356 Observations on the 
tiles and insects, it is curious to see birds belonging to other orders, 
likewise become carnivorous. Domestic birds are, for the most part, 
fed with flesh, of which hens and ducks are extremely fond, and it 
is not merely wild birds which leave grains and insects, their ordi- 
nary food, to feed on the flesh which the inhabitants hang out to 
dry in the sun. We have seen the finches, Icteri, and flycatchers 
search for this kind of food with a voracity and eagerness which are 
not natural to them in a wild state, and which can only be attribut- 
ed to the extreme facility with which they procure it. 
The partial comparisons which we have been able to make either 
of genera or species, show that in the old and new world birds 
of prey lay a similar number of eggs, and follow the same ge- 
neral mode of constructing their nests, and we do not hesitate to af- 
firm that the markings of the eggs are of the same form, and are ge- 
nerally distributed in the same manner. 
In their mode of walking, rapacious birds differ much among the 
different tribes. Thus the slow and measured pace of the caracaras 
and vultures distinguishes them well from the leaping of the fal- 
cons and buzzards. The birds of the two first series willingly alight 
on the ground ; some of them remain there continually, perching 
only at intervals, and then upon rocks ; while others, although oc- 
casionally observed walking, love to pass nearly their whole life in 
solitude upon trees. 
The eagles and the falcons, for example, very rarely light on 
the ground. They advance to the object of their search by suc- 
cessive leaps : but most commonly they seize their prey on the wing, 
carry it off in their talons, and go to devour it at a distance. They 
remain only for a short time on the ground, resume their flight, and 
perch while digesting their food on the low or elevated branches of 
trees in the skirts of woods. 
The manner of flight likewise differs much in the different tribes. 
Even among'the vultures it varies so much that it would be, difficult 
to assign it a general character. Most frequently, however, the 
flight is high, rapid at intervals, but rather slow for the greater part 
of the course. It is among the vultures, and not among the eagles, as 
Buffon supposed, that birds of the most lofty flight are to be found ; 
for the condor disappears from the sight above the plateau of the An- 
des, at a point more than 2000 toises above the sea, and at least an 
equal height may be allowed from the point of its departure ; an asto- 
nishing elevation, as will be admitted by every one, but which must 
appear still more extraordinary to an observer who becomes the vic- 
tim of the rarefaction of the air in regions from 16, 000 to 17,000 feet 
above the sea. Some other birds ha've a singular habit of whirling 
about in a particular spot, at a prodigious elevation, from which they 
