S90 Colorado College PuBLicAtioN 



in by an eddy from the stream. When the Ousel was ready 

 to go into the water it dove in head first and lit on the bottom 

 of the pool where it walked or ran about as if on dry 

 ground. It chased and seized in its beak certain small particles 

 of the drift that were perhaps water insects or insect larvae. 

 The time spent under water was some seconds, perhaps a 

 minute. When he was ready to come out for breath he walked 

 over to his resting place, popped to the surface of the water 

 like a bit of cork and stepped out perfectly dry onto the stone. 



What a remarkable provision of Nature is this which 

 enables a little song bird to float without effort upon the water's 

 surface, or to sink at will and walk securely along- the bottom 

 beneath I The explanation, however, is not difficult. Its body 

 plumage is long, dense, and impervious to water. Under or- 

 dinary circumstances, and particularly if floating, the feathers 

 stand out loosely from the body and the outward -bulk of the 

 bird is great in proportion to its weight. Its bulk is lighter 

 than the same bulk of water and it floats. But if its plumage 

 and wings are tightly pressed against the body excluding all 

 air, the bulk is reduced so that its weight is greater than the 

 same bulk of water and the bird sinks." 



Oreoscoptes montanus. Sige Thrasher. Mountain Mock- 

 ingbird. 



Migrant ; not common. Arrives early in Apf il, from the 

 7th to the 15th. There are no breeding records. The only 

 autumn date we have, if it can be called such, is one seen by 

 Aiken six miles north of Colorado Springs, July 25, 1898. 



This bird is not at all common in El Paso County, and is 

 only seen during migration. In the breeding season it inhabits 

 the greasewood and sage brush plains, of which there are 

 none in the County. An occasional bird may be seen at the 

 time of the spring snowstorms when they are driven from 

 the mountains. 



