THE CASSIN VIREO. 



365 



bux, a raltling, ruliljing, shaking note, of three or more vibrations, ending 

 in a little vocal flourish. 



These Vireos swing a bulky basket from the lower or middle 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 tin_\- weed- 

 shoot germinating from the 

 bottom of the cup. 



Further Mr. Bowles 

 says 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- 



Takcn near Tocoiua. Photo by Bozi-lcs and Daicson. tWCeU niuc o'clock iu 



A DECOR.vTED xEST. the moming and noon, 



and the . nest is not 

 hard to find if his song can be traced. The l)ird student must work 

 quietly, however, as the song at once ceases should any unusual noise 

 occur. The}' are most courageous while on the nest, seldom leaving until 

 removed by hand, when ].)oth birds remain within a few feet of the 

 intruder, scolding \-igor(_)usly. So much noise do thev make that all 

 the birds in the vicinity are attracted — indeed this is about the onlv 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 

 seventv-five vards distant, and sat on a branch overhead, screamino- 



- - ■ o 



at me. 



"They are the quickest as well as the slowest birds in com- 

 pleting their nests that have come under my notice. One pair built a 



