82 BULLETIN 15 3, UNITED STATES NATIONAL MUSEUM 



Mearns are typical poliopterus in coloration. They constitute the 

 northernmost records for the race; in fact, extend the known range 

 north well into Ethiopia, whereas the form was previously unre- 

 corded from that country. 



The immature male does not agree with anj'^ published description 

 of the Juvenal plumage and is different from comparable specimens 

 of musicus from South Africa and of tnetdbates as well. It is much 

 lighter above and below than musicus and the bars on the underparts 

 are much narrower than in the latter. The outer, upper, middle and 

 lesser wing coverts are terminally edged with white in the young 

 poliopterus, while in musicus no such edges are present. Likewise the 

 secondaries are tipped with white in the former and not in the latter. 

 From metabates it differs in being darker above and below, more 

 narrowly barred beneath, and in having white edges to the upper 

 outer wing coverts, as mentioned above, and white tips to the second- 

 aries. The upper tail coverts are unbarred in poliopterus; barred in 

 metabates. From both it differs in having the under tail coverts 

 nearly pure white, only faintly, sparsely, and narrowly barred with 

 pale tawny, whereas the other two have these feathers heavily and 

 abundantly marked with brown. 



Sjostedt ^^ describes a young poliopterus which resembles the pres- 

 ent specimen more than any other published description. Lov^e- 

 ridge ®^ writes of a nearly fledged nestling that, " * * * the lower 

 breast shows signs of barring like the adult," which may be taken to 

 mean that the bars were fairly narrow. The rest of the description, 

 however, is less in agreement with the speciments I have examined. 

 Loveridge writes that, " * * * its plumage was strikingly differ- 

 ent from the adult. The back plumage is nearly black; it has a 

 central gular streak. * * * 55 



Immature birds have the primaries largely white or whitish, 

 banded with fuscous brown, only the outer webs and most distal inch 

 or two of the inner webs being solid fuscous brown. In the process 

 of assuming adult plumage, the old primaries do not molt until the 

 body molt is very nearly complete, and then they molt from the 

 inside out, that is, the innermost primary is shed first, the outermost 

 one last. This explains why numbers of specimens in apparently 

 fully adult plumage have some of the jjrimaries of this type, instead 

 of having them all solid fuscous as in really adult birds. Occasion- 

 ally, however, adults have remiges that are slightly mottled, but the 

 majority have them dark and uniform. 



The female collected at Bodessa, Ethiopia, is unusually large, ex- 

 ceeding another adult female from Tanganyika Territory, in wing 

 length, by 30 millimeters. Swann '^^ gives the wing measurements of 



^ Kilimandjaro-Meru Exp. Reports, vol. 1, p. 77. 



s«rroc. Zool. Soc. Lond., 1923, p. 915. 



sa Monogr. Birds of Prey, pt. 3. 1925, p. 169. 



