90 BULLETIN 15 3, UNITED STATES NATIONAL MUSEUM 



sex examined (5) has each of these feathers siibterminally banded 

 with brown, and most of them with at least one more basal band as 

 well, while of three j'Oung males examined, tw^o have these coverts 

 pure white, and the third has a small subterminal brown spot on 

 each one. 



The throat streaks in young birds vary from light rufous tan to 

 dark brown or earth brown. Swann ' writes that in this plumage 

 the throat and breast are rufous with very distinct central streaks of 

 dark brown. Of eight immature birds examined, only one fits this 

 description — a young female from Dinder River, Sudan. All the 

 others have the throat and breast distinctly white, the feathers with 

 broad, brown median streaks and wide white margins. The brown 

 streaks are narrowest in a male from Tanganyika Territory, and 

 widest and darkest in one from Fazogli, Blue Nile, Sudan. The 

 Dinder River specimen not only differs from all the others in having 

 the throat and breast brown, but also in having the bars on the rest 

 of the underparts wider, and more reddish. The feathers of the 

 upper parts in all the specimens are edged with rufous cinnamon, 

 but in a few cases the feathers of the top of the head and the lateral 

 margins of the nape are edged with whitish instead. The white tips 

 of the secondaries vary a great deal. This is not to be accounted for 

 by wear, as the specimen with the most white has the cinnamon 

 edges of the feathers of the back almost completely worn away, while 

 in other birds where these margins are still present, the amount of 

 white on the secondaries is much less. 



Unlike the large species of Melierax, gdbar does not acquire uni- 

 form unbarred remiges in the adult plumage, but the number of 

 cross bars in adult remiges is just as great as in young birds. It is 

 materially reduced, however, in birds of the black phase. 



Adult birds usually have the upper tail coverts pure white, but 

 occasionally specimens are found with brownish bars or spots. 

 Swann ^ writes that a bird from Aden, Arabia, differs from African 

 specimens in having the underparts more strongly barred, and in 

 having black bands on the upper tail coverts. This specimen (to- 

 gether with the rest of the Swann collection) is now in the Museum 

 of Comparative Zoology where I have examined it. I find that the 

 female collected by Mearns at Sadi Malka matches it very closely 

 except in size. It seems that heavier markings would be a very 

 natural occurrence in a species that so frequently produces melanistic 

 individuals. 



This hawk is found in the lower parts of Ethiopia (not over 

 about 5,000 feet, or 1,500 meters) and is therefore absent in large 

 parts of Arussi-Gallaland and central Ethiopia. Its main strong- 



■'Monogr. of Birds of Prey, pt. 3, 1925, pp. 172-175. 

 "Ibis, 1923. p. G07. 



