How does the shape of the wing and hindlimb bones of aquatic birds relate to their locomotor abilities?

Aquatic birds represent diverse ecologies and locomotion types. Some became flightless or lost the ability for effective terrestrial locomotion, yet, certain species excel in water, on land, and in air, despite differing physical characteristics associated with each medium. In this exploratory study, we intend to quantitatively analyze the morphological variety of multiple limb bones of aquatic birds using 3D geometric morphometrics. Morphological variation is mainly driven by phylogeny, which also affects size and locomotion. However, the shape of the ulna, including the proportion and orientation of the epiphyses is influenced by size and aquatic propulsive techniques even when phylogeny is taken into consideration. Certain trends, possibly linked to functions, can be observed too in other bones, notably in cases where phylogenetic and functional signals are probably mixed when some taxa only englobe species with similar functional requirements: penguins exhibit the most distinctive wing bone morphologies, highly adapted to wing-propulsion; advanced foot-propellers exhibit femur morphology that reduces proximal mobility but supports stability; knee structures, like cnemial crests of varied sizes and orientations, are crucial for muscle attachments and efficient movement in water and on land; taxa relying on their feet in water but retaining terrestrial abilities share features enabling swimming and walking postures. Size-linked changes distinguish the wing bones of non-wing-propelled taxa. For hindlimbs, larger size relates to robust bones probably linked to terrestrial abilities, but robustness in femora can be connected to foot-propulsion. These results help us better understand birds' skeletal adaptation and can be useful inferring extinct species' ecology.

Microplastic Quantification in Aquatic Birds: Biomonitoring the Environmental Health of the Panjkora River Freshwater Ecosystem in Pakistan.

Microplastic pollution has become a global concern, with potential negative impacts on various ecosystems and wildlife species. Among these species, ducks (Anas platyrhynchos) are particularly vulnerable due to their feeding habits and proximity to aquatic environments contaminated with microplastics. The current study was designed to monitor microplastic (MP) pollutants in the freshwater ecosystem of the Panjkora River, Lower Dir, Pakistan. A total of twenty (20) duck samples were brought up for four months and 13 days on the banks of the river, with no food intake outside the river. When they reached an average weight of 2.41 ± 0.53 kg, all samples were sacrificed, dissected, and transported in an ice box to the laboratory for further analysis. After sample preparation, such as digestion with 10% potassium hydroxide (KOH), density separation, filtration, and identification, the MP content was counted. A total of 2033 MP particles were recovered from 20 ducks with a mean value of 44.6 ± 15.8 MPs/crop and 57.05 ± 18.7 MPs/gizzard. MPs detected in surface water were 31.2 ± 15.5 MPs/L. The major shape types of MPs recovered were fragments in crop (67%) and gizzard (58%) samples and fibers in surface water (56%). Other types of particles recovered were fibers, sheets, and foams. The majority of these detected MP particles were in the size range of 300-500 µm (63%) in crops, and 50-150 µm (55%) in gizzards, while in water samples the most detected particles were in the range of 150-300 µm (61%). Chemical characterization by FTIR found six types of polymers. Low-density polyethylene (LDPE) had the greatest polymer detection rate (39.2%), followed by polyvinyl chloride (PVC) (28.3%), high-density polyethylene (HDPE) (22.7%), polystyrene (6.6%), co-polymerized polypropylene (2.5%), and polypropylene homopolymer (0.7%). This study investigated the presence of microplastics in the crops and gizzards of ducks, as well as in river surface water. The results revealed the significant and pervasive occurrence of microplastics in both the avian digestive systems and the surrounding water environment. These findings highlight the potential threat of microplastic pollution to wildlife and ecosystems, emphasizing the need for further research and effective mitigation strategies to address this pressing environmental concern.

Influenza: Searching for Pandemic Origins.

From a farming family of 13 children in New Zealand, I graduated with a Master of Science degree in microbiology from the University of Otago (Dunedin, Otago, New Zealand). I established the first veterinary virology laboratory at Wallaceville Animal Research Station. I subsequently completed my PhD degree at Australian National University (Canberra, Australia) and a postdoctoral fellowship at the University of Michigan (Ann Arbor, Michigan). While in New South Wales, Australia, a walk on a beach littered with dead mutton birds (shearwaters) with Dr. Graeme Laver led to the surveillance of influenza in seabirds on the Great Barrier Reef Islands and my lifelong search for the origin of pandemic influenza viruses. Subsequent studies established that (a) aquatic birds are a natural reservoir of influenza A viruses, (b) these viruses replicate primarily in cells lining the intestinal tract, (c) reassortment in nature can lead to novel pandemic influenza viruses, and (d) live bird markets are one place where transmission of influenza virus from animals to humans occurs.

Detection and Phylogenetic Analysis of Extended-Spectrum ß-Lactamase (ESBL)-Genetic Determinants in Gram-Negative Fecal-Microbiota of Wild Birds and Chicken Originated at Trimmu Barrage.

Extended-spectrum ß-lactamases (ESBL) give rise to resistance against penicillin and cephalosporin antibiotics in multiple bacterial species. The present study was conducted to map genetic determinants and related attributes of ESBL-producing bacteria in three wild aquatic bird species and chickens at the "Trimmu Barrage" in district Jhang, Punjab province, Pakistan. To study the prevalence of ESBL-producing bacteria, a total of 280 representative samples were collected from wild bird species; cattle egrets (Bubulcus ibis), little egrets (Egretta garzetta) and common teals (Anas crecca) as well as from indigenous chickens (Gallus gallus domesticus) originating from a local wet market. The isolates were confirmed as ESBL producers using a double disc synergy test (DDST) and bacterial species were identified using API-20E and 20NE strips. A polymerase chain reaction (PCR) was used to detect ESBL genetic determinants and for genus identification via 16S rRNA gene amplification. A phenotypic antimicrobial susceptibility test was performed for ESBL-producing isolates against 12 clinically relevant antibiotics using the Kirby-Bauer disk diffusion susceptibility test. A phylogenetic tree was constructed for the sequence data obtained in this study and comparative sequence data obtained from GenBank. The overall prevalence of ESBL-producing bacteria was 34.64% (97/280). The highest percentage (44.28%; 31/70) of ESBL-producing bacteria was recovered from chickens (Gallus gallus domesticus), followed by little egrets (Egretta garzetta) (41.43%; 29/70), common teal (Anas crecca) (28.57%; 20/70) and cattle egrets (Bubulcus ibis) (24.28%; 17/70). Five different ESBL-producing bacteria were identified biochemically and confirmed via 16S rRNA gene sequencing, which included Escherichia coli (72; 74.23%), Enterobacter cloacae (11; 11.34%), Klebsiella pneumoniae (8; 8.25%), Salmonella enterica (4; 4.12%) and Pseudomonas aeruginosa (2; 2.06%). Based on PCR, the frequency of obtained ESBL genes in 97 isolates was blaCTX-M (51.55%), blaTEM (20.62%), blaOXA (6.18%) and blaSHV (2.06%). In addition, gene combinations blaCTX-M + blaTEM, blaTEM + blaOXA and blaCTX-M + blaSHV were also detected in 16.49%, 2.06% and 1.03% of isolates, respectively. The ESBL gene variation was significant (p = 0.02) in different bacterial species while non-significant in relation to different bird species (p = 0.85). Phylogenetic analysis of amino acid sequence data confirmed the existence of CTX-M-15 and TEM betalactamases. The average susceptibility of the antibiotics panel used was lowest for both Klebsiella pneumoniae (62.5% ± 24.42) and Salmonella enterica (62.5% ± 31.08) as compared to Enterobacter cloacae (65.90% ± 21.62), Pseudomonas aeruginosa (70.83% ± 33.42) and Escherichia coli (73.83% ± 26.19). This study provides insight into the role of aquatic wild birds as reservoirs of ESBL-producing bacteria at Trimmu Barrage, Punjab, Pakistan. Hence, active bio-surveillance and environment preservation actions are necessitated to curb antimicrobial resistance.

Phylogenetic analysis of avian schistosome Trichobilharzia regenti (Schistosomatidae, Digenea) from naturally infected hosts in northern Iran.

BACKGROUND: Trichobilharzia regenti (T. regenti) is an avian schistosomatid fluke species that causes human cercarial dermatitis (HCD) in areas of aquaculture in northern Iran. Understanding the phylogenetic relationships and genetic diversity of this thread-like fluke will deepen our thoughtful of avian schistosomiasis epidemiology and lead to more effective HCD control in the region. OBJECTIVES: To determine the life cycle of nasal Trichobilharzia in aquatic birds as well as aquatic snails and also identify the haplotype diversity of the isolates in Mazandaran Province, northern Iran. METHODS: In the present study, adult or egg of Trichobilharzia isolated from aquatic birds as well as schistosomes cercariae isolated from aquatic snails in Mazandaran Province, northern Iran, belonged to the authors' previous research, were examined. Molecular studies and phylogenetic analysis were carried out on these schistosomes samples. RESULTS: The phylogenetic analysis of the ITS1 and COX1 genes in isolated schistosomes revealed that all samples belong to the T. regenti clade. Remarkably, based on phylogenetic results, these schistosomes samples from Anas platyrhynchos domesticus, A. platyrhynchos, Spatula clypeata and Lymnaea stagnalis grouped together with previously sequenced samples from Iran (Trichobilharzia cf. regenti). Unlike the phylogenetic tree and haplotype network of COX1 gene, ITS1 did not show distinct clusters. CONCLUSION: This study completed the puzzle of the disease in Mazandaran Province by isolating and genotyping furkocercariae from L. stagnalis that was consistent with the isolated new genotype from ducks. For the first time in Iran, this confirmed the potential role of L. stagnalis snails in the transmission of the disease.

Dissemination of carbapenemase-producing Enterobacterales through wastewater and gulls at a wastewater treatment plant in Sweden.

Here we report the detection of carbapenemase-producing Enterobacterales (CPE) isolated from Swedish wastewater and gull faeces. CPE have not been detected in samples from animals in Sweden preceding this report. Sampling of wastewater treatment plant (WWTP) inlet and outlet, sedimentation basins, surface seawater from key aquatic bird habitats and freshly deposited gull faeces was done on six separate occasions during May to September 2021. Following broth enrichment, selective screening of putative CPE was performed on mSuperCarba™ (CHROMagar). Species identification was done with MALDI-TOF. Antimicrobial susceptibility testing was performed according to EUCAST. In total, seventeen CPE were verified by genome sequencing carrying blaGES-5, blaIMI-3, blaOXA-181 or blaOXA-244. The blaGES-5 was carried on IncP plasmids in four different species; Escherichia coli ST10 isolated from WWTP outlet, Raoultella ornithinolytica isolated from WWTP inlet, outlet and sedimentation basins as well as gull faeces collected at the WWTP and Klebsiella spp. isolates from WWTP inlet and outlet. The genetic environment surrounding blaGES-5 was similar in two Citrobacter freundii causing human infections. The blaIMI-3 was carried on IncFII(Yp) plasmids in four Enterobacter ludwigii, isolated from WWTP outlet and gull faeces collected at a recreational city park 2 km from the WWTP. The blaOXA-181 was located on a COLKP3 plasmid found in an E. coli, while blaOXA-244 was chromosomally located in an E. coli ST10, both isolated from WWTP inlet. Phylogenetic analysis of R. ornithinolytica and E. ludwigii isolates indicate that the gulls carried strains related to those identified in the WWTP samples. The results thus add to the increasing evidence of WWTPs as anthropogenic reservoirs for mobile genetic elements with antibiotic-resistance functionality. Such environments could profoundly impact the dissemination and spread of such genetic elements via for example aquatic birds, thereby warranting further study and surveillance.

Cross-species infection potential of avian influenza H13 viruses isolated from wild aquatic birds to poultry and mammals.

Wild aquatic birds are the primary hosts of H13 avian influenza viruses (AIVs). Herein, we performed a genetic analysis of two H13 AIVs isolated from wild birds in China and evaluated their infection potential in poultry to further explore the potential for transmission from wild aquatic birds to poultry. Our results showed that the two strains belong to different groups, one strain (A/mallard/Dalian/DZ-137/2013; abbreviated as DZ137) belongs to Group I, whereas the other strain (A/Eurasian Curlew/Liaoning/ZH-385/2014; abbreviated as ZH385) belongs to Group III. In vitro experiments showed that both DZ137 and ZH385 can replicate efficiently in chicken embryo fibroblast cells. We found that these H13 AIVs can also efficiently replicate in mammalian cell lines, including human embryonic kidney cells and Madin-Darby canine kidney cells. In vivo experiments showed that DZ137 and ZH385 can infect 1-day-old specific pathogen-free (SPF) chickens, and that ZH385 has a higher replication ability in chickens than DZ137. Notably, only ZH385 can replicate efficiently in 10-day-old SPF chickens. However, neither DZ137 nor ZH385 can replicate well in turkeys and quails. Both DZ137 and ZH385 can replicate in 3-week-old mice. Serological surveillance of poultry showed a 4.6%-10.4% (15/328-34/328) antibody-positive rate against H13 AIVs in farm chickens. Our findings indicate that H13 AIVs have the replication ability in chickens and mice and may have a risk of crossing the host barrier from wild aquatic birds to poultry or mammals in the future.

Plastics and waterbirds in Brazil: A review of ingestion, nest materials and entanglement reveals substantial knowledge gaps and opportunities for research.

Plastic pollution is an increasing global problem, especially in aquatic environments. From invertebrates to vertebrates, many aquatic species have been affected by plastic pollution worldwide. Waterbirds also interact with plastics, mainly by ingesting them or using them as nest material. Brazil has one of the largest aquatic environment areas, including the most extensive wetland (the Pantanal) and biggest river (the Amazon), and a ∼7500 km long coastline, which hosts a remarkable waterbird diversity with more than 200 species from 28 bird families. Here, we synthesise published and grey literature to assess where, how, and which waterbirds (marine and continental) interact with plastics in Brazil. We found 96 documents reporting interaction between waterbirds and plastics. Only 32% of the occurring species in the country had at least one individual analysed. Plastic ingestion was reported in 67% of the studies, and seabirds were the study subject in 79% of them. We found no reports in continental aquatic environments, unveiling entire regions without any information regarding interactions. Consequently, this geographic bias drew a considerable taxonomic bias, with whole families and orders without information. Additionally, most studies did not aim to search for plastic interactions, which had a twofold effect. First, studies did not report their findings using the proposed standard metrics, hampering thus advances in understanding trends or defining robust baselines. Second, as it was not their main objective, plastics were not mentioned in titles, abstracts, and keywords, making it difficult to find these studies. We propose means for achieving a better understanding of waterbird-plastic interactions in space and time, and recommend searching for sentinel species and for allocating research grants.

Sex and Age Differences in Activity Budgets in a Population of Captive African Penguins (Spheniscus demersus).

The African penguin (Spheniscus demersus) is an endangered species that continues to experience population decline. Understanding the behavior of this species is a critical step in the conservation efforts to prevent their extinction. A comprehensive activity budget of this species has yet to be conducted in any captive population, which are critical for the Species Survival Plan (SSP) breeding programs. We performed scan sampling observations on a group of 19 penguins to construct an activity budget. We also investigated the behavioral differences between males and females, as well as between adults and juveniles. Results indicate there are minimal sex differences in time budget allocations, but there are some notable age related differences. Creating and comparing activity budgets between populations are critical for understanding animal welfare in captive settings.

Improved method for avian influenza virus isolation from environmental water samples.

Environmental water-targeted surveillance of migratory aquatic birds at overwintering sites is potentially one of the most effective approaches for understanding the ecology of avian influenza viruses (AIVs). In this study, we improved the method for AIV isolation from environmental water samples by making a minor modification to our previously reported process. We experimentally demonstrated that the AIV recovery efficiency of the modified method was 10-100-fold higher than that of the original method. This improved isolation method allowed us to isolate a considerably larger number of AIV isolates from environmental water samples collected at an overwintering site for tens of thousands of migratory aquatic birds in Japan during the 2018/2019 winter season, compared with those during previous winter seasons. Genetic and phylogenetic analyses revealed that AIVs of the same subtypes with multiple genetic constellations were circulating in a single overwintering site during a single winter season. These findings indicate that our improved isolation method contributes to enhance environmental water-targeted surveillance and to a better understanding of AIV ecology in migratory aquatic bird populations by monitoring ongoing AIV circulation.

Molecular Detection of Avipoxvirus in Wild Birds in Central Italy.

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.

Sequencing and phylogenetic analysis of the stn gene of Salmonella species isolated from different environmental sources at Lake Qarun protectorate: The role of migratory birds and public health importance.

BACKGROUND AND AIM: Salmonella causes most foodborne bacterial illnesses worldwide. It is found in various hosts, including pets, farm animals, and wild animals, as well as the environment. This study aimed to examine the epidemiological relationship between Salmonella isolates from aquatic environments and those from other avian hosts. MATERIALS AND METHODS: The study examined 12 water samples, 210 aquatic animals, and 45 migratory aquatic bird samples collected from the protected area of Lake Qarun in El-Fayoum Governorate, Egypt, during migration seasons from different waterfowl migration areas (from October 2018 to January 2019). In addition, 45 fecal samples from domestic chickens were collected from the same geographic location from poultry farms. Bacteriological examination and polymerase chain reaction assay of two virulence genes (i.e., invA and stn) were performed to isolate and identify Salmonella. RESULTS: Salmonella was isolated from 58.3% (7/12) of Lake Qarun water samples, 13.3% (6/45) of migratory waterfowl, 6.6% of (3/45) of chickens (Gallus gallus domesticus), and 4.3% (3/70) of fish and pooled brine shrimp. In migratory aquatic bird species that were sampled, Salmonella were isolated from 23.1% (3/13) of Eurasian coot (Fulica atra), 12.5%, (1/8) of green-winged teal (Anas cardolinesis), 10% (2/20) of northern shoveler (Spatula clypeata), and 0% (0/4) of mallard duck (Anas platyrhynchos). In 35 Tilapia, Salmonella was isolated by (8.6%) 5.7% of external surfaces, 2.85% from the intestine, and 0% from the muscle. No Salmonella was isolated from the 175 brine shrimp samples. Phylogenetic analysis using the stn genes of Salmonella isolated from the aquatic environment, migratory aquatic birds, and chicken showed a strong association between these isolates. In addition, a higher nucleotide identity percentage was observed between the sequences recovered from migratory aquatic birds and Lake Qarun water samples. CONCLUSION: Salmonella distribution was confirmed through migratory aquatic birds, based on our phylogeny tree analysis, Salmonella considered a likely carrier of zoonotic bacterial pathogens. Furthermore, the close relationship between chicken and fish sequences highlights the scenarios of using chicken manure in fish farms and its public health implications. The presence of Salmonella in different environmental sources spotlights the urgent need to control and break down its epidemiological cycle.

Longitudinal Analysis of Influenza A(H5) Sero-Surveillance in Myanmar Ducks, 2006-2019.

Between 2006 and 2019, serological surveys in unvaccinated domestic ducks reared outdoors in Myanmar were performed, using a haemagglutination inhibition (HI) test, to confirm H5 avian influenza virus circulation and assess temporal and spatial distribution. Positive test results occurred every year that samples were collected. The annual proportion of positive farms ranged from 7.1% to 77.2%. The results revealed silent/sub-clinical influenza A (H5) virus circulation, even in years and States/Regions with no highly pathogenic avian influenza (HPAI) outbreaks reported. Further analysis of the 2018/19 results revealed considerable differences in seroconversion rates between four targeted States/Regions and between years, and showed seroconversion before and during the sampling period. By the end of the trial, a high proportion of farms were seronegative, leaving birds vulnerable to infection when sold. Positive results likely indicate infection with Gs/GD/96-lineage H5Nx HPAI viruses rather than other H5 subtype low-pathogenicity avian influenza viruses. The findings suggested persistent, but intermittent, circulation of Gs/GD/96-lineage H5Nx HPAI viruses in domestic ducks, despite the veterinary services' outbreak detection and control efforts. The role of wild birds in transmission remains unclear but there is potential for spill-over in both directions. The findings of this study assist the national authorities in the design of appropriate, holistic avian influenza control programs.

Generalized estimation of nutrient loading of waterbirds on inland aquatic ecosystems.

Estimating the nutrient loading of aquatic bird is complicated because it is fundamentally dependent on several biological, environmental and methodological factors. The new Boros's generalized method is relatively easy to use based on the conventional bird counting and implemented excrement (faecal) analyses by integrated daily net rates data (g/day/ind.). According to the Boros's generalized method, the carbon (C), nitrogen (N) and phosphorus (P) loading of waterbirds on aquatic ecosystems can be estimated by determining the abundance of waterbird populations and the nutrient content (C, N, P) of their excrement. Weekly total loading of waterbirds = Σ species (A × E × RTF × D), where: A (ind./m2): the daily mean of abundance of waterbird species for each month, E (g/day/ind.): the daily net rate of C, N, P in the excrement of each species, RTF: the daily residency time factor (hours spent on soda pans/24 h) of each species in the target habitat, D (n days): the number of days of each month.•Waterbirds can cause extreme guanotrophication (max. 2500 mg P/m2/y) in waters.•The nutrient loading of waterbirds can be estimated by abundance of waterbirds.•Boros's method estimates the carbon, nitrogen and phosphorus loading of waterbirds.

Highly Pathogenic Avian Influenza Viruses at the Wild-Domestic Bird Interface in Europe: Future Directions for Research and Surveillance.

Highly pathogenic avian influenza (HPAI) outbreaks in wild birds and poultry are no longer a rare phenomenon in Europe. In the past 15 years, HPAI outbreaks-in particular those caused by H5 viruses derived from the A/Goose/Guangdong/1/1996 lineage that emerged in southeast Asia in 1996-have been occuring with increasing frequency in Europe. Between 2005 and 2020, at least ten HPAI H5 incursions were identified in Europe resulting in mass mortalities among poultry and wild birds. Until 2009, the HPAI H5 virus outbreaks in Europe were caused by HPAI H5N1 clade 2.2 viruses, while from 2014 onwards HPAI H5 clade 2.3.4.4 viruses dominated outbreaks, with abundant genetic reassortments yielding subtypes H5N1, H5N2, H5N3, H5N4, H5N5, H5N6 and H5N8. The majority of HPAI H5 virus detections in wild and domestic birds within Europe coincide with southwest/westward fall migration and large local waterbird aggregations during wintering. In this review we provide an overview of HPAI H5 virus epidemiology, ecology and evolution at the interface between poultry and wild birds based on 15 years of avian influenza virus surveillance in Europe, and assess future directions for HPAI virus research and surveillance, including the integration of whole genome sequencing, host identification and avian ecology into risk-based surveillance and analyses.

Parasite prevalence in intermediate hosts increases with waterbody age and abundance of final hosts.

Prevalence of a parasite may be influenced by age of the habitat (= time available for hosts and parasites to colonize habitats), assemblage composition of host and non-host species, or biotic and abiotic habitat features. For a trophically transmitted parasite, the intermediate host may be consumed by both final hosts and 'dead-end' predators that are incompetent to host the parasite. We tested biotic and abiotic factors that might influence parasite prevalence in a freshwater host-parasite system using a dataset collected from 36 water bodies in the vicinity of Edmonton, Alberta, Canada. In this system, eggs of thorny-headed worms (Acanthocephala: Polymorphus spp.) are eaten by intermediate-host amphipods (Gammarus lacustris Sars), which are then consumed by final vertebrate hosts (certain aquatic birds and muskrats) and various non-host waterbird species. We found that acanthocephalan prevalence in amphipods was positively correlated with waterbody age and with abundance of final-host species. In contrast, abundance of the intermediate host G. lacustris was less important and was negatively correlated with parasite prevalence ('encounter-dilution effect'). Similarly, parasite prevalence showed a marginally significant and negative correlation with abundance of 'dead-end' Gammarus-eating birds. We conclude that in our study system, time available for colonization and abundance of final hosts are more important for parasite prevalence in intermediate hosts than is abundance of intermediate and dead-end hosts.

Halogenated organic compounds in the eggs of aquatic birds from the Gulf of Gdansk and Wloclawek Dam (Poland).

Diet is the major route of exposure to environmental contaminants in biota and, after penetration into an organism, xenobiotics continue to accumulate in the body. In birds the egg-laying process acts as a transfer mechanism for the accumulated pollutants and results in the burdening of the next generation at an early stage of development. This transfer has a strong influence on developmental disorders and even breeding success. With this in mind polybrominated diphenyl ethers (PBDE), polychlorinated dibenzo-p-dioxins and polychlorinated dibenzo furans (PCDD/Fs), as well as polychlorinated biphenyls (PCBs), were analyzed in the eggs of aquatic birds from different habitats and with different diet preferences. The highest concentration of PBDE was noted in gull eggs (198.31 ng g-1 dw.) and the lowest in tern eggs (sandwich tern: 76.96 ng g-1 dw.; common tern: 113.73 ng g-1 dw). Deca-BDE was detected only in herring gull eggs from the Wloclawek reservoir. PCDDF/s were found in the eggs of terns from the southern coast of the Baltic Sea and gulls from an inland reservoir (dam) on the River Vistula close to the town of Wloclawek. The highest toxicity (birds Toxic Equivalent Factor) was found in the eggs of terns (sandwich tern - 93.97 pg g-1 dw., common tern - 68.35 pg g-1 dw.), and this was found to be several times higher than in herring gull eggs (18.80 pg g-1 dw.). Non-dioxin like PCBs were ten times higher than other analyzed PCB congeners, but the congener pattern was similar to other studies.

Escape o sea presa: nuevos registros y conocimiento actual sobre depredadores de ranas Pseudinae (Anura: Hylidae) en América del sur / Escape or be preyed: new records and current knowledge on predators of pseudinae frogs (anura: hylidae) in south america

ABSTRACT Neotropical amphibians play important roles as preys and predators in freshwater and terrestrial ecosystems. The subfamily Pseudinae includes small and medium-sized frogs within three genera representing 13 valid species. Most published records of predation on Pseudinae frogs are anecdotic and scarce. Herein, we provide five new reports of predation and presenting a detailed literature review on Pseudinae predation, with 15 studies published between 1983-2017. Pseudinae species were preyed at both day and night by a wide variety of predators, principally birds. Adults were preyed upon more frequently than juveniles and tadpoles. In the present study, most predators were diurnal, with birds accounting for most records. A variety of invertebrates prey on anurans, but water bugs and spiders are the most common ones. In the present study, water bugs comprised 75 % of the Pseudinae predation records by invertebrates. However, anuran predation by invertebrates remains poorly documented. Thus, the description of new cases of predation accompanied by a review of the data available in the literature is crucial to understanding Neotropical food webs.

RESUMEN Los anfibios neotropicales desempeñan papeles importantes como depredadores y presas en los ecosistemas dulce acuícolas y terrestres. La subfamilia Pseudinae incluye ranas pequeñas y medianas, distribuidas en tres géneros y representando 13 especies válidas. Los registros de depredación de Pseudinae son escasos y anecdóticos. Por lo tanto, el conocimiento de nuevos casos puede mejorar nuestra comprensión de las relaciones depredador-presa entre estas ranas y su papel en la cadena trófica. Presentamos cinco nuevos registros de depredación y revisamos los casos de depredación de la literatura, que incluyen 15 estudios publicados entre 1983 y 2017. Las especies de Pseudinae son depredadas, tanto durante el día como en la noche, por una gran variedad de depredadores, principalmente aves. Los adultos son más frecuentemente depredados que los juveniles y los renacuajos. En el presente estudio, las chinches de agua representan 75 % de los registros de depredación de Pseudinae por invertebrados. Sin embargo, depredación de anuros por invertebrados permanece poco documentada. Por lo tanto, la descripción de nuevos casos de depredación, junto a una revisión de los datos disponibles en la literatura es crucial para entender redes tróficas neotropicales.

Receptor-binding properties of influenza viruses isolated from gulls.

Ducks, gulls and shorebirds represent the major hosts of influenza A viruses (IAVs) in nature, but distinctions of IAVs in different birds are not well defined. Here we characterized the receptor specificity of gull IAVs with HA subtypes H4, H6, H14, H13 and H16 using synthetic sialylglycopolymers. In contrast to duck IAVs, gull IAVs efficiently bound to fucosylated receptors and often preferred sulfated and non-sulfated receptors with Galß1-4GlcNAc cores over the counterparts with Galß1-3GlcNAc cores. Unlike all other IAVs of aquatic birds, H16 IAVs showed efficient binding to Neu5Acα2-6Gal-containing receptors and bound poorly to Neu5Acα2-3Galß1-3-terminated (duck-type) receptors. Analysis of HA crystal structures and amino acid sequences suggested that the amino acid at position 222 is an important determinant of the receptor specificity of IAVs and that transmission of duck viruses to gulls and shorebirds is commonly accompanied by substitutions at this position.

Genotypic characterisation of Avian paramyxovirus type-1 viruses isolated from aquatic birds in Uganda.

Avian paramyxovirus type-1 (APMV-1) viruses of the lentogenic pathotypes are often isolated from wild aquatic birds and may mutate to high pathogenicity when they cross into poultry and cause debilitating Newcastle disease. This study characterised AMPV-1 isolated from fresh faecal droppings from wild aquatic birds roosting sites in Uganda. Fresh faecal samples from wild aquatic birds at several waterbodies in Uganda were collected and inoculated into 9-10-day-old embryonated chicken eggs. After isolation, the viruses were confirmed as APMV-1 by APMV-1-specific polymerase chain reaction (PCR). The cleavage site of the fusion protein gene for 24 representative isolates was sequenced and phylogenetically analysed and compared with representative isolates of the different APMV-1 genotypes in the GenBank database. In total, 711 samples were collected from different regions in the country from which 72 isolates were recovered, giving a prevalence of 10.1%. Sequence analysis of 24 isolates revealed that the isolates were all lentogenic, with the typical 111GGRQGR'L117 avirulent motif. Twenty-two isolates had similar amino acid sequences at the cleavage site, which were different from the LaSota vaccine strain by a silent nucleotide substitution T357C. Two isolates, NDV/waterfowl/Uganda/MU150/2011 and NDV/waterfowl/Uganda/MU186/2011, were different from the rest of the isolates in a single amino acid, with aspartate and alanine at positions 124 and 129, respectively. The results of this study revealed that Ugandan aquatic birds indeed harbour APMV-1 that clustered with class II genotype II strains and had limited genetic diversity.