The Detroit times. [volume] (Detroit, Mich.) 1903-1920, 1911-04-21
MYR|ADs OF BATS
GUARD TREASURES
Millions Of Them Occupy Shaft and
Levels ard Make Exploration
Impossible.

VEGA, Mexico. April 21.-The fam
Gus old Sivirijoa mines. situated four
miles west OF here, are infested by
millions OF bats OF enormous size.
When American engineers came into
this section TO lay out the route for
the Kansas City, Mexico a Orient
railroad they were greatly mystified by
the black column which poured out OF
the mountain each evening and rose
high into the air. At first they
thought II was smoke from a volcano
until the natives explained that what
seemed to be column OF smoke was
made up OF myriads of bats
The stream OF oats begins TO emerge
from the ancient shaft of the mines
Just at shutdown each evening, and for
three hours the solid column pours
through the opening, filing the space,
six feet square. The living column as
cends to a height of aboue FIVE hun
dred feet unbroken, and II is then
gradually dissipated by clouds OF bats
breaking away from the main mass.
Frequently these clouds OF bats are SO
dark and dense that they can be seen
for distances OF from fifteen to twenty
miles.
Meals for Birds Of Prey.
Notwithstanding the fact that
hawks, eagles and other birds OF prey
for miles around take advantage OF
the vast assembly Of bats to gain an
easy livelihood, there has been no
apparent decrease In the number OF
the insectiverous mammals. Each
evening when the flight of the bats
begins the barren sides OF the noun
tain are dotted with scores OF hawks
and eagles, each awaiting the oppor-
tunity TO obtain its evening meal.
While the bats are pouring out OF the
shaft the birds, one by one, laZily soar
close TO the moving column and pick
off enough to satisfy their hunger
The return OF the bats each morn
ing gives the birds another opportun-
ity for obtaining a meal with little
exertion. The mammals begin to re-
turn TO the underground workings OF
the mines at daylight, and each separ-
ate detachment seems TO time its ar
rival SO that II flies into the down.
pouring column without undue crowd
ing and disarranging the movement
into the shaft. The different return
ing detachmeQts converge into the
descending column at a height OF
about one thousand feet. and the mo-
ment they begin the descent they
close their wings and drop like shot
catching themselves In their descent
two or three times to relieve the veloc-
ity
Danger In Disturbing Them.
These bats occupy a great cavern
that was excavated as part OF the
mine workings more than one hun
dred years ago. Several attempts
have been made to explore that part
Of the mines that Is occupied by the
bats. but they are so numerous that
II was found an exploit fraught with
great dangers The members OF one
exploring party were nearly suffocated
by the bats a few years ago. They
were examining the ancient workings
with the view OF determining what
ore, II any, existed In the different
levels Suddenly the bats were dis
turbed from their day-sleep by the
invasion Of the men and they swoop-
cd down upon the latter in great
clouds. BY throwing themselves upon
the bottom of the cavern the men man.
aged to escape the suffocating swarm
OF mammals and they finally escaped
by slowly crawling through a tunnel
that led TO another part of the mines.
The history Of these mines shows
that from 1715 to 1900 they paid to the
Spanish crown in 20 per cent tax
S25.000,0 900 In silver. In 1900 an enor-
nous flow OF water was encountered.
The lower workings became flooded
and the property was abandoned. The
roomy cavern from which most OF the
rich ore was taken was quickly occu-
pied by bats and they have made 1t
their home ever since, increasing In
numbers until II is now probably the
largest bat colony in the world.