Letteratura scientifica selezionata sul tema "Mallard, Australia"

Subspecies delineations may not reflect actual intraspecific diversity; an issue that becomes important when conservation of populations and/or subspecies that face severe declines is involved. The Grey Duck in New Zealand is considered a separate subspecies Anas superciliosa superciliosa from the Pacific Black Duck A. s. rogersi of Australia, even though poorly differentiated morphologically. Because the New Zealand and Australian populations of A. superciliosa are considered taxonomically distinct, the decline of New Zealand's Grey Duck and its hybridization with the introduced Mallard A. platyrhynchos has led to assignment of "endangered" conservation status. Taxonomic distinction and absence of periodic gene flow between the Australian and New Zealand populations are crucial for acceptance of this status. We used phylogeographic analysis of mitochondrial DNA control region sequences to determine whether haplotypes representing current subspecies are unique or are more consistent with populations in the two countries being considered the same subspecies. Two highly divergent genetic lineages of Grey Duck occur in New Zealand. One lineage (Group I) is found only in New Zealand primarily on North Island, while the other (Group II), occurs in populations throughout New Zealand and Australia. The split between Group I and II lineages is on the order of that found between some avian species. Even though subspecific designations of A. s. superciliosa and A. s. rogersi do not hold up based on molecular data, we identify a need for Grey Duck in New Zealand to be conserved to maintain the historical diversity within the species.

Background. Migratory waterfowl annually migrate over the continents along the routes known as flyways, serving as carriers of avian influenza virus across distant locations. Prevalence of influenza varies with species, and there are also geographical and temporal variations. However, the role of long-distance migration in multispecies transmission dynamics has yet to be understood. We constructed a mathematical model to capture the global dynamics of avian influenza, identifying species and locations that contribute to sustaining transmission.Methods. We devised a multisite, multispecies SIS (susceptible-infectious-susceptible) model, and estimated transmission rates within and between species in each geographical location from prevalence data. Parameters were directly sampled from posterior distribution under Bayesian inference framework. We then analyzed contribution of each species in each location to the global patterns of influenza transmission.Results. Transmission and migration parameters were estimated by Bayesian posterior sampling. The basic reproduction number was estimated at 1.1, slightly above the endemic threshold. Mallard was found to be the most important host with the highest transmission potential, and high- and middle-latitude regions appeared to act as hotspots of influenza transmission. The local reproduction number suggested that the prevalence of avian influenza in the Oceania region is dependent on the inflow of infected birds from other regions.Conclusion. Mallard exhibited the highest transmission rate among the species explored. Migration was suggested to be a key factor of the global prevalence of avian influenza, as transmission is locally sustainable only in the northern hemisphere, and the virus could be extinct in the Oceania region without migration.

Inoculant rhizobia typically need to compete with naturalised soil populations of rhizobia to form legume nodules. We have used the polymerase chain reaction to test the ability of seed-inoculated rhizobia to compete with naturalised populations of rhizobia and form nodules on clover (Trifolium alexandrinum, T.�purpureum, and T. resupinatum) in alkaline soil. Clover rhizobia, Rhizobium leguminosarum bv. trifolii, were identified at the strain level using either a nif-specific RP01 primer or ERIC primers. Analysis of rhizobia isolated from nodules indicated that strain TA1 competed poorly for nodule occupancy at 2 field sites (Roseworthy and Mallala, South Australia), with the exception that it nodulated T. alexandrinum at a level of 39% at the Roseworthy site in the first year of the trial. Strains CC2483g and WSM409 successfully colonised nodules when inoculated onto a particular clover species (T. resupinatum and T. purpureum, respectively) in the first year of inoculation and persisted in the soil to form nodules in the following year. Nodules frequently contained naturalised strains of rhizobia, distinct from introduced commercial strains. Dominant isolates were specific to a field site and nodulated all 3 clover species in both years of the field trial, with each isolate occupying up to 19% of the total nodules at a field site. It was hypothesised that field isolates had a better alkaline soil tolerance conferring a greater ability to nodulate clovers under these edaphic conditions. The results indicate that soil populations of rhizobia may provide a significant constraint to the introduction of current Australian commercial clover rhizobia into alkaline soils, and a more profitable strategy may be to seek rhizobial inoculants that are adapted to these soils.

Annual clover species such as Trifolium purpureum Loisel., T. resupinatum L., and T. alexandrinum L. are adapted to alkaline soil conditions and provide certain agronomic advantages over annual medics (Medicago spp.). Annual clovers have not been widely grown in alkaline soils in Australia, and quantifying their dinitrogen (N2) fixation in alkaline soils is important in understanding their potential role in mixed farming systems of southern Australia. Using the 15N natural abundance technique, it was estimated that annual clovers fixed 101–137 kg N/ha at Roseworthy and 59–62 kg N/ha at Mallala, on Calcarosols with soil pH of 8.0 and 8.5, respectively. Species differed in the percentages of fixed N2 estimated in shoot dry matter, which was highest in T. alexandrinum (77–85%), moderate in T. resupinatum (76%), and lowest in T. purpureum (65–74%). Naturally occurring soil rhizobia (Rhizobium leguminosarum bv. trifolii) provided adequate nodulation, as inoculation with different strains of rhizobia had little influence on nodulation or N2 fixation. These results indicate that clovers can provide a significant contribution of fixed N2 to mixed farming systems. Examination of nodules indicated variable nodule occupancy by the inoculant rhizobia and that 69% of shoot N was fixed when clovers were nodulated by the soil populations of rhizobia. A simple model is defined to identify the potential interactions between inoculated legumes and soil rhizobia, and the options for enhancing symbiotic effectiveness are discussed.

The relevance of the study of hydrophilic birds in the urban areas of the Black Sea coast is due to their important role in the coastal biocoenosis structure and the need to preserve biodiversity in the conditions of anthropogenic transformation of Crimean coastal zone. The dynamics of species composition and abundance of birds in Kruglaya (Omega) Bay (Sevastopol) were investigated. The results of regular and episodic monitoring carried out in 1995 and 2005–2016 were used in this work. Quantitative accounting was carried out only in January and February (1–2 times per winter season) in 2005–2008, episodically in 2009–2013 and weekly in December — May 2014/2015 and September — May 2015/2016. Number of specimens per species was registered, and the ratio of young and adult specimens in mute swan (Cygnus olor), sex ratio in mallard (Anas platyrhynchos), common pochard (Aythya ferina) and tufted duck (Aythya fuligula) were determined. Russian and Latin names of birds are represented by L. S. Stepanian. Kruglaya Bay is one of Sevastopol bays which form the northern coastline of the Heraclea Peninsula, and it is a place of seasonal concentrations of hydrophilic birds. The basic morphometric characteristics of the bay are the following: the water area — 0.64 km2, length — 1.3 km, maximum width — 0.8 km, the average depth — 4.5 m. The water area of the bay did not freeze usually, only its inner part was covered with ice in extremely cold winters. Benthic macrophyte species are represented by two associations: Cystoseira crinita and C. barbata on stones and rocks, and Zostera noltii and Z. marina on sandy and silty areas. Two local areas of common reed (Phragmites australis) beds are located in the inner part of the bay. The zoobenthos is a significant part of the food supply of birds and includes 97 species, mainly polychaetes, molluscs and crustaceans. The ichthyofauna is represented by 42 fish species. 51 species of aquatic and semi-aquatic birds across 8 Orders were identified. The winter bird community was most diverse and numerous (32 species: 14 Anseriformes, 7 Charadriiformes, 5 Podicipediformes, 3 Gruiformes, 2 Pelecaniformes, 1 Gaviiformes). Eight species dominate regularly in winters and quantitatively — mute swan, mallard, common pochard, tufted duck, eurasian coot (Fulica atra), black-headed gull (Larus ridibundus), caspian gull (Larus cachinnans) and common gull (Larus canus). Rare species wintering in the Mountain Crimea, including horned grebe (Podiceps auritus), Bewick’s swan (Cygnus bewickii), red-breasted goose (Rufibrenta ruficollis), white-headed duck (Oxyura leucocephala), knot (Calidris canutus), is of great interest. The average ratio of young and adult mute swans in the main wintering period (December — February) was 61 : 39 % in 2014/2015 and 45 : 55 % in 2015/2016, respectively. The ratio of males and females were as follows: in mallard 49.5 : 50.5 % in 2014/2015, and 51.4 : 48.6 % in 2015/2016; in common pochard 54.8 : 45.2 % in 2014/2015, and 60.5 : 39.5 % in 2015/2016; in tufted duck 51.0 : 49.0 % in 2014/2015, and 51.4 : 48.6 % in 2015/2016, respectively. Formation of the winter bird community began in October, sometimes at the end of September when single specimens of mallard, coot, tufted duck, red-breasted merganser (Mergus serrator), black-necked grebe (Podiceps nigricollis) appeared. Common gull, great crested grebe (Podiceps cristatus) and the common pochard come flying in November; the mute swan appears at the beginning of December. Maximum and relatively stable number of most species was typical for January and the first half of February. Maximum number of specimens of all bird species was registered in January 13, 2015 (1288), and February 7, 2016 (1531 specimens). The feeding conditions of Kruglaya Bay allow overwintering of the birds with different feeding specializations. The benthophages (most of Anseriformes and Coot) rank first in species richness (at least 13 species) and in quantitative terms. Five species (black-throated diver (Gavia arctica), great cormorant (Phalacrocorax carbo), common sheg (Phalacrocorax aristotelis), red-breasted merganser, Sandwich tern (Thalasseus sandvicensis)) form the group of ichthyophages. The Grebes occupy an intermediate position between benthophages and ichthyophages: small fish and benthic invertebrates are present in their diet. Four species of gull (black-headed, Caspian, common, Mediterranean gull (Larus melanocephalus)) constitute a group of omnivores. The rare visitors in Kruglaya Bay are zoophagous and omnivorous birds foraging in the surf zone and at shallow depths, such as water rail (Rallus aquaticus), common moorhen (Gallinula chloropus), dunlin (Calidris alpina), knot (Calidris canutus), and herbivores which prefer to feed in terrestrial habitats — red-breasted goose (Rufibrenta ruficollis). The nutritional requirements of birds are compensated to a certain extent by additional feeding carried out by townspeople. In general 30 passing and nomadic species, mainly Charadriiformes (11), Anseriformes (7) and Ciconiiformes (5), were registered. A nesting bird community was absent, and only the nesting of little bittern (Ixobrychus minutus) was registered in 2016 for the first time in city zone. The spring migration took place from late February to May, the autumn migration — from August until the first decade of November. Kruglaya Bay is a valuable natural and ecological educational place and deserves status as a natural park.

The article addresses the classification of Kyiv murals of the early 21st century, made by foreign artists (USA, Canada, France, United Kingdom, Belgium, Australia, Spain, Portugal, Argentina, Brazil, Costa Rica, South Africa, etc.). The image of Ukraine in the work of these artists, who got to know Ukraine forcedly, episodically, and inevitably scarcely, isthe image of the Other on the territory of this Other. As a result, “others” (foreign artists) overcome their own otherness and enter into cultural dialogue with other culture and the city, the notable part of which their murals become. Along with animalistic motifs (mainly ornithological), this area is dominated by the archetypal images of Ukrainian history and culture, bizarrely supplemented by their own reminiscences and additions (mural Berehynia). However, signs of simulacrum is not the case. It is rather a carnival fantasy that traces the influence of Baroque culture, which has deep roots in Ukraine. There are precedents of collaboration with Ukrainian authors (mural Vidrodzhennia (Renaissance) by Julien Malland and Oleksii Kyslov). Occasionally, foreign artists use only certain attributes of local life (embroidery pattern), directly reflect on the impressions of the present, transplanting them into the European context (mural Night Kyiv). Also from time to time they turn to real characters of national history and culture (Serhii Nigoian, Lesia Ukrainka, in the latter case Guido van Helten boldly reformed the established image iconography of the “daughter of Prometheus”, giving his heroine the features of a modern feminist), as well as sports (gymnast Hanna Rizatdinova). It was concluded that there is a long-term cultural dialogue between the West and Ukraine, with the first party presenting maximum interest and tolerance.

AbstractCucurbit crops host a range of serious sap-sucking insect pests, including silverleaf whitefly (SLW) and aphids, which potentially represent considerable risk to the Australian horticulture industry. These pests are extremely polyphagous with a wide host range. Chemical control is made difficult due to resistance and pollution, and other side-effects are associated with insecticide use. Consequently, there is much interest in maximising the role of biological control in the management of these sap-sucking insect pests. This study aimed to evaluate companion cropping alongside cucurbit crops in a tropical setting as a means to increase the populations of beneficial insects and spiders so as to control the major sap-sucking insect pests. The population of beneficial and harmful insects, with a focus on SLW and aphids, and other invertebrates were sampled weekly on four different crops which could be used for habitat manipulation: Goodbug Mix (GBM; a proprietary seed mixture including self-sowing annual and perennial herbaceous flower species); lablab (Lablab purpureus L. Sweet); lucerne (Medicago sativa L.); and niger (Guizotia abyssinica (L.f.) Cass.). Lablab hosted the highest numbers of beneficial insects (larvae and adults of lacewing (Mallada signata (Schneider)), ladybird beetles (Coccinella transversalis Fabricius) and spiders) while GBM hosted the highest numbers of European bees (Apis mellifera Linnaeus) and spiders. Lucerne and niger showed little promise in hosting beneficial insects, but lucerne hosted significantly more spiders (double the numbers) than niger. Lucerne hosted sig-nificantly more of the harmful insect species of aphids (Aphis gossypii (Glover)) and Myzus persicae (Sulzer)) and heliothis (Heliothis armigera Hübner). Niger hosted significantly more vegetable weevils (Listroderes difficillis (Germar)) than the other three species. Therefore, lablab and GBM appear to be viable options to grow within cucurbits or as field boundary crops to attract and increase beneficial insects and spiders for the control of sap-sucking insect pests. Use of these bio-control strategies affords the opportunity to minimise pesticide usage and the risks associated with pollution.

Abstract Background The Australian black swan (Cygnus atratus) is an iconic species with contrasting plumage to that of the closely related northern hemisphere white swans. The relative geographic isolation of the black swan may have resulted in a limited immune repertoire and increased susceptibility to infectious diseases, notably infectious diseases from which Australia has been largely shielded. Unlike mallard ducks and the mute swan (Cygnus olor), the black swan is extremely sensitive to highly pathogenic avian influenza. Understanding this susceptibility has been impaired by the absence of any available swan genome and transcriptome information. Results Here, we generate the first chromosome-length black and mute swan genomes annotated with transcriptome data, all using long-read based pipelines generated for vertebrate species. We use these genomes and transcriptomes to show that unlike other wild waterfowl, black swans lack an expanded immune gene repertoire, lack a key viral pattern-recognition receptor in endothelial cells and mount a poorly controlled inflammatory response to highly pathogenic avian influenza. We also implicate genetic differences in SLC45A2 gene in the iconic plumage of the black swan. Conclusion Together, these data suggest that the immune system of the black swan is such that should any avian viral infection become established in its native habitat, the black swan would be in a significant peril.

Limited published data exists on the Australian duck industry, particularly in relation to the nutritional requirements of the commercial duck (Anas Platyrhynchos). A series of seven experiments was designed to determine whether current nutritional recommendations for energy, lysine, methionine, threonine and tryptophan were sufficient to optimise growth, feed efficiency, and carcass characteristics of the duck. The ability of the duck to perform diet self selection was then examined for its potential use in the Australian industry. The outcome of the diet self selection experiments showed that ducks sometimes self select diets when offered choices from four diets differing in nutrient density. A key outcome of this research was the development of a revised set of nutrient specifications designed to maximise the performance of the Australian commercially grown duck. These proposed specifications could be economically beneficial to the expanding Australian duck industry
Doctor of Philosophy (PhD)

Limited published data exists on the Australian duck industry, particularly in relation to the nutritional requirements of the commercial duck (Anas Platyrhynchos). A series of seven experiments was designed to determine whether current nutritional recommendations for energy, lysine, methionine, threonine and tryptophan were sufficient to optimise growth, feed efficiency, and carcass characteristics of the duck. The ability of the duck to perform diet self selection was then examined for its potential use in the Australian industry. The outcome of the diet self selection experiments showed that ducks sometimes self select diets when offered choices from four diets differing in nutrient density. A key outcome of this research was the development of a revised set of nutrient specifications designed to maximise the performance of the Australian commercially grown duck. These proposed specifications could be economically beneficial to the expanding Australian duck industry

Themparks is a creative and critical thesis consisting of a book of poems—The Bloomin’ Notions of Other & Beau—and two experimental essays that illuminate the praxis behind the book of poems, not by auto-critique, but via a study of other contemporary Australian poets whose poetry involves similar compositional approaches. The Bloomin’ Notions of Other & Beau hijacks the prose poems of Arthur Rimbaud’s famously incomplete manuscript Illuminations and re-verses their content—a “Down Under conceit”—to create “inversions”, radically new poems that are ludic and multiple in form, that complicate authorial subjectivity by employing various methods of (mis)translation and appropriation, and whose subject matter reflects and refracts political and personal fragmentation in twenty-first century Australia. “Themparks”, the first critical essay, is a divagation into thempark by contemporary Australian poet Michael Farrell, the poems of which transpose/depose the structures of poems by John Ashbery; “Themparks” also analyses John Ashbery’s translations of the Illuminations of Arthur Rimbaud via a re-reading of Rimbaud’s famous formulation, “I is an other” (Je est an autre). “Aussi/Or”, the second critical essay, is a disquisition on Stéphane Mallarmé’s late innovative poem Un Coup de dés and its various antipodean versions and (mis)translations written by Christopher Brennan (in 1897), Chris Edwards and John Tranter (both in 2006). Both essays/assays explore the (anti)genre of poetic rewritings of previous poems; both trace certain homosocial poetic lineages from self-consciously “experimental” contemporary Australian poets back through American and Australian postmodernists to early modernist French poets; both raise/raze issues of translation, appropriation, plagiarism, and reproduction while employing—metonymically—some parallel theoretical tropes from psychoanalysis, linguistics, philosophy, and science. The guiding thread—the fil conducteur latent in Mallarmé—between the creative and critical components of this thesis is a poetics of the pun. The pun’s promiscuity highlights the highly libinal nature of language-tampering while working to both associate and dissociate parataxis and parapraxis.

Hybridisation between closely-related species is an ongoing threat to many species that can be exacerbated by anthropogenic practices. The Pacific Black Duck (Anas superciliosa) is a dabbling duck native to the southwest Pacific that is currently under threat of hybridisation with introduced Mallard (A. platyrhynchos). Mallard are known to hybridise with and threaten many other dabbling duck species throughout the world. To evaluate the threat posed by hybridisation with introduced domestic Mallards to the Australian subspecies of the Pacific Black Duck (A. s. rogersi), a set of nine microsatellite markers were selected to genetically differentiate these species and detect hybrids. The use of these microsatellite markers on putative Pacific Black Ducks found that the overall frequency of hybridisation in Australia is currently low (1.5%) and also revealed that the frequency of hybridisation tended to be higher in urban compared to rural Victoria. Behavioural observations suggested that while Mallards are dominant over Pacific Black Ducks, the latter have not been excluded from parks inhabited by Mallards. In contrast to mainland Australia, most birds on Lord Howe Island appear to be Mallards of New Zealand stock descent. It’s unclear whether hybrids resident were bred locally or whether they emigrated from New Zealand. The lack of Pacific Black Duck phenotypes on Lord Howe Island suggests that this species has been outcompeted by Mallards. In addition to hybridisation with Mallards, anecdotal reports have suggested that Pacific Black Ducks are also hybridising with Chestnut Teals (A. castanea). Based on microsatellite analysis, Chestnut Teal - Pacific Black Duck hybrids were detected, albeit at a low frequency (0.5%), among a sample of putative Pacific Black Ducks sampled throughout Australia Overall, Mallard – Pacific Black Duck hybridisation does not currently seem to be widespread. However, the precautionary principle would advise eradication methods to be put into place to prevent the spread of the Mallard genome throughout Australia’s Pacific Black Duck population to protect the genetic integrity of the Australian subspecies.