The Savannah morning news., 1901-12-28


they follow after them. Flocks of
migrating swallows and martins may
be seen in late October with never an
old bird among them. And they fly
for 100 miles or so in a given direction,
then turn at an acute angle and fly
for several hundred miles more in a
totally different direction. and so
change their course two or three times
over This, regarded as an instinct is
utterly incomprehensible. One can only
suppose that somehow or other.
guide is picked out on the way.
The birds are not absolutely tied
down, however, to one definite route.
1t is with them very much as 1t is
with human travellers en- route from
England to France, who can cross
either from Dover to Calais or from
Folkestone to Boulogne, or from New
haven to Dieppe, as may be most con-
venient. They have a "fiy-line," for
example, from Marlborough Head,
another from Spurn Head and others
from various points on the eastern and
southern coasts to certain definite
spots on the shores of Denmark, Hol-
land, and France. And a bird can take
its choice between them. In most cases,
probably 1t chooses that point of de-
parture which is nearest to it's place
of residence at the time. In the same
way 1t can cross the Mediterranean
at the Straits of Gibraltar, or 1t can
travel from the Gulf of Genoa, via
Corsica and Sardinia, to Tunis, on the
African Coast or II can pass down
Italy and across Sicily to Tripoll,
touching at Malta on the way; or, IL
convenient, il can leave from the south
of Greece, cross over Crete, and so
make its way to Egypt.
Limit of Unbroken Flight.
These are the four recognized Fly
lines" across the Mediterranean, and 1t
is noticeable that they all seem to fol-
low the lines of ancient land connec-
lions. 1t is the greatest of all mistakes
with regard to bird migration to sup
pose that the travellers fly for hun
dreds of miles over the sea. They never
cross the sea at all unless they are abb
solutely obliged to do so, and even then
they usually choose the shortest route.
These four Mediterranean "fly-lines,'
ii will be seen, involve but a very
short sea passage. In the first case,
there is only the narrow channel to
cross between Gibraltar and Tangier;
more than half of the second is over
land, from Northern Corsica to South
ern Sardinia in the third, from South
eim Sicily to Tripoli, there is a rest at
Malta upon the way; while Crete
breaks the journey in the fourth.
The fact is that migrant birds, with
a few exceptions are not sufficiently
strong upon the wing to undertake an
unbroken fight of more than thirty
or forty miles, with the wind perhaps
against them. Even as ii is, they fire.
quently rest upon the rigging of ships
with which they happen TO meet on the
way. And in the spring one may see
flights Of swallows come In and settle
down at once for a couple of hours
repose upon the shore: while in Au-
tumn the woodcock arrive in a state
of such utter exhaustion that any one
who knows their landing places can
go out on or about Oct. 20 and pick
them up with his hands. Twenty four
hours at the least does II take these
birds to recover from the effects of
their journey.
The ZigznR Course Explained.
Now the remote ancestors Of the mi
grant birds seem TO have entertained
just the same strong objection to
long sea passage which characterizes
their descendants Of to-day. Not the
worst OF bad sailors" could have
dreaded the crossing more fervently
than they. And this no doubt, was
the reason why the "ny-lines" were in
the first place Instituted. These lines
cross both the EnBliSn Cndnnel ana the
Mediterranean at points where there
was originally either no sea passage
at all, or. at any rate a far shorter one
than there is at present.
The birds which are now coming in to
US in such numbers from Scandinavia
travel Via Denmark and the Dogger
Bank, which seems TO mark the line
OF an old connection with the Euro
pean continent. while we also know
that the Mediterranean. instead OF be-
ing an inland sea In communication
with the Atlantic, was originally a Sc
ries OF great lakes. There were no
Straits Of Gibraltar In those days:
Corsica almost certainly jutted out
from Southern Europe and Sardinia
from Northern Africa: while the two
i'm addition, were undoubtedly united
Probably. too, the South Of Sicily
was IN actual connection with Africa
In the neighborhood of Tunls; while
Egypt very possibly, ran further TO
the north than II does at present. And
the first bird migrants, In travelling.
followed the line OF land. Their de-
scendents did the same thing after
them for countless generations, and so
In process OF time tho "hy-lInes" be-
came traditional Tho ziEzag course
which swallows. martins and the rest
follow now simply testincs 10 the-in-
grained dislike of land birds 20 flying
over the sea. and 10 the innate conscf-
yatism Of their nature,