402 AXIMAL LIFE IX THE TO SEMITE 



scattered out, each little swale in the rolling lands being occupied by one 

 or more pairs. The males were then in full courting display. The break-up 

 of the flocks elsewhere in the San Joaquin Valley occurs about the end 

 of March and probably at about the same time in the Yosemite section. 

 Examination of a colony on the Tuolumne River below Lagrange on 

 May 7, 1919, showed that some of the pairs had commenced nesting early 

 in April; and at Snelling, in 1915, mixed flocks comprising males and 

 females were seen on May 29, and, on that date, there were fully fledged 

 young in the tules. These facts would again place the beginning of nesting 

 early in April. But on May 6, 1919, females seen near Lagrange were 

 carrying wet nesting material, and sets of fresh eggs were found on the 

 following day; and at Snelling, in 1915, young just hatched were found 

 on May 29, so that the nesting season of the Bi-colored Red-wing extends 

 at least from early April to the latter part of June. Once the young 

 are grown, the flocking instinct is quickly manifested, and birds of both 

 sexes and all ages band together and roam about in search of food. It 

 seems probable that the representatives of the Bi-colored Red-wing which 

 summer in the foothills drop down to the San Joaquin Valley for the 

 winter season and thus augment the resident population of the plains 

 during the rainy months. 



The Nevada Red-winged Blackbirds which occur in Mono Valley are 

 only summer visitants there. On April 26, 1916, when Mr. Dixon arrived 

 at Williams Butte, the male Red-wings were already on hand and had 

 taken their stations in the willow^ thickets; but no females were observed 

 until May 6, when a flock of about 15 was noted. Most of the male birds 

 taken during that part of the season gave evidence that they were summer 

 residents and ready to mate, while a small minority were transients, en 

 route to more northern localities. The species remains in the region at 

 least until September, for a flock of 25 or so Avas seen, in a wet meadow 

 near Williams Butte, on September 14, 1915, and lone individuals were 

 noted on September 21 and 23. On the latter date observations were 

 concluded in that locality for the season. 



Our field party first noted Red-winged Blackbirds in Yosemite Valley 

 on May 23, 1919, although Miss Margaret W. Wythe (MS) found a few 

 in the willow thickets east of Sentinel bridge in July, 1914. In 1919 at 

 least 8 pairs were apparently settled for nesting in the wet meadows both 

 east and west of Kenneyville. When the Valley was visited in 1920, the 

 Red-wings were twice as numerous. On June 23 a nest was found in an 

 open field situated 6 inches above wet ground in tall saw-grass. It con- 

 tained 5 small young. Mr. C. W. Michael (MS) reports that small flocks 

 were seen there on various dates up until September 25, and thereafter 

 a solitary Red-wing was observed on October 7, 1920. The birds of 



