Evening star. [volume] (Washington, D.C.) 1854-1972, 1906-11-17
MIGRATION OF BIRDS
QUESTIONS THAT STILL ACETATE
THE SCIENTIFIC MIND.
Suggestion That Birds Have a Sixth
Sense AN Intuition Of Direc-
ton Now Raised.
Written for The Star.

Il
Written for The Star.
| What becomes of summer birdsfe
| Where do they spend the winter" BY
what routes do they travel?" How do
| they find their way?"
These are questions asked by Wells w.
| Cooke in a recent government report con-
corning the migration OF birds. And for
hundreds of years these same questions
have been asked and answered-and the
| answers have changed from time to time,
as the answers to many other scientific
questions have changed. For many years
1t was taught that the moon was q
cold Ed purnt-out cnder. without atmos-
phere or life of any kind, and 1t is but very
lately that Prof Pickering has given us
reas on to believe that our satellite is proba-
bly, very much alive, with an atmosphere
and vegetation somewhat similar to our
own. 1t was but yesterday that we all
were taught that the earth in its present
form had evolved from a heated gaseous
mass that had gradually cooled and solidi-
ned. that was still cooling and would within
calculable time become too cold to sus-
tain life. Recent Investigations tend to
prove that 1t has probably evolved from
cold mass and has become warm during
the process of condensation, and that, so
far from its being on the decline, It is COM
paratively young and In the early days Of
Its career. In the same way the theories
concerning bird migration have changed az
men have become broader in their views
and as exact information has accumulated.
There was a time when 1t was believed that
birds migrated to the moon every autumn
and returned thence in the spring, and a
later fancy concerning migration was that
cranes, while flying across the Mediterra-
mean, carried small birds across on their
backs. Until very recently there were
many English-speaking people who believed
that swallows spent the winter at the bot
toms of ponds, alternating in the mud, and
there has been no end of so-called proof
advanced in support of this belief. Even
today, when bird migration Is somewhat
better understood our ideas the subject
are undergoing continual modification, as
newly discovered facts result In the ex.
plosion of old theories the establish.
ment of new ones.
No Answer as Yet.
For about twenty-three years now the
biological survey at Washington has been
collecting data concerning the migration OF
birds, and during this time it's own field
naturalists have visited practically all re-
gions of the North American continent,
from Guatemala to the arctic circle. In adj
dition to the immense amount of Informal
ton received from these men, reports are
sent in twice a year by hundreds of or
nithologists, scattered throughout the coun-
try. AS result a good deal has been
learned concerning the extent of the jour
neys taken by certain birds, and the routes
followed in taking them, but 1t Is frankly
admitted that no conclusive answer has
yet been given to the question: why do
birds mgrate?' The once rather generally
accepted theory that spring migration was
caused by love of home, and that the fall
migration was made by the failure of the
food supply. no longer completely satisfies
the serious student why" he asks, 'if
birds have so strong a love for home as to
brave the greatest perils in order to reach
M nf han 1An ~
practically the moment they have reared
their families? And II the return journey
is made because of lack of food. why does
1t begin when food Is most abundant" BY
recently collected careful data it is shown
that the southwark migration probably be-
birds migrate?' The once rather generally
gins by the list of July, and certainly by
the 10th Of that month, insectivorous birds
leaving when insects most abundant,
and the grain-eaters before the height of
the harvest. 1t is evident that while mi.
grafton may originally have been the result
of periodic changes in temperature and food
supply, today these motives are by no
means the only ones, and it must be con-
fessed that the others are either unknown
or but imperfectly understood.
Sense of Direction.
Have birds a sixth sense-that of direc-
ton? If not. how can they, on occasion,
fly for scores of miles across the ocean, en-
veloped in dense fog through which a
Cooke, in his report states that ''in Alaska
few years ago, members of the biological
survey on the Hartman expedition went by
steamer from the Island of Unalaska to
Bogoslof Island. distance of about sixty
miles. dense fog had shut out every OBJ
ject beyond hundred yards. When the
steamer was half way across, fiocks of
INJURIES, returning to Bogoslof, after long
quests for food, began to break through the
fog wall astern. fly parallel with the yes
sci, and disappear in the mists ahead. By
chart and compass the ship was heading
straight for the island; but its course was
no more exact than that taken by the
birds" On many a cloudy night focks of
birds leave the coast of Cuba for the un.
seen Florida shores which they reach i'm
safety unless a storm arises to bewilder
them and blow them out of their course.
Still more wonderful is the crossing of the
Gulf of Mexico, a feat accomplished sue
cesSfully twice every year by myriads of
warblers scarce bigger than ones thumb,
1t is not possible for them to see even one
third of the way across, and they have no
compass unless 1t be one they carry be-
meath their tiny feathered caps, and the
character of which can only be guessed at.
Even the very interesting belief. held by
SO many, that during their migrations birds
follow recognized highways, such as coast
lines, mountain ranges and the courses OF
large rivers, seems doomed to considerable
modification. There is no doubt, of course,
that such routes are followed to consider
able extent but in many instances 1t is GER
tain that the birds summering in given
locality depart in no one direction but in
all directions, reaching their winter homes
by entirely different routes. Moreover,
birds of the same species often follow ono
route on their journey north, and quite a
different the return trip The fact
that birds seldom, if ever, migrate above
the clouds, dropping nearer the earth
soon as clouds arise, would seem to indicate
that they depended, at least to a large ex-
tent, upon their eyesight, which is undoubt-
eddy very keen in most cases. Even when
migrating at night their distance from the
earth is largely determined. by the clearness
or haZiness of the atmosphere But that
there is some other sense which guides these
feathered voyagers at times when no eye
sight, however keen, could help them to
steer their course Alright Is an interesting
theory, which further observation and ex-
pertinent may prove.
ERNEST HAROLD BAYNES.