208 BULLETIN OF WISCONSIN NATURAL HISTORY SOCIETY. VOL. 2. NO. 4. 
Dr. Brewster at Point Lepreaux Light-house in 1881 (51). No 
set of data or description can convey so good an idea of the actual 
state of affairs as the observation of the phenomena themselves 
through the telescope. With regard to nocturnal migrants the 
following general conclusions are apparent : ( i ) that they per- 
form their journeys both singly and in compact flocks, the dif- 
ferent individuals and groups being more or less united into strag- 
gling bands or streams ; ( 2 ) that single individuals and groups 
fly independent of one another, but to some extent may be de- 
pendent upon the general movement of the stream; and (3), that 
there is a great diversity of species and individuals associated to- 
gether in migration. 
The data for any one evening that has seemed favorable for 
migrating birds will establish these general statements. (See data 
in appendix.) The continuous stream-like movement over some 
routes has already been referred to and it will only be necessary 
to call attention here to the extent of these bird-streams, and to the 
fact that they are composed both of single individuals and flocks. 
Throughout the observations when the number of birds was not 
exceptionally large, from two or three to about fifteen for a period, 
it was very noticeable that the majority of birds were not col- 
lected into compact flocks. Although it was not uncommon to 
have several appear in fairly rapid succession, it was more often 
the rule to see them following one another in a straggling man- 
ner ; impressing the observer with the idea of a regular straggling 
stream, such as one might see anywhere near a school just after 
the hour of dismissal. 
From the entire set of observations collected with the teles- 
cope, the immense numbers of birds recorded when the field of 
vision extended along a highway, and the apparent regularity with 
which the birds passed — in some instances for several hours at a 
time, — it is quite evident that along the main highways and the 
more important tributaries birds fly in such numbers that for miles 
we have one long, almost continuous stream of birds. When we 
consider that from fifty to eighty birds were recorded on the Rock 
River in fifteen minutes, that the average number remained high 
for more than an hour, and that these birds must have departed 
from a similar stream of even greater magnitude along the Mis- 
sissippi River, the nocturnal movem.ent becomes not merely in- 
teresting but marvelous. 
51. Brewster. Mem. Nutt. Ornith. Club. Xo. 1, 1885. 
