THE PIED WAGTAIL. 307 



open, and are on the fields as soon as the ploughs can be got 

 in, they cannot come from a very great distance, unless we 

 suppose that some messenger sends them word that the 

 northern country is fit for their reception. It must never 

 be lost sight of, that birds all animals are affected only by 

 present circumstances, by circumstances present both in 

 time and in place ; and though Iceland were heated like a 

 furnace by the action of its volcanoes, that would not occa- 

 sion the migration of one bird from the south. Besides, the 

 pied wagtail undergoes a considerable change of plumage 

 preparatory to the winter ; and birds require that, in order 

 to temper them to the climate, and having done so, they 

 never migrate farther than is necessary in order to find food. 



The wagtail sings early, and sweetly, though its song is 

 neither very long nor very loud. It sings from a low perch, 

 the point of a rock by the water's edge, the parapet of a 

 bridge, on an old stump of a tree, a mill, or even the top of 

 an outhouse or cottage. It is a very familiar bird, and, at 

 the same time, very lively and very pretty, so that it is a 

 general favourite. A meadow of short soft herbage by the 

 brook, or a well-mown lawn near the bank of a river, is a 

 very favourite morning or evening pasture for the wagtail, 

 and it will run about there with great alacrity and glee, ever 

 and anon dipping its head, and again recovering its balance, 

 by the peculiar motion of the tail, as if it took pleasure in 

 a place neatly kept. But the fact is, that the short grass, 

 more especially if it is newly mown, enables the bird to see 

 its insect prey readily, and capture it with ease. 



The situation of the nest is varied according to the haunt. 

 It may be in a bank of stones by the brook, a shelf of the 

 bank, a hole in the wall, or a thick old tree. The external 

 structure is composed of vegetable fibres filled with wool, and 

 the internal lining hair ; but these, of course, vary with the 

 materials that are to be had. The eggs are four or five, 



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