March, 1898. Birds 0/ the Pacific Slope of Los Angeles County. 



153 — 421. Chordeilcs acutipeyinis texc7isis (Lawr. ). 

 Texao Nightl^awk. 

 Abundant summer resident, principally of the mesas and dry 

 washes. First spring arrival noted by H. A. Gaylord, March 21 ('96). 

 Last individual in the fall, seen by me, Sept. 4 ('94). Breeds mainly 

 in May. First set, taken by me near Pasadena, two fresh, April 21 

 ('97); latest set, two slightly incubated, taken July 11 ('95), by H. S. 

 Swarth in San Fernando Valley. 



154 — 4.22. Cypseloides niger borealis (Kennerly). 



Black Swift. 

 Rare migrant. I have seen it on two occasions toward the last of 

 August flying southeast over Pasadena. W. H. Wakeley has a spec- 

 imen mounted which was shot near Pasadena late in summer several 

 years ago. 



155 — 424. Cheetura vauxii (Towns.). 



Yaux's Swift. 

 Common migrant. Generally seen flying in scattered flocks over 

 the mesas or along the bases of the mountains. Sometimes large com- 

 panies tarry about reservoirs or ponds. According to my field notes 

 the migrations occur as follows: In spring, April 22 ('96) to May 2 

 (■96); and in fall, Sept. 3 ('95) to Oct. 13 ('94). 



15ii — ^25. Aeronautes melanoleucus (Baird). 



White-throated Swift. 

 Common in mountain regions in summer, and occasionally seen 

 during' the winter over the lowlands and mesas. Nests in crevices of 

 the rock in the most inaccessible cliffs. E. Simmons took a set of two 

 eggs, about one-third incubated, in a mountain canon north of Pasa- 

 dena, May 30, '97. H. G. Rising took a set of two fresh eggs in the 

 Santa Monica Mountains, June 16, '97. 



157 — 4.29. Trochilus alexandri Bourc. & Muls. 



Black-chinned Hummingbird. 

 Summer resident from the lowlands to the summit of the moun- 

 tains, but most abundant in the foothill regions, where it breeds in the 

 cations in .some years by the thousands. Nests are generally situated 

 near a stream, and are found mostly after the middle of May. I have 

 taken fresh eggs by April 29 ('95), which I consider very early for this 

 species, and as late as July 8 ('95); I found a nest containing two half- 

 grown young near Pasadena, Aug. 24 ('95), which of course is very 

 late. The abundance of the Hummingbirds is very variable, depend- 

 ing on the growth of flowering plants. Usually after a wet winter 

 they are far more numerous than after a dry one. The Black-chinned 

 Hummingbird arrives in the vicinity of Pasadena from the middle of 

 April to the first week in May, and the majority disappeaj- by the last 

 of July. Extreme records from my note-book, April 3 ('95) and 

 Sept 3 ('95). By the first of July, when the vegetation of the foot- 

 hills becomes dry, and flowers cease to bloom, the Hummingbirds are 

 found in countless thousands at higher elevations (6000 to 8500 feet), 

 where summer is just dawning. 



