xxii Birds of Colorado 



rufus, Corvus c. sinuatus, Cyanocephalus cyanocephalus, 

 Passericulus s. alavdinus, Spizella p. arizonce, Piranga 

 ludoviciana, Vireo g. swainsoni, Lanivireo s. plumheus, 

 Dendroica aiiduboni, D. nigrescens ?, Oporornis tolmiei, 

 Wilsonia p. pileolata, Cinclus m. unicolor, Sitta c. 

 nelsoni, Penthestes a. septentrionalis, Myadestes town- 

 ^endi. 



(f) Birds chiefly confined during tlie breeding season 

 to the mountains, between 8,000 and 11,500 feet — 39 in 

 number, or 17 per cent. : — 



Mergus americanus ?, Clangula islandica, Histrionicus 

 histrionicus, Gallinago delicata, Dendragapus obscurus, 

 Lagopus leucurus (up to 13,500 feet), Falco c. richardsoni, 

 Cryptoglaux acadicus, Picoides a. dorsalis, Sphyrapicus 

 V. nuchalis, 8. thyroideus, Cypseloides borealis, Aero- 

 Tiautes melanoleucus, Nuttallornis borealis, Empidonax 

 difficilis, E. hammondi, E. wrighti, Cyanocitta s. 

 diademata, Cractes c. capiialis, Nucifraga Columbiana, 

 Hesperiphona v. montana, Pinicola e. montana, Car- 

 podacus cassini, Leucosticte australis, Zonotrichia 

 leucophys, Junco caniceps, Melospiza lincolni, Oreospiza 

 chlorura, Tachycineta i. lepida, Dendroica gracioe, Anthus 

 rubescens (to 13,000 feet), Certhia f. montana, Sitta 

 canadensis, S. pygmcea, Penthestes gambeli, Regulus s. 

 olivaceus, R. calendula, Hylocichla u. sivainsoni, H. g. 

 auduboni. 



Acknowledgments. 



I am deeply indebted to Mr. Charles E. Aiken of Colorado 

 Springs, for constant help and advice during the prepara- 

 tion of this work. As has already been stated, the descrip- 

 tions are all based on the large collection of Colorado birds 

 made by him, and now the property of Colorado College ; 

 but apart from this, I have been able through his kindness 



