YELLOW-BILLED CUCKOO. 393 



grey; irides dark brown, orbits greyish white. There is no external 

 difference between the sexes ; but young birds are said to be without the 

 chestnut on the primaries, as in the Black-billed Cuckoo, from which they 

 may always be distinguished by the yellow on the bill. 



An example of the Black-billed Cuckoo (Coccyzus erythrophthalmus] was 

 shot by Dr. Rea at Killead, ten miles from Belfast, near -the end of 

 September 1871. It was erroneously recorded ('Zoologist/ 1872, p. 2943) 

 as a Yellow-billed Cuckoo; but Lord Clermont subsequently identified it as 

 the black-billed species (' Zoologist/ 1872, p. 3022). The only other 

 example obtained in Europe occurred in Italy near Lucca in 1858 (Bolle, 

 Journ. Orn. 1858, p. 457). Newton, in his edition of YarrelFs 'British 

 Birds/ does not devote an article to this species, though in the ' Ibis List ' it 

 is mentioned without brackets. It is very difficult to determine whether an 

 American bird, which has only appeared once or twice in Europe, should 

 be included in the British list or not ; but much may be said in favour of 

 excluding American birds that have only once been obtained in our islands. 

 Many species of American birds occasionally wander far from home, and 

 some habitually visit the Bermuda Islands. Most of these birds which 

 visit this country are inhabitants of the north-west of America, many of 

 them even breeding on the Siberian coast ; and there can be little doubt 

 that they travel across Asia, appearing on our islands in the great stream 

 of migration which reaches us in autumn from the east. It seems pro- 

 bable, however, that others cross or attempt to cross the Atlantic birds 

 that have lost their way in migrating southwards from Labrador, or have 

 been driven out to sea by heavy gales. Probably the greater "number of 

 these birds perish ; but some succeed in reaching Europe with or without 

 the help of an occasional rest on the rigging of some of the numerous 

 ships crossing the ocean. 



The Black-billed Cuckoo inhabits the eastern half of the North- American 

 continent, breeding as far north as Labrador, and as far south as Georgia 

 and Texas. In winter it is found in Mexico, Central America, some of 

 the West Indies, and the northern portions of South America. The habits 

 of this bird differ little from those of the Yellow-billed Cuckoo. Its egg 

 is figured on Plate 68. They vary in length from 1/15 to T05 inch and 

 in breadth from *9 to *8 inch. The eggs of the Black-billed Cuckoo are on 

 an average considerably smaller than those of the Yellow-billed Cuckoo ; 

 but small eggs of the latter are indistinguishable from large eggs of the 

 former. 



The Black-billed Cuckoo may be distinguished from its near ally by 

 being slightly smaller, by having very little chestnut on the primaries, 

 both mandibles of the bill nearly black, the orbits dull scarlet, and the 

 white tips to the tail-feathers much less conspicuous. The sexes do not 

 differ in colour. 



