GREEN, GREENISH GRAY, AND OLIVE 449 



Nest : Made of dry leaves, cocoons, and spider webs ; lined with grass and 



bark ; hung in thickets, bushes, oaks, and alders. 

 Eggs: 3 or 4 ; white, sparsely speckled with burnt umber. Size 0.80 X 



0.58. 



The Cassin Vireo is more common along the Sierra 

 Nevada than through the valleys, and is most abundant 

 in the coniferous forests half-way up the mountains. 

 Here its characteristic song, " Mary, Mary, Mary I look 

 up here ! " bears so close a resemblance to that of the 

 yellow-throated vireo of the Eastern States as to make 

 it seem like the same bird. 



His beautiful basket nest will be swung from the 

 branches of an oak or spruce, and, so long as the little 

 green mother is brooding, his happy warble will ring 

 from the nest tree begging her in tenderest tones to 

 " look up here ! " At Slippery Ford on the Lake 

 Tahoe road, one of these little singers followed me from 

 tree to tree, whenever I was within fifty feet of his nest, 

 singing from the lowest twigs a foot or two above my 

 head and peering down at me curiously as he repeated 

 his quaint invitation. His nest was only six feet from 

 the ground and, June 3, contained four eggs. Sitting 

 began that day, and two days later both nest and con- 

 tents had disappeared and, with them, the happy singer 

 and his mate, probably into a collecting basket. I 

 searched for them day after day, but found no trace of 

 them in the neighborhood. Another pair of the same 

 species were finishing their nest in a tree not far from 

 the hotel, and it, like the first, was decorated with white 

 cocoons until it looked almost like a hornet's nest among 

 the green leaves. These birds, although building nearer 



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