July, 1908 ANNOTATED LIST OF THE BIRDS OF MESA COUNTY, COLORADO 177 



Geothlypis tolmiei. Tolmie Warbler. Miss Egglestoii writes regarding this 

 species: "Migrant. For a few days in the first warm weather these warblers are 

 heard and seen in the trees bordering the road- ways. They do not remain long 

 however." Prof. Cooke states that this is one of the commonest warblers of west- 

 ern Colorado, so should be found more or less abundantly as a breeder thruout the 

 higher portions of Mesa County. 



Geothlypis trichas occidentalis. Western Yellowthroat. Miss Eggleston says 

 of this warbler, "Summer resident, arriving early in May. These birds stay 

 thruout the summer near Grand Junction." The writer has never seen the bird in 

 Plateau Valley. 



Icteria virens longicauda. Long-tailed Chat. Summer resident, not uncom- 

 mon in the lower part of the County. The only place I have seen this bird is along 

 the Grand River bottom, where it is a regular summer resident and undoubtedly 

 breeds. It was not recorded in Plateau Valley at 6000 to 6500 feet during seven 

 years' observation and its occurrence is probably rare any distance above the Grand 

 River. Mr. Sullivan has found them breeding near Grand Junction but says the 

 birds are very scarce. He says, "Toward August the bird becomes almost silent 

 and toward the close of that month it slinks around the bushes, silently diving 

 here and there into the brush and undergrowth that were once its home, making 

 one wonder at the transition from the noisy customer of the early spring." 



Wilsonia pusilla pileolata. Pileolated Warbler. Prof. Cooke writes, "Several 

 seen September 20-23, 1906, by Merritt Cary a few miles north of the northern 

 boundary of Mesa County. As these birds were there in fall migration, they would 

 have entered the County a few hours later." 



Anthus pensilvanicus. American Pipit. Miss Eggleston writes of this species, 

 "Early in the spring these birds arrive in large flocks. They start from the ground 

 or low bushes and fly upward with a startled cry, remain almost stationary in the 

 air for an instant and then drop quickly back again showing the white of their 

 tail as they alight." It is not probable that the County affords any regions of suffi- 

 cient altitude for their nesting site as they never breed below timberline. 



Cinclus mexicanus. American Dipper. Resident, common locally. The dip- 

 per is rather common in all suitable localities from 6000 feet up during the summer 

 and breeds wherever found. During the winter they move somewhat lower, but 

 thruout the severest weather are found as high as 6000 feet. The nesting period 

 extends thruout June and first half of July. Frequents the clear rapid moun- 

 tain streams. 



Oroscoptes montanus. Sage Thrasher. Summer resident, not uncommon. 

 Miss Eggleston writes, "These birds are quite common on the long stretches of un- 

 irrigated land covered only with sage brush." Breeds in the lower part of the 

 State wherever sage-brush or grease- wood is plentiful, but is much more common 

 in migration than as a breeder. During the migration period the}^ are quite com- 

 mon up to at least 6500 feet. 



Mimus polyglottos leucopterus. Western Mockingbird. Mr. Sullivan saj^s, 

 they breed but are not very plentiful and are usually wary and hard to approach. 

 He says they depart for the south about September 1. Miss Eggleston writes, 

 "Summer resident. With us near Grand Junction this bird breeds, bringing out 

 two broods each season. Evidently the same pair returns each year, for a nest in 

 a pile of prunings from an orchard was inhabited season after season." 



Galeoscoptes carolinensis. Catbird. Summer resident, not common. Occas- 

 ionally found in suitable localities up to at least 7000 feet and breeds as high as 



