SECOND ANNUAL KEPORT OF BIRD COUNTS IN THE U. S. 9 



orchard, near Grand Junction, the trees from 3 to 6 years old; the 

 area was interspersed with small fields of alfalfa, grain, and root 

 crops, and contained about ten sets of farm buildings, sheds, and 

 yards for live stock. The native birds were represented by 116 pairs 

 of 17 species (in addition to a colony of 65 pairs of violet-green 

 swallows, most of which had come within the last few years), 5 

 pairs of English sparrows, and 12 pairs of the introduced California 

 quail; a total of 198 pairs of birds on the 320 acres. Just above 

 this irrigated land lay a tract of 320 acres in its original wild state, 

 of low hills and small gullies; the hills sparsely covered with sage, 

 saltwort, and other desert plants, and the gullies lined with bushes. 

 Its bird life consisted of the following pairs: Burrowing owl, 3; 

 Arkansas kingbird, 1 ; Say phcebe, 1 ; desert horned lark, 5 ; western 

 lark sparrow, 2; white-rumped shrike, 2; and rock wren, 3; a total 

 of 17 pairs of 7 species. The irrigated land supported a bird popu- 

 lation at the rate of 66 pairs to 100 acres, while on the contiguous 

 nonirrigated land the bird life shrank to 5 pairs to 100 acres. 



A 40-acre tract on the outskirts of Tombstone, Ariz., containing 

 in one corner a few houses with their yards, but for the most part 

 covered with a sparse growth of desert shrubs, " not heavy anywhere, 

 but quite general," and with no surface water, had a bird population 

 of 50 pairs of 26 species, of which only 4 species were seed-eaters 

 and the rest insectivorous. At a little distance from the town a 

 40-acre tract of " semidesert " covered with a rather heavy growth 

 of brush, mostly less than 6 feet high, showed 31 pairs of 16 species. 

 No enumeration has yet been made on the real desert. In the 

 mountains of Arizona, near Flagstaff, a tract of 70 acres at about 

 7,100 feet elevation, covered with western yellow pine and Gambel 

 oak, supported a bird population of 31 pairs of 18 species. 



A public park in Missoula, Mont., with exceptionally favorable 

 conditions for bird life, showed 59 pairs of 20 species on 40 acres. 

 Along the shore of Flathead Lake, Mont., 45 acres of woodland had 

 67 pairs of 24 species. A tract of 48 acres near Missoula, Mont., with 

 6^ acres in orchard and the rest in native prairie, furnished a home 

 in the orchard for 16 pairs of birds, while only 4 pairs could be dis- 

 covered on the 40 acres of shrubless prairie. 



These examples make it plain that there is a much smaller bird 

 population per acre west of the one hundredth meridian than in the 

 Northeastern States. Just how much smaller can not be estimated 

 from the reports so far received. 



Probably no State in the Union has greater variations in bird life 

 than California. A few examples will show some of these, though 

 it will require many more bird counts than those so far made to 

 furnish an adequate basis for estimates of averages. A plot of 20 

 acres of the campus of the University of California, with conditions 

 47849°— Bull. 396—16 2 



