Mar., 1917 LIST OF BIRDS BREEDING IN SAN FRANCISCO COUNTY 57 



larger waterfowl, which have non-breeding individuals remaining with us 

 throughout the year. Loons are to be seen at Lake Merced throughout the en- 

 tire summer; and scoters are apt to appear at any time of year on the ocean 

 just off-shore. 



These are non-breeding birds, but we do not believe that this habit of re- 

 maining for a season in their winter homes is to be found among the smaller 

 birds. Neither would this rule apply to certain birds which evidently make 

 San Francisco a feeding ground while nesting elsewhere. 



The Great Blue Heron, Black-crowned Night Heron and the Anthony 

 Green Heron all come frequently into the Lake Merced region and less fre- 

 quently to the Islais Marshes, but their nesting places are probably in San 

 Mateo County or possibly in Alameda County. The American Bittern is a 

 not-infrequent visitor to Lake Merced, but no man seems to be able to name its 

 nesting place. Vultures and crows come over occasionally from Marin County, 

 and it is a common experience on a summer evening to hear the hoarse croak 

 of ravens overhead and to see these birds winging their way southward down 



Pig. 21. TtTLE-FRINGED SHORES OF LAKE MERCED, SAX FrAXCISCO COUNTY. 



the coast. Gulls of several species are present through the summer, and in mid- 

 summer the great run of the Dark-bodied Shearwaters is at its height just off- 

 shore, and sometimes they pursue their finny prey into the bay. 



There are a few other birds the nesting of which within the county, while 

 it cannot be affirmed, is not yet wholly beyond the limits of possibility. The 

 Western Bluebird has been known to nest in the Mission District and may yet 

 be found again nesting in the county. Eared Grebes are seen throughout the 

 year on Lake Merced and it would not be surprising if they should sometime 

 be found to nest there. Some kind of small owl has been shot occasionally by 

 the park game wardens near the Prayer Book Cross. It is possible that they 

 were Coast Screech Owls and that they nest somewhere in the county. The 

 Dusky Horned Owl has been reported several times recently from Sutro Forest. 



We are indebted to Jesse Klapp, game warden in Golden Gate Park, for 

 valuable assistance in our field work in the park. We have also gleaned a 

 number of nesting records from Milton S. Ray's paper on the "Summer Birds 

 of San Francisco County, California" (Condor xvm, 1916, p. 222). However, 



