The Madison daily leader. [volume] (Madison, S.D.) 1890-current, 1916-03-30
MIGRATION Of BIRDS
THEY HAVE THEIR TIMETABLE
AND ONLY BAD WEATHER
DELAYS THEM.

FRANK M. Chapman IN 81. NlCHOIdS
Magazine: When W. consider the
great distances some birds travel and
the dangers they encounter by the
way, it il remarkable that they usual
ly arrive on time.
That the daily trips to and from
the roosts should be made regularly
is not surprising. The birds have
only a short way to go, and they
leave soon after daybreak and return
just before dark. But when, year
after year, the bobolink, the Balti-
more %oriole, the midget humming
birds, many warblers, and other birds
arrive from journeys thousands of
miles in length on exactly or nearly
the same day, we ask how they can
possibly be so prompt.
In order to answer this question
we must know something about the
birds timetable. Anyone who has
studied the birds about his home for
many years can make a timetable
giving the dates of arrival and de
parture of all the migratory birds
which V Isit him
In this timetable we shall notice
that the early birds-those which
come in March-are much less
prompt than the later ones-those
which come in May. This is because
the weather of March is so much
more uncertain than that of May. In
some years, near New York city,
snow covers the ground and the
ponds are frozen almost until April.
In others, the snow melts and the
ice disappears before the middle Of
March. But by May j, the weather
is more settled. The first week in
May of one year is much like the
first week in May of another year.
So ii follows that the exact time of
the arrival of the birds is more or
less dependent on the weather. 1t is
not the weather which induces them
to come. What can the Baltimore
oriole m Central America know
about the weather near New York
city? Not a thing. He leaves Cen
trail America without regard TO the
weather there or any other place.
But his journey may be delayed by
bad weather or fastened by favorable
weather, If, therefore, he finds the
weather of one year much like that
of another year, he is apt to reach
the same place at about the same
time year after year.
In flying from Europe TO Africa
birds cross the Mediterranean sea at
a point where the water is SO shall
low that it is believed the two con
tinents were formerly connected
there. The land bridge, which it is
thought formerly guided the birds in
their flight, has disappeared, but the
habit of crossing at this particular
place still remains.
Though | do not know of any
cases OF this kind in America, we
shall find equally interesting facts
concerning the air lines of u birds.
For example, how do you suppose the
little wheatear, no larger than a u
bird. formed the habit of migrating
from Europe to Greenland? Prob
ably he comes by way of England
and Iceland, but at the best il is a
long journey and seems to take y
bird much farther than it is neees-
sary to go. In the autumn he goes
back to winter in Africa.
Doubtless some European water
birds visit us every year, but the
wheatear so far as | know, is the only
land bird which migrates regularly
between North America and Africa.
! With this exception, no North Amer
lean land birds leave the western
hemisphere in their migrations.
Their MOTTO might be See America
first" Certainly many of them see
a large part OF it.
The birds of the western United
States are not such great travellers as
those of the eastern part of the coun-
try. Some of them only travel from
the higher parts of the Rocky noun
tains or Sierras, where they nest. 10
the low, warm valleys in which they
winter.
Those that leave the United States
go into Mexico. Some contine their
Journey as far south as Guatemala,
but few go farther south than that.
They can, therefore, make their jour
ney overland and so do not encounter
the dangers to which many of Il
eastern migrants are exposed.