CONSIDERATION OF BRITISH BIRDS 113 
scanty ; and in the case of the Sparrow, may 
be entirely absent. The dome of the Sparrow’s 
nest is never well-made nor very complete. 
It is necessary now to return to Division IT: 
“Birds having Conspicuous Colouring in Both 
Sexes.” 
As would be expected, the majority of these 
make closed nests. There are, however, some 
which make open ones but whose females are 
not cryptically coloured (see Table V) ; in some 
of these the conspicuous colouring is concealed 
whilst the hen is sitting (Table V, * birds) ; 
others are powerful birds, or birds which nest 
in colonies and whose females are not liable 
to be attacked whilst sitting (Table V, birds 
marked f). 
Four birds, the Water-hen and the Coot, 
the Red- and Black-throated Divers, are able 
to leave their nests unobserved, and do so at 
the least alarm, so that it is very difficult to 
view these birds sitting. 
In two birds, the Lapwing and the Oyster- 
catcher, the male keeps guard over the sitting 
female and warns her on the approach of 
danger; she is thus able to leave the nest 
when the enemy is far distant. Without opera 
glasses, it is difficult to view these birds 
whilst sitting. 
H 
