576 BULLETEST 20 3, UNITED STATES NATIONAL MUSEUM 



in southern California from late September to mid-March. Common through- 

 out year on breeding grounds. 



Geographic range — In breeding season vicinity of San Francisco Bay, Marin 

 County, and Napa sloughs, southern Sonoma County, on the north, east to 

 Carquinez Strait, and south to vicinity of San Jose, Santa Clara County. In 

 winter, coastal marshes from San Francisco Bay region south to San Diego; 

 also, twice recorded north to Humbolt Bay. Life-zones, Upper Sonoran and 

 Transition ; localities of nesting all below 1,000 feet elevation. • * * 



HaMtat — In summer, fresh and salt water marshes, but chiefly the former. 

 More commonly found near salt and brackish water in fall and winter. Requires 

 plant cover similar to that frequented by the race Oeothlypis trichas occidentalis 

 [the western yellow-throat]. * * * Tall grasses, tule patches and willow 

 thickets provide normal plant environment for nesting activity. 



Milton S. Ray (1916) found three nests of the salt-marsh yellow- 

 throat in the Lake Merced region of San Francisco County on April 22, 

 1911. Two of the nests had four eggs each in advanced stages of incu- 

 bation and one contained three fresh eggs. All three nests were about 

 two feet up in wiregrass and were made of coarse flat weed stems lined 

 with fine light-colored grasses, loosely put together. Mr. Ray states 

 this yellowthroat does not inhabit the salt marshes exclusively but 

 is much more abundant along fresh-water lakes and streams and in 

 wet meadow land. However, one nest with 4 eggs was found in a 

 salt marsh north of San Rafael on April 12, 1914. This nest was on 

 high ground not subject to overflow. An excellent account of the nest- 

 ing habits of the salt-marsh yellowthroat in the Lake Merced region 

 has been written by G. W. Schussler (1918) , as follows : 



The nesting period ranges from middle April until .Tune, fresh eggs having 

 been taken on April 2 and June 18. The yellowthroats, habitually suspicious, 

 become doubly vigilant during the breeding season and I think only twice in 

 all the years I have studied them have I surprised the female in the act of 

 carrying nesting material. It has been my experience that if any unfinished 

 structure not containing eggs is located, the birds promptly abandon it. The 

 nest, a cup-shaped, fairly compact receptacle is usually composed of lengths 

 of dried grass well interwoven with the supporting stems. It is commonly 

 hidden in bunches of wire grass or weeds among willows and placed from six 

 to twenty-four inches above the ground. The bowl-like interior is often lined 

 in rather a loose manner with dried grass or thin fiber. The usual complement 

 is four though a set of three, particularly when laid late in the season, is not 

 rare. The eggs are taperingly oval in shape, white, with a decided pink tinge 

 when fresh, and circularly splotched about the larger end with dots and dashes 

 of black, brown, and deep lavender, varying in size from minute markings 

 on some specimens to a pronounced ring of color on others. Incubation, which 

 is performed by the female, usually occupies about fourteen days. 



While incubating, the females show remarkable shyness in slipping off the 

 nest and keeping well ahead of the observer, with short undulating flight. Oc- 

 casionally as evening approaches they are apt to flush from directly beneath one's 

 feet, particularly should he beat quietly up toward them against the wind. 

 When startled from her nest the female disappears and maintains silence for 

 some moments but if the intruder remains in the vicinity, or removes the nest 

 or eggs, her sharp chack of alarm will rapidly summon the male and the pair 



