KENNEDY, M., GRAY, R. D. & SPENCER, H. G. (2000)
The Phylogenetic Relationships of the Shags and Cormorants: Can Sequence Data Resolve a Disagreement between Behavior and Morphology?
Molecular Phylogenetics and Evolution 17 (3): 345-359.
Abstract:
Taxonomic arrangements for the cormorants and shags (Phalacrocoracidae) had varied greatly until two quite similar arrangements, one based on behavior and the other on osteological characters, became the basis for current thought on the evolutionary relationships of these birds. The terms cormorant and shag, which had previously been haphazardly applied to members of the group, became the vernacular terms for the two major subdivisions within this family. The two taxonomies differ in places, however, with the behavioral taxonomy placing several species within the shags and the osteological taxonomy and phylogeny grouping those species (as the marine cormorants) and placing them within the cormorants. In an attempt to resolve the differences in the relationships hypothesized by behavior and morphology, we sequenced three mitochondrial genes (12S, ATPase 6, and ATPase 8). Initial equally weighted parsimony trees differed slightly from our two weighted parsimony trees, one of which was also our maximum-likelihood tree. Many of the branches within our trees were well supported, but some sections of the phylogeny proved difficult to resolve with confidence. Our sequence trees differ substantially from the morphological phylogeny and show that neither the shags nor the cormorants are monophyletic, but form an intermingled group. Some of the groups supported by both the behavioral and the morphological taxonomies (e.g., the cliff shags, Stictocarbo) appear to be polyphyletic. Conversely, the monophyly of the blue-eyed shags, a traditional group that the osteological analysis had found to be paraphyletic, was supported by the sequence data. Until more taxa are sampled and a fully robust phylogeny is obtained, a conservative approach accepting a single genus, Phalacrocorax, for the shags and cormorants is recommended.
kennedy-biblio
ROBIN, K., GRAF, R. F. & VOGEL, M. (2012)
Der Kormoran.
Wildbiologie - Biologie einheimischer Wildtiere 1/64. 16 Seiten.
Hrsg.: Wildtier Schweiz, Winterthurerstrasse 92, CH-8006 Zürich.
Auszug:
Als fischfressender Wasservogel, der an heimischen Gewässern in Scharen überwintert und seit 10 Jahren in der Schweiz brütet, löst der Kormoran Kontroversen aus. Während ihn der Naturschutzbund Deutschland NABU zum Vogel des Jahres 2010 erklärt hatte, sehen fischnutzende Kreise in ihm eine echte Gefahr für Fangertrag und aquatische Artenvielfalt. In den letzten rund 30 Jahren haben sich in ganz Europa zahlreiche Spezialisten damit befasst, Biologie, Bestandesentwicklung, Massnahmen zur Bestandeskontrolle, Raumnutzung und Migrationsverhalten des Kormorans zu erforschen. Auch in der Schweiz sind verschiedene Projekte zu dieser spannenden Art durchgeführt worden. Dieser Artikel geht einerseits auf die Biologie der Art ein und legt andererseits Erkenntnisse aus regionaler und europäischer Perspektive vor. Offensichtlich kann die Bestandesentwicklung des Kormorans und seine Wirkung auf die Mitwelt nur verstanden werden, wenn stets bewusst bleibt, dass die Art sich in einem grossräumigen System zwischen Russland und Nordafrika bewegt.
robin-biblio