The Experts below are selected from a list of 105 Experts worldwide ranked by ideXlab platform
Adriana Bravo - One of the best experts on this subject based on the ideXlab platform.
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Ecology and Management of Nesting Blue-and-Yellow Macaws (Ara ararauna) in Mauritia Palm Swamps
Biodiversity & Conservation, 2006Co-Authors: Donald Brightsmith, Adriana BravoAbstract:This paper reports on the nesting ecology of Blue-and-Yellow Macaws ( Ara ararauna ) and the structure, conservation, and management of the Mauritia flexuosa palm swamps where they nest: clutch size averaged 2.6 and the number of chicks fledged per nesting attempt was 0.5. Macaws nested in tall dead palms in healthy palm swamps and in palms of all heights in open dieing palm stands. All nesting palms rose well above the surrounding vegetation presumably to discourage terrestrial predators. PVC nest boxes failed to attract nesting Blue-and-Yellow Macaws. A small section of palm swamp was managed to encourage Macaw nesting by cutting the tops off of M. flexuosa palms and clearing the understory vegetation. The palms remained standing from 4 to 7 years and were occupied by nesting Macaws at a rate of 24%. The data presented here suggest that cutting five palms a year in perpetuity would produce a stand of approximately 20 standing dead palms used by 6 or more pairs of Macaws annually. However, Macaw occupancy rates would depend on the density of Macaws and density of naturally occurring nest sites. This management scheme could be conducted on a 100-year rotation in an area of 1–4 ha or more depending on the palm density. Such a colony could be used to increase reproductive success of Blue-and-Yellow Macaw populations, create a valuable ecotourism resource, and concentrate Macaw nesting in protected areas.
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Ecology and Management of Nesting Blue-and-Yellow Macaws (Ara ararauna) in Mauritia Palm Swamps
Biodiversity and Conservation, 2006Co-Authors: Donald Brightsmith, Adriana BravoAbstract:This paper reports on the nesting ecology of Blue-and-Yellow Macaws (Ara ararauna) and the structure, conservation, and management of the Mauritia flexuosa palm swamps where they nest: clutch size averaged 2.6 and the number of chicks fledged per nesting attempt was 0.5. Macaws nested in tall dead palms in healthy palm swamps and in palms of all heights in open dieing palm stands. All nesting palms rose well above the surrounding vegetation presumably to discourage terrestrial predators. PVC nest boxes failed to attract nesting Blue-and-Yellow Macaws. A small section of palm swamp was managed to encourage Macaw nesting by cutting the tops off of M. flexuosa palms and clearing the understory vegetation. The palms remained standing from 4 to 7 years and were occupied by nesting Macaws at a rate of 24%. The data presented here suggest that cutting five palms a year in perpetuity would produce a stand of approximately 20 standing dead palms used by 6 or more pairs of Macaws annually. However, Macaw occupancy rates would depend on the density of Macaws and density of naturally occurring nest sites. This management scheme could be conducted on a 100-year rotation in an area of 1–4 ha or more depending on the palm density. Such a colony could be used to increase reproductive success of Blue-and-Yellow Macaw populations, create a valuable ecotourism resource, and concentrate Macaw nesting in protected areas.
Donald Brightsmith - One of the best experts on this subject based on the ideXlab platform.
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Ecology and Management of Nesting Blue-and-Yellow Macaws (Ara ararauna) in Mauritia Palm Swamps
Biodiversity & Conservation, 2006Co-Authors: Donald Brightsmith, Adriana BravoAbstract:This paper reports on the nesting ecology of Blue-and-Yellow Macaws ( Ara ararauna ) and the structure, conservation, and management of the Mauritia flexuosa palm swamps where they nest: clutch size averaged 2.6 and the number of chicks fledged per nesting attempt was 0.5. Macaws nested in tall dead palms in healthy palm swamps and in palms of all heights in open dieing palm stands. All nesting palms rose well above the surrounding vegetation presumably to discourage terrestrial predators. PVC nest boxes failed to attract nesting Blue-and-Yellow Macaws. A small section of palm swamp was managed to encourage Macaw nesting by cutting the tops off of M. flexuosa palms and clearing the understory vegetation. The palms remained standing from 4 to 7 years and were occupied by nesting Macaws at a rate of 24%. The data presented here suggest that cutting five palms a year in perpetuity would produce a stand of approximately 20 standing dead palms used by 6 or more pairs of Macaws annually. However, Macaw occupancy rates would depend on the density of Macaws and density of naturally occurring nest sites. This management scheme could be conducted on a 100-year rotation in an area of 1–4 ha or more depending on the palm density. Such a colony could be used to increase reproductive success of Blue-and-Yellow Macaw populations, create a valuable ecotourism resource, and concentrate Macaw nesting in protected areas.
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Ecology and Management of Nesting Blue-and-Yellow Macaws (Ara ararauna) in Mauritia Palm Swamps
Biodiversity and Conservation, 2006Co-Authors: Donald Brightsmith, Adriana BravoAbstract:This paper reports on the nesting ecology of Blue-and-Yellow Macaws (Ara ararauna) and the structure, conservation, and management of the Mauritia flexuosa palm swamps where they nest: clutch size averaged 2.6 and the number of chicks fledged per nesting attempt was 0.5. Macaws nested in tall dead palms in healthy palm swamps and in palms of all heights in open dieing palm stands. All nesting palms rose well above the surrounding vegetation presumably to discourage terrestrial predators. PVC nest boxes failed to attract nesting Blue-and-Yellow Macaws. A small section of palm swamp was managed to encourage Macaw nesting by cutting the tops off of M. flexuosa palms and clearing the understory vegetation. The palms remained standing from 4 to 7 years and were occupied by nesting Macaws at a rate of 24%. The data presented here suggest that cutting five palms a year in perpetuity would produce a stand of approximately 20 standing dead palms used by 6 or more pairs of Macaws annually. However, Macaw occupancy rates would depend on the density of Macaws and density of naturally occurring nest sites. This management scheme could be conducted on a 100-year rotation in an area of 1–4 ha or more depending on the palm density. Such a colony could be used to increase reproductive success of Blue-and-Yellow Macaw populations, create a valuable ecotourism resource, and concentrate Macaw nesting in protected areas.
Richard O. Prum - One of the best experts on this subject based on the ideXlab platform.
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development of colour producing β keratin nanostructures in avian feather barbs
Journal of the Royal Society Interface, 2009Co-Authors: Tim Quinn, Richard O. Prum, Eric R Dufresne, Karla WatersAbstract:The non-iridescent structural colours of avian feather barbs are produced by coherent light scattering from amorphous (i.e. quasi-ordered) nanostructures of β-keratin and air in the medullary cells of feather barb rami. Known barb nanostructures belong to two distinct morphological classes. ‘Channel’ nanostructures consist of β-keratin bars and air channels of elongate, tortuous and twisting forms. ‘Spherical’ nanostructures consist of highly spherical air cavities that are surrounded by thin β-keratin bars and sometimes interconnected by tiny passages. Using transmission electron microscopy, we observe that the colour-producing channel-type nanostructures of medullary β-keratin in feathers of the Blue-and-Yellow Macaw (Ara ararauna, Psittacidae) develop by intracellular self-assembly; the process proceeds in the absence of any biological prepattern created by the cell membrane, endoplasmic reticulum or cellular intermediate filaments. We examine the hypothesis that the shape and size of these self-assembled, intracellular nanostructures are determined by phase separation of β-keratin protein from the cytoplasm of the cell. The shapes of a broad sample of colour-producing channel-type nanostructures from nine avian species are very similar to those self-assembled during the phase separation of an unstable mixture, a process called spinodal decomposition (SD). In contrast, the shapes of a sample of spherical-type nanostructures from feather barbs of six species show a poor match to SD. However, spherical nanostructures show a strong morphological similarity to morphologies produced by phase separation of a metastable mixture, called nucleation and growth. We propose that colour-producing, intracellular, spongy medullary β-keratin nanostructures develop their characteristic sizes and shapes by phase separation during protein polymerization. We discuss the possible role of capillary flow through drying of medullary cells in the development of the hollow morphology of typical and spongy feather medullary cells.
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Development of colour-producing beta-keratin nanostructures in avian feather barbs.
Journal of the Royal Society Interface, 2009Co-Authors: Richard O. Prum, Tim Quinn, Eric R Dufresne, Karla WatersAbstract:The non-iridescent structural colours of avian feather barbs are produced by coherent light scattering from amorphous (i.e. quasi-ordered) nanostructures of beta-keratin and air in the medullary cells of feather barb rami. Known barb nanostructures belong to two distinct morphological classes. 'Channel' nanostructures consist of beta-keratin bars and air channels of elongate, tortuous and twisting forms. 'Spherical' nanostructures consist of highly spherical air cavities that are surrounded by thin beta-keratin bars and sometimes interconnected by tiny passages. Using transmission electron microscopy, we observe that the colour-producing channel-type nanostructures of medullary beta-keratin in feathers of the Blue-and-Yellow Macaw (Ara ararauna, Psittacidae) develop by intracellular self-assembly; the process proceeds in the absence of any biological prepattern created by the cell membrane, endoplasmic reticulum or cellular intermediate filaments. We examine the hypothesis that the shape and size of these self-assembled, intracellular nanostructures are determined by phase separation of beta-keratin protein from the cytoplasm of the cell. The shapes of a broad sample of colour-producing channel-type nanostructures from nine avian species are very similar to those self-assembled during the phase separation of an unstable mixture, a process called spinodal decomposition (SD). In contrast, the shapes of a sample of spherical-type nanostructures from feather barbs of six species show a poor match to SD. However, spherical nanostructures show a strong morphological similarity to morphologies produced by phase separation of a metastable mixture, called nucleation and growth. We propose that colour-producing, intracellular, spongy medullary beta-keratin nanostructures develop their characteristic sizes and shapes by phase separation during protein polymerization. We discuss the possible role of capillary flow through drying of medullary cells in the development of the hollow morphology of typical and spongy feather medullary cells.
Karla Waters - One of the best experts on this subject based on the ideXlab platform.
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development of colour producing β keratin nanostructures in avian feather barbs
Journal of the Royal Society Interface, 2009Co-Authors: Tim Quinn, Richard O. Prum, Eric R Dufresne, Karla WatersAbstract:The non-iridescent structural colours of avian feather barbs are produced by coherent light scattering from amorphous (i.e. quasi-ordered) nanostructures of β-keratin and air in the medullary cells of feather barb rami. Known barb nanostructures belong to two distinct morphological classes. ‘Channel’ nanostructures consist of β-keratin bars and air channels of elongate, tortuous and twisting forms. ‘Spherical’ nanostructures consist of highly spherical air cavities that are surrounded by thin β-keratin bars and sometimes interconnected by tiny passages. Using transmission electron microscopy, we observe that the colour-producing channel-type nanostructures of medullary β-keratin in feathers of the Blue-and-Yellow Macaw (Ara ararauna, Psittacidae) develop by intracellular self-assembly; the process proceeds in the absence of any biological prepattern created by the cell membrane, endoplasmic reticulum or cellular intermediate filaments. We examine the hypothesis that the shape and size of these self-assembled, intracellular nanostructures are determined by phase separation of β-keratin protein from the cytoplasm of the cell. The shapes of a broad sample of colour-producing channel-type nanostructures from nine avian species are very similar to those self-assembled during the phase separation of an unstable mixture, a process called spinodal decomposition (SD). In contrast, the shapes of a sample of spherical-type nanostructures from feather barbs of six species show a poor match to SD. However, spherical nanostructures show a strong morphological similarity to morphologies produced by phase separation of a metastable mixture, called nucleation and growth. We propose that colour-producing, intracellular, spongy medullary β-keratin nanostructures develop their characteristic sizes and shapes by phase separation during protein polymerization. We discuss the possible role of capillary flow through drying of medullary cells in the development of the hollow morphology of typical and spongy feather medullary cells.
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Development of colour-producing beta-keratin nanostructures in avian feather barbs.
Journal of the Royal Society Interface, 2009Co-Authors: Richard O. Prum, Tim Quinn, Eric R Dufresne, Karla WatersAbstract:The non-iridescent structural colours of avian feather barbs are produced by coherent light scattering from amorphous (i.e. quasi-ordered) nanostructures of beta-keratin and air in the medullary cells of feather barb rami. Known barb nanostructures belong to two distinct morphological classes. 'Channel' nanostructures consist of beta-keratin bars and air channels of elongate, tortuous and twisting forms. 'Spherical' nanostructures consist of highly spherical air cavities that are surrounded by thin beta-keratin bars and sometimes interconnected by tiny passages. Using transmission electron microscopy, we observe that the colour-producing channel-type nanostructures of medullary beta-keratin in feathers of the Blue-and-Yellow Macaw (Ara ararauna, Psittacidae) develop by intracellular self-assembly; the process proceeds in the absence of any biological prepattern created by the cell membrane, endoplasmic reticulum or cellular intermediate filaments. We examine the hypothesis that the shape and size of these self-assembled, intracellular nanostructures are determined by phase separation of beta-keratin protein from the cytoplasm of the cell. The shapes of a broad sample of colour-producing channel-type nanostructures from nine avian species are very similar to those self-assembled during the phase separation of an unstable mixture, a process called spinodal decomposition (SD). In contrast, the shapes of a sample of spherical-type nanostructures from feather barbs of six species show a poor match to SD. However, spherical nanostructures show a strong morphological similarity to morphologies produced by phase separation of a metastable mixture, called nucleation and growth. We propose that colour-producing, intracellular, spongy medullary beta-keratin nanostructures develop their characteristic sizes and shapes by phase separation during protein polymerization. We discuss the possible role of capillary flow through drying of medullary cells in the development of the hollow morphology of typical and spongy feather medullary cells.
Renato Caparroz - One of the best experts on this subject based on the ideXlab platform.
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In silico identification and characterization of novel microsatellite loci for the Blue-and-Yellow Macaw Ara ararauna (Linnaeus, 1758) (Psittaciformes, Psittacidae).
Genetics and Molecular Biology, 2019Co-Authors: Cássia Alves Lima-rezende, Gislaine Aparecida Fernandes, Helder Elias Da Silva, Sarah Dobkowski-marinho, Victor Fernandes Santos, Fernando Pacheco Rodrigues, Renato CaparrozAbstract:: The illegal trade is a major threat to many bird species, and parrots are common victims of this activity. Domestic and international pet markets are interested on different parrot species, such as the Blue-and-Yellow Macaw (Ara ararauna). This South American Macaw is not globally threatened, but is under protection from over-exploitation. This study aimed to identify and characterize novel microsatellite loci for population and parentage analysis of A. ararauna. Scaffold sequences of Ara macao available in the NCBI database were used for microsatellite searches using MsatCommander software. We tested a total of 28 loci, from which 25 were polymorphic, one was monomorphic, and two did not generated amplification products. For polymorphic loci, the mean number of alleles was 8.24 (4 - 15 alleles per locus), the observed heterozygosity ranged from 0.333 to 0.917, and the expected heterozygosity from 0.353 to 0.890. The paternity exclusion probability and identity probability were highly discriminatory. Thus, these novel microsatellite markers can be useful for population assignment and paternity tests, helping the authorities to manage Macaws from the illegal trafficking and control commercial breeders.
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Genetic evaluation of the mating system in the Blue-and-Yellow Macaw (Ara ararauna, Aves, Psittacidae) by DNA fingerprinting
Genetics and Molecular Biology, 2011Co-Authors: Renato Caparroz, Cristina Yumi Miyaki, Allan J. BakerAbstract:More than 90% of birds are socially monogamous, although genetic studies indicate that many are often not sexually monogamous. In the present study, DNA fingerprinting was used to estimate the genetic relationships between nestlings belonging to the same broods to evaluate the mating system in the socially monogamous Macaw, Ara ararauna. We found that in 10 of 11 broods investigated, the nestlings showed genetic similarity levels congruent with values expected among full-sibs, suggesting that they shared the same parents. However, in one brood, the low genetic similarity observed between nestlings could be a result of intraspecific brood parasitism, intraspecific nest competition or extra-pair paternity. These results, along with available behavioral and life-history data, imply that the Blue-and-Yellow Macaw is not only socially, but also genetically monogamous. However, the occurrence of eventual cases of extra-pair paternity cannot be excluded.
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contrasting phylogeographic patterns in mitochondrial dna and microsatellites evidence of female philopatry and male biased gene flow among regional populations of the blue and yellow Macaw psittaciformes ara ararauna in brazil
The Auk, 2009Co-Authors: Renato Caparroz, Cristina Yumi Miyaki, Allan J. BakerAbstract:ABSTRACT. Comparing the patterns of population differentiation among genetic markers with different modes of inheritance can provide insights into patterns of sex-biased dispersal and gene flow. The Blue-and-Yellow Macaw (Ara ararauna) is a Neotropical parrot with a broad geographic distribution in South America. However, little is known about the natural history and current status of remaining wild populations, including levels of genetic variability. The progressive decline and possible fragmentation of populations may endanger this species in the near future. We analyzed mitochondrial DNA (mtDNA) control-region sequences and six microsatellite loci of Blue-and-Yellow Macaws sampled throughout their geographic range in Brazil to describe population genetic structure, to make inferences about historical demography and dispersal behavior, and to provide insight for conservation efforts. Analyses of population genetic structure based on mtDNA showed evidence of two major populations in western and eastern ...
