EASTERN REDWING 127 



checks her flight and is soon again at her station near the male. Such maneuvers 

 announced the arrival of the resident females. 



About the first week in May, after most of the adult resident birds 

 have begun to nest, the resident immature males begin to appear in 

 numbers. From the second week in May until the last of the month, 

 these flocks continue to arrive The resident immature females begin 

 to appear with the immature males about the middle of the month. 

 They increase in numbers until the first of June, when they far out- 

 number the males, and by the second week, when the last migrating 

 birds are recorded, they compose the entire flocks. Says Allen (1914), 

 "It is doubtless through some of these birds, at a time when unattached 

 males are difficult to find, that many of the cases of polygamy arise." 



Probably the movements of the different classes of migrants are 

 not always as clearly defined as indicated by Allen. Fred M. Packard 

 (1937), while banding redwings at the Austin Ornithological Research 

 Station, at North Eastham, Mass., found "unsuspected variation in 

 the behavior of the migrating birds on Cape Cod. Some were appar- 

 ently true migrants; they were caught but once, and did not repeat. 

 Others lingered for a few days or even a month, repeating during that 

 period, and then left; these also were migrants. A third group stayed 

 in the vicinity from the time of their arrival through the nesting 

 period, as true residents. A large fourth group was composed of 

 individuals that were trapped once or twice on arrival, and then 

 disappeared, exactly like migrants; but these returned after an interval 

 varying from 2 months to 2 weeks, some to nest nearby, others to 

 disappear again." Cape Cod is a long, narrow, curving peninsula 

 pointing northward at its terminus and facing a broad expanse of 

 water. Perhaps the returning birds of the fourth group preferred to 

 turn back, rather than risk the long flight over the water. 



Territory. — As indicated above and as noted by all observers, the 

 resident adult male, on his arrival on the breeding grounds or soon after 

 that, "stakes out his claim" to the territory that he has decided to estab- 

 lish and to defend. This claim may be large or small, depending on the 

 size of the marsh and the density of its population ; in a large marsh with 

 few redwings nesting in it, the territories may be extensive and well 

 outlined; but in a dense colony, the claims are close together and the 

 boundaries are not so well marked. The male stands his ground and 

 defends his territory against intruding male redwings and other 

 trespassing birds; he even drives away female redwings until he is 

 ready to mate. 



Ernst Mayr (1941) writes as follows on territorial behavior: 

 "Early in the season, when the weather was still cold and the males had 

 just recently established themselves in their territories, they spend a 

 good deal of their time sitting on thb top of small bushes or old cat-tail 



