birds, yet at a distance it closely resembles a henharrier, and it also
readily attacks young, sick, and wounded birds; all others know how
little they have to fear from it. When it appears unexpectedly,
sweeping over a hedge or grove with a rapid flight, it is sometimes
mistaken for a more dangerous species; there is then a little flutter of
alarm, some birds springing into the air, but in two or three seconds of
time they discover their mistake, and settle down quietly again, taking
no further notice of the despised carrion-eater. On the other hand, I
have frequently mistaken a harrier (Circus cinereus, in the brown state
of plumage) for a chimango, and have only discovered my mistake by
seeing the commotion among the small birds. The harrier I have
mentioned, also the C. macropterus, feed partly on small birds, which
they flush from the ground and strike down with their claws. When the
harrier appears moving along with a loitering flight near the surface,
it is everywhere attended by a little whirlwind of alarm, small birds
screaming or chirping excitedly and diving into the grass or bushes; but
the alarm does not spread far, and subsides as soon as the hawk has
passed on its way. Buzzards (Buteo and Urubitinga) are much more feared,
and create a more widespread alarm, and they ars certainly more
destructive to birds than harriers. Another curious instance is that of
the sociable hawk (Rostrhanrus sociabilis). This bird spends the summer
and breeds in marshes in La Plata, and birds pay no attention to it, for
it feeds exclusively on water-snails (Ampullaria). But when it visits
woods and plantations to roost, during migration, its appearance creates
as much alarm as that of a true buzzard, which it closely resembles.
Wood-birds, unaccustomed to see it, do not know its peculiar preying
habits, and how little they need fear its presence. I may also mention
that the birds of La Plata seem to fear the kite-like Elanus less than
other hawks, and I believe that its singular resemblance to the common
gull of the district in its size, snowy-white plumage and manner of