The Alaska citizen., 1911-06-05
BATS GUARDIANS OF
 OLD MINE

VEGA. Sinaloa. Mexico. April 23- The famous Cld Sivirijoa mines. situ- a,ed four miles west ot here. are in tested by millions of bats of enor. nous size. When American engineers came into this section to lay out the route for the Kansas City. Mexico & Orient railroad they were greatly mystiiied by the black column which poured GU; ui the mountain each evening and rose high into the air. Al first they thought il was smoke from a volcano until the natives cN- plained that what seemed to be a column of smoke was made up of my riads Of bats.
 The stream of bats begins to emerge from the ancient shaft of the mines just al sundCwn each evening, and for three hours the solid column pours through the opening, The liv- ing column ascends 10 q he.ght of about 900 feet unbroken. and it 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 he seen fGr distances of from fifteen To twenty miles.
 otwithstanding the fact that hawks. eagles and other birds of prey for miles around take advant- age Of the vast assembly of bats 10 gain an easy livelihood. there has been no apparent decrease in the number of the insectivOrOuS nam mals Each evening when the flight of the bats begins the barren sides rf n fCffpf scores of hawks and eagles. each awaiting the opportunity to obtain it's evening meal While the bats are pouring out of the shaft the birds. one by one lazily soar close 10 the moving column and pick of enough to satisfy their hunger.
 The return of the bats each morn ing gives the birds another oppor- tunty for obtaining a meal with lit tie exertion. The mammals begin to return to the underground workings of the mines at daylight, and each separate detachment seems 10 time its arrival so that it flies into the downpouring column without undue Crowding and disarranging the move ment into the shaft. The different returning detachments converge into the descending column at a height of about l 900 feet. and the moment they begin the descent they close their wings and drop like a shot. catching themselves in their descent TWO or three times tO relieve the velocity.
 These bats occupy a great cavern that was excavated as a part of the mine workings more than 100 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 it was found an exploit fraught with great dangers The members of one exploring party were nearly suffOcat ed by the bats few years ago. They were examining the ancient workings with view of determining what ore. if any, existed in the different levels. Suddenly the bats were disturbed from their day sleep by the invasion of the men. and they swooped down upon the latter in great clouds. By throwing themselves upon the bottom of the cavern the men managed to escape the suffocating swarm of man. mals, and they finally escaped by crawling through a tunnel that led to another part Of the mines.
 The history of these mines shows that from 11l5 to 1900 they paid to the Spanish crown in 20 per cent tax $25 100000 in silver. In 1900 an enormous flow of water was encOunt- cred. The lower workings became flooded and the property was aban- doned The rOOmy cavern from which most of the rich ore was taken was quickly occupied by bats. and they have made il their home ever since. increasing in numbers until il is now probably the largest bat colony in inc world