I 40 CiiADBOURNE, Sfviiig Plumage of the Bobolink. LApril 



alone), — there would be hetiveen 11^ and ^y additional cast-off 

 feathers in or near the cage each day. It is hardly supposable that 

 anyone at all interested in the question of a spring ' moult ' could 

 fail to detect its presence with such evidence daily before him 

 during at least three weeks. 



In the living bird, accurate data of the loss before and during 

 the progress of a complete 'moult,' are, I believe, unpublished, 

 for any of our native species certainly none are known to me for 

 the Bobolink; and as my bird did not 'moult,' it is impossible 

 to supply the deficiency. But the record of a pair of tame 

 Screech Owls {^Megascops asio)., shows well how sudden may be 

 the onset, and how great the loss during the period of a complete 

 feather-change; and it will also be noticed, that in this, — the 

 only species of which we have exact data, — the total number 

 of loose feathers yt'z/;?^^/ while the change was most active, exceeds 

 our theoretical estimate based on the skin of the Bobolink. 



AVERAGE NUMBER OF FEATHERS FOUND PER OWL.' 



From July 24 to July 31 — ave. dailj- h. feather. 



" August I to Aug. 7 — ave. daily 5 feathers. 



" Aug. 8 to Aug. 31 — ave. daily 9^ feathers. 



" September i to Sept. 30 — ave. daily 9 feathers. 



" October 1 to Oct. 38 — ave. daily 9^ feathers. 



" " 29 to Nov. 2 — ave. daily g^ feathers. 



" November 3 to Nov. 30 — ave. daily 90^ feathers, varying 

 between 81 and 95. 

 From December i to Dec. 7 — ave. daily 17^ feathers. 



" " 8 to Jan. 1 1 — ave. daily 4 feathers. 



During the time that 'moulting' was most active, — namely 

 from Oct. 29 to Nov. 30, — a total of 2806 feathers were actually 

 foimd'^ for each of the two Owls ; yet their cage was much of the 

 time out of doors and exposed to the wind, while being made of 



' As there were two Owls, the numbers given are one half the feathers 

 actually found in the cage. 



* It may be well to state here that almost without exception the cast-off 

 feathers were practically without any brown or tawny shades, though the bird 

 was in well marked intermediate plumage ; while the feathers in which there 

 was considerable brownish, usually showed some mechanical injury, on careful 

 examination. 



