Rosinson & Kioss : Birds of West Sumatra. 227 
The Aur pair are an adult female and a young (?) 
male which was flying in company, either her mate or 
her young. The female is of considerably larger size. 
That the white-breasted male is an immature bird, was 
clearly shown by the colour of its eyes and by the soft 
yellowish gape. 
My series of specimens and my personal observations, 
comprising a large number of cases, prove beyond any 
doubt that, as said above, both colour variations have no 
specific value and are neither an indication of age or sex. 
Sp. limnaetus is of all the birds of prey in Sumatra the 
greatest robber of poultry and surpasses in this respect 
Haliastur intermedius which, besides live birds, feeds also 
on fish, carrion, and animal refuse. The true Falcons also 
feed exclusively on birds and small mammals, but they 
are such rare visitors to Sumatra, that their depredations 
are insignificant in comparison with those of Sp. limnaetus. 
I am ignorant as to whether the latter also feeds on small 
mammals and reptiles. Although Sp. limnaetus is a 
common bird everywhere in the Padang Highlands, I have 
observed nowhere so many of them as in the country round 
Buo and Aur, where they are a great nuisance to poultry 
raising. The birds are often to be seen in gardens and 
plantations in the villages, or circling, mostly in pairs, high 
in the air on the look-out for some prey. Their shrill call- 
note is a familar sound in the Padang Highlands. 
The birds are not shy at all, and although they show 
great circumspection, they seem not to realize always the 
danger that threatens them from a gun, and are therefore 
not difficult to approach. In this respect they are far 
inferior in cunning to crows. 
60. Spizaetus alboniger Blyth. 
é. Rimbo Pengadang, Lebong, Bencoolen, 
1000 M. 
Iris lemon, bill horn black, cere blackish, feet pale 
yellow, claws blackish. 
Measurements in the flesh 6 total length, 585, t. 267, 
w. 300, bill from gape, 40, ts. 78 mm. 
The specimen is in immature plumage ; brown above, 
salmon-buff below, breast with a few dark spots and flanks 
and legs with dark cross bars. 
This bird attains a larger size than is generally 
recorded : we have seen an adult female from N. E. Sumatra 
with a wing of 365 mm. 
PANDIONIDAE. 
61. Pandion haliaetus (Linn.). 
@. Korinchi Lake, 733 M. 
