DIPPER 87 



which he is perpetually rushing. In like manner we invariably 

 think of the dipper in connection with the swift, brawling mountain- 

 torrent he inhabits. He is never, or very seldom, found removed 

 from it, and is probably more restricted to certain conditions, and 

 consequently more bound to his home, than any one of the species 

 just named. The stream he attaches himself to must have quiet 

 and comparatively deep pools, and the water must be clear to enable 

 him to detect the larvss of water-beetles, dragon-flies, and other 

 aquatic insects he preys on, all of which have a protective colouring. 

 He does not range up and down a stream, like the kingfisher, to 

 visit the various feeding-places ; he limits himself to a portion of 

 it, in many cases not more than a hundred yards in length, and 

 explores the bottoms of the same pools from day to day, until they 

 must be as familiar to him all their inequalities, their stony ridges 

 and half-buried boulders, and sandy or pebbled places, and all the 

 holes and secret corners where sediment collects as the rooms we 

 live in are to us, and about which we are able to move freely in the 

 dimmest light. In ascending a mountain stream such as these 

 birds love, abounding in deep, quiet pools, with noisy cascades and 

 shallow rapids, its bottom strewn with great fallen boulders partly 

 submerged, the rocky banks overgrown with sheltering bushes and 

 vines, when you disturb a dipper he flies up stream a short 

 distance, perhaps twenty yards, and alights on a boulder, or in the 

 shadow of an overhanging rock, and there waits, silent and motion- 

 less, until, disturbed again, he takes a second short flight up stream, 

 and so on to the limit of his range, whereupon, rising up and doubl- 

 ing back, he flies to the spot he started from. And as often as you 

 disturb him he will act in the same way, going just so far, and no 

 farther. If you leave him behind and go on, you will find another 

 pair of dippers, whose portion of the stream begins just where that 

 of the first pair ends. They, too, will act in the same way, and fly 

 on until the end of their range is reached, and will not venture 

 beyond where a third pair are in possession. Where they are not 

 disturbed a mountain stream may be found parcelled out in this 

 way among a dozen or twenty couples. Probably the dipper, like 

 the robin, jealously resents the intrusion of another bird of his kind 

 into his chosen ground. Concerning this habit of the dipper, and 

 its strange way of feeding under the water, something still remains to 

 be known. It is, indeed, strange that this little perching song-bird 

 should have the habit of diving for its food like a grebe or a guille- 

 mot, and other species that have structures specially adapted to 



