LARID.E THE GULLS AND TERNS. 225 



The great Burgomaster Gull is an Arctic species which occa- 

 sionally visits Lake Michigan in winter. It is the largest of 

 the gulls, excepting only the Black-backed Gull, or ''Saddle- 

 back" (L. marinus). 



In Greenland, where it is almost a resident species, a few in- 

 dividuals (chiefly young birds) being seen in the very coldest 

 weather, it is said to pirate upon the eiders (Somateria mdlis- 

 siina b&realis), often compelling them to surrender the mussels 

 which they have brought up from the bottom of the bays or 

 fiords. There, "the principal breeding place of this gull in the 

 vicinity of Ivigtut is close by the open sea, near the mouth of 

 the fiord, where they congregate in considerable numbers. In 

 August the young birds assemble in the fiord, especially near 

 the narrow channels, as at Karsuk and Ellerslie, and feed dur- 

 ing that month and the next on the berries of Empetrwm ni- 

 grum. At that season they are easily shot, and their flesh is of 

 a very savory flavor. The breasts of the young of all species 

 of guil are eaten here as a delicacy." * 



Larus leucopterus Faber. 



ICELAND GULL. 



Popular sy;onym. White-winged Gull. 



Larus argentatus SABINB, Trans. Linn. Soc. xii. 1818, 546 (not of BBT^NN. 176v 

 Larus leucopterus FABEB, Prodr.Isl. Orn.1822, 91. Sw. & RICH. F. B.-A. ii, 1831, 418. NUTT. 

 Man. ii, 1834, I5. AUD. Orn. Biog. iii, 1835, 553, pi. 282; Synop 1839, 327; B. Am. vii.1844, 

 159, pi. 447. LA WE. in Baird's B. N. Am. 1858, 843. BATED, Cat. N. Am. B. 1859, No. 658. 

 COOES, Key, 1872, 311 ; Chejk List, 1873, No. 544; 2d ed. 1882, No. 769; B. N. W. 1874, 

 622. RIDGW. Norn. N. Am. B. 1881, No. 661; Man. N. Am. B. 1887, 26. B. B. & R. Water 

 B. N. Am. ii, 1381, 216.-A. O. U. Check List, 1886, No. 43. 

 Larus arcticus MACGILL. Mem. Wern. Soc. v, 1824, L68. 

 Larus glaucoides "TEMM." MBYEE.Taschenb. Vog. Deutschl. iv, 1822, 197. TEMM. PI. Col. 77e 



livr. Introd. Larus, 1828. 



Larus islandicus EDMONST. Mem. Wern. Soc. iv, 1823, 506 (nee op. cit. p. 185=L. glaucus). 

 Larus minor BBEHM, Vog. Deutschl. 1831, 736. 

 Laroides subleucopierus BBEHM, t. c. 746. 

 Larus (Glaucus) glacialis BEUCH. J. f. 0. 1853, 101 (nee MACGILL. 1824). 



HAS. Range about the same as that of L. glaucus. South in winter to coast of Massa- 

 chusetts and the Great Lakes. 



SP. CHAB. Similar to L. glaucus, but much smaller, the young darker colored. Adult, 

 in summer: Mantle pale pearl-blue (a shade darker than in L. glaucus); remiges similar, 

 but slightly paler, passing terminally into pure white. Rest of the plumage snow-white. 



* M. CHAMBEBLAIN. in The Auk, July 1889, pp. 214-215. 



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