Page:Condor14(5).djvu/17

SepL,1912 DISCOVERY OF NEST AND EGGS OF CALIFORNIA PINE GROSBEAK 171 was not particularly easy; for each $ierran summer is somewhat different from the preceeding and what might be termed the "shift" of the $ierran season which results from a number of causes, is very puzzling. In lower zones, here along the coast, for instance, hummingbirds have been found nesting in January, bush-titmice in February, chickadees in March, juncos in April, warblers in May, flycatchers in June, and vireos in July. In the High Sierras, however, the season of reproduction is very short and with few exceptions all birds nest between May 15 and June 30; it is on account of this shortness of the season that the "shift" has such a marked effect. Above 7500 feet altitude there are but very few resident species and in the lower zones it is this class that con- tains the bulk of the early breeders. The season of 1910 in the Tahoe region was one of the earliest known to the old settlers and, in respect to nesting conditions, was at least from fourteen to l?ig. 70. HEINEMANN AND LITTLEJOHN ON THE SNOW NEAR TIMBERLINE AT ABOUT 8750 FEET ALTITUDE; PHOTO TAKEN JUNE 17, 1912, WHILE EN ROUTE TO PYRAMID PEAR sixteen days earlier than normal. On the other hand, 1911 was a year of very heavy snow-fall and about a week later than normal. On June 9, 1910, we found only scattered patches of light snow on the Forni meadow, while on June 11 of 1911 we found it from 6 to 10 feet in depth. With the coming of 1912 it seemed the weather pendulum was swinging back again, for the winter remained remark- ably mild in character. We kept a close watch on the snow reports of the U.S. Weather Bureau, and the following table shows comparative conditions for the last six years on February 28. TABLE SHOWING INCHES OF SNOW ON GROUND BEBRUARY ?8 Summit S. P. R. R., Placer Co., 7018 ft. altitude Tahoe City, Lake Tahoe, 6220 ft. altitude McKinney's, Lake Tahoe, 6220 fL altitude 213 72 [215 I 23 66 40 I 78 I 19 72 38 79 14