THE ROOK 
is an early breeder, its eggs being laid in March or 
April. By the end of February the big nests are being 
repaired and others are being made. Yearly the same 
trees and the same nests are used, so that in some cases 
the latter are very bulky, being added to each season. 
They are made of sticks, cemented with mud and 
turf, and lined with moss, wool, dry leaves, straws, and 
sometimes a few feathers; the cavity is rather flat, 
but the lining smooth, and the whole structure is very 
substantial. I have often stood on a Rook’s nest in 
perfect safety. The three to five eggs range from pale 
blue through various shades of green, blotched, spotted, 
and clouded with olive-brown and grey. ‘The bustle 
and din of a rookery whilst nesting is in progress is too 
well known to need detailed description. Both parents 
incubate, and one brings food to the other whilst doing so. 
When the young are hatched they are fed assiduously by 
both parents, and it is now that the Rooks in many 
London rookeries must have a hard time of it, flying many 
miles over the houses and streets to grass-lands and other 
places in quest of food. As soon as the young Rooks leave 
the nest they resort to the fields and parks with the old 
birds, and during summer and autumn often wander far 
out into the country to feed and to roost. 
The adult Rook is entirely black, with a metallic sheen 
of purple, specially on the upper parts; the throat and 
space round the base of the bill is bare of feathers and 
covered with a grey, warty skin. Bill black; tarsi and 
toes black; irides brown. Length 17 inches. ‘The 
nestling is dull black, with little or no metallic sheen, and 
the face and throat are covered with feathers. ‘This bare- 
ness is gradually assumed, and usually completed after 
the autumn moult, but is sometimes partially deferred 
until the following spring. Young Rooks may be distin- 
guished from Carrion Crows by the concealed grey bases to 
the body feathers, those of the latter being white. 
O 209 
