BIEDS OF ETHIOPIA AND KENYA COLONY 279 



3. Centropus monachus occidentalis. — West Africa from the Gold 

 Coast, Nigeria, Cameroon, Gaboon, and northern Anoohi (possibly 

 distinct — angolensis) east to the northern Belgian Congo and the 

 Sudan to the southwestern side of the Congo-Nile watershed. 



4. Centrofus monachus cu-preicaudus. — Southern Angola, Bechu- 

 analand, the Zambesi Valley, and southern Nyasaland. 



The geographical variations of this species afford a clue as to 

 its center of origin and to the apparent phylogenetic relationships 

 of its races. The coppery tailed form is obviously an offshoot of 

 the green-tailed birds as the latter character occurs over a very 

 much greater area than the former, and among green-tailed birds 

 there seems to be a tendency to produce bronzy or coppery rectrices. 

 Several such cases are known in monachus and in occidentalis. The 

 dark-backed green-tailed form occidentalis seems to be the an- 

 cestral type and the birds become lighter backed in the northeastern 

 part of the range of the species (m. TRonachus). That dark backs 

 are more ancient than light ones in this group, is indicated by the 

 fact that in the geographical aggregate of individuals in the region 

 between the two extremes (y?5<?^m), the dark back character is 

 more striking in the immature than in the adult plumages. It looks 

 as though the lighter back is a more recently acquired coloration. 

 Of course, it should not be forgotten, for the sake of the above 

 argument, that adults of fischeri are usually dark, even darker than 

 occidentalis, but not markedly so. Apparently, then, occidentalis 

 represents the original condition which has given rise, on the one 

 hand to cupreicaudus, and, on the other, to fscheri and monachus. 

 The " typical " race is far from being typical of the specific stock. 



The species has three distinct plumages, as follows : 



The Juvenal plumage resembles the adult stage on the underparts 

 except that the feathers of the throat and upper breast are weaker, 

 making the shafts appear more conspicuous. Above it is quite 

 different. The head, nape, and hind neck are dull black, the feathers 

 dark brown for their basal halves ; the entire back dark brown trans- 

 versely banded with pale rufous brown; inner secondaries like the 

 back; outer secondaries and primaries bright rufous, barred with 

 dull dark brown on the terminal third of their length (half on the 

 outermost primaries) ; upper wing coverts grayish rufous, barred 

 narrowly with fuscous brown; rectrices greenish brown, tipped with 

 dull brown which is crossed by two narrow white bars, one terminal, 

 the other between the green and the brown ; sometimes other narrow 

 white lines are faintly visible as well. A complete postjuvenal molt 

 replaces this plumage by the next. 



The immature bird has only a very little bluish sheen on the nape ; 

 has the scapulars, interscapulars, back, and wings narrowly barred 

 with fuscous black; and the rectrices tipped with whitish and nar- 



