476 Birds of Colorado 



close to the surface with, a rapid chattering note. Occa- 

 sionally it alights on a rock or stone in mid-stream, and 

 commences a series of little curtseyings or bobs, at the 

 same time flicking its tail and alternately compressing 

 its body and spreading its Avings. It is this habit which 

 has got it its name of Dipper. Presently it plunges 

 into the icy water and dives ^ith the help of its Avings, 

 or even walks along the pebbly bottom quite submerged, 

 in search of the small water insects which it feeds on. 

 In winter it mil freely go below the ice, reappearing 

 at some air-hole a few yards off, wdthout hesitation. 

 At this season it is often found at mountain lakes, 

 especially if there is open water, owing to warm springs. 

 It is a somewhat unsocial bird, and a single pair usually 

 monopolize a stream or section of a stream to the 

 exclusion of others. The song is clear and sweet, some- 

 what Wren-hke in tone ; according to DreAv it is to be 

 heard all the year round, both in winter and summer. 

 The nest (Plate 16) is placed on a rocky ledge over- 

 looking the stream, on an island rock, behind a water- 

 fall, or sometimes under a bridge, but nearly always 

 within reach of the spray of the water, so that it is always 

 moist and damp. It differs somewhat in shape in order 

 to suit the cavity where it is situated, but is nearly 

 always oven-shaped, a little longer than broad, \vith a 

 front entrance. It is constructed chiefly of moss, with 

 some decayed leaves and other rubbish, strongly put 

 together in a wet state. Inside is the nest proper, saucer- 

 shaped, about 1| inches deep and 3| wide. It is 

 composed of a peculiar non-absorbent wiry grass, lined 

 with a few willoAV leaves flat and intact, and all perfectly 

 dry. The nest harmonizes with its surroimdings, and 

 is made use of after repairs year after year, probably 

 by the same pair of birds. The hen undertakes most 



