VOL. ww] Birds of San Pedro Martir. 237 
I found a small flock of these swifts flying about over a pool of 
water in company with Petrochelidon and Tachycineta thalassina, 
Later they were seen in several localities as far south as Colnett 
and San Telmo; at this point they were quite common April 30, 
and evidently migrating in company with swallows. A single 
bird was seen at La Grulla May 18. 
Aéronautes melanoleucus. W¥HITE-THROATED SWIFT. Seen 
in several valleys between Tia Juana and the base of San Pedro 
but all evidently migrating. On top of the mountain they 
appeared about our camp by dozens and could easily have been 
taken in large numbers; they were mating and preparing to nest 
in the high cliffs on the eastern side of the mountain where I 
found them in 1889. A small colony was found nesting in the 
cliffs at San Ysidro in May, 1887. On the Coronado Islands, 
twenty miles from San Diego, a colony was discovered nesting in . 
a cliff overhanging the surf, not over thirty feet above the water, 
but as usual the nests were inaccessible. 
Calypte costae. Costa's Hummincsirp. Very abundant in 
all of the valleys along the coast and base of the mountain; not 
seen in the pines until about May 20; on May 28 they were 
building at 7500 feet. 
Calypte annae. ANNA’s HumMINGBIRD. A very common 
resident of the coast region; not seen until May 15 at La 
Grulla. As this species, as well as the preceding, nest in March, 
sometimes as early as February in the lower valleys, it is not at 
all improbable that the birds that we found in May on the mount- 
ain had raised a brood before migrating. 
- Tyrannus verticalis. ARKANSAS KINGBIRD. One was seen 
May 15 at La Grulla, the only one seen in the pines; very 
common in the coast valleys. 
 Myiarchus cinerascens. ASH-THROATED FLYCATCHER. A 
few were seen on San Pedro in 1889, and again the past season, 
but it was not at all abundant; in the lower valleys it is more 
common. A nest and set of four fresh eggs were taken from a 
- hollow on an elder in the Guadaloupe Valley, June 2. 
ss Sayornis saya. SAv’s PuaBr. Quite common along the 
ra sone of the mountain and in all of the coast valleys below 4000 
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