PRAIRIE MARSH WREN 249 



live and build their nests. The rush-like plants in which they breed 

 are chiefly as follows, belonging to several widely separated families : 

 great bulrush {Scirjms lacustris), horse-tail {Equisetum limonsuin), 

 sweet flag {Acorus calamus)^ blue joint-grass {CalaTriagrostis cana- 

 densis)^ reed canary-grass {Phalaris arundinacea) y 



Spring. — Very little seems to be known about the migrations of 

 the marsh wrens. Elon H. Eaton (1914) says: "Evidently they 

 migrate at night, and high in the air, so as to see their way and escape 

 their enemies more successfully." They arrive in central New York 

 from May 4 to 16. 



Dr. Wilfred A. Welter (1935) has given us such a fine life history 

 of the prairie marsh wren, based on extensive observations at Ithaca, 

 N. Y., and at Staples, Minn., that I cannot do better than to quote 

 from the results of his work. At both places he found that the average 

 date for the arrival of the males was May 10 and that the females 

 came between May 20 and 28. Males begin to select and defend their 

 breeding territories soon after their arrival. He says: 



The preferred habitat is not, as one might suppose, a dense tangled mass of 

 dried and broken cat-tails, remnants of the preceding season, but a compara- 

 tively open area with a few tattered stalks and an abundance of some species of 

 Carex. 



* * * Fighting over territorial rights between males is, to a large extent, 

 a matter of outblufling the opponent. A male approaching too closely to the 

 boundary of another's area is challenged by the song of the rightful owner. 

 This is usually sufficient for the intruder, but sometimes the challenge is accepted 

 by the visitor giving voice to his emotions and continuing to transgress upon 

 the area in question. The first male in this case fluffs out his feathers to impress 

 the other and, if necessary, fiies at his opponent. The usurper usually recipro- 

 cates by flying at his neighbor a time or two and then, at least in all instances 

 observed, becomes the vanquished and departs from the scene of battle. 



* * * In an area 400 by 650 feet in the Renwick Marsh at the head of Lake 

 Cayuga eight males took up residence in the spring of 1931. * * ♦ The cat- 

 tail-sedge association was greatly preferred to the grass association by the 

 male birds in selecting territories. * * * TypJia angustifolia is much pre- 

 ferred to T. latifolia as a nesting site. * * * The male territories in the 

 favored area were noticeably smaller than in the grassy area. A single monog- 

 amous male occupied a territory of from 13,000 to 15,000 square feet, while 

 in the grass association this was extended to approximately 30,000 square feet. 

 The territory of a polygamous male, on the other hand, was considerably larger 

 than that of a monogamous male nesting in the same sort of vegetation. * ♦ * 

 This difference in size can readily be accounted for by the fact that the female 

 birds do not tolerate each other during the nesting season. As a result those 

 males inteut upon leading dual lives must separate the objects of their atfection 

 as widely as possible. 



Courtship. — The courtship of the marsh wren is expressed in song 

 and in display. According to Dr. Welter (1935) , "song does not seem 

 to be as important in attracting the female as display. Of course the 

 song originally attracts the prospective mate into the territory and then 

 display becomes first in importance. When the females begin to arrive 



