132 BY THE WATERSIDE ONCE MORE 
its head and back are bluish-grey, though the 
under parts are yellow like the yellow wagtail. 
Young birds of the greyspecies of the first year 
have not yet the yellow on the under parts, the 
plumage there being grey. Thus the majority 
of the birds are grey, and this species has been 
consequently so named. The yellow wagtail 
is a visitor to this country, arriving in March 
or April and going away in autumn, whilst 
many of the pied and the grey are with us all 
through the year, though not remaining always 
in the same locality, and others migrate and 
somecome tous. The nests of all three species 
are built on the ground amongst tall grasses. 
But the birds often perch on trees, and as we 
have just seen on telegraph wires. Their 
nests are open, the cup being shallow, and 
made of hay, grass, and fine fibres, and lined 
with feathers and hair. The eggs number 
from four to six. The colours are: (1) Yellow 
Wagtail: white ground mottled with pale 
olive brown ; (2) Pied Wagtatl: pale bluish 
spotted greyish brown; (3) Grey Wagtail - 
white or grey mottled and spotted pale brown 
