Evening star., 1938-12-10
OF Stars, Men
And Atoms
Notebook Of Science Progress
In Field, Laboratory
And Study
BIZ Thomas r. Henri.

A strange case of bird migration in
reverse has Just been reported to the
American Ornithological Union by DR..
Dominion National Parks Bureau at
Ottawa.
On lovely May morning with all the
northern woods fragrant with spring, he
said, thousands of birds OF 35 unrelated
s. ecies which were on their way north
suddenly turned around and flew south
ward as If driven by some mad, ire
sistible impulse.
He observed this phenomenon, he said
at Pelee Island off the Ontario coast in
Lake Erie. Almost continuous stream
Of red-headed woodpeckers, Baltimore
or orchard orioles, cedar waxwings, pine
siskins, blue Jays, vireos, starlings, barn
swallows, gold f1nches, mourning doves,
chimney swifts and other birds were
headed southwark to the next nearest
resting place in Lake Erie, Middle Island
These families have different migrat-
ing habits and some hardly can be said
to migrate at all. Some had just arrived
from the South. Others had been in
Southern Canada since late winter
Some had just started to build nests
while others were well advanced toward
Matching their young. Flocks of different
species were moving independently, but
all in the same general direction. Some
were hurrying. others were pausing to
feed In the trees near the lake shore.
The Ottawa naturalist asked his fel-
low bird experts for some explanation
which he has been unable to figure out
for himself. Careful inquiries failed to
reveal any possible danger to the north
ward to which any large number of
birds would have been subjected that
day and of which they might have had
some instructive and inexplicable pre-
cognition.
| Several instances Of reverse migration.
but none on the same scale or involv-
Ing diversity of species, have been re-
! ported by European ornithologists. Vari-
GUS explanations have been offered, none
OF which fits the observed Ontario case
One explanation is that the northward
migrating bird is guided by tempera-
ture sense and always moves toward a
cooler area, which is shifting northWard
from day to day in the spring. The
reverse Of course, guides the southern
mlgratlon in autumn, according to this
theory. But at all seasons the directions
OF warmer and cooler shift from time to
time and United States Weather Bureau
| records showed that on this particular
day 1t was warmer around Sanduskv
Ohio, toward which the birds seemed TO
| be moving than on the Canadian shore
OF Lake Erie. Another theory which
didn't fit the facts was that birds have an
instructive meteorological sense of low
and high pressure areas, which may save
| them from flying into storm and that,
regardless OF the direction OF migration,
| they will fly away from pronounced
| loW-pressure center toward a high
| center.
On this particular day, it was shown
| by both United States and Canadian
weather maps there were no dangerously
developing pressure centers. There was
a low center" hundreds Of miles to the
| westward over Saskatchewan. The
nigh center" was far to the southeast
| ward over the Atlantic east of the Caro-
hnas. The orientation of the birds was
| neither away from or toward either of
these, which did not amount to much
anyway. 1t is true, he pointed out, that
the region around Sandusky had a
| slightly higher pressure than Pelee
Island, but 1t required an accurate ba-
rometer to measure the difference. If
birds had been Influenced by such a
factor they would be turning around
almost every day and would never get
away.
The wind across the lake was from the
south. 1t was not heavy wind. Some
| ornlthologists maintain that birds ALWAYS
| prefer to fly against the wind than with
IL and this is responsible for various
"tacking' operations observed in bird
| mlgrations. Flying with the wind, DR..
Lewis pointed out. bird may be in the
! position OF canoeist in a swift current,
unable to regulate its speed. It must
turn around to make a landing in order
10 iced. But here again, he believes, it
would have required very heavy wind,
N' w Ai"'S SoAA1p1CGcly reversed the
migrating instinct. If birds turned
around every time the wind changed
they would stay within few miles of the
same place most of the time.
Besides, he said, when a bird is in
flight, with pressure equalized on all
SIDES OF its body, it can't tell the direc-
ton OF light wind. It can only tell its
direction by sighting objects on the
ground-or by the stars, II there happen
to be bird astronomers, which he doubts,
This had been. and continued to be, q
normal season as far north as the Arctic,
There were no great forest fires. which
the birds might have sensed, ahead.
Ihey did not seem to be frightened. or
particularly hurried in their flight.
There was no frantic quarreling of the
different species. No particular psychic
phenomenon was observed that day
among the mammals or insects on the
| island.
Apparently it is something for the
ornlthologists to puzzle over until they
know lot more about what actuates
the minds Of birds than they do now.