GREAT NORTHERN DIYEK. 133 



chin, and throat, deep black, with strong reflections of green 

 and purple; on he front of the upper part of the last-named 

 there is a crescent-shaped band, and lower down on each side 

 an oblong space of the same colour, barred with black, the 

 feathers having raised white margins. Breast, white, streaked 

 on the sides with dusky greyish white, the feathers having 

 raised white margins. Back, dusky, spotted all over with 

 oblong, oval, and round spots of white; each feather has two 

 spots, one on each side of the shaft near the tip, forming 

 rows. 



The wings extend to the width of from four feet eight 

 inches to five feet or more, the axillary feathers white, with 

 a black streak down the centre of each; greater and lesser 

 wing coverts, black, with the white spots smaller than on the 

 back; primaries, black; the tertiaries end in white. Tail, 

 black; upper tail coverts with small white spots. Legs and 

 toes, dusky black on the outer surface, and greyish on the 

 inner; webs, dusky black. 



It would appear that at the autumnal moult the bird re- 

 assurnes the dress of the young. (See 'Zoologist,' page 2775.) 



In the autumn the dark feathers of the head and neck are 

 more or less replaced by white ones, and the back becomes 

 likewise beautifully spotted by the feathers being tipped with 

 white. 



The female is not so large as the male. 



The young are at first covered with black down; subse- 

 quently they have the upper bill dusky grey, the lower one 

 paler, and are dusky grey on the back and upper parts, the 

 breast being white. When nearly full grown, the young male 

 has the bill pale horn-colour, the lower mandible much paler 

 than the upper one; iris, reddish brown. Head, crown, neck, 

 and nape, greyish black, with a tinge of brown; chin, throat, 

 and breast, white. Back, deep brown, the edges of the feathers 

 paler, and of a grey tint. Legs and toes on the front, light 

 greenish brown. 



'After the second general moult,' says Mr. Selby, 'a dark 

 band appears on the middle of the neck, and the upper 

 plumage becomes darker, losing the pale grey edges that 

 distinguish the young of the year, and a few white spots 

 begin to shew themselves. The succeeding moult developes 

 still more the bar and neck collar, and the head and neck 

 become darker, or of a blackish green, speckled upon the 

 chin and throat with white. The upper plumage also acquires 



