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BIRDS OF THE BRITISH ISLES. 



pomatorbinc Shua. 



JOHAf I?(//VCAA/. 



The Poniatorhine Skua {Stercorarms pomatorhmus, Tem- 

 minck) is a more or less common autumn and spring 

 coasting migrant to the British Isles, examples occasion- 

 ally being met with in winter. It inhabits the Northern 

 Nearctic and Palearctic Regions. This skua varies 

 considerably in the colouration of the plumage. There 

 is a light and dark variety, neither of which appears to 

 be influenced by sex or age. The adult of the light form 

 has the upper plumage mostly dark brown ; the two central 

 rectrices reaching about four inches beyond the others, and 

 twisted upwards ; crown, black ; neck, white, tinged with 

 buffish-yellow ; breast, dullish white ; lower belly and under 



