SMELL. 249 
their opinions doubtful. Wilson, for example, 
speaking of the turkey-vulture (Cathartes aura, I1- 
LicER), Says, “ These birds, unless when rising from 
the earth, seldom flap their wings, but sweep along 
in ogees, and dipping and rising lines, and move with 
great rapidity. They are often seen in companies, 
soaring at an immense height, particularly previous 
to a thunder-storm. Their wings are not spread 
horizontally, but form a slight angle with the body 
upward, the tips having an upward curve. Their 
sense of smelling is astonishingly exquisite, and 
they never fail to discover carrion, even when at 
the distance from it of several miles.”* Their 
soaring in the air, whether during a thunder-storm 
or at any other time, must evidently be not for the 
purpose of smelling out, but for discovering by the 
eye some piece of carrion. The Abbé Clavigero’s 
account of the black vulture (Catharte urubu, Virw- 
LoT) is precisely similar. “ They fly so high,” he 
says, ‘that although they are pretty large, they are 
lost to the sight; and especially before a hailstorm, 
they will be seen wheeling in vast numbers under — 
the loftiest clouds, till they entirely disappear. 
They feed upon carrion, which they discover by the 
acuteness of their sight and smell, from the great- 
est height, and descend upon it with a majestic flight 
in a great spiral course.” 
The raven is another of those birds which have 
been celebrated for discovering distant objects by 
the smell, which Bingley thinks “ must be very 
acute ; for in the coldest winter days, at Hudson’s 
Bay, when every kind of effluvia is almost instanta- 
neously destroyed by the frost, buffaloes and other 
beasts have been killed where not one of these birds 
was to be seen, but in a few hours scores of them 
have been found collected about the spot, to pick up 
the blood and offal.”{ Mr. Knapp is also disposed 
* Amer. Ornith., ix., 98, first edit. + Hist. Mexico. 
{ Animal Biography, ii., 242. 
