tribes, which present a marked difference in the plumage of the old
and young, we observe that the latter are expelled by their parents
from the breeding-places, and appear both in summer and winter in
districts which none of the old birds visit. From a consideration of
these and similar facts, we are inclined to believe that, of the species
which are found all the year within certain parallels, the younger
individuals make the widest excursions in search of food or proper
breeding places, and that, as their strength is matured by age, they
fill up the casual vacancies which occur in the districts best adapted
for their constant residence.
A number of species, which rear two or more broods within the
United States, raise only one in the Fur-countries, the shortness of
the summer not admitting of their doing more. The Passenger
Pigeons do not visit the Fur-countries, where they breed, until after
they have reared a brood, and quitted the breeding-places in Kentucky.
It is probable that some other birds also breed in succession
in different districts; and it is even possible that a few of the Falco-
nidce and some species of certain families of Grallatores, after
spending the short summer of a high northern latitude in rearing one
family, may gain a similar climate in the southern hemisphere for
the purpose of rearing another brood, passing, of course, nearly one
half of the year in the transit to and from these breeding-places*.
This hint is thrown out as simply conjectural; but, in the families
to which I allude, seldom more than two young are produced at a
* I have several times, when cruizing between Minorca and Sardinia, seen large flocks of .Swallows,
attended by great numbers of Hawks and a very small species of Owl, holding a direct course
from the coast , of Africa towards the Gulf of Lyons. From the direction of their flight, it did
not appear that they could have rested on any part of the islands I have just mentioned; so that
the traverse they attempted was full seven degrees of latitude. Both Swallows and birds of prey
appeared much tired, and settled for several days on the masts and yards of all the ships of the fleet,
from whence vast numbers were taken by the crews. Having no acquaintance whatever with Ornithology
at die time, I do not know the species of the small Owl, but I have a distinct recollection of
its being no bigger than a Sparrow; and in this I can scarcely be mistaken, as I kept one for nearly
a week before it made its escape. It was fed on Swallows, which it invariably strangled by grasping
them by the neck with one foot. If a bird of this size can cross such an expanse of sea at one flight,
the greatness of the distance to be traversed, according to the supposition in the text, does not seem
to be of itself a sufficient reason for rejecting the hypothesis, particularly if the length of time occupied
in the passage and the long halts at the various resting-places be considered.
time, which would seem scarcely sufficient to supply the waste by
the numerous casualties which occur, unless more than one brood
were raised in the year. Captain King found several northern birds
in the Straits of Magellan.
A large proportion of the migratory birds arrive in the higher latitudes
in flocks, but disperse in pairs soon afterwards; and some, as the
Emberiza nivalis and Lapponica, which winter within the limits of
the Fur-countries, assemble during that season in large flocks, but
separate when they reach their breeding-places. Parus atricapillus
and Linaria minor live in small families in the winter only; the
Tetrmnidee form coveys of ten or twelve in summer and the middle
of winter, but make their spring and autumn movements to and from
their breeding-places in great assemblages. The Corvus corax congregates
only in the pairing season, in the beginning of March, when
as many as fifteen or twenty may be seen together for a few days, until
each has chosen a mate. Many of the Sturnidte, the Columba migrai-
toria, and Pelecanus onocrotalus fly in dense flocks all the summer.
The Hirundinidm and Laridce breed in societies, and hunt for their
food in numbers together; but they do not appear to move in concerted
flights, like the birds we have last mentioned. The Anatidte,
again, feed together, but generally make their nests in remote and
solitary spots.
The following Table requires no explanation. The fourth column is
taken from the Prince of Musignano’s work above alluded to (p. xvii.),
and the fifth column is filled up on the authority of that naturalist,
Wilson, Audubon, and some others. A partial analysis of this Table
is given in the succeeding ones.