22 
INTRODUCTION. 
Dujon ; one of these suffered itself to be shot at, and, falling down, 
as if dead, was put into a little wheelbarrow, and conveyed away 
by one of its comrades. 
The docility of the Canary and Goldfinch is thus, by dint of se- 
vere education, put in fair competition with that of the Dog; and 
we cannot deny to the feathered creation a share of that kind of 
rational intelligence, exhibited by some of our sagacious quadrupeds, 
an incipient knowledge of cause and effect far removed from the 
unimprovable and unchangeable destinies of instinct. Nature, proba- 
bly, delights less in producing such animated machines than we are 
apt to suppose ; and amidst the mutability of circumstances by which 
almost every animated being is surrounded, there seems to be a 
frequent demand for that relieving invention, denied to those animals 
which are solely governed by inflexible instinct. 
The velocity with which birds are able to travel in their aerial 
element, has no parallel among terrestrial animals ; and this power- 
ful capacity for progressive motion, is bestowed in aid of their pe- 
culiar wants and instinctive habits. The swiftest horse may perhaps 
proceed a mile in something less than two minutes, but such exertion 
is unnatural, and quickly fatal. An Eagle, whose stretch of wing ex- 
ceeds seven feet, with ease and majesty, and without any extraordinary 
effort, rises out of sight in less than three minutes, and therefore 
must fly more than 3,500 yards in a minute, or at the rate of sixty 
miles in an hour. At this speed a bird would easily perform a 
journey of 600 miles in a day, since ten hours only would be required, 
which would allow frequent halts, and the whole of the night for 
repose. Swallows, and other migratory birds, might therefore pass 
from Northern Europe to the equator in seven or eight days. In 
fact, Adanson saw, on the coast of Senegal, swallows that had 
arrived there on the 9th of October, or eight or nine days after their 
departure from the colder continent. A Canary Falcon, sent to the 
Duke of Lerma, returned in sixteen hours from Andalusia to the 
island of Teneriffe, a distance of 750 miles. The Gulls of Bar- 
badoes, according to Sir Hans Sloane, make excursions in flocks 
to the distance of more than 200 miles after their food, and then 
return the same day to their rocky roosts. 
If we allow that any natural powers come in aid of the instinct 
to migration, so powerful and uniform in birds, besides their vast 
capacity for motion, it must be in the perfection and delicacy of their 
vision, of which we have such striking examples in the rapacious 
tribes. It is possible, that at times, they may be directed principally 
