64 
THE CONDOR 
Vol. XIII 
stream, which flows in a southeasterly direction, issues from a narrow canyon into 
a broad drainage basin, from one to several miles in width, with a flood-plain half 
a mile or more wide. It should be explained, however, that the entire creek is 
now taken up and held in reservoirs for irrigation. On the north side the land 
rises by a steep, continuous slope for a distance of several hundred to perhaps a 
thousand feet, but on the south a series of low hills leads gradualh' up from the 
flood-plaini to the rim of the valley. Besides the main canyon two or three small 
tributary danyons enter the valley within the limits covered by our observations; 
only one o;f these, however, contains a permanent stream. This is known as Pole 
Creek, and is very small, in fact quite disappearing in places, where it sinks among 
the rocks dnd sand of its bed. The main canyon is from one to several hundred 
yards in width, with steep, often ]irecipitous walls. 
So far as the vegetation of the region is concerned, the flood-plain association 
of plants is of course sharply marked off from that of the upland or .sage-brush sec- 
tion. The former consists largely of a tall rank grass {Elynius coudensatus ) , 
known as rye-grass, together with other grasses, sedges, and rushes, and where the 
soil is strongly alkaline, of various halophytic species. Certain tall weeds, espec- 
ially the common sunflower ( Hcliaiithus anHniis) also abound. Along the imme- 
diate bank of the creek there is a more or less continuous belt of willow thickets, 
consisting mainly of shrubby species, commonly not much over fifteen feet in 
height, but frecpiently forming a very dense growth. At Brogan, however, there 
is a tract of some fifteen or twenty acres of what may be designated timber, con- 
sisting wholly of willow trees, some of which reach a height of thirty or forty feet 
and a diameter of twelve or fifteen inches. Among the trees is a den.se tangled 
undergrowth of red osiers, rose bushes and other .shrubs, with various rank weeds, 
especially thistles and nettles, forming all together an almost impenetrable jungle. 
In the canyons are considerable thickets of willow, some shrubby birches 
{Bctula micfop/iyllti) , occasional small shad-berry trees iAnielaiichie?' ciisickii ?) , 
and also alders and chokecherries, and numerous clumps of cottonwood ( Popu/us 
a)ig'usti folia) , the trees sometimes sixteen inches in diameter. Excepting these 
narrow canyons and the flood-plain of Willow Creek, the whole area over which 
our observations extended is an almost uninterrupted wa.ste of sage-brush and such 
other xerophytes as usually accompany it. 
It is needless to say that the character of the vegetation constitutes the domi- 
nant factor in determining the avian life in each of the .sections above indicated. 
In the flood-plain area birds were not, in general, remarkably plentiful; however, 
the bit of willow timber displayed an abundance of individuals and variety of species 
rarely seen surpassed in any section of equal extent. Some idea may be gained of 
the richness of this locality from an examination of the list which follows. The 
chief requirements, protection from enemies and from the elements, and an abundant 
food supply, were here to be met with as nowhere else for miles around. Insects 
appeared to be remarkably plentiful; one would scarcely find them more so in a 
tropical forest. 
This lower portion of the valley has been in ranches for manv years, and a 
considerable part of it is devoted to alfalfa raising. About the ranch hou.ses are 
considerable orchards and shrubbery and tall Lombardy poplars, forming a favorite 
resort for a number of species, which were here found in great abundance. Fur- 
thermore, large numbers of Fringillidae were noted in the extensive patches of sun- 
flowers, the seeds of which, when in season, probably formed their principal food. 
In Willow Creek Canyon birds were found in only moderate numbers, but in the 
little canyon of Pole Creek both species and individuals were abundant. 
