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Mironov S.v. - One of the best experts on this subject based on the ideXlab platform.

Pereira Alice - One of the best experts on this subject based on the ideXlab platform.

  • Análise morfológica e morfométrica de duas espécies de albatroses : Albatroz-de-sobrancelha (Thalassarche melanophris) e Albatroz-de-nariz-amarelo (Thalassarche chlororhynchos) (Procellariformes : Diomedeidae)
    2018
    Co-Authors: Pereira Alice
    Abstract:

    Os albatrozes estão amplamente distribuídos ao longo dos oceanos do Hemisfério Sul, com algumas poucas espécies ocorrendo no Hemisfério Norte. A família Diomedeidae abrange 22 espécies distribuídas em quatro gêneros: Diomedea, Phoebetria, Phoebastria e Thalassarche. Este último apresenta as menores espécies dentre os quatro gêneros. Os albatrozes são reconhecidos pelo seu estilo de voo e grande envergadura. Além disso, são aves marinhas monogâmicas e filopátricas, retornando todos os anos para suas colônias reprodutivas. Indivíduos juvenis e imaturos só retornam após muitos anos em dispersão pelos oceanos onde forrageiam. O albatroz-de-sobrancelha Thalassarche melanophris apresenta colônias reprodutivas espalhadas ao longo de ilhas subantárticas nos oceanos Atlântico, Pacífico e Índico. O albatroz-de-nariz-amarelo T. chlororhynchos está restrito ao Atlântico Sul, nidificando unicamente nas ilhas Tristão da Cunha e Gough. Ambas espécies forrageiam no Atlântico Sul e são abundantes em águas brasileiras. São comumente vistos seguindo barcos pesqueiros já que essas aves marinhas se alimentam do descarte e de iscas utilizadas na pesca de espinhel. A captura acidental de albatrozes durante atividades da indústria pesqueira é a maior causa de mortalidade dessas aves. Ao longo da costa sul e sudeste do Brasil, indivíduos de albatroz-de-sobrancelha e albatroz-de-nariz-amarelo podem ser encontrados encalhados. Ambas as espécies podem ser identificadas pelo padrão de plumagem e coloração do bico, a idade de albatrozes jovens e imaturos determinada pelo ciclo de muda. No entanto, durante contagens de aves encalhadas, carcaças sem plumagem ou coloração de bico tem sua identificação restrita à aspectos morfológicos do crânio. A análise morfológica do esqueleto requer conhecimento específico e, na falta do crânio, o pós-crânio não oferece diferenças consistentes para identificação das duas espécies. A identificação a nível específico é fundamental para a coleta de dados sobre as espécies e avaliação dos impactos que sofrem. Assim, avaliando 151 espécimes provenientes de coleções ornitológicas, este estudo estabeleceu uma função discriminante para determinar as espécies por meio de peças anatômicas da asa e esterno. Ademais, este estudo avaliou o desenvolvimento osteológico pós-natal de T. melanophris e T. chlororhynchos. Após estabelecer os caráteres ligados ao desenvolvimento, o estudo associou-os aos padrões de desenvolvimento da plumagem, ciclo de muda e ciclo de vida até que as espécies tenham atingido a maturidade sexual. A fauna de albatrozes está ameaçada globalmente, assim, qualquer esforço na identificação e conhecimento das aves que frequentam as águas do sul do Brasil é importante.Albatrosses are widely distributed across Southern Hemisphere oceans, and few species occur along the North Pacific Ocean. The family Diomedeidae comprises 22 species distributed in four genera: Diomedea, Phoebetria, Phoebastria, and Thalassarche. The species of the last genus are called mollymawks and are the smaller species of those genera. Albatrosses are recognized by their flight style and great wingspan, and as other seabirds, albatrosses are monogamic and filopatric, returning every year to their breeding colonies. Juvenile and immature individuals will only return after many years of dispersal within their foraging range. The Black-browed Albatross Thalassarche melanophris has breeding colonies spread along subantartic islands of Atlantic, Pacific and Indian Oceans. The Atlantic Yellow-nosed Albatross T. chlororhynchos is restricted to South Atlantic Ocean, breeding in subantartic islands as Malvinas/Falkland, Gough and Tristan da Cunha Group. Both species forage at Southwestern Atlantic Ocean and are abundant at South Brazilian waters. They usually follow fishing vessels as these seabirds may feed on fish discards or long-line fishery baits. Bycatch of albatrosses during fishing activities are the major cause of mortality within the species. Along South and Southeastern Brazilian coast several individuals of Black-browed and Atlantic Yellow-nosed Albatross are found beached. Both species are identified by pattern of plumage and bill coloration, and molt cycle determines the age of juvenile and immature albatross species. These features are useful for identifying at-sea individuals. However, carcasses without plumage or rhamphotheca can only be identified through cranial morphology. Morphological analyses require experience, besides when cranium is not available the postcranium material does not provide enough features for species identification. It is important for data collection and further analyses to identify a specimen at species level. In this study, we evaluated 151 specimens of both mollymawks from museum osteological collections searching for morphometric and morphological differences between Black-browed and Atlantic Yellow-nosed Albatross. We found significant differences between both species skeletal measurements, and we established a discriminant function to identify the species through postcranial osteological pieces. In addition, we evaluated the postnatal osteological development of T. melanophris and T. chlororhynchos. We associated it to plumage pattern information and the chronological period in which each plumage pattern appears. This morphological analysis showed that osteological development and plumage are not synchronic. However, the osteological sequences of ossification follow what is expected for Aves and for altricial birds. Albatrosses are a globally endangered fauna, then any effort to identify and understand these seabirds attending South Brazilian shelf is important

Gerald Mayr - One of the best experts on this subject based on the ideXlab platform.

  • a small narrow beaked albatross from the pliocene of new zealand demonstrates a higher past diversity in the feeding ecology of the Diomedeidae
    Ibis, 2020
    Co-Authors: Gerald Mayr, Alan J D Tennyson
    Abstract:

    We describe a nearly complete, three‐dimensionally preserved skull of a new albatross species from the late Pliocene (3.0–3.4 million years ago) Tangahoe Formation of New Zealand. Aldiomedes angustirostris, n. gen. et sp. has only about 90% of the length of the skull of the smallest extant albatross and is the geologically youngest record of a small‐sized albatross known to date. The new species is characterized by a mediolaterally compressed beak, which is not found in any living albatross. The small size and some cranial features of A. angustirostris indicate that, in spite of its comparatively young geological age, the new species was not part of crown group Diomedeidae. We hypothesize that A. angustirostris was more piscivorous than extant albatrosses, which predominantly feed on squid. The reasons for the extinction of smaller‐sized albatrosses are elusive but may be related to changes in seabird fauna during the Pliocene epoch, which witnessed the radiation of various non‐procellariiform seabird groups.

  • oligocene and miocene albatross fossils from washington state usa and the evolutionary history of north pacific Diomedeidae
    The Auk, 2017
    Co-Authors: Gerald Mayr, James L Goedert
    Abstract:

    ABSTRACT Albatross fossils have been collected from the late Oligocene Lincoln Creek Formation and the early/middle Miocene Astoria Formation near the townsite of Knappton, Pacific County, Washington (USA). The albatross from the Lincoln Creek Formation, Diomedavus knapptonensis, n. gen. et sp., is smaller than all extant albatrosses and represents the oldest published fossil albatross from the North Pacific Basin. Diomedavus knapptonensis is clearly distinguished from extant albatrosses in several osteological features; some are likely plesiomorphic, supporting a phylogenetic position outside the crown group. The unusual shape of the deltopectoral crest of the humerus suggests that D. knapptonensis also differed from extant albatrosses in its flight performance. A partial skeleton from the Astoria Formation likely represents another new albatross species; however, it is not named because there is no overlap with the skeletal elements of other fossil Diomedeidae. This species, here informally termed the “...

Hiroyoshi Higuchi - One of the best experts on this subject based on the ideXlab platform.

  • understanding prehistoric maritime adaptations in northern japan indirect evidence from ancient dna and histological observations of albatross aves Diomedeidae bones
    Quaternary International, 2016
    Co-Authors: Masaki Eda, Hiroko Koike, Hiroyoshi Higuchi
    Abstract:

    Abstract Prehistoric hunter–gatherers in Northeast Asia lived along coastlines and made abundant use of coastal resources in their subsistence strategies. However, the extent to which they operated only along the coastline or sailed out into deeper waters for hunting and fishing remains rather uncertain. In this case-study, we reconstruct past subsistence strategies through analysis of albatross (Diomedeidae) remains recovered from two hunter–gatherer archaeological sites in Hokkaido, Northern Japan (the Funadomari site, from the late Jomon period on Rebun Island and the Bentenjima site, from the Okhotsk period on Bentenjima Island). Three questions are examined: (1) were the birds hunted for meat or for feathers; (2) were the birds procured at coastal breeding grounds or out on the open water; (3) was hunting conducted in the shallow waters of the continental shelf or out in the deeper ocean? Analysis of the bone assemblages, and species determination by ancient DNA, indicate that people must have been hunting the bird in the open waters at the edge of the continental shelf. This provides strong, although indirect, evidence that Jomon and Okhotsk Culture communities must have possessed ocean-going boats and suitable sea-faring skills in order to undertake these kinds of operations. These insights, in turn, hint at the existence of sophisticated maritime traditions in prehistoric Northeast Asia.

  • mosaic gene conversion after a tandem duplication of mtdna sequence in Diomedeidae albatrosses
    Genes & Genetic Systems, 2010
    Co-Authors: Masaki Eda, Hiroyoshi Higuchi, Masaki Kuroo, Hiroshi Hasegawa, Hiroko Koike
    Abstract:

    Although the tandem duplication of mitochondrial (mt) sequences, especially those of the control region (CR), has been detected in metazoan species, few studies have focused on the features of the duplicated sequence itself, such as the gene conversion rate, distribution patterns of the variation, and relative rates of evolution between the copies. To investigate the features of duplicated mt sequences, we partially sequenced the mt genome of 16 Phoebastria albatrosses belonging to three species (P. albatrus, P. nigripes, and P. immutabilis). More than 2,300 base pairs of tandemly-duplicated sequence were shared by all three species. The observed gene arrangement was shared in the three Phoebastria albatrosses and suggests that the duplication event occurred in the common ancestor of the three species. Most of the copies in each individual were identical or nearly identical, and were maintained through frequent gene conversions. By contrast, portions of CR domains I and III had different phylogenetic signals, suggesting that gene conversion had not occurred in those sections after the speciation of the three species. Several lines of data, including the heterogeneity of the rate of molecular evolution, nucleotide differences, and putative secondary structures, suggests that the two sequences in CR domain I are maintained through selection; however, additional studies into the mechanisms of gene conversion and mtDNA synthesis are required to confirm this hypothesis.

Mario Urbina - One of the best experts on this subject based on the ideXlab platform.

  • nuevos restos de procellariiformes aves de la formacion pisco peru new remains of procellariiformes aves from the
    2005
    Co-Authors: Marcelo Stucchi, Mario Urbina
    Abstract:

    Procellariiformes fossil material from different locations of the Pisco formation (late Miocene - early Pliocene) is studied. The methodology was to study comparatively the extant species, in order to determine the differences between these and to use the same criteria to classify the fossil material. Due to the great morphologic similitude between the extantt species and due to the scarce fossil material in study, the results were that the paleontologic material could only be identified to family level in the case of Diomedeidae, and Tribe Puffinini in the case of Procellariidae. The Procellariiformes fauna of the Pisco formation supports the proposal of the existence of a cold marine current since the ending of the Miocene in the south Pacific.