THE CASSIN VIREO. 



365 



box, a railling. rubbing, sliaking note, of tliree or iiKire vibrations, ending 

 in a little vocal flourisii. 



These Vireos swing a bulky basket from the lower or mitUUe heights 

 of oak trees, fir trees, alders, or saplings of various sorts. Usually no 

 dependence is placed in cover, save that the ornamented nest corresponds 

 roughly with its general surroundings of leaf, moss and lichen. In shel- 

 tered places, the texture of the nest is so well preserved that it may 

 require close inspection the second season to distinguish it from a new 

 nest. One such I examined, green with growing moss, and stark at the 



lowermost branch-tip of an 

 unleafed cornel sapling, and 

 I could not have determined 

 its age save for a tiny weed- 

 shoot germinating from the 

 bottom of the cup. 



Further Mr. Bowles 

 sa\-s of their nesting 

 habits: "Both birds 

 assist in the duties of 

 incubation, the male 

 singing most assidu- 

 ously while on the 

 nest, and usually sing- 

 ing close to his mate 

 while she is sitting. 

 His turn at sitting 

 seems to come be- 

 tween nine o'clock in 

 the morning and noon, 

 and the nest is not 

 liard to find if his song can be traced. Tlie bin! student must work 

 cpu'etly, however, as the song at once ceases should any unusual noise 

 occur. They are most courageous while on the nest, seldom leaving until 

 removed by hand, when both birds remain within a few feet of the 

 intruder, scolding vigorously. So much noise do they make that all 

 the birds in the vicinity are attracted — indeed this is at)out tJie only sure 

 method of ascertaining the presence of some of our rarer Warblers. 

 On one such occasion a female Cooper Hawk left her nest, which was 

 .seventy -five yards distant, and sat on a branch overhead, screaming 

 at me. 



"They are the quickest as well ns the slowest Ijirds in com- 

 pleting their nests that ha\'e come under m\- notice. One pair l)uilt a 



Taken near Tocoma. Photo by Bowles 1 

 A DECOR.\TED .NEST. 



