296 



Bird- Lore 



more familiar with nesting possibilities 

 in the region, and also that these possi- 

 bilities are bettering as time goes on. At 

 the present writing (August 15), there are 

 still a good many young Wood Pewees 

 hereabouts, but most of the Orioles have 



left. 



The last spring - migrating Virginia 

 Warbler was seen in this neighborhood on 

 May 15; this species nests in the foothills 

 only fifteen miles west of Denver. The 

 first returning (?) Virginia Warbler was 

 seen in one of our parks on July 27, after 

 which date some were noticed every day 

 until July 30, none being seen thereafter. 

 These dates give one some idea of the 

 speed of the 'housekeeping' of this 

 particular species; from May 15 to July 

 27, to travel to the foothills or farther, 

 select mates, find a nesting-place, build a 

 nest, lay and hatch a set of eggs, and bring 

 a brood to maturity! A rather large 

 contract for such a mite; what it lacks in 

 size, it makes up, however, in energy and 

 efficiency! The presence of a young Sage 

 Thrasher in Denver on July 24 raises the 

 question if this individual could have been 

 reared within this region; it is possible, 

 though the writer is not acquainted with 

 any Denver breeding records of the species. 



He suspects that some Plumbeous 

 Vireos bred in Denver this summer because 

 many have been seen here all this time, 

 though no nests have been discovered. 

 The scarcity of Nighthawks noted this 

 spring has persisted during this season 

 just passed.— W. II. BERGTOLD, Denver, 

 Colo. 



San Francisco Region. — Some changes 

 in the population of breeding birds in the 

 Bay Region have taken place during 

 recent years and have been further con- 

 firmed by records made during the present 

 season. These changes may be due to the 

 increase in forcstation in the immediate 



locality, to the greater expanse of lawns 

 under 1 ultivation, or to overpopulation in 

 contiguous regions. The species notice- 

 ably affected arc the Coasl Jay, J.unco, 

 Creeper and Western Robin. 



From being a very rare bird in tin- 



canons of the Berkeley Hills in 1910, the 

 Coast Jay has become a localized species 

 in areas providing an environment similar 

 to that of its typical home in the humid 

 coast belt. More numerous in winter than 

 in summer, it is, nevertheless, an increas- 

 ingly common summer resident in the 

 East Bay region. 



Juncos are present in large flocks in the 

 entire section during the winter season, 

 and for several years there have been 

 straggling reports of breeding birds and 

 nests in various localities. This season they 

 were quite noticeable as summer residents, 

 particularly in localities where the Mon- 

 terey pines and cypresses are numerous. 

 Creepers, though less conspicuous than 

 the Juncos and probably less numerous, 

 except in the redwood region, are almost 

 certainly nesting in the East Bay region 

 in localities similar to those chosen by the 

 Juncos. The species of both Creepers and 

 Juncos in the territories recently adopted 

 by them have not yet been determined. 



The Western Robin was first reported as 

 nesting in Golden Gate Park in 1916, and 

 each year since that date occasional nests 

 have been found on the San Francisco 

 Peninsula. The next year (191 7) a nest 

 was found at the Claremont Country Club 

 on the east side of the bay. This year a 

 number of interested observers in Berkeley 

 have reported Robins in song, and one nest 

 has been located near the Greek Theatre on 

 the University Campus. 



These four species have moved into 

 the Bay region and henceforth must be 

 reckoned among the breeding birds. 

 Whether the Crossbills, reported from 

 Redwood Peak, will win the same recogni- 

 tion will depend on the records of future 

 years. 



The 'old-time' summer residents have 

 been present in ordinary abundance. 

 Two nests of the olive sided Flycatcher 

 have been found tins summer — tangible 

 proof that it is rightfully included among 



the breeding bird-- of the region. 



At present (August 10) many of the 

 land birds are moulting and no reports of 



migration have been received. Hut among 



the water-birds the advam c wave of 



