98 



be adapted to the type of nest to which the Redwings strictly 

 adhere. Thus, the outer basket may be composed entirely of 

 fibers of milkweed, or of grasses, or of strips of sedge. The 

 sedge, however, to be as flexible as the fiber and as adaptable 

 to the necessary weaving, must be wet. Hence, when such 

 material is used, it is always taken from the water and used 

 in a moist condition. The ''felting" of the nest may be dead 

 wood, decaying fragments of Typha, or mud. The exact kind 

 of material is not as important as its general nature. 



The time required for building a complete nest is usually 

 six days. Of this time, three days are spent on the outer 

 basket and ''felting," and three days on the lining. Many of 

 the later, more poorly built nests require much less time for 

 construction, some of them being completed in as few as three 

 days. The materials, as might be judged from their nature, 

 are frequently gathered from very different parts of the marsh; 

 the outer and lining layers generally come from the margins, 

 and the "felting" from the open marsh in the immediate 

 vicinity of the nest. 



The attachment for the chosen nesting site, which is shown 

 from the first arrival of the male bird, and which causes a pair 

 to nest time and again about the same spot when the nests are 

 destroyed, is equaled only by their sensitiveness to the dis- 

 covery of the nest before its completion. If a nest is discovered 

 before the deposition of the first egg, it is usually deserted. 

 Practically every nest constructed before the second week in 

 May, and discovered before its completion, has been deserted. 

 Generally the birds build a second nest a short distance away, 

 employing more or less .the materials from the first nest. 

 Very frequently the cause for desertion has been no more than 

 a person's walking past the nest at a short distance, and the 

 bending of a flag to mark the spot. Later in the season, espe- 

 cially in the case of the immature birds, this sensitiveness is 

 not so marked. 



The construction of the nest, in all cases observed at 

 Ithaca, has been entirely by the female. The male has never 

 been seen with nesting material in his bill. He is very atten- 

 tive, however, during the process. This usually takes place 



