Phylogeny and evolutionary ecology of modern seaducks (Anatidae: Mergini)

Article Abstract:

Cladistic analysis of 137 morphological characters to determine the phylogenetic relationships of modern seaducks, using characters of their skeleton, trachea, natal plumage and definitive plumages, efficiently resolved correlations among 25 recognized taxa in the species. Eiders were determined to be a monophyletic group, while the rest of the generic groups were inclusive of Histrionicus and Mergus. The Harlequin Duck, long-tailed Duck and Steller's Eider were classified to be highly autapomorphic.

Analysis, Morphology (Biology), Phylogeny, Morphology

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Morphometric comparison of skeletons of the Western Grebe complex Aechmophorus of the United States and Canada

Article Abstract:

A morphometric examination of Aechmophorus skeletons was conducted to analyze skeletal variations in two closely related species, A. occidentalis and A. clarkii. Univariate and multivariate methods were used to examine skeletal specimens, collected from the Museum of Zoology, University of Michigan. The A. occidentalis skeletons were found to be larger than the A. clarkii ones. Sexual dimorphism and differences in locomotion techniques influenced skeletal variation more than age and location.

United States, Canada, Ornithological research, Bird populations, Grebes

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A new species of small flightless duck from Amsterdam Island, Southern Indian Ocean (Anatidae: Anas)

Article Abstract:

Bird bones collected in the vicinity of the Amsterdam and St. Paul Islands that were measured and initially compared with the Amsterdam duck were found to be a small species of Anas. The new species, named Anas marecula, was defined by robust hindlimbs for land movement and small wings and pectoral girdles, indicating flightlessness. This Amsterdam Island Duck closely resembled the widgeons, which are practically categorized with Anas and possess a similarly short bill with a pointed tip.

Natural history, Animals, Fossil, Fossil animals, Sea birds, Indian Ocean Islands, Seabirds

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