22 ON THE MIGRATION OF BIRDS. 
manifestly absurd; therefore the Summer Birds must- 
migrate. 
Writers, in treating on the Periodical Birds, have 
confined their observations almost exclusively to the 
various species of Swallow, neglecting, in a great 
measure, the Short-winged Summer Birds, which 
seem to be the least qualified for migration, and the 
Periodical Winter Birds, which furnish some of the 
strongest arguments in support of it. 
If the Periodical Winter Birds do not leave this 
country in spring, they must stay with us the year 
through ; yet it is in the highest degree improbable 
that Woodcocks, Jack Snipes, Mountain Finches, and 
the numerous flocks of Redwings and Fieldfares which 
are seen in winter should remain here during the 
summer months and yet elude the observation of 
ornithologists. The Redwing is generally admitted 
to be a bird of song*; and as most of the Thrush 
tribe sing more or less, it is very probable that the 
Fieldfare is a singing bird also; yet we know nothing 
of their songs or summer notes, but are merely ac- 
quainted with their calls, which are heard in winter 
only ; and I believe there are very few well authenti- 
cated imstances of the nests of these birds having been 
found in England. 
According to Linnzus, Redwings and Fieldfares 
* Linneus says that “its lofty and varied notes rival those 
of the Nightingale.” See his ‘ Lachesis Lapponica,’ translated by 
J. E. Smith, M.D. &c., vol. i. p. 6. 
