The morning news. [volume] (Savannah, Ga.) 1887-1900, 1889-05-11
TIMING II ! Birds.
The Speed at Which They Fly in
Their annual y igrat ons
From the Washington Stur.

An INTEREST," g rep TT IN bird migration in
the Mississippi valley in the years 1884 and
1855, prepared by ". ". C5olA, under tn
dr ection of Or. c. Hart Merriam,
has just been issued by the depart
ment of agriculture. Tae migratlonS of
birds are Gated as the result of inherited
expe ience The first mi rations j. is he'd
were do. bless. Mr.. Cooke says, limited in
extent, and probably were int ligelt move
meuts which thr ugh repetition becam ha-
b uual, and the habit was transmitted from
parent to offspring until it has become thu
governing impulse of the birds life, 1t is
und ubtedly true, the writer says, that
love of the nesting ground, which is to them
their home, is the fou dation of the desire
for migration, and year after year. they
f ID their wav thousands of miles back 70
the same box or tree by the exercise OF
memory-nt always the memory of the
dividua, but the memory heri,ed
from numberless preceding generations
which have passed and repa ssd
over the same route. d. Merriam il
a no e added 20 this takes exception to the
syatene 10 ia 1T Low of the mes ting on ID
is the foundation Of the desire for luiera-
ton. This ex planatio , he as erts, is forced
and uuneoe,sar y. Birds desert their winter
homes, he holds, bee luse the food supply
iails; because the climatic conditions be-
approach of the bree ing season gives rise
to physiological restlessness, and because
they Inherit an irresistible impulse to move
at this particular time of the year.
The RETURN SOUTHWARK.
Mr.. Cooke says the retut movement of
birds out ward i, obviously the result of
two causes-the approac of winter and he
failure of tn food supply. OF these two,
the latter Is probably ny far the more
po verful, since it is well known that 81 gle
/ .divi0uals of spec es which retire far to
the south often remain behind, and, favored
by an abundance of food, Withstand tae
headed woodpeckers remain through the
wi ter in the cold climate of Northeastern
New York, frequenting the heavy timber,
where there Is grea, quaint .ty of their
favoritc food and it is not unusual for a
few robi 5 to sp.nd the winter in
North Central Wise )nsin, sheltered in
the thick pi forests; while ducks, and
even Wilson's snipe, have been known to
remain throughout the whole winter in
Wyomi &, near the hot springs, whose
warmth keeps the neighboring ~a,ers and
ground from freezing. N verthe es, L is
as vet unexplained why some birds, notably
many Of the warblerS, retire In winter TO
sucl a great dist nee south, some even
GRO sing the equator and passing several
cold nor hunger can be the cause Of such
wanGerings. 1t has been often not ced tina:
duri & tae fall migration many birds seem
TO be able t. foreLe.l the ipproacl OF storms
from the norta, and hurri dly depart
northward, before human eyes can detect
any signs of the coming change.
SPEED AT WHICH BIRDS MIGRATE.
In studyin the speed at which birds pro-
coed northward in their migrations, Mr.
Cook says, one is beset by many difficulties.
70 determine the com Curative speed of the
several species Is easy Ell ugh. but to deter.
mine the ABSOLUTE rate--the exact n.mbsr
of miles which a particular bird makes
dlri one DAYS jourLey--is beyond our
power, While in tle rail migration the
younger birds lead, in the spring they
loltsr behi d, and it is the old birds,
tho In whom g may suppose the love
Of home and the desire for p~ocrea-
ton are strongest, which press forward SO
eagerly M reover. of these old birds, those
" .ich arrive first at a givea place, as a
rule, are BIRDS which lived there the prev-
Gus summer a d which will remain there
TO breed. Thus the vanguard is constantly
arresting itself, and the forward move
ment must await the arrival Of the next
c rps, which ay be near at hand or far in
the rear. The movement of migrati w,
then, is made up of series OF co slant
ove-lappings, and one real speed is evil
IDENTIFY much greater than the apparent OF
this real speed of transit we take no nc
court, and our calculated rates, therefore,
are Of value only in so far as they show
tie relative speed of migration of the
different species. L toe accompany
ng report the speed of migration is calcu-
lated in the following manner: The most
southern reliable record Is selected for COM
parison with the most northern record Of
tue same character; the distance in miles
between tuese two ations is divided by
the number Of days elapsl from tho time
the species made its appearance at the
southern alton 20 the date ~ Which, II was
seq by the northern obse yer. Tne result
gives the -verage daily rae OF migration in
miles for the species. For example: The
III nore oi1le was sen at Rodney, NJ S.,
dat. 81 SCI, April Z. II was not seen at
Oak Poi.t, Manitoba dat DO 30l. until
May 2j. u was therefore ~ days in pas.