64 THE BIRDS OF MAINE 



Genus HYDROCHELIDON Boie. 



77. Hydrochelklon nigra surinamensis (Gmel.). Black 

 Tern. 



Plumage in summer adults : lower tail coverts white ; back, wings and tail 

 slate color ; otherwise black ; bill and feet black. Plumage in winter adults : 

 head, neck and lower parts white ; back, wings and tail deep gray ; back of 

 head black with some white. Immature plumage : washed with brownish 

 above and with grayish on sides, otherwise similar. Wing 8.28 ; culmen 1.05. 



Geog. Dist. — Temperate and tropical North America, breeding from the 

 Middle States west of the Alleghany Mountains north to Alaska and the Fur 

 Countries ; found as far south as Brazil and Chili ; casual on the Atlantic 

 coast north to Maine and Prince Edward Island. 



County Records. — Cumberland ; transient in autumn, uncommon, (Brown, 

 C. B. P. p. 35) ; two secured at Scarboro, August 28, 1897, they had been 

 feeding on insects, (Norton, Me., Sp. Oct., 1897, p. 8) ; I received three taken 

 near Portland in 1902, (Lord). Hancock; one seen near Castine August 14, 

 1901, by G. C. Shattuck, (Howe, J. M. 0. S. 1902, p. 18). York; occurs at 

 Wells Beach, (Brown, B. N. 0. C. 7, p. 190). 



Though occasionally taken along the coast this species is 

 only a mere straggler to Maine and also to Grand Menan, 

 Nezv Brunsivick, where Mr. Boardman reports it as accidental. 

 The nesting places about many of the ponds and marshes of 

 the Middle States are occupied by colonies of these birds. The 

 eggs vary from gray buff to olive brown, sometimes greenish 

 tinged, and are heavily spotted with chocolate and black and 

 often heavily wreathed with the same about the larger end. A 

 set taken at Luna Lake, Michigan, June 12, 1896, from a float- 

 ing nest of partly decayed grass, consists of three eggs measur- 

 ing 1.34 X 0.94, 1.30 X 0.96, 1.28 x 0.95. Another set from 

 same place and date measure 1.36 x 0.93, 1.37 x 0.93, 1.31 x 

 0.90. Another nest from Hennepin, Minnesota, was floating in 

 three feet of water and was a mass of decayed vegetable matter 

 on top of which was a slight hollow in which the eggs were 

 laid. These were fresh June 1, 1895 and measure 1.27 x 0.98, 

 1.25 X 0.93, 1.21 X 0.96. The nests are usually made on float- 

 ing bogs, old muskrat houses and similar masses of vegetation 

 in bogs and marshes. Insects form a large part of the diet of 



