SUMMARY

• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Arctic; Arctic skua; Great skua; Pomarine Skua
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.553.5212; http://www.mun.ca/biology/dmarshall/Cohen_et_al_1997.pdf

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