86 Zoology of Colorado 



first mentioned species. McCown's Longspur (Rhynchophanes 

 mccowni) is often found with C. ornatus; it is separated by the 

 more swollen bill, and the white on the tail transverse instead of ob- 

 lique. Sclater gives a special key to the species of the next five 

 genera, known collectively as Grass Sparrows. If the wing is over 

 three inches, the lateral tail-feathers white, and there is median stripe 

 on the crown, it is the very common Western Vesper-Sparrow 

 (Pooecetes gramineus confinis of Baird). If the wing is under 

 three inches, and the lateral tail-feathers are not conspicuously 

 white, the bird may have the edge of the wing yellow, and be the 

 rather uncommon Western Grasshopper Sparrow (Ammodramus 

 savannarum bimaculatus), or it may have the edge of the wing 

 white, and be one of the three following. Then, if the median 

 crown stripe is buffy in front, white behind, it is Leconte's Sparrow 

 (Passer herbulus caudacutus of Latham), which has been taken at 

 Breckenridge. But if the crown stripe is not thus bicolored, 

 should the superciliary stripes be bright yellow, it is the common 

 Western Savannah Sparrow (Passer cuius sandwichensis alaudinus), 

 or should they be buffy like the ear-coverts it is the rare Baird's 

 Sparrow (Centronyx bairdi of Audubon). The Western Lark 

 Sparrow (Chondestes grammicus strigatus) is a common summer 

 bird on the prairies; Sclater notes, " It has a clear, rich and varied 

 song, probably equal to that of any of the rest of the family. " It 

 is known by the bright chestnut color on the head, with a curved 

 contrasting pale band passing backward from behind the eyes, 

 and a median light stripe on the crown. The Swamp Sparrow 

 (Melospiza georgiana) has rather similar markings, but occurs 

 with us only as a rare straggler. The White-crowned Sparrow 

 (Zonotricha leucophrys) is one of our commonest birds, the pattern 

 of the head similar in principle to that of Chondestes, but the 

 colors black and white. It breeds in the mountains, from about 

 8,000 feet to timberline. Z. gambeli of Nuttall occurs as a migrant.* 

 The genus Spizella includes a number of birds of rather incon- 

 spicuous appearance, separated from Zonotrichia and Melospiza 

 by the end of the tail being notched in the middle. The wing 

 is not longer than the tail, as in Chondestes. The Western Tree 

 Sparrow (S. arborea ochracea) is the largest species (wing over three 



♦Usually called Zonotrichia leucophrys gambeli, but Swarth has recently (1926) given 

 good reasons for considering it a distinct species. 



