132 Practical Bird-Keeping. — II. The British Warblers.



connotes a species which generally haunts fairly thick covert,

into which it slips like magic when disturbed ; it is seldom seen

at any considerable height above the ground.


The more rounded tail connotes a species which has been

to some extent modified by environment; a species which spends

a large portion of its life in threading its way through dense

reed-beds and sedge tangles. A still more rounded tail is that

of the Grasshopper Warbler, a bird which I have watched for

hours creeping through the thickest undergrowth like a mouse.

We obtain a good idea of this type of tail if we imagine that the

undergrowth closing behind the passage of the bird has in the

course of long ages gradually worn away the tips of the outer

rectrices. (I do not say that the tail has actually been modified in

this way, though this is conceivable). This type of tail (though

carried to a greater extreme) is exemplified by the Bearded Tit,

which passes its life in slipping through the stems of the sedge

and which will perform the remarkable feat of flitting through a

reed bed without striking the reeds. This introduces us to

another use of this type of tail, namely, that of instantly altering

the line of flight by powerful leverage. Lastly, we come to the

forked tail, which connotes a bird which is constantly making

rapid darts into the air in pursuit of insects. Every one must

have noticed the little “leaf-inspectors” ( Phylloscopi ), such as

the Chiff-chaff and Willow Wren, eking out a scanty subsistence

during the cold days of early spring by catching gnats. This

type of tail, carried to a further stage of development, is found

in the Swallow-like birds.


Now, inasmuch as the more highly specialized species are

always least amenable to domestication, we should expect to find

that the Square-tailed Warblers will do better in a state of cap¬

tivity than the round- or forked-tailed species, and it is, I think,

some confirmation of the above suggestions, that the order of

precedence of the species in the above list might almost be

accepted as indicating their degree of suitability for cage-life.

There are some exceptions, of course; for instance, the Great

Reed Warbler is probably a much hardier bird than the Icterine,

or Melodious, Warbler, which is not surprising seeing that it is

a much larger bird. An old marshman who, long years ago,



