h suspicion
almost any bird of its own size, and will even pursue a Tree-Pipit if it
approaches too closely. The same is true of the Whinchat, and one would
scarcely expect to find this bird attacking Buntings as it sometimes
does. A Whinchat that occupied some marshy ground was constantly at war
with a pair of Reed-Buntings; their territories were adjacent and in
some measure overlapped, and the Whinchat drove away either sex
indiscriminately, and was not only always the aggressor but seemed to
be master of the situation.

Coming now to kindred forms, those, that is to say, which belong to the
same family, we find that, both in intensity and extent, the warfare far
exceeds anything that we have thus far considered. So frequent, indeed,
are acts of intolerance, and so readily awakened into activity is the
pugnacious nature of the bird, that the fighting will almost bear
comparison in volume with that which occurs between individuals of the
same species. Between the Thrush and the Blackbird there are incessant
quarrels early in the year, and the initiative seems to pass from one
to the other according to the circumstances in which they are placed. If
the territory of a Thrush is invaded the Thrush is the aggressor, and,
conversely, if that of the Blackbird is threatened, the Blackbird
becomes the aggressor; and so, when the territories of the two birds are
adjacent or overlap, as frequently they do, there is constant friction,
resulting in quarrels which attract attention on account of the
noisiness of the birds.

All the Warblers are exceedingly pugnacious, the fighting being
especially severe between those that are very closely related. The
Blackcap and the Garden-Warbler are constant rivals, and the scenes
which can be witnessed when the two meet in competition are interesting
from many points of view. The birds not only pursue and fight with one
another, but their emotional behaviour reaches a high level of
intensity--excitable outbursts of song are indulged in, tails are
outspread, wings are slowly flapped, and feathers raised--in fact the
attitudes assumed are similar in all respects to those which occur
during the contests which are so frequent between the respective
individuals of each species; and it would be difficult to point to any
one item of behaviour which is not also manifest at one time or another
during the battles between these rivals, and still more difficult to
trace any difference in the intensity