156 THE BEAVER 
piper fairly common. In the Yellowstone I saw both the 
solitary and spotted sandpipers, the former late in the sum- 
mer, after the fall migration had begun. ‘The latter was a 
summer resident, and seen not only at the beaver ponds, 
but along all the streams. 
Beaver ponds are likely to create along their shores 
conditions which will attract some of the swamp or marsh- 
loving warblers and sparrows, and induce them to nest 
there. 
