56 The Wilson Bulletin — No. 87 



of this depth around the part of the swamp studied. This 

 lay quite close to the south and east shores and was, as far 

 as our investigations exteiided, the deepest part. A belt of 

 water of this depth about one hundred yards Made lay in a 

 half moon shape along these shores while the center was much 

 shallower, being in many places not over eighteen inches deep. 



The period of nidification was represented in the colony in 

 nearly all of its stages from nests in which the clutch was 

 not yet completed to almost fully grown fledglings. The 

 cries of the young could be heard on all sides but it w^as 

 difficult to distinguish one from his surroundings after he 

 was in the weeds. One of the surprises of the study was 

 that of learning the extremely early age at which the young 

 left the nest. In the first ])rood studied, the young left 

 before the end of the first day's observations. At the time 

 they were in the pin feather stage of development and very 

 few of tlie feathers had even begun to show beyond the 

 sheath. That these nestlings did not leave any earlier on 

 account of the blind was proved by the finding of a number 

 of others in the same stage sitting on the broken down reeds 

 scattered through the swamp. It seemed to us at first as if 

 the obscurity of the reeds was much safer for the young than 

 the nests, which were at times rather conspicuous, but later 

 developments served to shake our faith in this explanation. 



On the morning of June 29 at 4 :00 A. ]\I. the blind, erected 

 between the Blackbird and Bittern nests, was entered by Mr. 

 Howard Graham and the writer. Watch was kept on both 

 nests and we soon had proof that the parents had not 

 deserted them. The female Yellow-head fed one of the nest- 

 lings at 4:35, or about thirty minutes after the blind was 

 entered. Constant observations were carried on until 4:30 

 P. M., at which time the wind blew the reeds about so violently 

 that it was impossible to see either nest more than a fraction 

 of the time. The action of the wind also made it difficult to 

 see out of the opening in the blind at all times, so the work 

 was closed for the day. This nest will be called nest A. 



July 3 the blind was placed in position at another YelloAV- 

 head's nest containing three young. The work was begun at 



