The Tricolored Redwing 



the highly varied results secured. Often the pigment is shadowed, or 

 "washed," along its edges, revealing thus its brown character. Not 

 infrequently a tinge of the pigment is suffused throughout the shell, and 

 we get such basic tints as glaucous, yellowish glaucous, "tilleul buff," 

 and even deep olive-buff. Again, and more rarely, the pigment is spread 

 about superficially, in whole or in part, paling thus to vinaceous buff, or 

 fawn-color. In two instances in the M. C. O. collections the color appears 

 as a uniform vinaceous clouding on a warm buff ground; and in one of 

 these the freckling is so minute and so uniform as to render the egg almost 

 indistinguishable from that of a Yellow-headed Blackbird. 



While I have not been able to detect any constant or divisive element 

 in local variations, i.e., no tendency to the formation of races; it is very 

 instructive to note the power of the localized or neighborhood sentiment 

 in the determination of the nesting dates. Thus, in a small colony, say 

 one of 2000 pairs, every nest will be at approximately the same stage of 

 construction on a given date. On a given day, four-fifths of the nests 

 will contain one, and only one, egg, etc. On the other hand, a large 

 colony, say one of 40,000 birds, will be divided up into a dozen separate 

 clans, or behavior groups. In one section of the swamp the investigator 

 will find only fresh-laid foundations; in another, nests with one egg each; 

 in another, perchance, full sets well advanced in incubation. I can only 

 account for this on the supposition that the nesting colony grows by 

 accretion. Day after day new groups from the outside join themselves 

 to the nesting, and immediately set to work on the occupation of some 

 closely contiguous section of reeds. The nesting is, thus, a sort of con- 

 tinuous Chatauqua, with fresh delegations arriving daily and being 

 assigned to reserved sections. 



This supposition receives striking confirmation from an experience 

 recorded by Mr. John G. Tyler, of Fresno 1 . At a point some thirty 

 miles southwest of the city, Mr. Tyler found a colony of Tricolors 

 occupying a dense but restricted patch of nettles. The center of the 

 patch, where the cover was densest and presumably most desirable, the 

 nests held young birds. Surrounding this choicest area was one in which 

 the nests held incubated eggs. And so, moving progressively outwards, 

 the cover dwindled and the eggs freshened, until the last comers were 

 actually building their nests upon the ground without protection of any 

 sort — gallery seats and standing room only. 



It goes almost without saying that the farmers are not enthusiastic 

 about this Summer Assembly of Blackbirds. It takes a very considerable 

 ration to supply the wants of so many picnickers. Either because the 

 morning hours are filled with labor, or because the grain is more easily 



'"The Condor." Vol. IX.. Nov. 1907. pp. 177-17S. 



"3 



