ADDENDA . 071 
12 inches long, female 15 inches), and the 
more fierce (for fierce is their characteristic). 
She alone it is said sits on the eggs though 
both male and female feed the young. I 
do not think there is more than one nest each 
season. Plumage: Male, upper parts dark 
bluish-grey, under parts reddish-white, barred 
transversely with dark brown. Tail grey, 
barred brownish black. Female, upper parts 
brown to blackish-grey, under parts grey- 
ish white, barred dark grey. Note the differ- 
ence in the plumage of the two sexes. 
The sestrel (length 15 inches) is known 
from the sparrow-hawk by looking smaller 
and by its habit of hovering with quickly- 
flapping wings and its power of doing 
so against the wind, even though a gale 
be blowing, over whatever attracts its atten- 
tion (hence its cognomens Windhover and 
Hoverer), and this is generally field mice or 
voles, for it does not as a rule, or perhaps 
ever, capture birds like the sparrow-hawk, 
nor is it so: fierce a bird as the latter. (The 
general colour of the adu/t bird (for it varies 
