140 CHADBOURNE, Spring Plumage of the Bobolink. Awa 
alone),—there would be between 115 and 57 additional cast-off 
Jeathers 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the progress of a complete ‘moult,’ are, I believe, unpublished, 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 found 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. daily 4 feather. 
‘« August 1 to Aug. 7 — ave. daily 5 feathers. 
‘“« Aug. 8 to Aug. 31 —ave. daily 94-feathers. 
«« September 1 to Sept. 30 — ave. daily 9 feathers. 
“October 1 to Oct. 28 —ave. daily 94 feathers. 
‘e ‘¢ 29 to Nov. 2— ave. daily 93 feathers. 
“November 3 to Nov. 30—ave. daily gog feathers, varying 
between 81 and 95. 
From December 1 to Dec. 7 —ave. daily 174 feathers. 
Ks ay 8 to Jan. 11 — 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 
found” 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 
1As 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. 
