Waterbirds Research Articles

Modelling association of waterfowl conglomerations and anthropogenic multi-stressor at Najafgarh Jheel, Delhi, India

Globally the inland urban freshwater wetland biodiversity is facing threat due to anthropogenic activities. Scientist worldwide are understanding the complex linkages between ecological impacts due to human induced pollution. Wetland systems are susceptible to changes in quality and quantity of water. The paper will focus on water quality based stressors and indicative changes in biodiversity including resident and wintering avifauna density. The avifauna is an indicator towards wetland and health of its ecosystem services. The present study provides an overview of a tropical inland wetland (Najafgarh Jheel) in Delhi, India which is exposed to multiple anthropogenic stressors. The wetland is a proposed bird sanctuary and is facing acute conservation issues due to expanding urbanization and extensive agriculture. We measure the data for number of birds at nine census transect points. The census was conducted once a month for a period of one year (2017), early morning 6 am- 9 am. To each census transect we associated eleven points for water quality parameters. The wetland is organically loaded with agricultural runoff and unregulated sewage drains deteriorating quality of water. Therefore, water quality is an immediate local stressor for the resident and wintering birds. The water quality parameters were partially correlated and further modelled with yearly bird density. The generalized linear mixed models depicted that DO, BOD and TDS have higher effect on conglomeration of birds. Further, CCA plot between wintering birds and water quality from two consecutive year data was plotted. The analysis depict the interlinkages of wintering birds with specific stressor. The combination of these multiple stressors have synergistic and antagonistic effects that are decisive for management and restoration of a lake. The current hypothesis based on understanding short term freshwater research, implication towards local management policy and baseline for long term comprehensive studies with holistic approaches. The concept of understanding short-term linkages using multivariate data analysis between water quality and bird density is relatively untested in urban tropical wetlands of India.

Comparative transcriptome analysis identifies crucial candidate genes and pathways in the hypothalamic-pituitary-gonadal axis during external genitalia development of male geese

BackgroundAll birds reproduce via internal fertilization, but only ~3% of male birds possess the external genitalia that allows for intromission. Waterfowl (e.g., duck and goose) are representatives of them, and the external genitalia development of male geese is directly related to mating ability. Notably, some male geese show abnormal external genitalia development during ontogenesis. However, until now little is known about the molecular mechanisms of the external genitalia development in goose. In the present study, comparative transcriptomic analyses were performed on the hypothalamus, pituitary gland, testis, and external genitalia isolated from the 245-day-old male Tianfu meat geese showing normal (NEGG, n = 3) and abnormal (AEGG, n = 3) external genitals in order to provide a better understanding of the mechanisms controlling the development of the external genitalia in aquatic bird species.ResultsThere were 107, 284, 2192, and 1005 differentially expressed genes (DEGs) identified in the hypothalamus, pituitary gland, testis and external genitalia between NEGG and AEGG. Functional enrichment analysis indicated that the DEGs identified in the hypothalamus were mainly enriched in the ECM-receptor interaction pathway. The ECM-receptor interaction, focal adhesion, and neuroactive ligand-receptor interaction pathways were significantly enriched by the DEGs in the pituitary gland. In the testis, the DEGs were enriched in the neuroactive ligand-receptor interaction, cell cycle, oocyte meiosis, and purine metabolism. In the external genitalia, the DEGs were enriched in the metabolic, neuroactive ligand-receptor interaction, and WNT signaling pathways. Furthermore, through integrated analysis of protein-protein interaction (PPI) network and co-expression network, fifteen genes involved in the neuroactive ligand-receptor interaction and WNT signaling pathways were identified, including KNG1, LPAR2, LPAR3, NPY, PLCB1, AVPR1B, GHSR, GRM3, HTR5A, FSHB, FSHR, WNT11, WNT5A, WIF1, and WNT7B, which could play crucial roles in the development of goose external genitalia.ConclusionsThis study is the first systematically comparing the hypothalamus, pituitary gland, testis, and external genitalia transcriptomes of male geese exhibiting normal and abnormal external genitals. Both bioinformatic analysis and validation experiments indicated that the neuroactive ligand-receptor interaction pathway could regulate the WNT signaling pathway through PLCB1 to control male goose external genitalia development.

Estimating the numbers of aquatic birds affected by oil spills: pre-planning, response, and post-incident considerations

Oil spills most visibly affect waterbirds and often the number of birds affected, a key measure of environmental damage from an incident, is required for public communication, population management, and legal reasons. We review and outline steps that can be taken to improve accuracy in the estimation of the number of birds affected in each of three phases: (1) pre-planning; (2) during a response; and (3) post-response. The more pre-planning undertaken, the more robust the estimates will be. Personnel involved in damage assessment efforts must have training in quantitative biology and need support during all three phases. The main approaches currently used to estimate the number of birds affected include probability exposure models and carcass sampling — both onshore and on the water. Probability exposure models can be used in the post-incident phase, particularly in offshore scenarios where beached bird surveys are not possible, and requires three datasets: (1) at-sea bird densities; (2) bird mortality; and (3) the spill trajectory. Carcass sampling using beached bird surveys is appropriate if trajectories indicate affected birds will reach shore. Carcass sampling can also occur via on-water transects and may overlap with risk assessment efforts. Damage assessment efforts should include a measure of sublethal effects following the post-acute phase of spills, yet this area has significant knowledge gaps. We urge jurisdictions worldwide to improve pre-incident planning. We provide guidance on how, in the absence of pre-incident data, quality data can be obtained during or after an incident. These recommendations are relevant for areas with aquatic-based industrial activities which can result in a spill of substances that could injure or kill waterbirds.

Larvae of Sulcascaris sulcata (Nematoda: Anisakidae), a parasite of sea turtles, infect the edible purple dye murex Bolinus brandaris in the Tyrrhenian Sea

Anisakid nematodes are among the most common helminth parasites of the marine realm, particularly important for their implications with human infections and/or allergies. Members of the Anisakidae use aquatic mammals, birds and fish as definitive hosts, and crustaceans, fish and molluscs as intermediate/paratenic hosts. Sulcascaris sulcata, the only species in the monotypic genus Sulcascaris, represents the exception being a parasite of sea turtles as adult. The recent findings of larvae of S. sulcata in scallops (Pecten jacobeus and Aequipecten opercularis) and Mediterranean mussels Mytilus galloprovincialis intended for human consumption from the Mediterranean Sea caused concern regarding the sanitary control of edible molluscs and consumer safety. Herein, we investigated the larval anisakids collected from the purple dye murex, Bolinus brandaris, harvested for human consumption from the Central Mediterranean Sea (Tyrrhenian Sea). Morphological study and sequence analysis of the internal transcribed spacer regions of the ribosomal DNA and the mitochondrial cytochrome c oxidase subunit 2 gene locus revealed the occurrence of fourth stage larvae of S. sulcata in 16% of the purple dye murex examined. The present study adds the purple dye murex to the list of the known intermediate hosts of this parasite in the Mediterranean Sea and the northern coast of Campania region as site where individuals of loggerhead turtle and purple dye murex may become infected. This is the first study reporting an anisakid nematode in edible gastropods. Epidemiological features of infection in the purple dye murex and implications for gastropod safety and risk for consumers are discussed.

Molecular Detection of Avipoxvirus in Wild Birds in Central Italy.

Simple SummaryAvipoxviruses (APVs) are responsible for diseases in domestic and wild birds. Currently, the disease in domestic animals is under control in many Countries by biosafety and vaccination. In wild birds, small disease events are frequently reported worldwide, but large outbreaks are generally rare. Nevertheless, some aspects of the epidemiology of these viruses are still unclear. In this study, we explored, through molecular investigations, the diffusion of APVs among wild birds, of different orders and species, without typical macroscopic lesions. A high percentage (43.33%) of positive specimens was detected, suggesting high diffusion of the viruses and a possible role of avian wildlife as a reservoir. Aquatic birds, mainly Anseriformes, were more often infected, probably in relation to the environment where they live; in fact, APVs are frequently transmitted by mosquitos, particularly abundant in humid areas.Avipoxviruses (APVs) are important pathogens of both domestic and wild birds. The associated disease is characterized by skin proliferative lesions in the cutaneous form or by lesions of the first digestive and respiratory tracts in the diphtheritic form. Previous studies investigated these infections in symptomatic wild birds worldwide, including Italy, but data about the circulation of APVs in healthy avian wildlife are not available. The present study tested spleen samples from 300 wild birds without typical lesions to detect Avipoxvirus DNA. Overall, 43.33% of the samples scored positive. Aquatic birds were more frequently infected (55.42%) than other animals (26.40%), and in Anseriformes, high positivity was found (52.87%). The obtained results suggest that wild birds could be asymptomatic carriers of Avipoxviruses, opening new possible epidemiological scenarios.

Avian Bornaviruses in Wild Aquatic Birds of the Anseriformes Order in Poland.

Bornaviruses are a diverse family of viruses infecting various hosts, including birds. Aquatic bird bornavirus 1 (ABBV-1) and aquatic bird bornavirus 2 (ABBV-2) have been found in wild waterfowl but data on their prevalence are scarce. To gain knowledge on the occurrence of ABBVs in Poland, samples originating from dead birds of the Anseriformes order collected in 2016–2021 were tested with a real time RT-PCR method targeting the ABBVs genome. A total of 514 birds were examined, including 401 swans, 96 ducks and 17 geese. The presence of ABBV-1 RNA was detected in 52 swans (10.1% of all tested birds) from 40 different locations. No positive results were obtained for ducks and geese. Sequences of about 2300 bases were generated for 18 viruses and phylogenetic analysis was performed. A relatively low genetic diversity of the examined ABBV-1 strains was observed as all were gathered in a single cluster in the phylogenetic tree and the minimum nucleotide identity was 99.14%. The Polish strains were closely related to ABBV-1 identified previously in Denmark and Germany, but a limited number of sequences from Europe hinders the drawing of conclusions about interconnections between Polish and other European ABBVs. The results of the present study provide new insights into the distribution and genetic characteristics of ABBVs in wild birds in Europe.

Highly pathogenic avian influenza is an emerging disease threat to wild birds in North America

AbstractPrior to the emergence of the A/goose/Guangdong/1/1996 (Gs/GD) H5N1 influenza A virus, the long‐held and well‐supported paradigm was that highly pathogenic avian influenza (HPAI) outbreaks were restricted to poultry, the result of cross‐species transmission of precursor viruses from wild aquatic birds that subsequently gained pathogenicity in domestic birds. Therefore, management agencies typically adopted a prevention, control, and eradication strategy that included strict biosecurity for domestic bird production, isolation of infected and exposed flocks, and prompt depopulation. In most cases, this strategy has proved sufficient for eradicating HPAI. Since 2002, this paradigm has been challenged with many detections of viral descendants of the Gs/GD lineage among wild birds, most of which have been associated with sporadic mortality events. Since the emergence and evolution of the genetically distinct clade 2.3.4.4 Gs/GD lineage HPAI viruses in approximately 2010, there have been further increases in the occurrence of HPAI in wild birds and geographic spread through migratory bird movement. A prominent example is the introduction of clade 2.3.4.4 Gs/GD HPAI viruses from East Asia to North America via migratory birds in autumn 2014 that ultimately led to the largest outbreak of HPAI in the history of the United States. Given the apparent maintenance of Gs/GD lineage HPAI viruses in a global avian reservoir; bidirectional virus exchange between wild and domestic birds facilitating the continued adaptation of Gs/GD HPAI viruses in wild bird hosts; the current frequency of HPAI outbreaks in wild birds globally, and particularly in Eurasia where Gs/GD HPAI viruses may now be enzootic; and ongoing dispersal of AI viruses from East Asia to North America via migratory birds, HPAI now represents an emerging disease threat to North American wildlife. This recent paradigm shift implies that management of HPAI in domestic birds alone may no longer be sufficient to eradicate HPAI viruses from a given country or region. Rather, agencies managing wild birds and their habitats may consider the development or adoption of mitigation strategies to minimize introductions to poultry, to reduce negative impacts on wild bird populations, and to diminish adverse effects to stakeholders using wildlife resources. The main objective of this review is, therefore, to provide information that will assist wildlife managers in developing mitigation strategies or approaches for dealing with outbreaks of Gs/GD HPAI in wild birds in the form of preparedness, surveillance, research, communications, and targeted management actions. Resultant outbreak response plans and actions may represent meaningful steps of wildlife managers toward the use of collaborative and multi‐jurisdictional One Health approaches when it comes to the detection, investigation, and mitigation of emerging viruses at the human‐domestic animal‐wildlife interface.

Genetic characterization of influenza A virus subtypes H11N6, H11N7, and H11N9 isolated from free-grazing ducks, Thailand.

Influenza A viruses (IAVs) infect avian species and several mammalian species including humans. Anseriformes water birds are an important reservoir of IAVs. In this study, we identified and characterized IAV subtypes H11N6 (n = 5), H11N7 (n = 3), and H11N9 (n = 3) isolated during the influenza surveillance program in free‐grazing ducks from 2012 to 2015 in Thailand. Eleven IAV‐H11 viruses were characterized by either whole genome sequencing (n = 5) or HA and NA gene sequencing (n = 6) for phylogenetic and amino acid analyses. Phylogenetic analysis showed that Thai IAV‐H11 were grouped into Avian Eurasian lineage. Amino acid analysis showed that all Thai IAV‐H11 viruses have low pathogenic avian influenza (LPAI) characteristics and sensitive to Oseltamivir and Amantadine. Novel reassortant viruses (IAV‐H11N7 and IAV‐H11N9) have been observed. The reassortant viruses contained NP, M, and NS gene segments which originate from intercontinental sources which never been reported in Thai IAVs. In summary, this study demonstrated high genetic diversity of IAV‐H11 circulating in free‐grazing ducks. Free‐grazing ducks infected with IAVs generated novel reassortant IAV‐H11. Thus, surveillance of IAVs in free‐grazing ducks should be routinely conducted to monitor novel reassortant viruses and subsequently potential virulence viruses.

A study of seasonal abundance of aquatic birds including migratory birds with a special focus on population of Bar-headed geese at Magadi Kere, Shirahatti Taluk, Gadag district, Karnataka, India

A study of the seasonal abundance of aquatic birds, including migratory birds, focuses on the population of Bar-headed geese coming from Siberia and Tibet to Magadi Kere, Shirahatti Taluk, Gadag District, and Karnataka was conducted over five years spanning from March 2015 to March 2020. A total number of 34 aquatic bird species were observed and recorded. At different time intervals, the abundance and frequency of visits of migvisitsy birds, especially of Bar-headed geese, were recorded and inferences were drawn. The Bar-headed geese followed a fixed migration pattern with the peak season starting from October-November, reaching the highest count in January-February and finally subsiding in March-April every year. The study also discerned that the feeding pattern of aquatic birds coincides with the local crops grown in the vicinity, which are at the harvesting stage during the peak season of migration.

An examination of trends in the growing scientific literature on approaching wildlife with drones

Drones or unoccupied aerial vehicles are rapidly being used for a spectrum of applications, including replacing traditional occupied aircraft as a means of approaching wildlife from the air. Though less intrusive to wildlife than occupied aircraft, drones can still cause varying levels of disturbance. Policies and protocols to guide lowest-impact drone flights are most likely to succeed if considerations are derived from knowledge from scientific literature. This study examines trends in the scientific literature on using drones to approach wildlife between 2000 and 2020, specifically in relation to the publication types, scientific journals that works are published in, purposes of drone flights reported, taxa studied, and locations of studies. From 223 publications, we observed a large increase in relevant scientific literature, the majority of which were peer-reviewed articles published across 86 scientific journals. The largest proportion of peer-reviewed research articles related to aquatic mammals or aquatic birds and the use or trial of drone flights for conducting population surveys, animal detection, or investigations of animal responses to drone flights. The largest proportion of articles were studies conducted in North America and Australia. Since animal responses to drone flights vary among taxa, populations, and geographic locations, we encourage further growth in the volume of relevant scientific literature needed to inform policies and protocols for specific taxa and (or) locations, particularly where knowledge gaps exist.

Understanding the mangrove-associated avifauna and their conservation status in the Gorai Creek, Western Mumbai, Maharashtra, India: A Recent Study

The research was conducted from June 2017 to June 2019 to better understand the diversity and current state of the avifauna in the Gorai Creek region. 96 species belonging to 39 families from 16 orders, including terrestrial and aquatic birds, were identified as surviving near the stream over the two-year research period, including residents, migratory, common, uncommon, and unusual species. 64 species were permanent birds, 28 were winter migrants, 4 were summer migrants, 23 were uncommon, 57 were common, and 16 were rare. Anatidae, Ardeidae, Cuculidae, Accipitridae, Sturnidae, Strigidae, Laridae, Charadridae, Scolopacidae, and Rallidae were the most regularly observed bird families. The extensive mangrove cover around the creek provided food for all the birds. The ferry system to Gorai village, as well as the Essel World Park, has been seen to mildly impair the birds' breeding and foraging. Seasonal changes have a significant impact on bird numbers. Except for the ferry system, anthropogenic disturbances are quite minimal in the area, therefore the creek has less pollution and dense mangrove foliage, which shelters the avifauna that thrives in the zone.

Lake-wide mapping of littoral habitat using underwater videography

Littoral zones − referring to benthic areas above the light compensation depth − provide numerous ecosystem functions, including mediating light, temperature, and nutrient dynamics, and supporting important foraging and refuge areas for macroinvertebrates, fishes and water birds. Habitat assessments of littoral zones remain fundamental to lake and fisheries management, however traditional field surveys are time-intensive and limited in their spatial extent, whereas desktop evaluations using remote sensing and aerial imagery are cost prohibitive and require considerable data processing expertise. In light of these challenges, this study demonstrated the ability to use simple, cost-effective underwater videography to conduct lake-wide spatially-continuous assessments of littoral habitat. For lakes across a gradient of shoreline and riparian development in northwestern United States, we map the areal coverage of macrophytes, coarse woody habitat, bottom substrates, and artificial structures in littoral zones. Underwater videography represents a relevant tool for environmental monitoring because it allows for the estimation of littoral habitats at fine spatial grains across broad spatial extents. Data can also be obtained rapidly and at relatively low cost, providing a permanent record of habitat conditions that can used to monitor trends over time.

New survey of Clare Island. Volume 9: Birds ed. by T.K. Kelly

Reviewed by: New survey of Clare Island. Volume 9: Birds ed. by T.K. Kelly Joe Furphy New Survey of Clare Island. Volume 9: Birds T.K. Kelly (ed.) (Royal Irish Academy; 166 pp; €35) ISBN: 978–1–911479–41–3 Any published work must be seen as a picture of a particular time and place, but one of the strengths of New Survey of Clare Island. Volume 9: Birds is the way in which comparisons are made with other locations and species. While it is particularly interesting to see the tables in the Appendices giving comparative statistics for several Irish islands, for many readers their fascination will be with the unanswered questions on bird population make-up and the differences between Clare Island and other islands, especially where habitats, food resources and land use etc., appear superficially similar. An early chapter lists the avian species so far recorded on Clare Island. Some are given longer descriptions, contributing towards an understanding of relationships not only inter-specifically, but also spatially in relation to the situation on the nearby mainland, although few direct comparisons to topography or land use are made. The Clare Island avifauna benefits from a lack of general human interference; only two species are listed as deliberate introductions: Canada goose Branta canadensis and Pheasant Phasianus colchius; ironically, throughout Europe both species are often unwelcome; questions therefore need to be asked about their effects on the native populations on Clare Island. Separate chapters are devoted to seabirds, land birds and water birds. The seabirds chapter raises several interesting and relevant questions regarding the population dynamics of several species. Contrasts with population changes in other seabird colonies not only make interesting reading but also pose questions as to why there is so much variation in numbers in colonies that externally appear similar in terms of habitat and available food supplies. By way of example, Gannets did not nest on Clare Island until 1978 but the numbers have dramatically increased, while the number of Fulmars, similarly open-sea feeders and cliff-nesters, has decreased. Fortunately, there have been several national and European censuses of seabirds, so there are sufficient data available to allow basic comparisons to be made and research projects instituted to ascertain reasons for such discrepancies. However, a full analysis of the causes for fluctuations in bird population requires evidence from a large range of parameters, several of which are not readily available. In considering the distribution and population changes in land birds, proximity to the mainland is a factor, and it is postulated that the changes on Clare Island may be related to fluctuations on the adjacent Mayo shores. Much of the land area of Ireland has been subject to changes in land use and land management, factors with profound effects on the distribution and population dynamics of land birds. Clare Island is fortunate in that it has been spared most of the recent changes, with the result that bird numbers and their distribution can be related much more to naturally induced fluctuations than in most of mainland Ireland. The major 21st-century survey involved a series of transects, after which estimates were made of the populations of the various species throughout the island. Most groups are open-habitat and generalist species, and it is noted that hole-nesting birds are absent, despite the presence of woodland. The absence of rooks is similarly remarked upon, and a chapter devoted to examining possible reasons for this concludes that the island is simply not large enough to sustain a colony of this species. The limitations of conducting detailed survey work on farmland are mentioned, especially the necessity to avoid walking on cropped land or through flocks of animals. A chapter is devoted to the land birds (excepting raptors) of other Irish islands. As well as producing a series of fascinating graphs, diagrams and lists, we learn about the difficulties in making accurate deductions on many aspects of the inter-island contrasts, due to the lack of statistics on which any conclusions can be based. The chapter on waterbirds highlights the difficulties in surveying breeding populations in certain locations, partly due to the secretive behaviour of several species during the...

Воздействие выбросов СХК и ОДЭК на гидробионты 30-км зоны СХК

Radiation doses to aquatic biota exposed to Siberian Chemical Plant (SCP, Tomsk) radioactive discharges, and Pilot-demonstration energy complex (PDEC) forecasting radiation doses from designed radioactive discharges were estimated. Doses to the biota in the habitat in the existing radiation situation were assessed with the use of measurements of water and bottom sediments samples collected during environmental monitoring of airborne radioactivity in 2017. Designed radioactivity discharges were assumed from normally operated PDEC modules for fabrication and refabrication and fuel reprocessing and reactor BREST-OD-300. It was found that the esti-mated highest radiation doses to biota were: for freshwater mammals – 24 μGy/day, it is 40 times below the reference levels; for fish – 7 μGy/day, it is 140 times below reference levels; for aquatic plants and mollusks – 1.2 μGy/day, it is about 10000 times below the reference levels. Anticipated radiation doses to the aquatic biota exposed to radiation discharged by PDEC were formed in the Lake Chernoe (Black Lake). The highest doses to fresh water mammals, fish and birds are 0.3 μGy/day, for aquatic plants and mollusks – 0.05 μGy/day. The main contributor to anticipated radiation doses to aquatic biota and birds is tritium, 3H.

Surto de botulismo tipo C em aves aquáticas de vida livre em Goiás

ABSTRACT: Botulism is generally a fatal disease caused by ingestion of neurotoxins produced by Clostridium botulinum. The present study describes the epidemiological, clinical, and laboratory aspects of a type C botulism outbreak in free-living aquatic birds residing in an urban park in Quirinópolis, Goiás, Brazil. Among a population of approximately 80 waterfowl, a total of 30 birds, including ducks (Cairina moschata), teals (Anas platyrhynchos), and geese (Anser cygnoides), died within 10 days. Of these, six birds showed signs of flaccid paralysis of the pelvic limbs, eyelids, neck, and wings. To confirm the suspicion of botulism, four lake water samples, two samples of the feed consumed by the birds, and samples of serum, intestinal content, stomach content, and liver tissue from two teals that died after presenting clinical signs were analyzed. Using bioassay and neutralization with homologous antitoxin in mice, it was possible to detect the presence of botulinum toxin type C in a water sample and in the intestinal content of one of the necropsied teals. Additionally, the presence of C. botulinum type C was identified in the lake water using polymerase chain reaction. Based on the clinical signs and laboratory results, a diagnosis of botulism caused by botulinum toxin type C was confirmed with probable transmission by lake water.

Foraging Strategy of Black-faced Spoonbill During Breeding Period in Rice Fields of Korea.

Rice fields are important habitats for a variety of water birds, and their importance is increasing with the destruction of natural wetlands. This study was conducted to understand the foraging strategy of the black-faced spoonbill, an internationally endangered species, in rice fields. To achieve this objective, the feeding success rate of black-faced spoonbills in rice fields was analyzed considering the species' feeding behavior, environmental factors, and external factors. The number of sweeps per minute and number of steps per minute were evaluated as features of feeding behavior; rice field type, water level, and rice height as environmental factors; and the size of a flock and number of other species in the fields when black-faced spoonbills were feeding as external factors. The feeding success rate of the black-faced spoonbills increased as they were feeding while moving at a fast pace in a rice field with a water level of 10 cm or below, rice height of 15 cm, and without herons (competitor species). These factors may be an effective strategy to increase the probability of food acquisition by black-faced spoonbills in rice fields. Therefore, to allow black-faced spoonbills during breeding season to use the rice fields for feeding, it is necessary to maintain a water level of 15 cm or less before transplanting rice. Moreover, the use of pesticides must be minimized to increase abundance of the food resources in rice fields.

ABANDONED SITES: BOON OR BANE FOR URBAN BIRD NESTINGA CASE STUDY FROM TIRUNELVELI, TAMIL NADU (INDIA)

A short duration observation on birds' nesting in an abandoned bungalow premise in the heart of Palayamkottai, Tirunelveli district in Southern Tamil Nadu is reported as a case study. Three species of water birds namely Black-crowned Night Heron (Nycticorax nycticorax), Intermediate Egret (Mesophoyxin termedia), and Little Cormorant (Phalacrocorax niger) were found to show mixed roosting. Recently infrastructural modification of the premise was undertaken, which influenced the nesting site of these colonial birds, considering their high sensitivity to disturbance.

Wintering of water birds in Silesia in the year 2020

Wintering of water birds in Silesia in the year 2020

Molecular Detection of Avian Influenza Virus in Wild Birds in Morocco, 2016-2019.

Avian influenza (AI) is a zoonotic disease significant to both public and animal health, caused by influenza virus A, and affects domestic poultry, wild birds, and mammals including humans. Aquatic birds are considered the natural reservoir of this virus. In 2016, Morocco experienced the first occurrence of low pathogenic H9N2 avian influenza virus (AIV) in poultry; however, no cases were reported in wild birds. The present study aimed to monitor the presence of AIV in wild birds in Morocco in order to trace the possible sources of the viruses affecting poultry. Between 2016 and 2019, 967 samples obtained from 480 birds representing 56 different wild bird species, 20 families, and 8 orders, mostly from Charadriiformes, Anseriformes, Pelecaniformes, and Passeriformes, were collected from various wetlands and relevant ornithologic sites in Morocco. These field samples consisted of 374 cloacal swabs, 321 tracheal swabs, 54 fecal samples, and 218 organ pools including the trachea, lung, liver, spleen, heart, intestine, and brain. The samples were examined for the presence of AIV using TaqMan-based real-time reverse transcriptase-PCR (rRT-PCR) targeting the matrix gene, followed by further subtyping rRT-PCR tests targeting the H1-H16 genes. The AI matrix gene was detected in 18 out of 967 samples (1.86%); positive samples were detected in 17 birds belonging to 10 bird species: two redshanks (Tringa totanus), one little stint (Calidris minuta), one ruddy turnstone (Arenaria interpres), one common snipe (Gallinago gallinago), one common greenshank (Tringa nebularia), one black-winged stilt (Himantopus himantopus), two black-headed gulls (Chroicocephalus ridibundus), one slender-billed gull (Chroicocephalus genei), six cattle egrets (Bubulcus ibis), and one Eurasian coot (Fulica atra). AIV was detected in 2 wetlands and 1 ornithologic site (Sidi Moussa Oualidia Complex, Smir lagoon and El Jadida Coast) and the highest positivity was revealed in fresh fecal samples (11.1%), indicating the suitability of this matrix for wild bird surveillance. Our results highlight that waders, gulls, and cattle egrets are the most affected species and may represent a potential risk for AI introduction in the poultry sector in Morocco. Regular monitoring of wild birds in Morocco, focusing in particular in the areas and species identified in this study as a high risk of virus circulation, should be implemented to anticipate and prevent possible AIV spread.

Causes of the dieback of littoral stands in an overpopulated water-bird reserve: Role of eutrophication, fish and geese

European fishponds can serve as refuges for water birds if the fish stocks are limited, but the effects of other ecological factors on their ecological stability are rarely considered. The aim of this study is to determine the causes of marked dieback of littoral stands dominated by Typha angustifolia L. in a hypertrophic fishpond that is also a valuable water bird reserve. A field study and two experiments were conducted in order to separate the effects of mineral nutrient availability, redox conditions, fish and water birds. The physico-chemical characteristics of the water and sediments confirmed hypertrophic conditions in the fishpond, but a mesocosm experiment did not indicate it had a negative effect on plant growth. On the other hand, a field enclosure experiment showed that in sparse stands, unfenced parts had a significantly smaller shoot density than fenced parts. This was attributed to grazing by greylag geese (Anser anser L.). In addition, damage to belowground parts of plants were ascribed to large individuals of albeit a few large common carp (Cyprinus carpio L.). This study highlights a conservation dilemma as large numbers of geese destroy littoral stands in fishpond nature reserves, which then become unsuitable nesting sites for other species of water birds.