1908.1 BIKDS. 261 



Stercorarius parasiticus (Linn.). Parasitic Jaeger. 



This freebooter breeds rather commonly about the eastern and 

 northern parts of Great Slave Lake, abundantly on the Barren 

 Grounds, and probably to some extent on the lakes in the intermediate 

 region. 



In 1901 we first saw this species about some semibarren islands in 

 Great Slave Lake, a few miles north of Stone Island. .Inly 10, when 

 several melanistic individuals were observed. During the evening of 

 the same day a male and female, evidently a pair, were shot on Loon 

 Island. Both were in the dark sooty plumage, the male being slightly 

 lighter in color beneath, the female nearly uniform sooty throughout. 

 Several, including one in the normal white-breasted plumage, were 

 seen about Loon Island, July 11 to 14. While we were crossing from 

 Loon Island to the north shore of the lake during the night of July 

 14, a number were seen and two females were collected. One of the-.' 

 is of a nearly uniform sooty color throughout. The other is white 

 beneath, slightly barred with dusky; lower tail coverts conspicuously 

 barred with black and brownish; upper tail coverts slightly barred 

 with dull fawn. The stomach -of one of these contained various in- 

 sects and the bones of a small bird, evidently a young tern ; the other 

 had eaten a dragon fly. various beetles, and a small fish. Several 

 individuals were seen July 15 near the mouth of the Northern Arm of 

 Great Slave Lake, but the species was not afterwards noted. 



In 1903 I observed numbers of this species on the Northern Arm 

 between Gros Cape and Trout Rock, July 23 and 24, and noted it 

 near Fort Rae, July 28. 



In the summer of 1904, while descending the Mackenzie, I saw 

 three individuals, exhibiting both the normal and melanistic plum- 

 ages, near Roche Trempe-lVau, June 8, and one near Fort Norman, 

 June 10. A specimen taken at Fort Providence is in the museum 

 at Fort Simpson. 



Swainson and Richardson, under the name Lestris richardsoni, 

 described a specimen killed at Fort Franklin." Fisher recorded four 

 seen June 10, 1820, on Melville Island.'' McCormick noted the species 

 on Wellington Channel August 30, 1852.' King reported the para- 

 sitic jaeger from Clinton-Colden Lake/' Armstrong records the ar- 

 rival of this species at Mercy Bay. Banks Land. May 31, L852. e 

 Baird, Brewer, and Ridgway recorded specimens from Fort Resolu- 

 tion, Fort Rae, Fort Simpson, and Fort Anderson/ MacFarlane 



"Fauna Boreali-Americana, II, p. 433, 1831. 

 6 Journ. Voy. of Discovery, p. i-MT. 1821. 

 "McCormick's Voyages, II. p. ill. 1884. 

 ^Narrative Journey t<> Arctic <>.<'.-in. I. p. 242, 1836. 

 e Narrative Discovery Northwesl Passage, p. 521, 1857. 

 f Water Birds X. A., II. p. 338, 1884. 



