1532 U.S. NATIONAL MUSEUM BULLETIN 23 7 part 3 



resemble closely merrilli, one of the races with which it intergrades. 

 Many individuals winter throughout the breeding range, but others 

 migrate, occasionally as far as northern Sonora. 



Breeding altitudes in California range between 300 and 8,000 feet 

 above sea level. But everywhere "riparian vegetation, marshes, and 

 lake borders" are sought out, for "the combination of dense low 

 cover and surface water with wet ground is essential for this race" 

 (Grinnell and Miller, 1944). Philip C Dumas (1950) has documented 

 the foregoing statement about the habitat in a series of detailed 

 density indices for this and other birds in the various environments 

 of southeastern Washington. 



Moisture-loving plants such as willows and cattails are the most 

 usual nest sites, which in California "commonly are above ground in 

 the branch-work of bushes" (Grinnell and Miller, 1944). Near Pull- 

 man, Wash. (Jewett et al., 1953), nests are often placed between 8 

 and 12 inches high in willows. Plants of dry associations, e.g., small 

 conifers and shrubs, are also sometimes used for nests, which have 

 been found as high as at least 7 feet (Mailliard, 1919b). Ground 

 nests are also found. Nests are described as loosely woven of weeds 

 and grasses. L. R. Dice (1918) once found a structure in which 

 some of the material had been picked green. W. L. Dawson (1923) 

 reports a most unusual nest in Modoc Coimty, California; it had been 

 built into the side of a large paper wasp nest hanging 5 feet up in a 

 willow, and scraps of newspaper were among the materials used in the 

 construction of the outer surface. In Washington full sets of fresh 

 eggs have been found as early as March 30, and L. R. Dice (1918) 

 found well feathered young in a late nest on July 13. 



Feeding "occurs on the moist ground or at the water's edge, or on 

 plants over the water or floating in it," state Grinnell and Miller 

 (1944); and Jewett et al. (1953) describe some birds as "almost 

 semiaquatic" in their foraging on the floating green leaves of water 

 plants. H. C. Bryant (1911) found only insects in one stomach he 

 examined. 



Grinnell and Miller state: "In winter, restriction to riparian growth 

 is less rigid, but seldom are the birds found far from moist situations 

 and the associated plant species." 



H. C. Oberholser (1911) described Jlsherella as being similar to 

 heermanni, "but larger; upper surface paler, less rufescent; streaks on 

 lower parts less blackish (more brownish)." M.m. Jisherella differs 

 from montana "in its darker upper parts, more blackish brown streaks 

 of under surface, heavier bill, and shorter wing." 



