The Sunday telegram. [volume] (Clarksburg, W. Va.) 1914-1927, 1915-04-11
NO MIGRATORY
Land BIRDS IN
SOUTH AMERICA
Distribution of Bird Food is
Much Different from That
of This Country.

I6Dloll!UullUIlS5su III 0llu F-UUus IS
Much Different from That
4 of This Country.
WASHINGTON, Apr. 1O Though
Il North American birds living In the
a colder part Of the continent return
South for the winter, there is no sim
liar movement of the birds from the
III colder to the warmer parts OF South
America. according to a bulletin 5(So.
NJ 1850 OF the United States DEPARTING nt
Il of Agriculture. II the birds in North
II America did not go South during the
"a winter, they would perish Also if
i the birds remained in the South later
n than spring, there would be over
4 crowding;; SO they are drawn north
n ward again by the enormous summer
N supply OF bird food. In South Amer
lea, on the contrary. there are almost
no migratory land birds. because the
II south temperate ATTITUDES, on account
\ of their small area, offer no such In
tants Of the Emitless forests along
\ the Amazon
The new pamphlet. which is entit1-
j ed Bird Migration gives much in
I formation regarding the habits OF the
| migratory birds of North America
4 The fact that the routes OF migration
.are long and complex does not mean
4 that these routes were so in the be-
i ginning. says the bulletin. III the
early ages. fight was probably short.
\ easily accom- p1ished, and comparative
4 1y free from danger. Each length
entnR OF the course was adopted per
tmanent1y only after experience in
many generations had proved its adj
ivantages.
There are some who argue that love
of birthplace is the impulse which
cause spring migration, and these call
Fattention to the seeming ampatience Of
1.-The earliest arrivals. Ducks and geese
push northWard with the beginning Of
open water so early, so far, and SO
1 last that many are caught by late
storms and wander disronsoiate1y
4 over frozen ponds and rivers. pre-
\ ferrins to risk starvation rattle than
to retreat. The purple martins often
arrive at their nesting boxes SO pre-
4 marturely that the coy home be
lcomes tomb If a sleet storm sweeps
their winged food from the air. The
| bluebird's cherry MARBLE we welcome
as a harbinger of spring, often only
to ind later lifeless body in some
shed or outbuilding where the bird.
n =
the sunny land so recently left
AS matter Of fact, however. only
a small percentage OF birds exhibit
/ these preseasonaI migration propen-.
sites. The great majority remain in
the security or their winter homes un-
TILL spring is SO far advanced that the
Journey can be made easily and with
comparatively slight danger; and they
reach the nesting spot when food
supply is assured and all the condi-
tons Of weather and vegetation are
| favorable for beginning Immediately
the rearing OF a family.
Breeding Instinct Governs Return.
~ may be safely stated that the
| Weatne Z ID the winter home has moth
| ing to do with starting birds on he
spring migration, except in the case
! of few, like some of the ducks and
geese, which press northWard as fast
as open water appears. There is no
| appreclaDle change in temperature to
warn the hundredAor more species If
our birds which visit South America
IN winter that it is time to- migrate.
IT must be a force from within q
physiological change warning them Of
! the approach of the breeding season.
| that impels them to- spread their
wings for. the long flight.
The habit Of migration has been
evolved through countless generations
and during this time the physical
structure and habits Of birds have
been ndergoing 4 process az evnI,,-
ton In adaptation to the climate or
the summer home. In spring and
early summer, climatic conditions are
decidedly variable. and yet there must
he some period that has on the aver
age the best weather for the birds
arrival. In the course OF ages there
have been developed habits OF migra-
ton, under the influence Of which the
bird SO performs its migratory move.
ments that on the average it arrives
at the nesting site at the proper time.
Local Conditions Minor Factors.
Local weather conditions on the
day Of arrival at any stated loca!.tt;;
are minor factors in determining the
appearance OF given species at that
place and time The major factors IN
the problem are the weather condi-
tons far to the southM ard, where the
Infght's flight began, and the relation
which that place and time bear to the
average positions OF the bird under nor
NAL weather conditions. Many. If not
most, Instances OF arrivals OF birds
under adverse weather conditions are
probably euplainab1e by the SUPPOSE
ton that the fight was begun under
Favorable auspices and that later the
weather changed Migration III spring
usually occurs with rising temper
AZURE and in autumn with falling
Temperature. IN each case the chang
ing temperature seems to be a more
potent factor than the absolute degree
OF cold.
The direction and force Of the
winds exceDt as thew = ral nrc., Glow
ally intimately connected with sud-
den and extreme variations IN tenn
perature, seem to have only slight
influence on migration.
Most Birds Migrate at Night
Some birds migrate by day. but
most OF them seek the cover OF dark
ness. Day migrants include ducks
and geese (Which also mi CRATE by
night, hawks, swal lows. the night