24 ON THE MIGRATION OF BIRDS. 
their haunts, both summer and winter, being known. 
That Redwings and Fieldfares migrate, those persons 
who are acquainted with their calls may be easily 
convinced, as the faint scream of the former and the 
chattering note of the latter may be heard frequently 
repeated through the nights of October and November 
as their numerous flights pass over head; and as that 
is the time at which these birds visit us, and as their 
calls cease to be heard at night soon after that period, 
they must then be on their passage from some other 
country to this, or to countries still further south. 
This circumstance also establishes the fact that some 
species of Periodical Birds perform their migrations in 
the night ; and it is probable that this is the case with 
most of them*, as I have frequently looked through 
the woods and plantations in Crumpsall with great 
care in April, the month in which most of the Summer 
Birds appear, without perceiving a single individual of 
any of the migratory tribes; yet early in the morning 
of the day following that on which the search was 
made, I have been surprised to hear the notes of the 
Redstart and Yellow Wren, and to find that the latter 
species had arrived in considerable numbers. From 
the undeniable fact that the males of several Migratory 
Summer Birds usually precede the females in spring, 
* M. Temminck, in treating upon the Quail, in the second 
edition of his ‘ Manuel d’Ornithologie,’ makes the following 
observation : ‘+ voyage le plus souvent au crépuscule ou pendant 
le clair de lune.” 
