AUKS, MURRES, AND PUFFINS 147 



bill, flying low over the water to the base of the breeding-cliff, then 

 rising abruptly to the nest in the rocks above. 



28. Cepphus mandti (Mandt). MANDT'S GUILLEMOT. Resembles 

 the preceding, but the bases of the greater wing-coverts are white instead 

 of black. 



Range. Arctic regions of both continents. Breeds on Arctic islands 

 s. to n. Hudson Bay and mainland of Siberia; winters in Arctic Ocean 

 and casually s. to Norton Sound and Lake Ontario; n. in migration to 

 lat. 84. 



Nest, in crevices and fissures of cliffs and rocky places. Eggs, 2-3, not 

 distinguishable from those of C. grylle, 2*34 x 1*15. 



A more northern species than the preceding, which it doubtless 

 resembles in habits. 



30. Uria troille troille (Linn.). MURRE. Ads. in summer. Upper- 

 parts, wings, tail and neck all around, dark sooty brown, blacker on back, 

 wings and tail; tips of secondaries, breast and belly white, sides more or 

 less streaked with blackish. Ads. in winter and Im. Upperparts, wings, 

 and tail much as in summer; underparts white, throat more or less washed 

 with sooty brown, flanks sometimes streaked with brownish, and feathers 

 of belly more or less lightly margined with blackish. L., 16'00; W., 8*00; 

 Tar., 1'40; B., 1'75; depth of B. at nostril, '50. 



Remarks. Some specimens have a white ring around the eye and a 

 white stripe behind it. They have been named U. ringvia (Briinn.), but 

 are generally believed to represent merely an individual variation. The 

 case is unusual. 



Range. Coasts and islands of N. Atlantic. Breeds in N. Am. from s. 

 Greenland and s. Ungava s. to N.F. and Magdalen Islands; winters s. 

 to Maine. 



Nests in communities, side by side on the bare ledges of rocky cliffs. 

 Egg, 1, pyriform, pale blue or greenish blue to whitish or buffy, singularly 

 spotted, scrawled, or streaked with shades of chocolate, rarely unmarked, 

 3'25 x 2'00. Date, Bird Rock, Que., May 15. 



When on the water, Murres bear a general resemblance to Ducks, 

 but may be distinguished by their short, thick necks and pointed bill. 

 Unlike the Razor-bill, they do not swim with upturned tail. When 

 nesting, probably no other birds are more closely associated than 

 Murres. They often gather on favorable ledges of rocky islets in such 

 numbers that a newcomer finds an alighting place with difficulty, 

 while the place vacated by a departing bird is immediately filled by 

 pressure from all sides. Nevertheless the birds lay their single egg on 

 the bare rock, and under these apparently unfavorable conditions 

 rear their young. Long-continued studies of Murres on the coast of 

 Yorkshire warrant the belief that, although the eggs of no* two Murres 

 (or Guillemot as it is termed in England) are alike, those of the same 

 individual more or less closely agree, and that the same bird lays year 

 after year on the same ledge. 



Murres perch on the entire foot or tarsus, and when undisturbed 

 usually turn their back to the sea and hold their egg between their legs 

 with its point outward. When alarmed they face about, bob and bow 

 and utter their bass-voiced murre. 

 12 



