TRICOLORED REDWING 189 



bird might result in a serious reduction in its numbers, or even practi- 

 cal extermination of the species. Describing this campaign and its 

 results, Thomas T. McCabe (1932) wrote at that time: 



I do not care to record in detail the minutiae of the technique employed, further 

 than to say that grain poisoned with strychnine was placed on a small area of 

 clean plow-ground close to the swamp, following several baitings with clean 

 grain, which had attracted the birds and accustomed them to feeding on the spot. 

 When the poison was finally placed, the effect was appalling. Great numbers died 

 at once on the poison-ground, where within a very small radius 1,700 dead birds 

 were tossed into a central pile. Later the surface of the shallow water beneath 

 the willows became an almost solid floor of floating bodies where the observers 

 hesitated to enter because of the stench which hung in the quiet air. Weeks 

 later the bases of the cattails were awash with countless dead. At the time of 

 our visit, May 21, the remainder of the grain was still doing its work, for fresh 

 as well as decayed birds were still in evidence, often hanging, caught by the 

 branches or clinging with the death grip of one foot, from the trees and from the 

 nefts in the rushes. 



The destruction of adult birds, however, was much the smaller fraotion of the 

 total effect. As is often the case in large Tri-color rookeries, the nests were 

 roughly divisible into groups. Only in two extremely small areas in the rushes 

 had the eggs not hatched. Elsewhere the vast majority contained either new- 

 hatched young or fledglings nearly ready to leave the nest. The enormous 

 number of nests in the willows (a single tree contained 34) were not closely investi- 

 gated. In the rushes, one might have spent a day forcing his way through the 

 tall dense greenery, with from two to five or six nests continually within reach, 

 yet leave untouched larger areas where no locomotion but swimming was possible. 

 Yet judging from the small fractions I had time to cover he could hardly have 

 found a dozen nests in which the young were alive and vigorous. Of the hundreds 

 of broods I saw, all, practically speaking, were either dead (the vast majority) or 

 feebly alive in some stage of starvation or grilling and parching by sunburn. A 

 few evidently healthy adults were still passing in and out of the swamp, but the 

 usual noisy cloud of enraged parents no longer hung over the invader's head. 



After making several very careful surveys and counts, a total of 30,000 

 birds destroyed seemed to him "very conservative." 



Winter. — The tricolored redwing is practically resident the year 

 round in most of its breeding range. It has no regular north and 

 south migration. After the breeding season and the molting period 

 is over, the birds leave their breeding grounds and wander about the 

 open country in search of good feeding places in the grain and stubble 

 fields and about the ranches; they travel mostly in large flocks of 

 their own species, but a few may mingle in the mixed flocks of other 

 blackbirds. 



DISTRIBUTION 



Breeding range. — The tricolored redwing breeds east of the coast 

 ranges from southwestern Oregon (Agency Lake, Klamath Falls) 

 south through California, west of the Sierra Nevada (Modoc Plateau, 

 Great Valley, Walker Basin, San Bernardino, and along the coast 



