20 ‘THE ‘CONDOR: «* . Vol. XXIV 
Park streams forces them to congregate along those still open. In this way, 
they begin increasing along the lower six miles of the Gardiner River that is 
open, about November first, and by Christmas this section supports a popula- 
tion of seventy-five Dippers as against the summer quota of perhaps ten. In 
the spring, usually towards the middle of March, they begin moving up as 
rapidly as the streams open again. 
Food is secured under water by diving, even through ‘‘anchor ice’’ on 
the surface and ‘‘slush ice’’ in the water; sometimes a Dipper stands in shal- 
low water and gleans from the bottom without diving; and once or twice I 
have found one apparently skimming his food from the surface of the pool 
over which he was swimming. Diving from the shore ice quite like human div- 
ers, from the surface of still water, they leap forward and down, only to re- 
appear after a minute or two with the sudden uprush of a cork. Water only 
slightly roily does not seem to bother them in the least and our clear mountain 
streams are not often worse than that. Occasionally the birds combine singing 
and eating, as already related in the paragraph under song. 
After a hearty breakfast, a Dipper usually comes out to bask and preen 
in the early morning sunlight. In fact, these little birds are given to sun- 
baths; they are often seen perched silently on a stone, so quietly as to simulate 
sleep except that their heads are not ‘‘under their wings’’ and the winking 
white eye-lid is easily seen. 
A bird almost continually in the water and the rest of the time in the 
spray of rushing rapids and waterfalls, one would not think in need of a bath. 
But the Dipper thinks otherwise, and when he bathes, he does it thoroughly. 
The first bather I found was standing on a stone in mid-stream, alert, and with 
tail perked up straight. Then he flew, hit the water three feet away, and shot 
- along the surface with head under so that the water rushed up over his back; 
then he flew away, and came back again immediately for another plunge. 
After that, he stood in shallow water covering legs and half his body, and 
fluttered in approved bird-bath fashion; then to a stone to shake himself, to 
dress his feathers, and to preen. 
I am doubtful whether Dippers mate anew each year, and I am inclined 
to believe in ‘‘mating for life’’ for this bird. They seem to have all paired 
early. On a few occasions, I have seen male Dippers singing very sweetly and 
very earnestly with tail perked up at an extravagant angle and wings slightly 
drooped, again very much like a wren. Probably these were birds not supplied 
with a mate from the previous year. 
When there is a suitable rafter low and moist enough, Dippers sometimes 
nest under bridges, but a niche in a boulder in mid-stream is much more likely 
to be selected. Once, on March first, a couple was seen building a nest in a 
boulder niche along the Gardiner River. The nest was a ball of moss about 
nine inches in diameter with a little mud inside, and mud was also used to 
cement the whole to the rock. Four feet above the rushing water, the nest 
faced north or downstream; as a rule the Dipper nests I have found have 
faced downstream. In the front of the nest ball was a round opening about one 
and a half inches in diameter, leading to the inner nest of coarse, wiry grass 
that did not wet down into a sodden mass. While this nest seemed to be com- 
pleted, I found it still unoccupied two weeks later, although the birds were 
frequently in its immediate neighborhood. About March 24 this nest was torn 
