The farmer and mechanic. [volume] (Raleigh, N.C.) 18??-19??, 1913-10-28
SMITHSONIAN SCIENTISTS SOIW, .
MYSTERY OF BIRD MIGRATION
Reach Conclusion That the ~Songsters Go North in Sum-
mer and South in Winter in Obedience to Physiology
cal Laws Governing Bird Life.

q. , an lnc SuperStltlonS OF
Mississippi valley regarding the
of birds and the weather will
noe stand. In fact, these records
practically r~elegate the whole goose
Done philosophy to oblivion.
IL is difficult, if not impossible to
tell what bird movements will ac-
company given weather conditions.
one autumn it would appear, the de-
parture or the birds is fastened by
.ne approach of a certain storm. and
the next year under precisely similar
conditions the fOcks hang about the
nelds inc woods two or three weeks
later. one spring it may seem that
the birds are held back by a heavy
storm, but the mex year, even in the
race or more u~nfavorable conditions,
the birds come northward in thous-
amos. They fail to cave in autumn
ana TO arrive in spring, when circum-
ar propitious, and move in
myrlads when conditions are adverse.
me Iact is, except in a comparatively
few instances, bird migration does
not proceed uniformly, but in a Sc
RES OF in~terspersed with
PERIODS of rest and inactivity.
Speed of the Birds.
In the Mississippi valley the aver
age daily advance northward or
southwark is about twenty-three
miles, scarcely more than half an
hours continuous flight, though in
spring the birds are inclined to hurry
over the last laps of their northward
journey, flying 200 or 300 miles at a
stretch. IT may be stated broadly
that weather conditions in the win
ter home have nothing to do with
starting the birds in
spring, and that the beginning Of the
tall migratiOns has nc relation what
ever to meteorological happenings
anywhere.
In studying the nocturnal flight of
birds recourse has been had to posts
of observation on high hills where
the birds come nearest to the earth,
and to the use of small telescopes and
field glasses where the passage of
the birds across the face of the moon
or the narrow circle illuminated by
ment.
One such observer posted himself
on a hill in the vicinity of Three
Lakes, Wis, where he could the bet
ter record the bird calls that he might
hear in the darkness. The ObServa-
ton was made on h night of Sep
tember IA, and the effort was merely
to hear and count as accurately as
possible the numbe Of birds calls in
the air n Within a period
Of ten hours $500 separate calls were
distinguished and recorded. This
was an average of about twelve to the
minute, but the rate was far from
uniform, and the ornithologist was
compelled at times to work with al
speed to tally the sounds heard during
a portion of the night, when the calls
were at the rate Of thirty-six to tn
. minute. At other times they were a
. the rate of two or three to the minute
) The highest record was between
, 2 and 3 o'clock in the morning, WheI
236 calls were recorded during tina
!, hour. The observer describes his ex
perience of that night as follows:
at times the air seemed to be aiIVl
with birds as their calls rang out II
the silence of night, now sharply an
: then apparently farther away. Their
4 were moments when a flock SCENE
so near that the presence OF the bird
could almost be felt. though darkness
yelled the procession from sign
Many varieties Of bird voices; could Q
+ recognized-the harsh squawk Of
water fowl, the musical cling OF tn
bobolink, the shrill notes of the Wart
y lers and the sparrows as they presse
southwark all that night.
n Another Observation.
n The great space of air aboy
Q swarmed with life. Slngly or !
r groups. large and small, more seldo1
in a great throng, the hurrying m,
RAIDS moved south. It was a mary
# and a mystery enacted under cove
# of the night, of which only fugitiN
N tidings reached the knowledge Of me
d below
st The same ornithologist, a year late
assisted hy q friend, carried on OF
is ~servation for three nights, Septemb'
"a II. u. and 13, with the aid OF
20 small telescope, so placed as TO reg
"A ter the shadows of birds passing II
:. disk IF the moon. The observation
Of we're over about five hours each nigh
q while the moon was in the De
of position for the purpose. The recol
a showed the passage OF 3o5 omr
20 across the disk Of the moon. II
"A highest number at any n M v
ne forty-fve within a period of nfte'
minutes, that being the time eacn 9
server had his eye glued to the ey
a r;ece Of the instrument. The MAY
m mum fight was about 1890 ca
a night. Thc time Of transit across I
IT. field of the telescope was one-ten
81, to one-half a second, swift indeed I
- oo,roto notation OF any maIerl