Maximum counts .— Flock of 5, 61 km SE Ocean City (38°02'N, 74°30'W), 2 

 Febuary 1974; 5-9 in 3.5 h, 67-111 km E Ocean City, 1 Febuary 1975; 4-6 in 3 

 h, 78-113 km E Ocean City, 1 February 1976. 



Remarks . --There is considerable uncertainty concerning the taxonomy and 

 field identification of skuas in the western North Atlantic. Until recently, 

 all skuas in this region were assumed to represent the North Atlantic breeding 

 stock of the great skua (C. skua skua). However, the south polar skua (C^. 

 maccormicki ) is a visitant, documented by specimens from Greenland (Solomonsen 

 1976) and North Carolina (Rowlett in press a), and by photographs taken in New 

 Jersey (Brady 1976, Buckley et al.l976) and over Georges Bank (Veit in press). 

 The brown skua (C^. s^. lonnbergi ) also is a reported visitant from the southern 

 hemisphere. 



Even with the use of Devillers (1977) descriptive accounts of the world's 

 skuas, field identification was difficult. All but two skuas seen in the 

 northern Chesapeake Bight from 1971 - 1977 were thus recorded as "skua" 

 ( Catharacta sp. ) . 



Two birds seen on 9 May 1976 near a fishing trawler, 117 km ESE Ocean 

 City (38°irN, 73°46'W) were identified as C. maccormicki , based on the 

 extreme wear of flight and body feathers and tHe uniform slate-brown mantle, 

 back, and head which contrasted strongly with pale buffy gray underparts and 

 collar on the hind neck. Worn plumage in May is to be expected on individuals 

 from the Southern Hemisphere. The normal period of greatest wear in C^. skua 

 skua is in mid-winter. 



Based on the above accounts, skuas in the northern Chesapeake Bight from 

 December to early April are probably C. s^. skua , although non-breeding south- 

 ern forms may occasionally remain in the northern hemisphere. The occurrence 

 of skuas in mid-April and May coincides with the northward passage of sooty 

 shearwaters and Wilson's storm petrels along the mid-Atlantic coast. These 

 skuas may be Southern Hemisphere forms C. s. lonnbergi , or C. maccormicki . 

 The recent confirmed sightings and specimens suggest that C. maccormicki is 

 the most likely to be seen in spring. 



Most skuas appeared after chumming had attracted hundreds of seabirds, 

 mostly gulls and gannets. Skuas seldom lingered near the boat, usually remain- 

 ing along the trailing fringes of the feeding flocks where close study of 

 plumage characteristics was not possible. Skuas usually foraged freely among 

 other seabirds and seldom displayed the aggressive behavior for which they are 

 notorious. 



Few sightings of skuas (reported as C. skua) in the northern Chesapeake 

 Bight off Delaware and Virginia have been reported (Rough 1940, Murray 1957, 

 Burford 1959, Scott 1968, Ake, 1971a, Rowlett 1974a), although I found skuas 

 to be more common than was previously suspected. 



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