The Indianapolis journal. [volume] (Indianapolis [Ind.]) 1867-1904, 1901-12-08

1t Is natural 10 ask why Sucn an eAOi
nous journey should be undertaken, see
ing that this little bird. gifted with powers
Of flight incomparably inferior to the swal-
low, is just as punctual in ~traversing thou
sands of miles as the swallow is in travel
ing hundreds.
The answer is still in a-nebulous phase,
but modern research seems to be clearing
away some Of the mists. Cold is not the d.
rect agent in regulating these mysterious
movements, for birds belonging to the
northern and temperate zones have marvel
Gus powers of resisting cold, and a Spanish
winter, for example, is often far more Sc
we're than an Irish one. But cold may be ac-
counted the indirect cause of the south
ward autumnal migration, which brings
some birds to the British isles and expels
others. Cold affects the food supply, de-
stroying the insects upon which soft-billed
birds depend. and burying in snow the
seeds which supply the others.
The late Herr Gatke for more than fifty
years kept accurate observation OF the pas
sage of birds in his island home of He'll
goland. His notes are of incalculable value
to ornithologists throwing, as they do, in
structive light on the probable cause of
migration. Thus, the first birds 10 begin
moving south are young starlings, In the
last ten days of June. 1t were wonderful
enough that old birds, of habits normally
diurnal, should find their way through the
darkness by a route which they had trav-
eled before; but hat young birds, newly
fedged, even if guided, as is possible. by a
few experienced individuals, should steer
straight to unknown winter haunts, trans
cends anything that we can understand at
present. Yet with most species it seems to
be the habit to send off the young birds
first. The cuckoo is a notable exception.
Having no domestic duties the old cuckoos
make a start as soon as ~caterpillars begin
to get scarce, and put in an appearance in
Heligoland about the middle of July, to be
followed by the young flight a month or
six weeks later.
PROBLEMS OF MIGRATION.
Two questions suggest themselves-why
is bird migration chiefly conducted during
the night? and why do the flocks move at
such great heights as they are known to
do? To the second question no satisfactory
answer can be offered at present. 1t might
be conceivable, if the movement took place
III daylight, that ground-loving birds like
robins, thrushes. and other common OBJ
jects of the lawn might ascend hundreds
of feet in order to obtain a 'bird's-eye
view of the landscape. But migrant birds
fly chiefly in the darkness, out of which
they descend, many of them to their de-
struction, when attracted by strong lights.
Possibly they are obeying an instinct which
warns them against hawks, owls and gulls,
chiefly to be encountered in the lower
strata of atmosphere, and in this also is to
he found tho nrohahIa ayplapa4ion rrb,,
daylight birds choose the night time for
their journeys.
But then, it may be asked, why don't
birds remain and breed in the regions
where food is always to be found? There
are always plenty of lapwings in England
in winter. and they find abundant prov
ender; why should English-bred l~apwings
take the trouble to travel all the way to
the Danube or Morocco, in order to have
their places taken by flights bred in Scan
dinavia and Iceland? That brings us to one
of the most suggestive aspects of the phe-
nomenOn of bird migration. Every species
of bird in the northern hemisphere, except
the sedentary game fowls, grouse, pleas
ant, partridge. and the like-move to the
northern limit of their annual migration to
nest. The limit for the nightingale is south
of the Trent; for the knot, as has been
shown, it is beyond where man can pene-
trate. or has as yet penetrated. Take that
characteristic in conjunction with the no.
torious and invincible impulse of every
bird to return to it's birthplace to rest, and
you will incline TO the conclusion that bird
life had its origin i'm high ATTITUDES. Adopt
that conclusion. and you will be tempted "A
little further. You will not dismiss with an
incredulous smile the opinion of those who
perceive in the polar circle the cradle of
terrestrial life. If the earth, as there is
! reason to suppose, vast ages ago were a
mass of incandescent matter, it would be
at the poles where it would first cool down
at the poles where an endurable climate
would first prevail. A tropical climate at
first, of which there Is abundant evidence
in the fossil plants of Franz Josef land and
Spitzbergen, where, if you penetrate the
frozen surface layers, you come upon rocks
yielding remains of tree ferns and giant
mares-tails-plants that could only exist i'm
a hot, steaming atmosphere. AS the cool
ing process went on, the winter cold about
the poles forced these tropical growths into
a zone which gradually parted with enough
heat TO receive them. With the plants
moved the animals, further and further
towards the equator as the temperature
permitted the advance. and i'm succession
behind the tropical zone. the subtropical,
temperate, subarctic and arctic regions de-
veloped in the slow succession Of ages. But
the birds have never forgotten their origi-
nal home. Year by year they press as far
n~orthward as they can find room. as if de-
ermined that their offspring should know
their true birthland. Perhaps Tennyson,
alert and true as he was in observing ma
ture, was not aware of the full significance
of the lines in the Princess:
o Swallow, Swallow. flying. flying south.
Fly TO her and fall upon her gilded caves,
And tell her, tell her what L tell TO thee.
o tell her, Swallow, thou that knowest
each.
That bright and fierce and tickle is the
South.
And dark and true and tender is the North.
Next Week:
History Told by Postage Stamps" by
Hugh Richardson. NJ. A.
I*Copyright in the United States Of Ameri-
: can by d. 7. Pierce.l