Enigmatic phylogeny of skuas (Aves: Stercorariidae)

Publication Type:Journal Article
Year of Publication:1997
Authors:B. L. Cohen, Baker, A. J., Bleschschmidt, K., Dittmann, D. L., Furness, R. W., Gerwin, J. A., Helbig, A. J., DeKorte, J., Marshall, H. D., Palma, R. L., Peter, H. U., Ramli, R., Siebold, I., Willcox, M. S., Wilson, R. H., Zink, R. M.
Journal:Proceedings of the Royal Society of London, Series B, Biological Sciences
Volume:264
Issue:1379
Pagination:181 - 190
Date Published:1997
Keywords:bird, Charadriiformes, Evolution, mitochondrial dna, mtax, parasite, PHP, populations, sequence, trees
Abstract:

Multiple sources of evidence show that the skuas (Aves: Stercorariidae) are a monophyletic group, closely related to gulls (Laridae). On morphological and behavioural evidence the Stercorariidae are divided into two widely divergent genera, Catharacta and Stercorarius, consistent with observed levels of nuclear and mitochondrial gene divergence. Catharacta skuas are large-bodied and with one exception breed in the Southern Hemisphere. Stercorarius skuas (otherwise known as jaegers) are smaller bodied and breed exclusively in the Northern Hemisphere. Evidence from both mitochondrial and nuclear genomes and from ectoparasitic lice (Insecta: Phthiraptera) shows that the Pomarine skua, S. pomarinus, which has been recognized as being somewhat intermediate in certain morphological and behavioural characteristics, is much more closely related to species in the genus Catharacta, especially to the Northern Hemisphere-breeding Great skua, C. skua, than it is to the other two Stercorarius skuas, the Arctic skua, S. parasiticus and the Longtailed skua, S. longicaudus. Three possible explanations that might account for this discordant aspect of skua phylogeny are explored. These involve (i) the segregation of ancestral polymorphism, (ii) convergent evolution of morphology and behaviour or (iii) inter-generic hybridization. The available evidence from both nuclear and mitochondrial genomes does not exclude any of these hypotheses. Thus, resolution of this enigma of skua phylogeny awaits further work.

URL:http://www.phthiraptera.info/sites/phthiraptera.info/files/38659.pdf
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Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith