310 U. S. NATIONAL MUSEUM BULLETIN 211 



edges of perpendicular banks. Ground nesting has also been reported 

 for California by Grinnell, Dixon, and Linsdale (1930), who also report 

 nesting in "a clump of sedge" and in "drowned brush-clumps out in 

 the water." Linsdale (1938) reports ground nesting in Nevada; 

 Cameron (1907) in Montana, and Schorger (1934) in Wisconsin. 



Among the writers who mentioned nest situations in willows 

 fringing a swamp or stream, in cottonwoods, and in various bushes 

 on river and creek banks are Dawson and Bowles (1909) for Washing- 

 ton and Cameron (1907) for Montana. 



Nesting in the broken tops of dead trees in the Lassen Peak region 

 of California is reported by Grinnell, Dixon, and Linsdale (1930). 

 Dawson and Bowles (1909) describe nests "in cavities near the tops 

 of some giant fir stubs none of them less than 150 feet from the 

 ground." But the "most favored nest sites" in California, according 

 to Grinnell and Miller (1944), "are in dense masses of foliage, espe- 

 cially of conifers." 



La Rivers (1944) found a large variety of trees and shrubs used for 

 nesting in Nevada; sagebrush (Artemisia), the most prevalent shrub, 

 was most often used. 



Although usually nesting in groups, the Brewer's blackbird does 

 not nest in such dense colonies as some other icterids, notably the 

 tricolored redwing (Agelaius tricolor). This may be due to wider 

 tolerance in habitat requirements, causing less concentration. Some 

 observers report the nesting pairs as "somewhat scattered" and other 

 pairs nesting "singly." Bailey (1902) writes that "it nests in much 

 smaller colonies than many of the blackbirds, five to ten pairs being 

 the common number." 



In California R. M. Bond (MS.) found a colony "in a row of small 

 Eucalyptus Jicifolia near Carpenteria, three adjacent trees contained 

 21 nests (spring of 1935) with none in the remaining half mile or so 

 of row. There were five or six nests in a yard tree (Acacia melan- 

 oxylon) about 30 feet from the nests in the eucalyptus * * *. The 

 next nearest nesting colony was about a mile away in a windbreak of 

 Monterey cypress." 



Linsdale (1938) writing of the Toyabe region of central Nevada 

 says that Brewer's blackbirds were found "in small colonies" and 

 that the colonies varied in size from 3 or 4 to about 20 pairs. Within 

 each colony "pairs tended to select similar nest sites." Ridgway 

 (1877) found a large colony in a group of pinion pines at the south 

 end of Pyramid Lake, Nev., on June 3, 1867. There were more than 

 100 nests, nearly every tree containing at least one. Several trees 

 had two or three nests. Each nest was on a horizontal limb, usually 

 near the top of the tree, well concealed in a tuft of foliage, and the 

 majority of nests contained young. 



