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Acetylcholinesterase (AChE) activity levels can be used as an indicator for AChE inhibition due to pesticide poisoning in bird species. We assessed the comparative brain cholinesterase (AChE) activity level of five bird species inhabiting pesticide exposed croplands and Protected Area i.e. Deva Vatala National Park (DVNP), Bhimber by using a spectrophotometric method. AChE activity levels ranged from 56.3 to 85.9 µmol/min/g of brain tissue of birds representing DVNP. However, AChE activity levels ranged from 27.6 to 79.9 µmol/min/g of brain tissue of birds representing croplands. AChE activity levels observed in Jungle babbler, Common babbler, and Red-vented bulbul showed significant differences (P < 0.05) at two sites. However, White wagtail and Black drongo demonstrated non-significant differences (P > 0.05). Maximum inhibition was recorded in Jungle babbler (53%) followed by Common babbler (35%), Red-vented bulbul (18%), White wagtail (15%), and Black drongo (7%). The brain cholinesterase inhibition levels under-protected ecosystems (DVNP, Bhimber) and agricultural landscape suggest insecticidal contamination and its impact on avifauna diversity. The study also emphasizes on the importance of pesticide-free zones to protect the biodiversity of birds. Resumo Os níveis de atividade da acetilcolinesterase (AChE) podem ser usados como um indicador para a inibição da AChE devido ao envenenamento por pesticidas em espécies de aves. Avaliamos o nível de atividade comparativa da colinesterase cerebral (AChE) de cinco espécies de aves que habitam áreas cultivadas expostas a pesticidas e Área Protegida, ou seja, Deva Vatala National Park (DVNP), Bhimber, usando um método espectrofotométrico. Os níveis de atividade da AChE variaram de 56,3 a 85,9 µmol / min / g de tecido cerebral de aves representando DVNP. No entanto, os níveis de atividade da AChE variaram de 27,6 a 79,9 µmol / min / g de tecido cerebral de aves representando áreas de cultivo. Os níveis de atividade de AChE observados no tagarela da selva, tagarela comum e bulbul vermelho exalado mostraram diferenças significativas (P < 0,05) em dois locais. No entanto, alvéola branca e drongo preto demonstraram diferenças não significativas (P > 0,05). A inibição máxima foi registrada no tagarela da selva (53%), seguido pelo tagarela comum (35%), bulbul vermelho (18%), alvéola branca (15%) e drongo preto (7%). Os níveis de inibição da colinesterase cerebral nos ecossistemas subprotegidos (DVNP, Bhimber) e na paisagem agrícola sugerem contaminação por inseticida e seu impacto na diversidade da avifauna. O estudo também enfatiza a importância das zonas livres de pesticidas para proteger a biodiversidade das aves.

BackgroundMixed-species flocks (MSFs) have been well sampled in the South Asia, but there has been as yet surprisingly little work on MSFs of Nepal, despite a diverse and well-studied avifauna. We surveyed MSFs in two forest types in and around the Important Bird Area of Chitwan National Park in Nepal, between 150 and 800 m a.s.l., to provide a first description of the composition of MSFs in this area. We also aimed to understand which species should be considered ‘nuclear species’, important to forming MSFs or leading them forward.ResultsIn total, we collected records on 222 MSFs that included 100 species, and 6097 individuals. The MSFs were similar to worldwide patterns in being dominated by leaf-gleaning, non-terrestrial insectivores. However, the MSFs were more dominated by canopy species than usual, and did not have a clear gregarious, understory leading species. Rather drongos (Family Dicruridae) and minivets (Family Campephagidae, GenusPericrocotus) acted as leaders, and a cluster analysis of composition showed one group of large body size MSFs particularly characterized by the presence of the Greater Racket-tailed Drongo (Dicrurus paradiseus).ConclusionsDrongos are known to provide both costs and benefits to other flock participants: they are aggressive birds that can steal food, and manipulate other species with their vocalizations, but at the same time they are ‘sentinel species’ that produce information about predation risk other species can use. This study demonstrates that drongos can be considered nuclear species for some types of MSFs, despite the potential costs of their presence. MSFs led by sentinel species thus may form in Asia, as well as in the Neotropics.

In April 2013, a transect c. 1100 km long with 100 points arranged in 5 sections was designed in northern Namibia between Ruacana Watefall (W) and Kongola (E) to study avian diversity in relation to gradual changes in precipitation (c. 350 mm in W to c.600 mm in E). In total, 81 bird species were recorded in all 100 points, but in particular section, the numbers were low, ranging from 22 to 38 species. In overall, the most frequent and most numerous (dominant) were the following species: Cape Turtle Dove, Blue Waxbill, Grey-headed Sparrow, Laughing Dove and Fork-tailed Drongo. Together they comprised 42.2 % of all individuals recorded. All of them, except for the Fork-tailed Drongo, were granivores. Only nine species were recorded in ten or more points. Besides the above-mentioned dominant species, the following other were in this group: Black-chested Prinia, Black-throated Canary, Pied Crow and White-browed Scrub Robin. In particular section the number of dominant species ranged from 5 to 7, without a gradient. Two species, the Cape Turtle Dove and Blue Waxbill, remained dominant in all fi ve sections. Th e Laughing Dove and Fork-tailed Drongo — in four sections, and the Grey-headed Sparrow — in three sections. Although, no gradient in species diversity, evenness, and dominance structure was recorded, signifi cant diff erences between two most western and two most eastern sections were apparent. Two species were more frequent and numerous in the eastern than in the western sections: White-browed Scrub Robin and Cape Turtle Dove; while the following species were more frequent and numerous in the western than the eastern sections: African Palm Swift , Black-chested Prinia, Black-throated Canary, Blue Waxbill, Grey-headed Sparrow and Pied Crow.

The Black Drongo Dicrurus macrocercus is a bird belonging to the group Passeriformes, distributed almost all over the country in China. The conservation status of this species is Least Concern (LC) in IUCN. In this study, the complete mitogenome of D. macrocercus was determined. The mitochondrial DNA is packaged in a compact 17,056 based pair (bp) circular molecule with A + T content of 57.04%. It contains 37 typical mitochondrial genes, including 13 protein-coding genes, 2 rRNAs and 22 tRNAs, and 1 non-coding regions. We reconstructed a phylogenetic tree based on mitogenome sequences of 15 Dicruridae species and one outgroup. In trees, D. macrocercus was clustered as an independent clade with high support value (100). The new mitogenome data would provide useful information for application in conservation genetics and further clarify the phylogenetic evolution of this species.

Black Drongo is an insectivorous bird native to Pakistan. The present study focused on its feeding preferences, behaviour, ecology and habitat relationships. The study was carried out from first week of December, 2019 to the second week of April, 2020 in the two villages of Rawalpindi named as Daultala (Location-I) and Nata Gujarmall (Location-II). Observations were made by point count method on foot using line transect method. Air (52.27%) was the most commonly used feeding substrate. Aerial feeding mode (52.27%) is preferred over plant or tree gleaning (n=58) and ground feeding (n=47). Most common perching site was man made obstacle, wire (37.72%). Thirteen indigenous tree species and two exotic trees including Eucalyptus (Eucalyptus camaldulensis) and Bottle brush (Callistemon citrinus) were used as perching site by Black Drongo throughout the study. Black Drongo remained solitary (36.36%) during feeding rituals and shared (63.63%) its intimate habitat with other birds. At Location-I and Location-II, habitat was shared with 12 and 16 bird species, respectively. The mean time of prey capturing attempt was lower at Location-I (1.93±0.17 min) than Location-II (2.16±0.16 min). The time range of prey capturing attempt was (0.1±0.16 min) to (11.5±0.17 min). Black Drongo captured prey successfully by first attempt (59.54%), maximum attempts noted were 6. After preying attempts Black Drongo came back to same perch site (67.27%); which is a representative of resource abundance.

The validity of recent changes in the taxonomic treatment of the Square-tailed Drongo Dicrurus ludwigii is assessed via analyses of morphological, morphometric, acoustic and distributional evidence. In addition to confirming the characters already recognised to distinguish West and Central African sharpei from the ludwigii group, we report previously undocumented but notable differences in voice and tail morphology. The occurrence of a hitherto unrecognised population of sharpei in south-east DR Congo, inferred from recent molecular studies, is confirmed, whilst evidence of the close approach of the two taxa in north-west Angola, within c.60 km of each other, further supports their distinctiveness. The proposal to separate sharpei itself into two species—with populations west of the Niger River recognised as occidentalis—is, however, not supported by vocal data, whilst differences in bill size, the sole known physical discriminant, are here found to be much more modest than previously reported, perhaps attributable to the larger sample sizes used in this study. Thus, on phenetic evidence, occidentalis merits no more than subspecific status.

Summary: Collective cell migration is involved in various developmental and pathological processes, including the dissemination of various cancer cells. During Drosophila melanogaster oogenesis, a group of cells called border cells migrate collectively toward the oocyte. Herein, we show that members of the Arf family of small GTPases and some of their regulators are required for normal border cell migration. Notably, we found that the ArfGAP Drongo and its GTPase-activating function are essential for the initial detachment of the border cell cluster from the basal lamina. We demonstrate through protein localization and genetic interactions that Drongo controls the localization of the myosin phosphatase in order to regulate myosin II activity at the back of the cluster. Moreover, we show that toward the class III Arf, Drongo acts antagonistically to the guanine exchange factor Steppke. Overall, our work describes a mechanistic pathway that promotes the local actomyosin contractility necessary for border cell detachment. : Zeledon et al. identify the ArfGAP Drongo as a regulator of border cell migration in Drosophila. Drongo acts antagonistically to the ArfGEF Steppke on Arf51F. By keeping the activity of Arf51F low, Drongo prevents the recruitment of myosin phosphatase and ensures proper contractility at the back of border cell clusters. Keywords: collective cell migration, Arf GTPases, actomyosin contractility, Drosophila, border cell migration, myosin phosphatase

The common passerine bird species of Bangladesh, the Black Drongo (Dicrurus macrocercus), was collected between November 2013 and March 2014 from paddy fields around the Chittagong University campus to study endohelminth parasites. In total, four helminth adult parasite species, one trematoda (Eumegacetes triangularis), one cestoda (Notopentorchis sp.), two nematoda (Viguiera dicrurusi and Diplotriaena bargusinica) and single unidentified pleurocercoid larva were evident from the body cavity and digestive tracts of the sampled birds. With prevalence, mean intensity and abundance of 52.94%, 3.33 ± 3.04 and 1.76, respectively. It was apparent that the nematodes were the most prevalent (41.18%) species and the male (60%) hosts were found to be more susceptible to infection with the helminths. The mean intensity and the abundance of male also followed the same trend. However, the maximum (100%) prevalence was in February 2014. Parasitic abundance was found to be dependent with total length (t = 40.19, p = 0.000), body length (t = 31.97, p = 0.000) and body weight (t = 39.88, p = 0.000) of the host. Among the identified helminths E. triangularis, Notopentorchis sp. and Diplotriaena bargusinica are the new records for Bangladesh and from the present host. Stomach contents showed that the bird is affirmed as insectivorous, predominant abundance of insect (97-100%) having an abundance gradient of lepidopteran > odonates > dipteran > coleopterans > hemipterans > hymenopterans. The present study coincided with the winter and spring season of an isolated study area, i.e. Chittagong University campus only. Therefore, a detailed study is expected to have a complete helminth profile and epidemiological aspects of the present host at different ecological areas of the country. Bangladesh J. Zool. 47(1): 159-171, 2019

This paper explores impoliteness-related discourse on Facebook as a form of expressing situated moral judgement. The analysis focuses on negative and aggressive comments as a response to one public post that claims the non-existence of Australia. The content of the post indicates the threat to national identity of anyone who associates themselves with the country. As a result, a large number of impolite comments were made. A qualitative analysis of the dataset (limited to one month from the post’s publication) reveals four main strategies that are used in order to express the judgement of the post’s inappropriateness and repair the wrongdoing. Those range from insults of the author’s mental abilities and suspicion of drug use to violence-related discourse (e.g., death threats) and counter-attack of the author’s national identity. This paper, thus, aims to contribute to a growing area of research into online impoliteness.

The Black Drongo (Dicrurus macrocercus) is an important beneficial bird widespread in China and other Asian countries. In this study, a complete mitochondrial genome of D. macrocercus has been obtained by polymerase chain reaction method for the first time. This circular molecule is 17,017 bp in length with A + T contents of 56.9% and contains 2 rRNA genes, 13 protein-coding genes, and 22 tRNA genes. Phylogenetic analysis shows that D. macrocercus is genetically closest to D. hottentottus.

La migration cellulaire joue un rôle essentiel dans le développement des organismes multicellulaires et dans certaines pathologies comme le cancer, où elle permet la formation de métastases. Le trafic vésiculaire est un régulateur clé de la migration cellulaire, notamment en contrôlant la localisation de protéines impliquées dans la migration telles que les intégrines, les cadhérines et les récepteurs transmembranaires. En particulier, notre laboratoire a montré que l'endocytose contrôle l'orientation et la communication cellulaire durant la migration cellulaire collective. Notre hypothèse est que d'autres événements du trafic vésiculaire pourraient aussi être impliqués dans ce type de migration. Ainsi, le but de cette thèse a été de déterminer la fonction des petites GTPases Arf, importantes pour la formation de vésicules et le tri de cargo dans ces vésicules et de leurs régulateurs dans la migration cellulaire collective. Un modèle pour étudier la migration cellulaire collective est les chambres d’œufs de Drosophila melanogaster. En effet, lors de l’ovogénèse, des cellules folliculaires appelées cellules de bordure migrent à travers les cellules nourricières pour atteindre l’ovocyte. Conformément à notre hypothèse, un fort défaut de migration est observé lorsque les Arfs sont déplétées spécifiquement dans les cellules de bordure. De plus, un constat similaire est observé après la déplétion de certains régulateurs des Arfs (ArfGAPs et ArfGEFs). Notamment, nous avons démontré que l’ArfGAP Drongo et sa fonction d'activation de l’activité GTPase sont essentielles pour le détachement initial des cellules de bordure du tissu folliculaire. Drongo promeut le détachement en contrôlant la localisation de la myosine phosphatase afin de réguler l’activité de la myosine II à l’arrière des cellules. De plus, nous avons montré que Drongo agit sur l’Arf de classe III (Arf51F) de manière antagoniste à l’ArfGEF Steppke pour déplacer la myosine phosphatase de l’arrière du groupe de cellules. D’un autre côté, nous avons aussi démontré qu’une autre GAP, ArfGAP1, contrôle la directionnalité de migration. Cette ArfGAP agit potentiellement en régulant la localisation de certains déterminants de la migration tels que l’E-cadhérine et les récepteurs tyrosine kinase. Ainsi, nos recherches ont démontré un rôle essentiel des Arfs ainsi que des rôles spécifiques de deux ArfGAPs dans la migration cellulaire collective., Cell migration is implicated in various important biological processes, notably it is central for the dissemination of cancer cells. Vesicular trafficking is a key regulator of cell migration, notably by controlling the localisation of proteins involved in migration such as integrins, cadherins and transmembrane receptors. In particular, our laboratory has shown that endocytosis controls orientation and cellular communication during collective cell migration. Our hypothesis is that other events of vesicular trafficking might be implicated in collective cell migration. Thus, the purpose of this thesis was to assess the function of small GTPases Arf, important for vesicle formation and cargo sorting into those vesicles, and their regulators in collective cell migration. A powerful model to study collective cell migration is the migration of follicular cells named border cells during oogenesis in Drosophila melanogaster. Border cells (BCs) detach from the follicle epithelium surrounding the egg chambers and form a small cluster of six to ten cells that migrates invasively between the giant nurse cells that compose the center of the egg chamber, toward the oocyte. Accordingly to our hypothesis, a strong migration defect is observed when the Arfs are depleted specifically in the border cells. Moreover, a similar finding is observed after depletion of some Arfs regulators (ArfGAPs and ArfGEFs). In particular, the ArfGAP Drongo and its GTPase-activating function are essential for the initial detachment of the border cell cluster from the basal lamina. We demonstrated through protein localization and genetic interactions that Drongo controls the localisation of the myosin phosphatase in order to regulate myosin II activity at the back of the cluster and promote border cells detachment. Moreover, we showed that Drongo acts on the class III Arf (Arf51F) antagonistically to the guanine exchange factor Steppke to displace myosin phosphatase from the back of the cluster. On the other hand, we have also demonstrated that the GAP ArfGAP1 controls the directionality of migration. This ArfGAP potentially acts by regulating the localization of certain determinants of migration such as E-cadherin and receptors tyrosine kinase. Thus, our research has demonstrated an essential role for Arfs in collective cell migration and specific contributions of two ArfGAPs in this migration process.

The Spangled Drongo Dicrurus bracteatus, a partly-migratory passerine, was observed in bushland remnants in southern Sydney. Here, we report two incidents of Spangled Drongos hunting and feeding on small passerines from mixed flocks. One was seen chasing a Spotted Pardalote Pardalotus punctatus, consuming much of the carcass in 17 minutes. Another was seen ambushing a Brown Gerygone Gerygone mouki from a hunting perch. Interesting insights include proceeding to pluck feathers before the prey was dead and ingesting some of the feathers.

Individuals that retain their former partners often perform better than conspecifics that switch partners. This may be due to high-quality individuals being more faithful to their partners and more productive. Investigations of the fitness benefits of mate retention that also control for potential confounding effects of individuals are scarce. We studied the influence of mate retention and breeding experience on breeding performance of the hair-crested drongo (Dicrurus hottentottus) by carrying out both cross-sectional and longitudinal analyses. Pairs with longer pair-bond duration did not fledge more young or fledglings of better body condition nor did they produce more or better fledglings than newly formed pairs consisting of at least 1 experienced breeder, that is, individuals that had bred before. Individuals produced fewer fledglings when they were paired with an inexperienced breeder, especially when females were paired with inexperienced males. Although clutch size was not affected by mate retention or breeding experience, pairs consisting of inexperienced breeder(s) had a relatively higher predation rate of eggs and/or nestlings because they may be less effective in nest defense. The onset of breeding was advanced in the year following mate retention, but not in the second year thereafter, when pairs still remained together. Furthermore, only the breeding experience of the male determined the onset of breeding: Pairs consisting of inexperienced males bred later in the season. Our results suggest that breeding experience, and particularly the breeding experience of the male, but not mate retention, is important in determining the breeding performance of hair-crested drongos.

Over a period of five breeding seasons (between November 2008 and January 2013) the breeding behaviour—including nest-site selection, nest building, incubation and care of nestlings and fledglings—of the Spangled Drongo Dicrurus bracteatus was observed at Coowonga on the central Queensland coast, and from this the breeding success was estimated. The breeding season was from November to January, with a consistent start date from year to year. The incubation and nestling periods were also consistent from year to year. A nest was generally positioned in a tree near a clearing and in the outer part of that tree. Several factors contributed to nest-site selection: nest-tree species, habit and height, diameter of the tree’s outer branches, availability of dead branches, proximity of the nest-tree to a clearing and to water, and height of the nest above the ground. New findings were the frequent attachment of a nest to dead twigs and the consistent placement of a nest on the first branch below the spreading canopy of the tree. The occurrence of colonial breeding was more difficult to determine, with many features of this behaviour (such as group nesting and co-operative defence against predators) being evident, but nests were widely dispersed over a large area. Rotation of nest-sites may be used to minimise predation, with some Drongos using a nest-site one year, but not the next, and then returning to that nest-site the following year.

This research study investigated the diet and foraging ecology of the Fork Tailed Drongo (Dicrurusadsimilis) inLeventis Foundation Nigeria Agricultural Training School, South Western Nigeria. Direct field observation method was used to collect data for 12 months on the diet and foraging ecology of these bird species. The study area was divided into three compartments according to land use types (secondary forest, Farmland and Developed Area). The result revealed that the Fork Tailed Drongo consumed variety of insects and pla nt species resources in the study area.Grasshoppers, butter flies and termites are the majorfood source and they also consumed the leaves and flowers of the Moringaoleifera and seeds, fruits of some tree species. Insect species provided the highest food source of 86% and plant species 14%. The result revealed that the Fork Tailed Drongo utilized the three Compartments within the study area and that secondary forest provided highest food materials of 65%, Farmland 23% and Developed area 12%.

The vertebrate diversity at the foot of Gunung Tebu Forest Reserve (GTFR) is not well documented therefore a study was conducted at lowland dipterocarp forest of Gunung Tebu Forest Reserve, Terengganu from 7th to 13th August 2016 and 27th August 2016 to 2nd September 2016 to record and construct a checklist of vertebrates from selected taxonomic group i.e.; mammals, aves and amphibians. A total of 470 individuals were observe and recorded consisting of 16 species of mammals (8 families and 4 orders), 64 species of aves (25 families and 10 orders) and 20 species of herpetofauna (6 families and a single order). The highest species abundance for bats recorded was Bicoloured Roundleaf Bat (Hipposideros bicolor) whereas for birds, the Greater Racket-tailed Drongo (Dicrurus paradiseus) shown highest species observed meanwhile for anurans, the highest species abundance documented was Spotted Litter Frog (Leptobrachium hendricksoni). An increase of sampling effort, number of transects and survey period could increase the number of species recorded in the area.

We describe a new species of drongo in the Square-tailed Drongo (Dicrurus ludwigii) complex using a combination of biometric and genetic data. The new species differs from previously described taxa in the Square-tailed Drongo complex by possessing a significantly heavier bill and via substantial genetic divergence (6.7%) from its sister-species D. sharpei. The new species is distributed across the gallery forests of coastal Guinea, extending to the Niger and Benue Rivers of Nigeria. We suspect that this taxon was overlooked by previous avian systematists because they either lacked comparative material from western Africa or because the key diagnostic morphological character (bill characteristics) was not measured. We provide an updated taxonomy of the Square-tailed Drongo species complex.

SummaryLong-term survey data can provide important information on temporal and spatial changes in bird populations and are needed for conservation management. We investigate population indices of seven landbird species using an 11-year dataset from the UNESCO World Heritage Site of Aldabra Atoll. We analysed the associations of location, season and habitat with abundance, assessed population trends, and examined the influence of monitoring circumstances on results. Populations of all species except for the Aldabra Drongo Dicrurus aldabranus increased over this period. Abundance was associated with season and habitat, and interactions were found between season and location that differed for each species. Bird count results were affected by the timing of monitoring, number of observers and weather conditions. We use the results to review the strengths and weaknesses of the current monitoring programme and make recommendations for improvements. Overall our results indicate no immediate cause for conservation concern for the Aldabra landbird species monitored.

The western Pacific island of Rota is the fourth largest human-inhabited island in the Mariana archipelago and designated an Endemic Bird Area. Between 1982 and 2012, 12 point-transect distance-sampling surveys were conducted to assess bird population status. Surveys did not consistently sample the entire island; thus, we used a ratio estimator to estimate bird abundances in strata not sampled during every survey. Trends in population size were reliably estimated for 11 of 13 bird species, and 7 species declined over the 30-y time series, including the island collared-dove Streptopelia bitorquata, white-throated ground-dove Gallicolumba xanthonura, Mariana fruit-dove Ptilinopus roseicapilla, collared kingfisher Todiramphus chloris orii, Micronesian myzomela Myzomela rubratra, black drongo Dicrurus macrocercus, and Mariana crow Corvus kubaryi. The endangered Mariana crow (x̄ = 81 birds, 95% CI 30–202) declined sharply to fewer than 200 individuals in 2012, down from 1,491 birds in 1982 (95% CI = 815–3,115). Trends increased for white tern Gygis alba, rufous fantail Rhipidura rufifrons mariae, and Micronesian starling Aplonis opaca. Numbers of the endangered Rota white-eye Zosterops rotensis declined from 1982 to the late 1990s but returned to 1980s levels by 2012, resulting in an overall stable trend. Trends for the yellow bittern Ixobrychus sinensis were inconclusive. Eurasian tree sparrow Passer montanus trends were not assessed; however, their numbers in 1982 and 2012 were similar. Occupancy models of the 2012 survey data revealed general patterns of land cover use and detectability among 12 species that could be reliably modeled. Occupancy was not assessed for the Eurasian tree sparrow because of insufficient detections. Based on the 2012 survey, bird distribution and abundance across Rota revealed three general patterns: 1) range restriction, including Mariana crow, Rota white-eye, and Eurasian tree sparrow; 2) widespread distribution, low abundance, including collared kingfisher, island collared-dove, white-throated ground-dove, Mariana fruit-dove, white tern, yellow bittern, black drongo, and Micronesian myzomela; and 3) widespread distribution, high abundance, including rufous fantail and Micronesian starling. The Mariana crow was dispersed around the periphery of the island in steep forested land-cover types. In contrast, the Rota white-eye was restricted to the high-elevation mesa. Only for the white-throated ground-dove was there a significant difference among cover types, with lower occupancy in open field than in forested areas. Vegetation was included in the best-fit occupancy models for yellow bittern, black drongo, Micronesian myzomela, and Micronesian starling, but vegetation type was not a significant variable nor included in the top models for the remaining five species: white tern, island collared-dove, Mariana fruit-dove, collared kingfisher, and rufous fantail. Given declining population trends, the Rota bird-monitoring program could benefit from establishing threshold and alert limits and identifying alternative research and management actions. Continued monitoring and demographic sampling, in conjunction with ecological studies, are needed to understand why most bird species on Rota are declining, identify the causative agents, and assess effectiveness of conservation actions, especially for the Mariana crow.

Currently, the attempt to choose the "best" content replica server for a client is carried out solely by CDNs. While CDNs have a decent view of load distribution and content placement, they receive little input from the clients themselves. We propose a hybrid solution, subnet assimilation, where the client participates in the server selection process while still leaving the final say to the CDN. Subnet assimilation allows clients to declare their own "network location," different from the actual one, which in turn drives a CDN towards making better decisions. To demonstrate, we introduce Drongo, a client-side system, readily deployable on existing clients without any changes to the CDNs, that employs subnet assimilation to dramatically improve replica server selection. We implemented and extensively evaluated Drongo on a set of 429 clients spread across 177 countries and 6 major CDNs. We show that Drongo affects 69.93% of all clients, prompting better CDN replica choices which reduce the latency of affected requests by up to an order of magnitude and by 24.89% on average across six major providers, with Google's performance improving by 50% in the median case. Our results indicate that client participation holds great opportunities for the advancement of CDN performance.

In order to estimate the diversity and status of avian species of Curzon Hall premises, University of Dhaka, Bangladesh, a study was conducted from January 2012 to January 2014. A total of 50 species of birds belonging to 30 families under 12 orders were recorded of which, regarding the relative abundance, 29 were common and 21 were uncommon. Twenty five species, in total, were identified as breeding residents, 13 as non-breeding residents and 12 as migrants. Of all the species identified from the study site, one was Critically Endangered (Alexandrine Parakeet Psittacula eupatria ) and six were new for the campus (Taiga Flycatcher Ficedula albicilla, Indian Silverbill Lonchura malabarica, Ashy Drongo Dicrurus leucophaeus, Eurasian Wryneck Jynx torquilla, Pied Cuckoo Clamator jacobinus, Lesser Whistling Duck Dendrocygna javanica ). Passerines were the dominating group as represented by 27 species from 16 different families. Species richness was in the highest peak in the late winter and early spring and comparatively less in other seasons. DOI: http://dx.doi.org/10.3126/eco.v20i0.11324 Ecoprint: An International Journal of Ecology Vol. 20, 2013 Page : 1-8

A growing number of studies have shown that vocal mimicry appears to be adaptive for some bird species, although the exact function of this behaviour varies among species. Previous work has looked at the function of the vocal mimicry of non-alarm sounds by the Greater Racket-tailed Drongo (Dicurus paradiseus). But drongos also imitate sounds associated with danger, such as predators' vocalisations or the mobbing-specific vocalisations of other prey species, raising the question of whether the function of mimicry can vary even within a species. In a playback experiment, we compared the effect on other species of different drongo vocalisations including: (1) predator mimicry, (2) mobbing mimicry, (3) drongo species-specific alarms, (4) drongo species-specific non-alarms and (5) a control (barbet) sound. Both mobbing mimicry and drongo species-specific alarms elicited flee responses from the most numerous species in the flocks, the Orange-billed Babbler (Turdoides rufescens). Mobbing mimicry also elicited mobbing responses from the Orange-billed Babbler and from another gregarious babbler, the Ashy-headed Laughingthrush (Garrulax cinereifrons); when responses from both species were considered together, they were elicited at a significantly higher level by mobbing mimicry than by the barbet control, and a level that tended to be higher (0.07lpl0.10) than the response to drongo-specific alarms. Predator mimicry elicited flee and mobbing responses at an intermediary level. Our results support the hypotheses that mobbing mimicry is a specific category of mimicry that helps attract the aid of heterospecifics during mobbing and that alarm mimicry can in some cases be beneficial to the caller.

Several species of birds vocally imitate sounds associated with danger. Two anecdotal studies suggest that such ‘danger mimicry’ increases during nesting, but such a relationship has not been quantitatively demonstrated. Sri Lanka drongos (Dicrurus paradiseus lophorhinus) are known to imitate predators and other species’ mobbing and alarm calls in alarm contexts. Here we investigated whether drongos vary their production of danger mimicry in different nesting stages (building, incubation, nests with hatchlings, fledglings still outside of mixed-species flocks), and when foraging away from young in mixed-species flocks. We recorded drongos over two breeding seasons at 14 different nesting trees, used year-after-year. We found that of all the types of danger mimicry, imitation of predators was the most common and exclusive to drongos that had young offspring. Such predator mimicry was observed at a higher rate during the hatchling and fledgling stages compared to incubation or flocks. Danger mimicry did not, however, increase during this stage in isolation: drongo species-specific alarm calls also increased, and the close connection between these two types of calls did not appear to change. Although it is possible that the association between danger mimicry and species-specific alarm calls could help young birds learn sounds associated with danger, the performance of this behaviour does not seem exclusive enough to interactions between adult drongos and their offspring to meet functional definitions of teaching.

We conduct a phylogeographic study of the Crested Drongo (Dicrurus forficatus forficatus), a broadly distributed bird species on Madagascar. We first determined the demographic and spatial pattern inferred from mitochondrial and nuclear data, and then compared these results with predictions from a present to 0.120-Myr-old reconstruction of the spatial dynamics of the range of D.f.forficatus on Madagascar, enabling putative areas of stability (lineage persistence) to be detected. Weak genetic structure along an eastwest pattern and comparatively low genetic diversity were recovered, with strong evidence of population expansion found at all ten loci sampled. The palaeoclimatic distribution models over the past 0.120Myr suggest the presence of extensive areas of suitable climate in the east and west for the species since its colonization of Madagascar, a result in strong concordance with the spatial and genetic signal derived from our multilocus data set.

To achieve proper RNA transport and localization, RNA viruses exploit cellular vesicular trafficking pathways. AGFG1, a host protein essential for HIV-1 and Influenza A replication, has been shown to mediate release of intron-containing viral RNAs from the perinuclear region. It is still unknown what its precise role in this release is, or whether AGFG1 also participates in cytoplasmic transport. We report for the first time the expression patterns during oogenesis for Drongo, the fruit fly homolog of AGFG1. We find that temporally controlled Drongo expression is achieved by translational repression of drongo mRNA within P-bodies. Here we show a first link between the recycling endosome pathway and Drongo, and find that proper Drongo localization at the oocyte's cortex during mid-oogenesis requires functional Rab11.

Different species of brood parasitic birds, which lay their eggs in the nests of host foster-parents, rarely target the same host species population. We report brood parasitism of Fork-tailed Drongos Dicrurus adsimilis in the southern Kalahari Desert by both African Cuckoo Cuculus gularis and Jacobin Cuckoo Clamator jacobinus serratus. Drongos are the only known host for the African Cuckoo, and were more frequently parasitised by this species (21.8% nests). Nevertheless, parasitism rates suggest that in the Kalahari, drongos are also an important host for Jacobin Cuckoo (4.6% nests). Jacobin Cuckoos likely compete with African Cuckoos for drongo hosts, as exemplified by the occurrence of both African and Jacobin Cuckoo eggs in the same drongo clutch. The drongo’s defensive adaptations to parasitism by African Cuckoos, including egg rejection, may also curtail parasitism by Jacobin Cuckoos. The extent of competition between these cuckoo species and whether they possess adaptations to prevent one another’s access to drongo hosts remains to be explored.Keywords: alloxenia, brood parasitism, coevolution, host selection, offspring competition

Fork-tailed drongos, Dicrurus adsimilis, are facultative kleptoparasites of many bird and mammal species. They use complex alarm call strategies, a combination of both true and false alarm calls, to procure food items from their hosts. The evolution of this interspecific interaction may have been catalysed by a selective benefit for drongos that were able to procure a wider diversity of food resources through kleptoparasitism. We tested the hypothesis that drongos, which principally hawk their prey from a perch, employ kleptoparasitism to exploit a terrestrial foraging niche for which they do not possess the appropriate morphological adaptations, as indicated by bill morphology. We analysed the bill characteristics of the terrestrially foraging pied babbler, Turdoides bicolor, a primary host for the fork-tailed drongo, and both drongo and pied babbler museum specimens to establish potential links between differences in functional morphology and foraging ecology. We also observed the foraging behaviour of babblers and drongos in the Kalahari Desert. Drongo bills were significantly shorter, thicker and less curved than those of pied babblers, and large energy-rich subterranean prey items, such as insect larvae, were not procured by drongos while self-foraging. Furthermore, drongos preferentially attempted to kleptoparasitize prey types that they did not capture while self-foraging. We suggest that the calorific and nutrient content of a larger and more diverse set of prey, particularly buried larvae, which drongos did not excavate on their own, establishes a selection pressure for kleptoparasitism and may have contributed to the complex behavioural interactions between drongos and their hosts.

The interaction between brood parasitic cuckoos and their hosts represents a traditional example of coevolution, whereby obligate interspecific brood parasitic cuckoos completely rely on their hosts to do their parental care for them by laying their eggs in the host’s nest. This thesis brings together a great deal of information documenting and clarifying the interactions between different species of hosts and their respective parasitic cuckoos in Bangladesh. I recorded parasitism rates to determine the extent of brood parasitism and to identify the host species that were parasitised by sympatric cuckoos. Four parasitic cuckoos were documented: the Asian koel ( Eudynamys scolopacea), the common hawk cuckoo (Cuculus varius; previously known as Hierococcyx varius), the pied cuckoo (Clamator jacobinus) and the Indian cuckoo (Cuculus micropterus). These cuckoos were sympatric and parasitised different host species, including the house crow (Corvus splendens), the long-tailed shrike (Lanius schach), the common myna (Acridotheres tristis), the jungle babbler (Turdoides striatus) and the black drongo (Dicrurus macrocercus). All of these cuckoo species are obligate brood parasites. The Asian koel utilised the following three hosts: the house crow, the common myna and the long-tailed shrike. The latter was recorded for the first time as a host for the Asian koel in Bangladesh. We found that koel eggs were highly non-mimetic to those of common myna and long-tailed shrike, but showed good mimicry to house crow eggs. Indian cuckoos showed excellent egg mimicry with the eggs of their black drongo hosts, as did common hawk cuckoos and pied cuckoos with their jungle babbler host. The hosts accepted the eggs of all four cuckoo species. However, the common myna was more likely to abandon nests parasitised by the koel than unparasitised ones. All of the host species suffered the costs of koel parasitism, showing reduced breeding success. Proximity to fruit trees was an important predictor of the probability of parasitism in the three koel host species studied. There was a significant positive relationship between nest volume and probability of parasitism by Asian koels. Furthermore, the colonial breeding house crows suffered comparatively less parasitism than the other two koel host species. Long-tailed shrike nests close to conspecific neighbours were less likely to be parasitised, and the risk of parasitism was increased in nests lower to the ground. The risk of parasitism increased during the breeding season for house crows and common mynas. All three Asian koel hosts tolerated multiple parasitism. We investigated whether there was any interspecific competition among the sympatric cuckoos. In theory, sympatric parasites should show niche segregation through variation in host use. As predicted, each cuckoo species parasitised different host species; however, host use overlapped in common hawk cuckoos and pied cuckoos, but interspecific competition was reduced because these two cuckoo species have different breeding seasons. Furthermore, there was a significant difference in parasitism rate among the three main habitats: human habitations, mixed scrub forests and monoculture plantations. This indicated that different cuckoos favour specific habitats, even if their favourite host also occurs elsewhere. Finally, I tested responses against foreign eggs by the cuckoo hosts as well as by potential cuckoo hosts in the study area. For this purpose, I used differently sized and coloured model eggs. Common mynas and jungle babblers accepted all non-mimetic eggs, as did most of the house crows (91 %). Long-tailed shrikes rejected 75 % of the non-mimetic model eggs. Finally, black drongos turned out to be strong rejectors and could do so without damaging any of their own eggs, most likely because they grasped and ejected the non-mimetic model egg. This result indicates that the black drongo has been in a coevolutionary arms race with the Indian cuckoo since drongos accepted mimetic cuckoo eggs. Species such as the Oriental magpie robin (Copsychus saularis), red-vented bulbul (Pycnonotus cafer) and Asian pied starling (Gracupica contra), which likely have no history of interaction with cuckoos, accepted 100 % of the non-mimetic model eggs. In conclusion, our findings describe host nest use cues used by the Asian koel, which may provide background for further studies in other sympatric brood parasites. In spite of the high degree of acceptance of parasitic eggs, the breeding success of both cuckoos and hosts should be more closely studied to obtain a better understanding of the costs of parasitism. Future experimental studies are highly recommended to achieve a better understanding of host responses to Asian cuckoo species.

This paper reports the foraging behavior of five insectivorous birds, namely White-breasted Kingfisher Halcyon smyrnensis, Small Bee-eater Merops orientalis, Indian Roller Coracias benghalensis, Common Myna Acridotheres tristis and Black Drongo Dicrurus macrocercus in Nagapattinam District of Tamil Nadu, India. The birds used a variety of perch types for hunting insect prey; in general the electric power line was a common perch type used by all species except the Common Myna. The perching and foraging height used by birds were classified into 3 meter categories, up to 12m. Aerial feeding or hawking in Bee-eaters and ground feeding in Common Mynas were major feeding techniques, recorded 68% and 86% of the time respectively. The other three species used gleaning as a feeding technique. The highest niche overlap was recorded between Indian Rollers and Black Drongos and between White-breasted Kingfishers and Indian Rollers.

The suggestion that some members of mixed-species bird flocks use alarm calls when predators are not present in order to startle other species and thereby gain access to additional prey, first postulated by Munn (Munn CA. 1986. Birds that ‘cry wolf’. Nature. 391:143–145.), has generated considerable interest due to its implication that the calling birds are intentionally deceiving listeners. Despite this interest, ‘‘false alarms’’ have been studied rarely and without detailed acoustical analysis. We explored whether false alarms are used by Greater Racket-tailed Drongos, which produce a distinctive set of notes when alarmed. We found that drongos did indeed make false alarms, defined as an alarm vocalization made either while the bird was on the perch or in the air, and followed within 10 s by a foraging attempt. However, the acoustic features of the call notes used, particularly of those calls made in the air, were more similar to aggressive calls, made when drongos chased each other, than to actual alarms produced when predators were present. Drongo foraging success was greater after false alarm calls than after silence or nonalarm vocalizations, and playback of false alarms in the air induced escape behavior in other species, though at a lower level than actual alarms. Thus, although drongos can use false alarms to startle other birds and gain foraging opportunities, such calls cannot be called ‘‘false’’ with certainty because they may also signal aggressive intent. Indeed, aggression and alarm may be intertwined in this family of birds as drongos actively mob or chase many predators, including bird-eating hawks. Key words: aggressive interactions, alarm calls, deception, Dicrurus paradiseus, false alarms, interspecific communication, mixed-species flocks. [Behav Ecol]

Mixed-species foraging associations may form to enhance feeding success or to avoid predators. We report the costs and consequences of an unusual foraging association between an endemic foliage gleaning tupaid (Nicobar treeshrew Tupaia nicobarica ) and two species of birds; one an insectivorous commensal (greater racket-tailed drongo Dicrurus paradiseus ) and the other a diurnal raptor and potential predator ( Accipiter sp.). In an alliance driven, and perhaps engineered, by drongos, these species formed cohesive groups with predictable relationships. Treeshrew breeding pairs were found more frequently than solitary individuals with sparrowhawks and were more likely to tolerate sparrowhawks in the presence of drongos. Treeshrews maintained greater distances from sparrowhawks than drongos, and permitted the raptors to come closer when drongos were present. Treeshrew foraging rates declined in the presence of drongos; however, the latter may provide them predator avoidance benefits. The choice of the raptor to join the association is intriguing; particular environmental resource states may drive the evolution of such behavioural strategies. Although foraging benefits seem to be the primary driver of this association, predator avoidance also influences interactions, suggesting that strategies driving the formation of flocks may be complex and context dependent with varying benefits for different actors.

While some avian mimics appear to select sounds randomly, other species preferentially imitate sounds such as predator calls that are associated with danger. Previous work has shown that the Greater Racket-tailed Drongo (Dicrurus paradiseus) incorporates predator calls and heterospecific alarm calls into its own species-typical alarm vocalizations. Here, we show that another passerine species, the Sri Lanka Magpie (Urocissa ornata), which inhabits the same Sri Lankan rainforest, imitates three of the same predator calls that drongos do. For two of these call types, there is evidence that magpies also use them in alarm contexts. Our results support the hypothesis that imitated predator calls can serve as signals of alarm to multiple species.

A study was conducted at the southern belt of Kaski District during August 2003 to July 2004 to identify natural enemies of honey bee Apis cerana Fab. and associated problems in beekeeping. Four species of wasps viz: Vespa velutina, V. bicolor, V. tropica and V. basalis were observed preying on Apis cerana. Six species of Ants were collected from hive attacking honey bees viz Componatus sp, Sima sp, Monomorium sp, Myrmica sp and two unidentified. Four species of spider viz Palatar indicus, Ariope areuta and the other two belonging to family Theridae and Araneidae were collected from the hives. Two species of Birds, Green bee- Eater and Drongo; One species of Beetle, One Chalcid ( Antrocephalus sp) were identified.The disease Thaisac brood, Mite, Wax Moth and pesticide damage, deforestation, absconding of bees, lack of technical knowledge were important problems for apiculture in study area. Key words: Apis cerana F; Enemies; Pesticide; Absconding; Kaski Journal of Natural History Museum Vol. 24, 2009 Page: 89-95

The dietary composition of the White-breasted Kingfisher Halcyon smyrnensis, the Small Bee-eater Merops orientalis and the Black Drongo Dicrurus macrocercus was studied between 2005 and 2006 in Nagapattinam District, Tamil Nadu, India by analyzing regurgitated pellets. The analysis revealed that the White-breasted Kingfisher preys mainly on arthropods (83.40%) and less on vertebrates; seven orders of insects were identified, with Coleoptera, Hemiptera, Hymenoptera and Orthoptera predominant. The small bee-eater diet is composed of Coleoptera (22.3%), Hymenoptera (20.8%), Hemiptera (14.1%), Orthoptera (12.6%), Odonata (10.7%), Lepidoptera (10.4%) and Diptera (8.6%). Beetles were also found to be the most frequent prey (23.7%) in the diet of black drongos, followed by Hemiptera (21.6%), Orthoptera (19.3%), Hymenoptera (14.4%), Lepidoptera (7.5%), Diptera (6.8%) and Odonata (6.0%).

Kleptoparasitism is a tactic used to acquire food opportunistically and has been shown to provide several benefits, including greater food intake rate and the acquisition of items not normally available during self-foraging. Host individuals may differ in their ability to defend themselves against kleptoparasitic attacks and therefore identifying those host individuals that are particularly vulnerable to attack could both provide energetic benefits and increase the efficiency of kleptoparasitism as a foraging strategy. Here, we show that the kleptoparasitic fork-tailed drongo (Dicrurus adsimilis) specifically targets juveniles when following groups of cooperatively breeding pied babblers (Turdoides bicolor). Drongos give alarm calls upon sighting a predator, thus providing extra predator vigilance to foraging pied babblers. However, drongos also use alarm calls to steal food items. During kleptoparasitic attacks, drongos give false alarm calls and then swoop down to steal food items dropped by alarmed babblers. Juvenile pied babblers are particularly vulnerable to attack because they (a) spend a longer period handling prey items prior to consumption and (b) respond to alarm calls primarily by immediately moving to cover, in contrast to adults who respond by looking up and visually scanning the surrounding area. Drongos attack juvenile babblers significantly more often than adults, with attacks on juveniles more likely to result in the successful procurement of a food item. This patterns of attack suggests that drongos are able to differentiate between individuals of different age when targeting pied babblers, thus increasing the efficiency of kleptoparasitism as a foraging strategy.

We studied a unique nest-dismantling behavior after fledging by Hair-crested Drongos (Dicrurus hottentottus) at the Dongzhai National Nature Reserve, Henan Province, China, during the summer of 2007. Of the 13 nests that fledged young, 12 were dismantled by the adults that built them after the young fledged. Some individuals initiated dismantling behavior on the same day the young birds left the nest and completed dismantling within a few days; others waited for a few days and took longer to finish. The mean rates of visitation and nest-dismantling behavior were 0.10 ± 0.04 and 0.06 ± 0.03 times hr-1 (± SE), respectively, once nest dismantling was initiated. We propose that the nest dismantling by the Hair-crested Drongo may be an adaptive behavior to increase fitness by reducing risk of future predation and competition for nest sites in the following breeding season.

The flow of information about predators in mixed-species groups is likely to influence the structure and organization of these communities. To map this flow, it is necessary to demonstrate in a playback experiment that animals use the information provided in heterospecific calls. We investigated the response of birds to conspecific and heterospecific calls in a mixed-species flock system of a Sri Lankan rainforest. We played back the aerial alarm calls of the species that produce the most alarms, the Orange-billed Babbler (Turdoides rufescens) and the Greater Racket--tailed Drongo (Dicrurus paradiseus), as well as natural choruses of alarm calls of several species, to 4 species of birds. We found that babblers moved quickly away from the playback speaker after hearing either babbler or drongo alarm calls. Ashy-headed Laughingthrushes (Garrulax cinereifrons) responded similarly to drongo alarm calls. Response by other species was less clear: Malabar Trogons (Harpectes fasciatus) stayed perched for longer during alarms of several species; drongos showed no difference in response to any treatment. We conclude that birds are listening to heterospecifics and suggest that their response is influenced by several factors, including their foraging technique. The fact that the babbler, the gregarious leading species of the flocks, gains information from another species is one of the first indications that such a "nuclear" species can benefit from its participation in mixed-species flocks, and the response of at least 2 species to drongo alarms emphasizes the importance sentinel species such as drongos may play in flock communities. Copyright 2008, Oxford University Press.

In many cases of interspecific kleptoparasitism, hosts develop defensive behaviors to minimize the impact of kleptoparasites. Because vigilance and defensive behaviors are often costly, selection should favor hosts that adjust the amount of investment needed to minimize losses to kleptoparasitism. However, examples of such facultative responses are rare. Here, we investigate the response of cooperatively breeding pied babblers (Turdoides bicolor) to the drongo (Dicrurus adsimilis), an avian kleptoparasite that regularly follows pied babbler groups, often giving alarm calls to alert the group to predators but also occasionally giving false alarm calls in order to steal food items. We show that pied babbler response to drongos varies markedly according to babbler group size. In small groups, where there are few individuals available to act as sentinels, babblers sentinel less when a drongo is present and respond strongly to drongo alarm calls. However, in large groups, where there are many individuals available to participate in predator vigilance, babblers sentinel more often when a drongo is present, rarely respond to drongo alarm calls, and aggressively displace drongos, with a consequent decline in the number of successful kleptoparasitism events. This behavior represent a facultative response to a kleptoparasite according to the costs versus benefits of tolerating their presence. Copyright 2007, Oxford University Press.

Little is known about how vocal mimicry affects the behaviour of members of other species. Such effects might, however, be especially likely in mixed-species flocks in which birds of some species directly benefit from the behaviour of members of other species. In mixed-species flocks in Sri Lanka, the greater racket-tailed drongo, Dicrurus paradiseus , mimics the songs and contact calls of other flock participants. We hypothesized that this mimicry attracts other species, as drongos are well known to increase their foraging efficiency in association with other species. Consistent with the predictions of this hypothesis, we recorded the most mimicked vocalizations during the rare occasions in which drongos were outside of flocks. In addition, we performed a playback experiment, which showed that taped drongo vocalizations that included song mimicry were more than twice as attractive to birds of other species as were taped vocalizations that lacked mimicry. We suggest that mimicry is a way in which drongos manage the behaviour of flockmates in what appears to be overall a mutualistic relationship.

How do birds select the sounds they mimic, and in what contexts do they use vocal mimicry? Some birds show a preference for mimicking other species' alarm notes, especially in situations when they appear to be alarmed. Yet no study has demonstrated that birds change the call types they mimic with changing contexts. We found that greater racket-tailed drongos ( Dicrurus paradiseus ) in the rainforest of Sri Lanka mimic the calls of predators and the alarm-associated calls of other species more often than would be expected from the frequency of these sounds in the acoustic environment. Drongos include this alarm-associated mimicry in their own alarm vocalizations, while incorporating other species' songs and contact calls in their own songs. Drongos show an additional level of context specificity by mimicking other species' ground predator-specific call types when mobbing. We suggest that drongos learn other species' calls and their contexts while interacting with these species in mixed flocks. The drongos' behaviour demonstrates that alarm-associated calls can have learned components, and that birds can learn the appropriate usage of calls that encode different types of information.