THE SPARROW-HAWKS. 
143 
The brown shade on the bars of the under surface is a sign 
of immaturity, and as the bird gets older, the rufous increases, 
and the bars get less and less distinct, till the under-parts are 
almost entirely rufous. This, however, is only the case in ex- 
tremely old individuals. 
Adult Fomule. — Larger than the male, and rather lighter grey ; 
below whitish, with ashy bars, narrower than in the male, and 
liaving a large tuft of downy rufous feathers on the flanks. 
Totallength, 15-5 inches; wing, p'S; tail, 7'o; tarsus, 2-5. 
Young Birds. — General colour above sepia-brown, all the 
feathers margined with rufous, especially on the crown ; occi- 
put and nape mottled with white ; a distinct eyebrow, cheeks 
and ear-coverts, white, streaked with blackish, the hinder mar- 
gin of the ear-coverts brown, washed with rufous ; quills brown, 
barred across with darker brown, more distinct on their loryer 
surface ; tail ashy-brown, with whitish tips, and crossed with 
five bars of darker brown ; under surface of body white, the 
throat narrowly streaked with black, the forc-neck and chest 
with broad rufous streaks, the flanks and thighs distinctly barred 
with dark brown ; under tail-coverts white ; under wing-coverts 
buffy-white, with numerous spots or bars of dark brown ; iris 
pale yellow. 
It takes some time before the young birds attain the adult 
plumage, and it is certain that they breed while still in the im- 
mature plumage. The first adult dress w’ith bars underneath 
seems to be gained by the breaking up of the pattern on thtf 
feather, rather than by a complete moult. The feathers on the 
chest have, in the first stage of plumage, a broad longitudinal 
centre of pale rufous, and, as time goes on, this alters in shape 
and breaks off into bars, the colour being distributed laterally 
instead of longitudinally, and the rufous colour giving place to 
dark brown. Thus two brown bars may be seen on a feather, 
while the terminal one may be represented by a heart-shaped 
spot of light brown, with a rufous “eye,” the last remains of 
the streak of the immature plumage, and when this spot of 
rufous is at last absorbed, and the brown bars complete, the 
bird shows the first stage towards the adult plumage. T. he next 
change is by a moult, which seems to take place at irregular 
seasons, and not in the first autumn, as with most birds, and 
