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Wild Birds (wild + bird)
Terms modified by Wild Birds Selected AbstractsRecent expansion of highly pathogenic avian influenza H5N1: a critical reviewIBIS, Issue 2 2007M. GAUTHIER-CLERC Wild birds, particularly waterfowl, are a key element of the viral ecology of avian influenza. Highly pathogenic avian influenza (HPAI) virus, subtype H5N1, was first detected in poultry in November 1996 in southeast China, where it originated. The virus subsequently dispersed throughout most of Asia, and also to Africa and Europe. Despite compelling evidence that the virus has been dispersed widely via human activities that include farming, and marketing of poultry, migratory birds have been widely considered to be the primary source of its global dispersal. Here we present a critical examination of the arguments both for and against the role of migratory birds in the global dispersal of HPAI H5N1. We conclude that, whilst wild birds undoubtedly contribute to the local spread of the virus in the wild, human commercial activities, particularly those associated with poultry, are the major factors that have determined its global dispersal. [source] Species-specific injury-induced cell proliferation in the hippocampus and subventricular zone of food-storing and nonstoring wild birdsDEVELOPMENTAL NEUROBIOLOGY, Issue 1 2010L.M. Law Abstract Cells are continuously born and incorporated into the adult hippocampus (HP). Adult neurogenesis might act to increase the total number of cells or replace dead cells. Thus, neurogenesis might be a primary factor in augmenting, maintaining, or even recovering functions. In zebra finches, HP injury increases cell proliferation in the HP and stem cell rich subventricular zone (SVZ). It is unknown what effect injury has on a species dependent upon the HP for survival in the wild. In food-storing birds, recovery of caches is seasonal, necessary for survival, dependent upon the HP and is concomitant with a peak in HP neurogenesis. During the fall, food-storing black-capped chickadees (BCCs) and nonstoring dark-eyed juncos (DEJs) were captured and given a unilateral penetrating lesion to the HP one day later. On day 3, birds were injected with the mitotic marker 5-bromo-2,-deoxyuridine (BrdU) and perfused on day 10. If unlesioned, more BrdU-labeled cells were observed in the HP and SVZ of BCCs compared to DEJs, indicating higher innate cell proliferation or incorporation in BCCs. If lesioned, BrdU-labeled cells increased in the injured HP of both species; however, lesions caused larger increases in DEJs. DEJs also showed increases in BrdU-labeled cells in the SVZ and contralateral HP. BCCs showed no such increases on day 10. Thus, during the fall food-storing season, storers showed suppressed injury-induced cell proliferation and/or reduced survival rates of these new cells compared to nonstorers. These species differences may provide a useful model for isolating factors involved in cellular responses following injury. © 2009 Wiley Periodicals, Inc. Develop Neurobiol, 2010 [source] 2,3,4,7,8-pentachlorodibenzofuran is a more potent cytochrome P4501A inducer than 2,3,7,8-tetrachlorodibenzo- p -dioxin in herring gull hepatocyte culturesENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 9 2010Jessica C. Hervé Abstract Concentration-dependent effects of 2,3,7,8-tetrachlorodibenzo- p -dioxin (TCDD), 2,3,4,7,8-pentachlorodibenzofuran (PeCDF), and 2,3,7,8-tetrachlorodibenzofuran (TCDF) on cytochrome P4501A (CYP1A) induction were determined in primary cultures of embryonic herring gull (Larus argentatus) hepatocytes exposed for 24,h. Based on the concentration that induced 50% of the maximal response (EC50), the relative potencies of TCDD and TCDF did not differ by more than 3.5-fold. However, also based on the EC50, PeCDF was 40-fold, 21-fold, and 9.8-fold more potent for inducing ethoxyresorufin- O -deethylase (EROD) activity, CYP1A4 mRNA expression, and CYP1A5 mRNA expression than TCDD, respectively. The relative CYP1A-inducing potencies of PeCDF and of other dioxin-like chemicals (DLCs) in herring gull hepatocytes (HEH RePs), along with data on concentrations of DLCs in Great Lakes herring gull eggs, were used to calculate World Health Organization toxic equivalent (WHO-TEQ) concentrations and herring gull embryonic hepatocyte toxic equivalent (HEH-TEQ) concentrations. The analysis indicated that, when using avian toxic equivalency factors (TEFs) recommended by the WHO, the relative contribution of TCDD (1.1,10.2%) to total WHO-TEQ concentration was higher than that of PeCDF (1.7,2.9%). These results differ from the relative contribution of TCDD and PeCDF when HEH RePs were used; PeCDF was a major contributor (36.5,52.9%) to total HEH-TEQ concentrations, whereas the contribution by TCDD (1.2,10.3%) was less than that of PeCDF. The WHO TEFs for avian species were largely derived from studies with the domestic chicken (Gallus gallus domesticus). The findings of the present study suggest that it is necessary to determine the relative potencies of DLCs in wild birds and to re-evaluate their relative contributions to the biochemical and toxic effects previously reported in herring gulls and other avian species. Environ. Toxicol. Chem. 2010;29:2088,2095. © 2010 SETAC [source] A nonlethal microsampling technique to monitor the effects of mercury on wild bird eggsENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 3 2009Katherine R. Stebbins Abstract Methylmercury is the predominant chemical form of mercury reported in the eggs of wild birds, and the embryo is the most sensitive life stage to methylmercury toxicity. Protective guidelines have been based mainly on captive-breeding studies with chickens (Gallus gallus), mallards (Anas platyrhynchos), and ring-necked pheasants (Phasianus colchicus) or on field studies where whole eggs were collected and analyzed and the effects of the mercury were measured based on the reproductive success of the remaining eggs. However, both of these methods have limitations. As an alternative, we developed a technique that involves extracting a small sample of albumen from a live egg, sealing the egg, returning the egg to its nest to be naturally incubated by the parents, and then relating the hatching success of this microsampled egg to its mercury concentration. After first developing this technique in the laboratory using chicken and mallard eggs, we selected the laughing gull (Larus atricilla) and black-necked stilt (Himantopus mexicanus) as test subjects in the field. We found that 92% of the microsampled laughing gull eggs met our reproductive endpoint of survival to the beginning of hatching compared to 100% for the paired control eggs within the same nests. Microsampled black-necked stilt eggs exhibited 100% hatching success compared to 93% for the paired control eggs. Our results indicate that microsampling is an effective tool for nonlethally sampling mercury concentrations in eggs and, as such, can be used for monitoring sensitive species, as well as for improving studies that examine the effects of mercury on avian reproduction. [source] Epoxiconazole causes changes in testicular histology and sperm production in the Japanese quail (Coturnix coturnix japonica)ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2008Konstanze Grote Abstract The fungicide epoxiconazole (Epox), a triazole, belongs to the group of azole compounds that are extensively used as fungicides in various fruit crops. The frequent use of agricultural lands for wintering by migrating birds can be the source of their increased dietary intake of agricultural pesticides. We investigated whether exposure to Epox causes effects on avian fertility and reproduction, using the Japanese quail (Coturnix coturnix japonica) as a model species for the assessment of reproductive effects of pesticides in wild birds. Epox was administered to adult Japanese quail for three weeks at dietary levels of 10, 50, and 500 ppm, and possible effects on reproduction were investigated. Epox administration resulted in a significantly decreased number of spermatids in the 50- and 500-ppm dose groups. Histopathology showed a reduced number of testicular canaliculi with visible germ cells and a reduction in spermatid number. However, testis weight was not affected up to the highest dose level. No impact was observed on hormone levels, fertility, and reproductive outcome, as laying rate and percentage of fertile eggs were not altered. Likewise, treatment had no influence on the egg or chick parameters evaluated. A time- and dose-related transfer of Epox into the eggs was determined in all treatment groups. We conclude that dietary treatment of Japanese quail with 50 and 500 ppm of the triazole fungicide Epox resulted in a clear impact on the testis. The evaluation of the additional endpoints spermatid count and testicular histology have proven useful and are recommended for future studies on avian reproduction. [source] Innate and Learned Components of Defence by Flickers Against a Novel Nest Competitor, the European StarlingETHOLOGY, Issue 10 2004Karen L. Wiebe Defence against predators is an important component of fitness in wild birds but the first step of defence, predator recognition, is not well understood. Anti-predator behaviour may innate, in which case the individual responds without prior contact with that predator, and/or there may be a learned component that develops only after direct experience. In the wild, the development of anti-predator behaviour is studied by exposing naive individuals to novel predators. I studied responses of 71 naive and experienced northern flickers Colaptes auratus, to a novel nest predator and competitor, the European starling Sturnus vulgaris that was introduced to North America. Naive individuals responded more intensely to the model starling than to the control model suggesting an innate component to recognition. However, there was also a learned component to defence because flickers nesting near to starlings reacted more aggressively than naive individuals far from starlings. Consistent with theory on life histories and optimal defence levels, no significant differences in aggression were found between the sexes or between age classes. Selection should favour more intense, and possibly innate, defence against the introduced starling. Variation in responses of naive individuals suggests that there may already be some alleles in the population associated with higher defence, but that these may not be uniform within the population. [source] Use of TLC-FID and GC-MS/FID to examine the effects of migratory state, diet and captivity on preen wax composition in White-throated Sparrows Zonotrichia albicollisIBIS, Issue 4 2010RAYMOND H. THOMAS Preen wax is important for plumage maintenance and other functions. Its chemical composition is complex, and separating and quantifying its components, commonly by gas chromatography (GC), can be challenging. We present a simple analytical system consisting of thin-layer chromatography/flame ionization detection (TLC-FID) using a solvent system of 100% toluene to analyse the complex compound classes present in preen wax. We used GC and TLC-FID to investigate the effects of migratory status, diet and captivity on the preen wax composition of White-throated Sparrows Zonotrichia albicollis, and to measure the quantity of preen wax on the head, primary and tail feathers. White-throated Sparrows produced preen wax containing only monoesters regardless of migratory state. The monoesters contained several isomers consisting of homologous series of fatty alcohols (C10,C20) and fatty acids (C13,C19) esterified together in different combinations to form monoesters with total carbon numbers ranging from C23 to C38. Weighted average monoester carbon number was greater in captive birds than in wild birds and was greater in captives fed a formulated diet enriched with sesame oil than in birds fed the same diet enriched with fish oil. Captivity and migratory state also affected the complexity of the mixture of monoesters. There was significantly more preen wax on head feathers compared with primary and tail feathers. We suggest that among its many functions, preen wax may play a role in drag reduction by affecting the physical properties of feathers, and/or the fluid flow at their surfaces. [source] Preen waxes do not protect carotenoid plumage from bleaching by sunlightIBIS, Issue 2 2008ADRIAN SURMACKI The plumage coloration of wild birds often changes during the breeding season. One of the possible reasons for this is that sunlight, and particularly ultraviolet (UV) wavelengths, degrades the pigments responsible for plumage coloration. It has been suggested that birds may apply preen wax to feathers to protect feathers from bleaching. This hypothesis is tested by exposing carotenoid-based breast feathers of Great Tits to ambient light, light filtered to exclude UV and darkness. Preen waxes were experimentally removed from feather samples and the effect of light on coloration of treatment and control feathers compared. Ambient light had an effect on feather colour but preen wax did not. Feathers exposed to sun gradually became less saturated and hues shifted towards shorter wavelengths. This was not apparent in control feathers kept in darkness. Feathers exposed to full-spectra sunlight faded more than those that were kept in light with UV wavelengths removed. There was a decrease in brightness of feathers in both experimental and control groups, which was assumed to be an effect of dirt accumulation. This experiment confirmed earlier suspicions regarding the detrimental effects of UV irradiation on carotenoid-based coloration of avian feathers but failed to show any protective function of preen waxes. The possible consequences of these mechanisms of colour change for birds with regard to mating strategies are discussed. [source] Adult sex ratios in wild bird populationsIBIS, Issue 4 2007PAUL F. DONALD Offspring sex ratios in wild bird populations, and the extent to which they vary from the equality expected by random genotypic sex determination, have received much recent attention. Adult sex ratios (ASRs) in wild birds, on the other hand, remain very poorly described, and many of the questions about them posed by Ernst Mayr in 1939 remain unanswered. This review assesses population-level sex ratio patterns in wild bird populations, with an emphasis on the ASR. A quantitative assessment of over 200 published estimates of ASR, covering species from a wide range of taxa, regions and habitats, supported Mayr's assertion that skewed ASRs are common in wild bird populations. On average, males outnumbered females by around 33%, and 65% of published estimates differed significantly from equality. In contrast, population-level estimates of offspring sex ratio in birds did not generally differ from equality, and mean ASR across a range of wild mammal species was strongly female-skewed. ASR distortion in birds was significantly more severe in populations of globally threatened species than in non-threatened species, a previously undescribed pattern that has profound implications for their monitoring and conservation. Higher female mortality, rather than skewed offspring sex ratio, is the main driver of male-skewed ASRs in birds, and the causes and implications of this are reviewed. While estimates of ASR in wild bird populations may be subject to a number of biases, which are discussed, there is currently no quantitative evidence that an ASR of one male to one female represents the norm in birds. A better understanding and reporting of ASRs in wild bird populations could contribute greatly to our understanding of population processes and could contribute much to theoretical and applied research and conservation. [source] Recent expansion of highly pathogenic avian influenza H5N1: a critical reviewIBIS, Issue 2 2007M. GAUTHIER-CLERC Wild birds, particularly waterfowl, are a key element of the viral ecology of avian influenza. Highly pathogenic avian influenza (HPAI) virus, subtype H5N1, was first detected in poultry in November 1996 in southeast China, where it originated. The virus subsequently dispersed throughout most of Asia, and also to Africa and Europe. Despite compelling evidence that the virus has been dispersed widely via human activities that include farming, and marketing of poultry, migratory birds have been widely considered to be the primary source of its global dispersal. Here we present a critical examination of the arguments both for and against the role of migratory birds in the global dispersal of HPAI H5N1. We conclude that, whilst wild birds undoubtedly contribute to the local spread of the virus in the wild, human commercial activities, particularly those associated with poultry, are the major factors that have determined its global dispersal. [source] A comparison of infestation patterns by Ixodes ticks in urban and rural populations of the Common Blackbird Turdus merulaIBIS, Issue 4 2002Arnaud Gregoire Although spatial variation in the patterns of parasite infestations among host populations may have important ecological and epidemiological consequences, the causes underlying such variation are poorly known. In the context of a long-term study on the population biology of Common Blackbirds Turdus merula, we examined the prevalence and intensity of infestation by Ixodes ticks between birds living in rural vs. urban habitats. The overall prevalence of tick infestations was significantly higher in the rural habitat where 74% of individuals (n = 130) were infested. This result contrasted markedly with the situation in the urban habitat where less than 2% of individuals (n = 360) carried ticks. There was no significant effect of the sex of the host on the intensity or prevalence of tick infestations. There was a significant effect of the age of the host on tick infestations essentially due to the absence of ticks on nestlings. Possible mechanisms responsible for the differences between habitats could include differences in tick survival and/or host resistance towards ticks. Previous studies have shown higher population densities and suggested longer survival for Blackbirds in urban than in rural habitats. Given that ixodid ticks are known to transmit pathogens like Borrelia spp. to wild birds, and that Blackbirds can act as reservoirs for these pathogens, the infection patterns observed in our study area provide a suitable situation to study the interrelations between ticks, Blackbirds and pathogens. [source] Avian influenza surveillance in wild birds in the European Union in 2006INFLUENZA AND OTHER RESPIRATORY VIRUSES, Issue 1 2009Uta Hesterberg Abstract Background, Infections of wild birds with highly pathogenic avian influenza (AI) subtype H5N1 virus were reported for the first time in the European Union in 2006. Objectives, To capture epidemiological information on H5N1 HPAI in wild bird populations through large-scale surveillance and extensive data collection. Methods, Records were analysed at bird level to explore the epidemiology of AI with regard to species of wild birds involved, timing and location of infections as well as the applicability of different surveillance types for the detection of infections. Results, In total, 120,706 records of birds were sent to the Community Reference Laboratory for analysis. Incidents of H5N1 HPAI in wild birds were detected in 14 EU Member States during 2006. All of these incidents occurred between February and May, with the exception of two single cases during the summer months in Germany and Spain. Conclusions, For the detection of H5N1 HPAI virus, passive surveillance of dead or diseased birds appeared the most effective approach, whilst active surveillance offered better detection of low pathogenic avian influenza (LPAI) viruses. No carrier species for H5N1 HPAI virus could be identified and almost all birds infected with H5N1 HPAI virus were either dead or showed clinical signs. A very large number of Mallards (Anas platyrhynchos) were tested in 2006 and while a high proportion of LPAI infections were found in this species, H5N1 HPAI virus was rarely identified in these birds. Orders of species that appeared to be very clinically susceptible to H5N1 HPAI virus were swans, diving ducks, mergansers and grebes, supporting experimental evidence. Surveillance results indicate that H5N1 HPAI virus did not establish itself successfully in the EU wild bird population in 2006. [source] Surveillance for highly pathogenic avian influenza in wild birds in the USAINTEGRATIVE ZOOLOGY (ELECTRONIC), Issue 4 2009Thomas J. DELIBERTO Abstract As part of the USA's National Strategy for Pandemic Influenza, an Interagency Strategic Plan for the Early Detection of Highly Pathogenic H5N1 Avian Influenza in Wild Migratory Birds was developed and implemented. From 1 April 2006 through 31 March 2009, 261 946 samples from wild birds and 101 457 wild bird fecal samples were collected in the USA; no highly pathogenic avian influenza was detected. The United States Department of Agriculture, and state and tribal cooperators accounted for 213 115 (81%) of the wild bird samples collected; 31, 27, 21 and 21% of the samples were collected from the Atlantic, Pacific, Central and Mississippi flyways, respectively. More than 250 species of wild birds in all 50 states were sampled. The majority of wild birds (86%) were dabbling ducks, geese, swans and shorebirds. The apparent prevalence of low pathogenic avian influenza viruses during biological years 2007 and 2008 was 9.7 and 11.0%, respectively. The apparent prevalence of H5 and H7 subtypes across all species sampled were 0.5 and 0.06%, respectively. The pooled fecal samples (n= 101 539) positive for low pathogenic avian influenza were 4.0, 6.7 and 4.7% for biological years 2006, 2007 and 2008, respectively. The highly pathogenic early detection system for wild birds developed and implemented in the USA represents the largest coordinated wildlife disease surveillance system ever conducted. This effort provided evidence that wild birds in the USA were free of highly pathogenic avian influenza virus (given the expected minimum prevalence of 0.001%) at the 99.9% confidence level during the surveillance period. [source] The occurrence of Campylobacter in river water and waterfowl within a watershed in southern Ontario, CanadaJOURNAL OF APPLIED MICROBIOLOGY, Issue 3 2010M.I. Van Dyke Abstract Aims:, Quantitative PCR and a culture method were used to investigate Campylobacter occurrence over 3 years in a watershed located in southern Ontario, Canada that is used as a source of drinking water. Methods and Results:, Direct DNA extraction from river water followed by quantitative PCR analysis detected thermophilic campylobacters at low concentrations (<130 cells 100 ml,1) in 57,79% of samples taken from five locations. By comparison, a culture-based method detected Campylobacter in 0,23% of samples. Water quality parameters such as total Escherichia coli were not highly correlated with Campylobacter levels, although higher pathogen concentrations were observed at colder water temperatures (<10°C). Strains isolated from river water were primarily nalidixic acid-susceptible Campylobacter lari, and selected isolates were identified as Campylobacter lari ssp. concheus. Campylobacter from wild birds (seagulls, ducks and geese) were detected at a similar rate using PCR (32%) and culture-based (29%) methods, and although Campylobacter jejuni was isolated most frequently, C. lari ssp. concheus was also detected. Conclusions:,Campylobacter were frequently detected at low concentrations in the watershed. Higher prevalence rates using quantitative PCR was likely because of the formation of viable but nonculturable cells and low recovery of the culture method. In addition to animal and human waste, waterfowl can be an important contributor of Campylobacter in the environment. Significance and Impact of the Study:, Results of this study show that Campylobacter in surface water can be an important vector for human disease transmission and that method selection is important in determining pathogen occurrence in a water environment. [source] Eucalyptus pollen grain emptying by two Australian nectarivorous psittacinesJOURNAL OF AVIAN BIOLOGY, Issue 3 2001B. D. Gartrell The relative importance of pollen as a source of protein to vertebrates is controversial. In nectarivorous psittacine birds, field studies support its importance, but an experimental study in a nectarivorous parrot showed that less than 7% of pollen grains were emptied. We investigated pollen grain emptying by two nectarivorous Australian parrots, the Swift Parrot Lathamus discolor and the Musk Lorikeet Glossopsitta concinna. We used a controlled experiment, and examined pollen located at different levels through the alimentary tract of wild L. discolor. There was significant emptying of pollen grains (x=45.4%±1.91 s.e.) by all birds in the experimental trials. There was also a progressive increase in the percentage of pollen grains emptied at different sites along the alimentary tract in wild birds (crop x=24.2%±4.44 s.e., proventriculus x=34.0%±7.29 s.e., duodenum x=54.3%±5.42 s.e. and distal intestine x=64.2%±4.68 s.e.). The percentage of pollen grains emptied by captive L. discolor in the experimental trial (x=44.1%±2.77 s.e.) was not significantly different from that found in wild L. discolor (x=40.3%±4.25 s.e.). Both species of nectarivorous parrot were able to rapidly ingest large quantities of Eucalyptus pollen and appeared to empty the pollen grains efficiently. Eucalyptus pollen appears to be an important source of protein for these birds. [source] COMMENTARY,Ipecac: an improved emetic for wild birdsJOURNAL OF FIELD ORNITHOLOGY, Issue 4 2007Antony W. Diamond First page of article [source] Outbreak of Salmonella typhimurium in cats and humans associated with infection in wild birdsJOURNAL OF SMALL ANIMAL PRACTICE, Issue 8 2000M. A. Tauni An outbreak of Salmonella typhimurium infection in cats and humans in Sweden in 1999, associated with wild birds, is described. In the county of Värmland, 62 sick cats were examined. All were anorectic and lethargic, 57 per cent had vomiting and 31 per cent had diarrhoea. It was considered likely that salmonellosis was transmitted from cats to humans, but there were only a few such cases. [source] Comparative genomics of the poultry major histocompatibility complexANIMAL SCIENCE JOURNAL, Issue 2 2006Takashi SHIINA ABSTRACT This review summarizes the latest findings regarding the avian major histocompatibility complex (MHC), focusing particularly on the genomics of MHC in the Japanese quail (Cotrnix japonica) and other birds, as well as haplotype, genomics, function and disease resistance in the chicken (Gallus gallus). This information provides important insight into the breeding of disease resistance in poultry, natural selection of disease resistance in wild birds, and the effects of recombination and hitchhiking on the evolution of multiple MHC gene families. [source] The initial journey of juvenile emperor penguinsAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue S1 2007Gerald L. Kooyman Abstract 1.The first major journey of emperor penguins, among several in their lifetime, is the juveniles' dispersal from their natal colony on a trip that takes them beyond Antarctic waters. The route taken by fledglings from Cape Washington (74.5°,S; 165.4°,E) was studied by applying satellite transmitters to ten individuals during December 1994,1996. In January 2001 transmitters with longer transmission capacity were also applied to six hand-fed fledglings, which had been held captive for one month while attaining a body mass exceeding that of wild birds. These post-captive birds were released at the ice edge of McMurdo Sound (77.5°,S; 165.0°,E), which is in the vicinity of other emperor penguin colonies, and 320,km south of their natal colony of Cape Washington. 2.Independent of their parents, the wild birds travelled north-east for the next two months, reaching locations as low as 57°,S. The post-captive birds travelled north also, but their trek reached only to about 63°,S before they turned south, or remained near their most northerly position from March through May. 3.It was concluded that among colonies in the southern Ross Sea: (a) most healthy fledglings survive at least the first two months at sea, feeding themselves as they go; (b) the Cape Washington fledglings travelled as far north as 57°,S, and much of this journey was in ice free waters; (c) by April, the post-captive birds reached at least as far as the large-scale pack ice edge and possibly beyond the edge at 63°,S; (d) by early March the trend north ends, and by about late March the birds travel to, or remain near the northern ice edge. 4.The reason the birds travel so far north remains a mystery. Copyright © 2008 John Wiley & Sons, Ltd. [source] Australian surveillance for avian influenza viruses in wild birds between July 2005 and June 2007AUSTRALIAN VETERINARY JOURNAL, Issue 7 2009L Haynes Objective To identify and gain an understanding of the influenza viruses circulating in wild birds in Australia. Design A total of 16,303 swabs and 3782 blood samples were collected and analysed for avian influenza (AI) viruses from 16,420 wild birds in Australia between July 2005 and June 2007. Anseriformes and Charadriiformes were primarily targeted. Procedures Cloacal, oropharyngeal and faecal (environmental) swabs were tested using polymerase chain reaction (PCR) for the AI type A matrix gene. Positive samples underwent virus culture and subtyping. Serum samples were analysed using a blocking enzyme-linked immunosorbent assay for influenza A virus nucleoprotein. Results No highly pathogenic AI viruses were identified. However, 164 PCR tests were positive for the AI type A matrix gene, 46 of which were identified to subtype. A total of five viruses were isolated, three of which had a corresponding positive PCR and subtype identification (H3N8, H4N6, H7N6). Low pathogenic AI H5 and/or H7 was present in wild birds in New South Wales, Tasmania, Victoria and Western Australia. Antibodies to influenza A were also detected in 15.0% of the birds sampled. Conclusions Although low pathogenic AI virus subtypes are currently circulating in Australia, their prevalence is low (1.0% positive PCR). Surveillance activities for AI in wild birds should be continued to provide further epidemiological information about circulating viruses and to identify any changes in subtype prevalence. [source] How to tweak a beak: molecular techniques for studying the evolution of size and shape in Darwin's finches and other birdsBIOESSAYS, Issue 1 2007Richard A. Schneider A flurry of technological advances in molecular, cellular and developmental biology during the past decade has provided a clearer understanding of mechanisms underlying phenotypic diversification. Building upon such momentum, a recent paper tackles one of the foremost topics in evolution, that is the origin of species-specific beak morphology in Darwin's finches.1 Previous work involving both domesticated and wild birds implicated a well-known signaling pathway (i.e. bone morphogenetic proteins) and one population of progenitor cells in particular (i.e. cranial neural crest), as primary factors for establishing beak size and shape. But these results were limited in their ability to explain fully the morphogenetic bases of patterned outgrowth. So in a quest to identify novel genes whose expression correlated with differences in beak anatomy among Darwin's finches, a DNA microarray approach was undertaken using tissues harvested from the Galápagos Islands. The results are striking and point to a protein called calmodulin, which is a mediator of cellular calcium signaling, as a key determinant of beak length. BioEssays 29: 1,6, 2007. © 2006 Wiley Periodicals, Inc. [source] Hatching asynchrony and growth trade-offs within domesticated and wild zebra finch, Taeniopygia guttata, broodsBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 4 2010MARK C. MAINWARING The Australian zebra finch, Taeniopygia guttata, is a widely used model organism, yet few studies have compared domesticated and wild birds with the aim of examining its relevance as an evolutionary model species. Domestic and wild broods hatch over approximately 4 and 2 days, respectively, which is important given that nestlings can fledge after as little as 12 days, although 16,18 days is common. We aimed to evaluate the extent to which the greater hatching asynchrony in domestic stock may effect reproductive success through greater variance in size hierarchies, variance in within-brood growth rates, and partial brood mortality. Therefore, by simultaneously controlling brood sizes and experimentally manipulating hatching intervals in both domesticated and wild birds, we investigated the consequences of hatching intervals for fledging success and nestling growth patterns, as well as trade-offs. Fledging success was similarly high in domestic and wild broods of either hatching pattern. Nonetheless, between-brood analyses revealed that domestic nestlings had significantly higher masses, larger skeletal characters, and longer wings than their wild counterparts, although wild nestlings had comparable wing lengths at the pre-fledging stage. Moreover, within-brood analyses revealed only negligible differences between domestic and wild nestlings, and larger effects of hatching order and hatching pattern. Therefore, despite significant differences in the hatching intervals, and the ultimate size achieved by nestlings, the domestication process does not appear to have significantly altered nestling growth trade-offs. The present study provides reassuring evidence that studies involving domesticated zebra finches, or other domesticated model organisms, may provide reasonable adaptive explanations in behavioural and evolutionary ecology. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 100, 763,773. [source] The integration of digestion and osmoregulation in the avian gutBIOLOGICAL REVIEWS, Issue 4 2009Todd J. McWhorter Abstract We review digestion and osmoregulation in the avian gut, with an emphasis on the ways these different functions might interact to support or constrain each other and the ways they support the functioning of the whole animal in its natural environment. Differences between birds and other vertebrates are highlighted because these differences may make birds excellent models for study and may suggest interesting directions for future research. At a given body size birds, compared with mammals, tend to eat more food but have less small intestine and retain food in their gastrointestinal tract (GIT) for shorter periods of time, despite generally higher mass-specific energy demands. On most foods, however, they are not less efficient at digestion, which begs the question how they compensate. Intestinal tissue-specific rates of enzymatic breakdown of substrates and rates of active transport do not appear higher in birds than in mammals, nor is there a demonstrated difference in the extent to which those rates can be modulated during acclimation to different feeding regimes (e.g. diet, relative intake level). One compensation appears to be more extensive reliance on passive nutrient absorption by the paracellular pathway, because the avian species studied so far exceed the mammalian species by a factor of at least two- to threefold in this regard. Undigested residues reach the hindgut, but there is little evidence that most wild birds recover microbial metabolites of nutritional significance (essential amino acids and vitamins) by re-ingestion of faeces, in contrast to many hindgut fermenting mammals and possibly poultry. In birds, there is some evidence for hindgut capacity to breakdown either microbial protein or protein that escapes the small intestine intact, freeing up essential amino acids, and there is considerable evidence for an amino acid absorptive capacity in the hindgut of both avian and mammalian hindgut fermenters. Birds, unlike mammals, do not excrete hyperosmotic urine (i.e. more than five times plasma osmotic concentration). Urine is mixed with digesta rather than directly eliminated, and so the avian gut plays a relatively more important role in water and salt regulation than in mammals. Responses to dehydration and high- and low-salt loads are reviewed. Intestinal absorption of ingested water is modulated to help achieve water balance in one species studied (a nectar-feeding sunbird), the first demonstration of this in any terrestrial vertebrate. In many wild avian species the size and digestive capacity of the GIT is increased or decreased by as much as 50% in response to nutritional challenges such as hyperphagia, food restriction or fasting. The coincident impacts of these changes on osmoregulatory or immune function of the gut are poorly understood. [source] Carriage of Rickettsia spp., Coxiella burnetii and Anaplasma spp. by endemic and migratory wild birds and their ectoparasites in CyprusCLINICAL MICROBIOLOGY AND INFECTION, Issue 2009I. Ioannou No abstract is available for this article. [source] | |||||||||||||