30 resultados para CORVUS-MONEDULOIDES


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Wild bearded capuchin monkeys, Cebus libidinosus, use stone tools to crack palm nuts to obtain the kernel. In five experiments, we gave 10 monkeys from one wild group of bearded capuchins a choice of two nuts differing in resistance and size and/or two manufactured stones of the same shape, volume and composition but different mass. Monkeys consistently selected the nut that was easier to crack and the heavier stone. When choosing between two stones differing in mass by a ratio of 1.3:1, monkeys frequently touched the stones or tapped them with their fingers or with a nut. They showed these behaviours more frequently before making their first selection of a stone than afterward. These results suggest that capuchins discriminate between nuts and between stones, selecting materials that allow them to crack nuts with fewer strikes, and generate exploratory behaviours to discriminate stones of varying mass. In the final experiment, humans effectively discriminated the mass of stones using the same tapping and handling behaviours as capuchins. Capuchins explore objects in ways that allow them to perceive invariant properties (e.g. mass) of objects, enabling selection of objects for specific uses. We predict that species that use tools will generate behaviours that reveal invariant properties of objects such as mass; species that do not use tools are less likely to explore objects in this way. The precision with which individuals can judge invariant properties may differ considerably, and this also should predict prevalence of tool use across species. (C) 2010 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

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Observations are presented of Forest Ravens Corvus tasmanicus, and an Australian Magpie Gymnorhina tibicen, foraging by gleaning the sand on a beach.

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The Little Raven Corvus mellori is an omnivore that occasionally eats small birds. Most birds taken are thought to be eaten as carrion, though several records exist of ravens hunting and killing Budgerigars Melopsittacus undulates and a Spotted Turtle-Dove Streptopelia chinensis (Higgins et al. 2006). Both cases of bird depredation record Little Ravens attacking from above and stabbing prey to death with their beaks. Here, we report a pair of Little Ravens hunting, killing and eating a lone Sharp-tailed Sandpiper Calidris acuminita at Cheetham Wetlands, near Melbourne, Victoria (37° 53' 56"S, 144° 47' 33"E; 420 ha; see Antos et al. 2007 for a description). We also report an event which strongly implies they hunted and ate an adult Red-capped Plover Charadrius ruficapillus, and observations of hunting and eating eggs and chicks.

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Context In peri-urban environments, high availability of anthropogenic resources may result in relatively high abundances of some species, with potentially negative implications for other native biota. Effective management of such impacts requires understanding of the spatial ecology of problem species. However, home range and habitat use have not been described for the little raven (Corvus mellori), a superabundant native predator that occurs in urban and natural habitats, including those where threatened shorebirds breed. Aims The aim of this study was to provide basic information on little raven home range, habitat use and movements in a coastal peri-urban landscape. Methods Between October 2011 and January 2012 we radio-tracked 20 little ravens captured in a coastal wetland (near Melbourne, Australia). Key results Little ravens were highly mobile, moving up to 9.9km in an hour (median≤2km), and had large ranges: Minimum Convex Polygons were 1664-9989ha (median≤3362ha). Although most birds used both anthropogenic and natural habitats, some birds strongly selected for coastal wetland habitat. Birds used multiple roosts during the study period, most of which occurred in grassland (58.7%) or urban (22.3%) areas. Movement of up to 8.3km (median≤2.2km) between roosts during the night was also detected. Conclusions Ravens were highly mobile and used large home ranges and a variety of habitats, with habitat preferences varying between birds. Implications Considering the large home ranges and inter-individual variation in habitat preferences of little raven populations, localised management to reduce their impacts on breeding shorebirds is unlikely to be successful. Journal compilation

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 Little ravens were major predators of ground-nesting red-capped Plover and burrow-nesting Little penguin eggs. Ravens also congregated at the breeding sites of these two species to exploit eggs. As raven numbers increase with human habitation of land, their impact on other bird species needs to be monitored and managed.

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The formation of social bonds outside the mated pair is not frequently reported in monogamous birds, although it may be expected in some species like rooks, living in groups all year round. Here we explore the social structure of captive adult rooks over three breeding seasons. We recorded proximities and affiliations (i.e., allofeeding, allopreening, contact-sit) to classify relationships according to their strength. Three categories of relationships emerged: primary (i.e., pairs), secondary and weak relationships. Affiliations and sexual behaviours were not restricted to pairs, and secondary relationships were clearly recognizable. Mixed-sex secondary relationships were qualitatively equivalent to pairs (i.e., same behaviours in the same proportions), although they were quantitatively less intense. Same sex pairs occurred, and were qualitatively equivalent to mixedsex pairs. Overall we found that rooks social structure is more than just an aggregation of pairs, which highlights the importance of considering extra-pair relationships in socially monogamous birds.

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2007年9~11月和2008年4~5月,对云南省丽江玉龙雪山自然保护区的鸟类资源进行了调查,共记录鸟类184种,结合中国科学院昆明动物研究所鸟类标本室收藏的该地区标本和文献记录的种类,保护区内共记录鸟类330种(另13亚种),隶属47科(另4亚科),18目,占云南省所录鸟类种数848种的38.92%,全国鸟类种数1329种的24.83%。其中国家一级保护物种1种,二级保护物种29种。黑眉长尾山雀Aegithalos iouschistos和大嘴乌鸦Corvus macrorhynchos为保护区内的优势种类。保护区记录的鸟类有留鸟230种和亚种,占所录鸟类种和亚种数的67.05%。区系成分以东洋界物种为主,有182种,占繁殖鸟类总种数的66.42%。亚区级区系分析表明保护区的鸟类以西南山地亚区的种类为主。结合该区鸟类生境分布的特点,提出云南松高山松林、针阔混交林和寒温性暗针叶林的保护是保护工作的重点。

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Chicken pancreatic polypeptide is the prototype of the neuropeptide Y (NPY)/PP superfamily of regulatory peptides. This polypeptide was appended the descriptive term avian, despite the presence of some 8600 extant species of bird. Additional primary structures from other avian species, including turkey, goose and ostrich, would suggest that the primary structure of this polypeptide has been highly-conserved during avian evolution. Avian pancreatic polypeptides structurally-characterised to date have distinctive primary structural features unique to this vertebrate group including an N-terminal glycyl residue and a histidyl residue at position 34. The crow family, Corvidae, is representative of the order Passeriformes, generally regarded as the most evolutionarily recent and diverse avian taxon. Pancreatic polypeptide has been isolated from pancreatic tissues from five representative Eurasian species (the magpie, Pica pica; the jay, Garrulus glandarius; the hooded crow, Corvus corone; the rook, Corvus frugilegus; the jackdaw, Corvus monedula) and subjected to structural analyses. Mass spectroscopy estimated the molecular mass of each peptide as 4166 +/- 2 Da. The entire primary structures of 36 amino acid residue peptides were established in single gas-phase sequencing runs. The primary structures of pancreatic polypeptides from all species investigated were identical: APAQPAYPGDDAPVEDLLR-FYNDLQQYLNVVTRPRY. The peptides were deemed to be amidated due to their full molar cross-reactivity with the amide-requiring PP antiserum employed. The molecular mass (4165.6 Da), calculated from the sequences, was in close agreement with mass spectroscopy estimates. The presence of an N-terminal alanyl residue and a prolyl residue at position 34 differentiates crow PP from counterparts in other avian species. These residues are analogous to those found in most mammalian analogues. These data suggest that the term avian, appended to the chicken peptide, is no longer tenable due to the presence of an Ala1, Pro34 peptide in five species from the largest avian order. These data might also suggest that, in keeping with the known structure/activity requirements of this peptide family, crow PP should interact identically to mammalian analogues on mammalian receptors.

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Thesis (Ph.D.)--University of Washington, 2016-03

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Entre el 29 de setiembre y 3 de octubre 2011, se determinó la estructura de las comunidades, en términos de abundancia relativa, riqueza y diversidad y relación con el medio ambiente de la isla Lobos de Tierra (noreste de isla Rata, El Ñopo y La Grama). En los cálculos de diversidad específi ca se usó métodos uni y multivariados para hacer comparaciones en los lugares estudiados. En la zona mesolitoral se registró alta riqueza específi ca asociada a comunidades de fondos duros destacando el noreste de isla Rata con 58 especies. El grupo dominante fue moluscos en todas las zonas de estudio, sobresaliendo Tegula corvus y Acanthopleura echinata con mayores niveles de abundancia (296 a 412 ind.m-2). El índice de diversidad (H’) promedio por estación mostró valores >1,5 bits/ind en todas las zonas, con valores de dominancia y equitatividad <1,0. En el submareal, la riqueza fue de 124 especies. Los crustáceos y poliquetos tuvieron la mayor riqueza de especies y densidad. Los principales representantes fueron Gammarus sp. (26.607 ind.m-2), Spionidae (2.227 ind.m-2) y Diopatra rhizoicola (2.073 ind.m-2). El índice de diversidad promedio fue 2,2 bits, valor considerado de alta diversidad. La fauna íctica submareal estuvo conformada por 16 especies, destacando los géneros Auchenionchus y Labrisomus y en el intermareal se registraron 7 especies destacando Tomicodon chilensis. Se detectaron 24 especies de macroalgas: Rhodophyta (16 especies), Chlorophyta (5 especies) y Phaeophyta (3 especies), predominó Caulerpa fi liformis (submareal) y Gymnogongrus furcellatus (intermareal).

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Connaître le sexe d’un oiseau est important pour divers domaines notamment pour les vétérinaires, les écologistes ainsi que pour les éleveurs d’oiseaux qui veulent former des couples qui serviront à la reproduction. Plusieurs espèces d’oiseaux, juvéniles et adultes, n’ont pas de dimorphisme sexuel. L’utilisation de l’ADN est une façon rapide de déterminer le sexe à partir d’un échantillon de sang, de muscle, de plumes ou de fèces. Par contre, la méthode devrait être validée pour chaque espèce et idéalement, standardisée. Le premier objectif de cette étude est de développer une méthode de sexage par séquençage des oiseaux à partir des séquences du gène CHD, en utilisant les oiseaux de proie et les perroquets vus en clinique au Québec. Un deuxième objectif est de faire l’identification de l’espèce à sexer, à partir du gène mitochondrial COX-1 et aussi à partir des séquences CHD-Z et CHD-W, utilisés pour le sexage. Un troisième objectif est d’évaluer les séquences sorties (CHD-Z, CHD-W et COX-1) en vue d’une étude phylogénique. Une extraction d’ADN a été effectuée chez 27 espèces de perroquets, 34 espèces d’oiseaux de proie, une corneille (Corvus brachyrhynchos) et un poulet (Gallus gallus). Une amplification par PCR a été exécutée pour les exons partiels 23 et 24 du gène CHD. Le séquençage de cet amplicon permettait de savoir s’il s’agissait d’un mâle (séquence simple CHD-Z) ou d’une femelle (séquences CHD-Z et CHD-W qui se chevauchent). Afin d’avoir des séquences CHD-W distinctes, un sous-clonage a été fait chez les femelles de chaque espèce. De cette manière, les séquences partielles du gène CHD, Z et W, ont été trouvées pour les espèces échantillonnées. Une étude phylogénique a été effectuée avec les séquences de COX-1, CHD-Z et CHD-W grâce au site « Clustal-Omega ». La méthode de sexage des oiseaux par séquençage du gène CHD est standard et efficace. Le gène COX-1 permet une meilleure identification des espèces parentes et le gène CHD-Z est le plus utile pour étudier la phylogénie profonde.