VOICES OF BIRDS. 
303 
^ion, depression, or modulation, conveys intelligence 
pdvalent to an uttered sentence. The voices of birds 
applicable, in most instances, to the immediate 
necessities of their condition ; such as the sexual call, 
p invitation to unite when dispersed, the moan of 
a u Ser, the shriek of alarm, the notice of food. But 
. 6 re are other notes, the designs and motives of which 
7* not so obvious. One sex only is gifted with the 
,!' v ’er of singing, for the purpose, as Button supposed, 
f cheering his mate during the period of incubation ; 
p this idea, gallant as it is, has such slight foundation 
'1, Probability, that it needs no confutation; and after 
p perhaps, we must conclude, that, listened to, admired, 
M pleasing, as the voices of many birds are, either 
' J ’’ their intrinsic melody, or from association, we are 
/"certain what they express, or the object of their 
The singing of most birds seems entirely a 
Jt'ditaneous effusion, produced by no exertion, or 
passioning no lassitude in muscle, or relaxation of 
S parts of action. In certain seasons and weather, 
J* nightingale sings all day, and most part of the 
pht ; and” we never observe that the powers of 
are weaker, or that the notes become harsh and 
pUnable, after all these hours of practice. The song 
wash, in a mild moist April, will commence his tune 
in the morning, pipe unceasingly through the 
!p> yet, at the close of eve, when he retires to rest, 
■"ere is no obvious decay of '..is musical powers, or any 
psible effort required to continue his harmony to 
P last. Birds of one species sing in general very 
pe each other, with different degrees of execu- 
J? 1 *. Some countries may produce tiuer songsters, hut 
Iphout great variation in the notes. In the thrush, 
/""'ever, it is remarkable, that there seems to be no 
"Sttlar notes, cacli individual piping a voluntary of his 
‘"’n. Their voices may always be distinguished amid 
«l r * ' f - 
choristers of the copse ; yet some ouo performer 
""U more particularly engage attention by a peculiar 
emulation, or tune; and should several stations of 
birds be visited in the same morning, few or none 
