, 1880-11-19
The Migration of Birds.

Familiar as this migration Of birds is
to us, there is, perhaps, no question in
zoology more obscure. The long fights
they take, and the unerring certainty
with which they wing their way be-
tween the most distant places, arriving
and departing at the same period year
after year, are points in the history of
birds of passage as mysterious as they
are interesting. We know that most
migrants fly after sundown, though
many Of them select moonlight night
to cross the Mediterranean. But that
their meteorogical instinct is not uner-
ring is proved by the fact that thou
sands are every year drowned in their
flight over tho Atlantic and other
oceans Northern Africa and Western
Asia are selected as Winter quarters by
most of them, and they may be often
noticed on their way thither to
hang oven towns at night, puzzled, in
spite of their experience, at the shifting
lights of the streets and houses. The
swallow or the nightingale may some.
times be delayed by unexpected circuln-
stances. Yet it is rarely that they arrive
or depart many days sooner or later one
year with another Prof. Newton con-
sidered that were sea-fowl satellites re-
volvlng round the earth their arrival
could hardly be more surely calculated
by an astronomer. Foul weather or
fair, heat or cold, the puffins repair to
some Of their stations punctual]y on a
given day, as if their movements were
regulated by clock-work. The swiftness
of flight which characterizes most birds
enables them to cover vast space in
brief time. The common black swift
can fly 276 miles an hour, a speed
which, if it could be maintained for less
than half day, would carry the bird
from its Winter to its Summer quarters.
The large purple swift Of America is Ca
pable Of even greater feats on the wing
The chimney-swallow is slower-90
miles per hour being about the limit of
its power; but the rassenger-pigeon of
the United States can accomplish a
journey Of 1000 miles between sunrise
and sunset. 1t is also true, as the in
genious Herr Palmen has attempted to
show, that migrants during their long
flights may be directed by an expert
ence partly inherited and partly ac-
quired by the individual bird. They
often follow the coast lines of continents,
and invariably take, on their passage
over the Mediterranean, one OF three
routes. But this theory will not ex-
plain how they pilot themselves across
broad oceans, and is invalidated by the
fact that, familiar to every orintholo-
gist, that the old and young birds do
not journey in company. Invariably
the young broods travel together; then
come, afte: an interval, the parents
and, finally the rear is brought up by |
the weakly, in6rm, molting and broken
winged. This is the rule in Autumn.
The return journey is accomplished in
the reverse order. The distance trav-
eled seems, moreover, to have no relation
to the size of the traveller. The Swed-
ish blue-throat performs its maternal
functions among the Laps, and enjoys
its Winter holiday among the negroes
of Soudan, while the tiny, ruby-throated
humming-bird proceeds annually from
Mexico to Newfoundlal and back
again, though one would imagine that
SO delicate little fairy would be more
at home among the cacti and agaves Of
the TERRA Caliente than among the frs
and fogs of the North.
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