subsequent recital.
As might be expected, the towering elevations influence the movements of
the feathered tenants of the district. There is here what might be
called a vertical migration, aside from the usual pilgrimages north and
south which are known to the more level portions of North America. The
migratory journeys up and down the mountains occur with a regularity
that amounts to a system; yet so far as regards these movements each
species must be studied for itself, each having manners that are all its
own.

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 canyons 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.

[Illustration: _White-Crowned Sparrows_]

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 en