iQiQ'] Hieraaetus ayresi. 173 



three adults and two young, I have seen numerous specimens 

 of H. spilogaster in all stages of plumage, living, dead, and 

 skins. 



In the first place, H. ayresi has a distinct crest 1^ to 

 1| inches in length, but in mounted specimens and skins 

 this is not always apparent unless looked for. H. spilogaster 

 never has a crest, although, like many birds of prey, when 

 angry or excited, it sometimes raises tlie feathers of the 

 nape, giving a slightly crested appearance. Therefore, 

 I venture to say, that all Hawk-Eagles that have so far 

 been identified as H. spilogaster, if they have a crest will 

 be found to be referable to H. ayresi. 



Secondly, the question of size : H. ayresi is a smaller bird 

 than H. spilogaster, but I am not quite sure whether it is a 

 question of wing-measurement alone, as it has seemed to 

 me that H. ayresi has a longer wing, in proportion to its size, 

 but I have been handicapped in this matter by the fact that 

 some of the specimens I have examined have appai'ently been 

 wrongly sexed, as all have had approximately the same wing- 

 measurement, i. e. 16 inches. I think we may safely say 

 that the male oi II. spilogaster and the female oi H. ayresi are 

 about the same size. It seems to me, however, that H. ayresi 

 is a rather differently proportioned bird to H. spilogaster, 

 having a longer tail and shorter legs than the latter, and 

 more like H. pennatus in general appearance. Other dif- 

 ferences that have struck me I give in the following parallel 

 columns : — 



Adults. 



H. ayresi. 



General colour above darls sepia- 

 brown ; head black, feathers of 

 scapulars and greater wiug-coverts 

 with more or less concealed spots 

 or bars of brownish grey, only 

 extreme bases white. Many of 

 these feathers tipped with whitish 

 in fresh plumage. 



Ear-coverts and cheeks black, 

 very slightly streaked with white 

 next throat. 



H. spilogaster. 



General colour above black or 

 brownish black. The head the 

 same colour as rest of upper sur- 

 face, conspicuously varied ou sca- 

 pulars and wing- coverts, with 

 white bars and mottling towards 

 bases of feathers. These feathers 

 never tipped with whitish. 



£ar-coverts and cheeks white, 

 streaked witli black. 



