BRITISH WARBLERS 
tentatively flies or, rather, springs at him, and sometimes they 
seem to momentarily hold one another by the beak. 
I have seen considerable commotion caused by a male 
Blackcap which, occupying the same territory as a White- 
throat, happened to be paying attention to a female at the 
same time. Whilst the males were thus pursuing their 
respective females the four birds often encountered one 
another in the same bush. Whenever this occurred the 
male Blackcap exhibited every sien of anger, flying at and 
vigorously attacking the male Whitethroat, who, as regards 
strength, was by no means a match for him; and not content 
only with this attack he would, in his excitement, often 
imitate the Whitethroat’s song. 
Assemblies of five or more excited individuals are not of 
infrequent occurrence, and are very similar to those which 
we find amongst the Blackcaps. They are not limited to any 
one sex, but may consist of two females and three males, 
or two males and two females. The males warble, the 
females utter their call note, and both sexes show the usual 
sions of excitement by spreading and waving their tails and 
erecting their feathers, and although they never go very far 
distant, but remain more or less in the same locality, yet 
they move rapidly from tree to tree or along the hedgerows. 
The nest is placed in thick undergrowth of some kind, 
either in the lower parts of tangled hedgerows or in clumps 
of bramble overgrown with coarse grass, or sometimes in 
the thick vegetation that grows so luxuriantly in the drier 
portions of osier beds, no partiality being shown for any one 
particular herbage. It is usually placed from six inches to 
three feet from the ground, and is a rather deep but lightly 
built structure, composed principally of dead grass. But like 
the nests of many other species the grasses placed at the base 
are coarser than those used in the interior; wool and pieces 
of dead thistle are often mixed with the grass, and I have 
found one nest in which a considerable quantity of cotton- 
wool had been utilised. The lining, which is of slight 
thickness, is of horsehair. 
16 
