In regions of a comparatively low altitude many birds, as is well known, hie to the far North to find the proper climatic conditions in which to rear their broods and spend their summer vacation, some of them going to the subarctic provinces and others beyond. How different among the sublime heights of the Rockies! Here they are required to make a journey of only a few miles, say from five to one hundred or slightly more, according to the locality selected, up the defiles and cañons or over the ridges, to find the conditions as to temperature, food, nesting sites, etc., that are precisely to their taste. The wind blowing down to their haunts from the snowy summits carries on its wings the same keenness and invigoration that they would find if they went to British America, where the breezes would descend from the regions of snow and ice beyond the Arctic Circle.
It will add a little spice of detail if we take a concrete case. There is the handsome and lyrical white-crowned sparrow; in my native State, Ohio, this bird is only a migrant, passing for the summer far up into Canada to court his mate and rear his family. Now remember that Colorado is in the same latitude as Ohio; but the Buckeye State, famous as it is for furnishing presidents, has no lofty elevations, and therefore no white-crowns as summer residents. However, Colorado may claim this distinction, as well as that of producing gold and silver, and furnishing some of the sublimest scenery on the earth; for on the side of Pike's Peak, in a green, well-watered valley just below timber-line, I was almost thrown into transports at finding the white-crowns, listening to their rhythmic choruses, and discovering their grass-lined nests by the side of the babbling mountain brook. Altitude accomplishes for these birds what latitude does for their brothers and sisters of eastern North America.
There is almost endless variety in the avi-faunal life of the Rockies. Some species breed far above timber-line in the thickets that invade the open valleys, or clamber far up the steep mountain sides. Others ascend still higher, building their nests on the bald summits of the loftiest peaks at an altitude of fourteen thousand feet and more, living all summer long in an atmosphere that is as rare as it is refreshing and pure. Among these alpine dwellers may be mentioned the brown-capped leucostictes, which shall be accorded the attention they deserve in another chapter. Then, there are species which have representatives both on the plains and far up in the mountain parks and valleys, such as the western robin, the western meadow-lark, and the mountain bluebird.