450 Birds of Colorado 



again for the south in September. It nests chiefly in the plains but 

 also in the mountains, perhaps up to 9,700 feet (Breckenridge, Carter). 

 It is common throughout the State from Routt co. (Warren 08) to 

 La Plata co. (Oilman), and from Weld co. (Markman) to Baca co. 

 (Warren 06), and Costilla co. (Henshaw). In Mesa co., where it is 

 the commonest Warbler, it breeds up to 7,000 feet. 



Habits. — ^The Yellow Warbler is perhaps the best 

 known of all the familj' owing to its conspicuous 

 coloration and familiar habits. It is fond of frequenting 

 parks and gardens, and is very common about the 

 suburban parts of towns, where it frequently builds 

 its nest. Its more natural surroundings in Colorado 

 are willow and cotton-wood trees and bushes along 

 streams, but it does not care for thick forest or pine 

 woods. 



Like other Warblers, its food consists entirely of insects, 

 and it is alwaj^'s busy searching for these among the 

 leaves and smaller branches of the trees. The song is 

 rather simple, but sweet and Uvely and highly character- 

 istic, and is indulged in even in the middle of the day. 



The nest, according to Gale, is placed in a crotch of 

 a small tree, or more often in a low bush, usually a willow 

 or cotton-wood ; in the latter case it is pensile, bemg 

 fastened to the surrounding twigs at the rim. It is 

 woven of wild hemp or vine stems and grasses, and 

 lined with the cotton from the cotton-wood trees, and 

 is a Hght, compact and well-built structure. 



Fresh eggs are to be met with about June 12th (Dille) ; 

 the clutch is usually four, sometimes five, and the eggs 

 are greyish to greenish- white, marked with spots, splashes 

 and blotches of various shades of lilac and brown. They 

 average "68 x '50. This Warbler is one of the most 

 frequent victims of the parasitic Cow-bird, and appears 

 to reaUze the fact, as it is one of the few birds which 

 constantly build a second and sometimes a third story 



