a total of 17 different vertebrate species across 15 sites, over 498 sessions of observations. We carried out network analysis to understand the dynamics of the system and found that the free-ranging dog and common myna were key species within the scavenging networks. This study revealed the complexity of scavenging networks within human-dominated habitats. This article is part of the theme issue 'Connected interactions: enriching food web research by spatial and social interactions'.

A PRELIMINARY SURVEY ON DIVERSITY OF AVIFAUNA IN KATWA, PURBA BURDWAN, WEST BENGAL, INDIA

Birds are used as bio-indicator due to their sensitivity to minor environmental changes. A survey was done from July 2022 to February 2023 to study the avifaunal diversity of Katwa. A total of 67 bird species were recorded during the study period. The species were categorized in three namely common resident (CR), not common resident (NCR) and migratory (M) of which 40 are common resident, 24 are not common resident and 3 are migratory. The found common birds species were house crow, common myna, red vented bulbul, house sparrow, spotted dove, asian koel, little ringed plover etc. Among the not common resident avifauna were Long-legged Buzzard, Cotton teal, Pied-cuckoo, Grey Wagtail, yellow Wagtail, White Wagtail etc. and the three migratory birds were Common Pochard, Red-crested Pochard and Northern Pintail. Katwa and adjoining Ajay Baadh has wide variety of trees, wetland, grassland and agricultural land which is the major contributing factor for the rich avifaunal diversity found during the short study period. This is a preliminary effort for documentation of the avifauna, but more studies and suitable conservation strategies are required in the study area.

Nest site selection of cavity-nesting birds at Jahangirnagar University campus, Bangladesh

Understanding nest site selection by cavity-nesting birds is important for their conservation implications. We examined the preferences and characteristics of nesting trees and cavities used by cavity-nesting birds at Jahangirnagar University (JU) campus from January 2020 to October 2021. A total of 30 tree- cavity nests of 11 species of birds belonging to 4 orders and 7 families were recorded where 36% were primary excavators and 64% were secondary cavity-nesters. Out of 14 species of trees used in cavity-nesting, the most of the nests were built in Mahogany Swietenia mahagoni (n=8) followed by White siris Albizia procera (n=6) and Rain tree Samania saman (n=3). Diameter at breast height (DBH) of the nesting trees varied from 27 cm to 112 cm (52±23.2 cm). The highest mean DBH was recorded in Samania saman (85 cm) followed by Swietenia mahagoni (67 cm). Common Myna showed the widest selection of nesting tree species (n=9) followed by Black-rumped Flameback (n=4) and Lineated Barbet (n=4). Majority of the nesting trees (87%) were found in roadside (within 1-5 m) vegetation while 60% nesting trees located within 30 m from the nearby water bodies. The cavity-nesting species preferred to nest between 2 m to 12 m (5.2±2.6 m) height from the ground level. The entrance width and the depth of tree holes (n=30) used by cavity-nesters varied from 5 cm to 22 cm (7.5±3.5 cm) and 13 cm to 45 cm (23.2±6.5 cm), respectively. Suitable cavities are critical for reproductive success of cavity-nesting birds and our results highlight the conservation value of cavity-bearing large trees to maintain a healthy population of cavity-nesting birds at JU campus. Jahangirnagar University J. Biol. Sci. 12(1 & 2): 1-10, 2023 (June & December)

Reducing nest box entrance diameter impacts mammal occupancy

Tree hollows are an important resource for cavity‐nesting birdlife. When large, old trees are removed from a landscape, nest boxes are often installed as part of restoration efforts to replace lost natural cavities. If nest boxes are to be successful conservation tools, non‐target species, particularly competitive and predatory species, need to be prevented from entering nest boxes. Several different modifications to nest boxes aimed at excluding non‐target species have been trialed in previous studies. We tested the effectiveness of reducing the entrance diameter of nest boxes to exclude non‐target species in Southeast Queensland, Australia. We used restrictor plates to reduce the entrance diameter of nest boxes from 90 to 60 and 50 mm and compared the wildlife occupancy of nest boxes with these three entrance diameters. We found that Common brushtail possums, a predator of cavity‐nesting birds and eggs, were significantly less likely to occupy nest boxes with reduced entrance diameters and were excluded from nest boxes with a 50‐mm entrance diameter. Squirrel gliders occupied nest boxes with all three entrance diameters. Introduced species, namely the Common myna and the European honeybee, also occupied nest boxes with restrictor plates. Installation of nest boxes with reduced entrance diameters is a simple and effective strategy to exclude brushtail possums from nest boxes. However, a reduced entrance diameter cannot exclude other non‐target species, and we suggest that other exclusion strategies should be used in conjunction with reduced entrance diameters to increase the occupation of nest boxes by native birds.

Enhancing bird conservation in tropical urban parks through land sparing and sharing strategies: Evidence from occupancy data

Urban green spaces such as parks, play a vital role in relieving pressure on urban biodiversity. In Southeast Asia, urban park management often prioritises aesthetic appeal over urban biodiversity conservation. Management of wildlife habitat at the stand and landscape scales is necessary to support land-sharing and land-sparing conservation strategies in urban environments. To date, few studies have looked at the occurrence of urban birds in the context of land sharing and sparing strategies. We investigated how resident and migratory birds utilise urban parks based on stand-level habitat characteristics and landscape metrics. We conducted point count surveys at 49 points to estimate site occupancy and detection probability in 40 parks within highly urbanised Klang Valley, Peninsular Malaysia. Out of 90 species recorded, 14 species had more than 50 % site occupancy. The abundance of palm trees, percentage of shrub, and height of ground vegetation and woody trees positively influenced the occupancy of Black-naped Oriole, Javan Myna, House Crow, Oriental Magpie-Robin, and Yellow-vented Bulbul. While the number of woody trees and elevation negatively influenced the occupancy of Asian Glossy Starling, Spotted Dove, Zebra Dove, and Common Myna. Our findings can contribute to the effective management of urban parks, considering both stand and landscape-level characteristics to support urban biodiversity, ultimately benefiting both resident and migratory bird populations. Our research emphasises the significance of implementing both land-sparing and land-sharing strategies in urban park management. By doing so, we can promote greater avian biodiversity, preserve diverse habitats for birds, and establish crucial ecological corridors within urban landscapes.

Adaptive patterns of anti-predator escape behavior in a globally introduced bird species

Introduced species can represent quasi-experimental, anthropogenic case studies of both ecological and evolutionary principles. When these species are firmly established, competitive interactions between native and introduced species interactions, including foraging, spacing, and breeding competition, may be among the ecological costs incurred from such species invasions. In turn, genetic and/or plasticity-driven changes in behavior and morphology could also take place in the invading species with increasing introduction lag (time since the onset of introduction). Critically, however, introduction lag is difficult to study in any single non-native population without long-term observations, and, instead, it requires geographically repeated measures of the focal response variables across invasive populations that were introduced at different times. Here we tested a priori predictors of predator-avoidance behaviors through the flight initiation distance (FID) assay of a widely distributed invasive bird species, the common myna Acridotheres tristis. The species was extensively and consistently sampled throughout most of its independently introduced ranges across all hemispheres. Critically, FID increased with greater introduction lag. We also detected additional functional patterns in that FID increased towards the rural range within a continuous metric of urban-rural gradient and also at shorter distances from the Equator. Any robust study of FID must also include proximate predictors as well and, accordingly, we found that FID increased with greater starting distance, with lower immediate human density, with flighted over walking escape responses, and at lower heights of a bird’s perch above ground but was unrelated to myna group size. Respectively, these factors are informative about the sensory cues triggering anti-predator behaviors in invasive mynas and imply an adaptive set of patterns of anti-predator responses in the introduced ranges of this species. Control measures of invasive common myna populations should take into account their extensive behavioral and cognitive flexibilities and adjust the planned management methods accordingly.

Observations on rare nesting site of Common Myna (Acridotheres tristis) in District Udhampur, J&K UT, India

Common Myna (Acridotheres tristis) generally build their nest on tree cavities, rock scarps, vertical earth banks, crevices in walls of houses, ventilators between ceiling and roof of buildings, utility poles, and sewage and gas pipes; occasionally inside canopy of trees and rarely on open trees. In this study we documented the pictorial data on nesting site of Common Myna during March 2023 to August 2023 in Seyal Sallan village of district Udhampur JK, UT (32º91’N, 75º14’E; 704m SL), India. During investigations 3 nos. of open nests of Common Myna were found on the Phulai tree (Acicia modesta) in the study area. It was also found that the open nests of Common Myna turned to be unsuccessful one due to the predation by the predatory animals like Common Crow and Rufous treepie.

Asian koel rapidly locates host breeding in novel nest sites.

Avian brood parasites depend upon locating host nests to lay their eggs. However, how brood parasites locate host nests and select the nests for parasitism remains poorly studied. Here, we examined how a non-evicting brood parasite, the Asian koel (Eudynamys scolopaceus) were able to locate host nests in locally novel nest sites. We provided a set of novel nest sites (i.e., nestboxes, n = 100) to the common myna (Acridotheres tristis), a regular host of the Asian koel, at a field site in Central Bangladesh. We found that common myna quickly utilized the novel breeding sites (n = 99 nests across 59 boxes) and similarly, 21.2% of these nests were parasitized by the Asian koel. Unsurprisingly, none of the inactive nest boxes were parasitized, neither were empty nests of common myna (i.e., either predated or fledged clutches, thus lack of parental activity, n = 83). Our results provide an experimental demonstration of the Asian koel ability to rapidly locate nests in locally novel nest sites, potentially facilitated by close monitoring of host activity and behavior around the nest site. However, the underlying mechanisms for this rapid adjustment to novel nest sites remain unresolved.

Experimentally elevated corticosterone increases song output and complexity in common mynas.

Vocalization is an important communication tool that can reflect many aspects of an individual's internal and external condition. This is especially true for birds. Previous research has shown that bird calls and songs change in response to a variety of potential stressors, although the extent and direction of the changes depend on the nature of the stressor and the environment. Circulating glucocorticoids, such as corticosterone, often increase in response to stressors and mediate some of the observed changes via alterations of the individual's physiological state. Acute elevations of corticosterone often occur as a physiological response to short-term stressors; however, the effects of this elevation on adult vocalizations have not been well documented. Here, we experimentally elevated corticosterone at two different levels using a noninvasive method and examined the effects on the vocal communication of male and female adult common mynas (Acridotheres tristis). Corticosterone elevation temporarily increased song output and some measures of song complexity, while call output decreased. These effects were dosage dependent (higher corticosterone levels had a stronger effect), most evident 40 min after ingestion, and some vocal changes were sex-specific. Future studies should investigate whether the changes in vocal performance due to elevated glucocorticoids have consequences for the birds' behavior, reproductive success, and survival.

Avifaunal Diversity in Telangana State: A Case Study in Campus of Professor Jayashankar Telangana State Agricultural University, Rajendranagar, Hyderabad, India

Population Studies on different agricultural and other bird species were carried out at Students farm, College farm, Agri biodiversity park, and Agricultural Research Institute farm areas of Professor Jayashankar Telangana State Agricultural University (PJTSAU) Campus in semiarid region of Telangana state covering an area of about 36 Sq.km. for a period of eleven years (2012 to 2023). Population diversity of 92 species of different birds, and their distribution within the university campus farm areas were recorded. Important among them are 9 species namely: Blue rock pigeon (Columba livia), Spotted dove (Streptopelia chinensis), Rose ringed parakeet (Psittacula krameri),Common myna (Acridotheres tristis), House crow (Corvus splendens), House sparrow (Passer domesticus), Baya weaver bird (Ploceus philippinus), White throated munia (Lonchura malabarica), and Peafowl (Pavo cristatus) which depredate experimental field crops among them only few birds such as: Rose ringed parakeets, House crows, House sparrows, Pigeons, Baya weavers, Peafowls and Munias were serious bird pests to major agricultural and horticultural crops. The University farm areas were found to be the most preferred habitat for many of these birds, it could be due to availability of food, breeding, roosting and resting sites in abundance because of more agricultural croplands and agro forestry trees.

Assessment of Cyclical Spreading and Ecological Extortions to the Avian Species in Distt. Jhang, Punjab, Pakistan

The study was conducted to estimate the bird diversity and the risks they confront at Head Trimmu, Distt. Jhang, Punjab, Pakistan. A number of field surveys were managed over 12-months by employing both direct and indirect means during certain hours of a day. The study found a total of 54 species from 15 orders and 31 families. The bird species were classified as residents (64.4%), breeders (8%), migrants (26%), and passage migrants (1.4%). The most frequent species observed during the study were house sparrow, house crow, domestic rock pigeon, ring-necked dove and common myna. Overall, the study revealed a diversified avian community with Shannon-Wiener diversity index of 3.3367. Only two species found near threatened like the Houbara bustard (Chlamydotis undulata)and Alexandrine parakeet (Psittacula eupatria) but the majority of the species are of least concern. The ecological richness of the area is under threat by urban development due to growing human population. So, the major threats to avian species in the study area are habitat degradation, Illegal hunting and lack of awareness. It is suggested to preserve avian diversity by the involvement of government agencies, private groups (WWF, IUCN, BirdLife International) and the general public.

Assessment of diversity, abundance, and seasonal variations of bird species in Bengaluru District, India during COVID-19 lockdown

The study investigates bird population dynamics in Bengaluru, India, post-lockdown, focusing on occurrence, seasonal abundance, species diversity, richness, dominance, and evenness. It covers 55 bird species across 52 genera, grouped into 32 families within 13 orders, with a notable peak in winter. Various indices, including Shannon Wiener, Margalef’s, Pielou’s, and Simpson’s, reveal significant seasonal differences in bird population characteristics. The Rock Pigeon Columba livia dominates, while the Black-headed Ibis Threskiornis melanocephalus is less prevalent. The study identifies Near Threatened species like Black-headed Ibis and Oriental Darter Anhinga melanogaster, along with Least Concern species per the IUCN Red List. Common species include Rock Pigeon, Large-billed Crow Corvus macrorhynchos, House Crow Corvus splendens, Black Drongo Dicrurus macrocercus, Brown Shrike Lanius cristatus, Common Myna Acridotheres tristis, Jungle Myna Acridotheres fuscus, Red-whiskered Bulbul Pycnonotus jocosus, and Streak-throated Swallow Petrochelidon fluvicola. The study aims to inform improved management and conservation strategies for Bengaluru’s diverse bird species.

The genome of a globally invasive passerine, the common myna, Acridotheres tristis.

In an era of global climate change, biodiversity conservation is receiving increased attention. Conservation efforts are greatly aided by genetic tools and approaches, which seek to understand patterns of genetic diversity and how they impact species health and their ability to persist under future climate regimes. Invasive species offer vital model systems in which to investigate questions regarding adaptive potential, with a particular focus on how changes in genetic diversity and effective population size interact with novel selection regimes. The common myna (Acridotheres tristis) is a globally invasive passerine and is an excellent model species for research both into the persistence of low-diversity populations and the mechanisms of biological invasion. To underpin research on the invasion genetics of this species, we present the genome assembly of the common myna. 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 evolution. Finally, we use demographic analysis to identify that some native regions underwent a dramatic population increase between the two most recent periods of glaciation, and reveal artefactual impacts of genetic bottlenecks on demographic analysis.

Socio-Cultural Impact of Avian Diversity in the Himalayan Region: A Comprehensive Study of Bird Species in Huddu Village, Chopta, and Deoriatal

The study employed a random visualization method to count and describe bird species in the Huddu Village, Chopta, and Deoriatal regions of the Himalayas. The data, collected through global positioning system (GPS) recordings between March and April, revealed 48 bird species across these areas, belonging to 20 different families and varying orders. The observations included 33 bird species in the Huddu region, 10 in Chopta, and 9 in Deoriatal, each displaying different elevations and geographical coordinates. Aside from birds, the fieldwork documented various flora and fauna species. The research detailed the relative abundance, distribution, and feeding habitats of bird species through recorded tables. Notable high-abundance species in Huddu Village included the streaked laughing thrush, common myna, various drongo species, grey treepie, and yellow or red-vented bulbul. Conversely, low-abundance species like alpine chough, Asian koel, scarlet minivet, and fire-breasted flowerpecker were rare, with their occurrences graphically depicted in the results. The identification of bird species utilized diverse methods, including internet resources and field guides. The study contributes valuable insights into the avian biodiversity of the Himalayan regions, emphasizing the importance of random visualization techniques and recording detailed ecological characteristics.

Predatory Birds Fauna of Desert Locust, Schistocerca gregaria (Forskal) (Acrididae: Orthoptera) in Barmer, Rajasthan (India)

This field study was conducted on birds as natural predators of desert locust, S. gregaria and recorded to be the indicator along the movement of hoppers during the occurrence. Eight birds were observed to prey on different stages of locust. Indian myna, common crow, spotted babbler in flocks, desert lark, variable wheatear in small groups and rock bush quail in group were observed to pick and feed on locust. However, Gouriya and Bagula in folks were observed to prey on I to II and III to IV instars hoppers but folks of both seen near villages. The congregation of any one or combination of species of the eight identified bird species can be used as the ‘indicators’ of presence of desert locust hoppers for survey by locust surveyors and to strategize further management practices.