2Life Enters the Caverns

At the time the limestone beds were beginning to crack, which we noted was some 60,000,000 million years ago, the huge reptiles and other prehistoric animals were playing hide and seek on the surface above the site of the developing Caverns. At that time the cave hadn't yet been formed—the underground seepage of water was just beginning to find the crevices below the gypsum and rock salt and begin its erosion which was to continue slowly for so many centuries.

Recent forms of life seem to have a more or less direct bearing on the bat, and scientists remain quiet on what forms of life, if any, used the cave for their domicile between the earliest times and the arrival of the bat.

At least, the nocturnal creature is a sure resident, for he still makes his home there, and in numbers running into the millions.

But when did the bat first inhabit the cave? That is difficult to answer, except to say that it was several thousands of years ago.

How can scientists be so sure the years are so many? There are several ways in which they have been able to establish that the centuries have been numerous since the bats first discovered this haven.

One of the best is by the guano deposits found on the floor of the cave. Observations have shown that the excrement from the bats accumulates at the rate of approximately one-half inch per year. Thus 25 years is required for a foot of the substance to materialize. This would indicate it would require about 1,000 years for 40 feet to accumulate.

Unfortunately, the exact thickness or depth of the guano deposits was not carefully measured when my father first discovered them, but I have heard him describe them many times as being at least 100 feet deep in places. That would be almost conclusive proof that the bats had been living in the cave for at least 2,000 years!

It should also be remembered that as guano ages and dehydrates, it sort of packs down, so that although a half inch of guano might be deposited in a year's time, several years later this guano will have decayed and packed down to half that thickness.

This would extend the time to far more than the estimated 2,000 years, but just how much is extremely difficult to estimate.

Also, the amount of guano growth varies with the years, for when insects are plentiful, bats gorge themselves and the guano deposits are much greater than in lean years when their food supply is low, sometimes to the extent that the bats will go elsewhere for one or two seasons, at which times there is no guano accumulation at all.

At one time, during an exploration of the cave some years ago, a scientist discovered the remains of a bat sticking out of the side of a stalagmite where it had undoubtedly fallen from its perch above, having perchance died of old age.

With no disturbance to blow its remains away, it rotted there and the stalagmite grew over it, so to speak. Scientists, estimating the rate of growth of stalagmites, were able to calculate approximately how long ago the bat had fallen. The head and wing bones were barely discernable.

It is also known that the bats have moved around in the cave, for their tiny skeletons have been found in remote sections at points where the bats are no longer found clinging to the ceiling for their daytime sleep. Such findings indicate one of two possibilities; one, that some bats might have gotten lost in the cave and died there, away from their normal resting place, and, second, that previous openings have since been closed, due to various earth movements,forcing the bats to use new openings and thus change their location within the cave.

Scientists place little credence on the former possibility because bats seldom get lost. They can find their way in any dark cave or passageway and know how to get out the same way they went in.

The second possibility is the most likely, that centuries ago there were other openings to the cave through which the bats entered and spent the daylight hours. As old age overtook them they would die and fall to the floor. Then, as subsequent earth movements closed the openings, the bats would find new doorways to their daytime abode. This also accounts for large quantities of guano which were found in portions of the cave where no bats were to be seen sleeping on the ceiling above.

There are eighteen species of bats to be found in New Mexico, and thirteen are known in the Carlsbad region. In the United States as a whole, scientists have classified over 251 varieties of these winged mammals.

Of the thirteen found near the Caverns, eight are known to have made use of the cave at one time or another. Old skeletons have been found in remote sections of the cave which have been identified as those of the Large Pale Bat (Antrozous pallidus), wing bones of which were found in one of the innermost rooms; the Big Brown Bat (Eptesicus fuscus), a skull and wing bones having been discovered in an inner room; House Bat (Myotis incautus), several skull fragments of which were found in one of the lower rooms of the cave; Red Bat (Nycteris borealis), two old skulls of which were found on the floor of one of the deepest rooms; Cave Bat (Myotis velifer), evidenced by imperfect skull fragments found deep in the cave; Great Hoary Bat (Nycteris cinerea), largest of the northern bats, possessing silvery grey fur and not normally a cave dweller, but wing bones were found in the cave, indicating they may have lived there at one time, and the Little California Bat (Myotis californicus pallidus), whose presence was indicated by a skull picked up amid the dust and debris of a low, inner room.

The chief resident of the caves for centuries has been the Mexican Free-tailed Bat (Tadarida mexicana), also sometimes called the guano bat because its species is especially noted for the huge quantities of commercially excellent guano it produces.

The Free-tailed Bat is distinguishable from the northern bats byits extended tail which reaches about an inch beyond the interleg membrane, by its short fur, and by a strong odor not found with other species. They also possess short, stubby ears, will weigh between 10 and 12 grams, and prefer caves more than most any other species.

The life of the bat is somewhat of a mystery to the average person, partly because they seclude themselves during the day in places relatively safe from discovery, and venture out at night when humans are not around and couldn't very well see them if they were.

Bats resemble the ordinary field mouse in appearance, except for their large, expansive wings. They are mostly insectivorous, living almost exclusively on insects they catch while in flight, chewing their prey into the finest bits with their sharp teeth. A bat will eat enormous quantities of food between sunset and sunrise, and on the basis of only two full meals a night will consume an amount almost half its own weight.

Their diet consists of beetles, flies, and other flying insects, most of which are enemies of civilization; thus the bat is economically a valuable animal.

They leave the mouth of the cave at dusk, heading first for a drink of water at the nearest available spot, then spend the night in search of their food. As the sun's rays begin to appear in the east they fly back to the cave where they dig their tiny claws into the ceiling and remain there sleeping until the sun sets in the west and the cycle starts all over again.

Due to their habits they have few enemies, the great horned owl being one. Very wide awake at night, he often catches an unsuspecting bat, chews the flesh, letting the bones drop to the ground where they remain as evidence of the owl's dinner.

The mating season is normally in March. Along about June the young are born, with this species only one to a female, although in some species a litter of four is born.

The single baby will weigh a fourth as much as its mother. Upon birth it clings to its mother's body night and day until it is strong enough to fly by itself, remaining tight even while the mother flies into the night in search of food.

The habits of bats vary in respect to their living quarters. When insects are abundant, the size of the bat population increases, having been estimated at times to be as high as 7 million in the Carlsbad Caverns alone. As the supply of insects decreases, so does the number of bats. Where they go, and whether or not the same specific bats return in times of insect plenty is not definitely known.

One of the first surveys of the bats in the Caverns discovered that the number seems to grow in the fall, indicating that the cave was used primarily as a home principally for hibernation during the winter.

More recent observations indicate that, at the present time at least, the bats winter somewhere else and live in the cave only during the summer months, going elsewhere to spend the winter. Recently several thousand bats were banded by naturalists and of those which have been returned, one came from Jalisco, Mexico, some 800 miles south of the Caverns.

If both observations were correct, and it may be assumed that they were, for both were made by naturalists, then the habits of the bats do change, but what prompts these changes is still a matter of speculation.

Other matters of speculation are just how the bat flies so accurately in the dark, darting swiftly past innumerable objects yet never hitting one of them. Scientists call this phenomenon "echolocation," a sort of sonar principle by which the little mammals let out a high frequency squeak and judge the distance of objects by the time required for the echo to bounce back to their sensitive ears.

Another mystery is how they find their way unerringly back to the cave, in the early morning as well as after a sojourn to some other area of the world, and how they know when the supply of food has increased to the point that it is sufficient for them to return.

Visitors to the cave often wonder how the numbers can be estimated. 7,000,000 is a lot of bats. This has been reduced to a relatively simple calculation. Cavern authorities counted the number sleeping in one square foot of space, found between 250 and 300 could squeeze into the area. The number of square feet of ceiling space occupied by the sleeping creatures was then multiplied by the bats per square foot, and the estimate was reached.

Life in the cave, it seems, has been governed by the bat, and even this little fellow can hardly be said to live there. Actually, he onlysleeps there winters and during the day. He can't live in the cave all the time since there is no food there for him.

Are there any living creatures that dwell in the cave all the time? Only those that can find food in the cave, and since the eternal darkness prohibits photosynthesis which is vital to all growing plants, other animals or insects would find a food supply almost practically nonexistent, at least any form of plant food.

Yet there are cave crickets. One species was found which was entirely new to science, and they named it after the Caverns, calling the speciesCeutophilus carlsbadensis. Their eyes do not seem to function, apparently depending upon their long antennæ to guide them.

But what do they eat? The contents of their stomachs have revealed bits of insect remains which they have scavenged from the piles of guano. Thus the cave crickets depend upon the bat for their existence.

The cave worm, actually an insect's larva, and a small spider also make their homes in the cave. How long these insects have lived in the cave is anybody's guess. Naturalists think the first few crickets may have fallen into the cave and remained there due to the abundance of the food supply, living peacefully and multiplying at leisure.

But this cricket's Shang-ri-la lost its comparative safety one day, maybe centuries ago, when a cave mouse is thought to have fallen in. He found the crickets abundant and tasty and, since he couldn't climb out, stayed in his new subterranean home. Maybe later Mrs. Cave Mouse met the same fate and together they became parents and grandparents of litters who have lived in the cave ever since.

The cliff mouse also lives his complete life cycle in the black depths of the Caverns, and together with the cave mouse they have a carefree existence, for none of their natural enemies live in the cave.

Any herbivorous animals which might have fallen into the cave would soon die, for the only vegetation to be found in the cave, aside from a certain amount of mold, exists in scant proportions near the cave entrances where there is some light and a little moisture. Thus only carnivorous or insectivorous animals or insects could exist in the vegetation-free depths.

Of the animals which occasionally frequent the cave, the cacomixle, commonly known as a ring-tailed cave cat or even just "ring-tail," is perhaps the best known. This slender raccoon-like animaldoesn't spend all his time in the cave, for he is able to crawl in and out, but he does raise his family in the cracks and crevices of the walls, and eats an occasional cave mouse or guano bat. Outside he eats fruit and other small animals and insects. Apparently they have never been too numerous in the Caverns.

The only other animal to have made the cave its home is the great horned owl. His nests have been found in considerable numbers near the entrances where he has been living for countless years in comparative safety. But, like the bats, he ventures outside in search of food, and spends his nights away from the cave, so at best he, like the ringtail, is only a part-time resident.

So the cricket depends on the bats, the mice on the cricket, and the ringtail on the mice. Thus is the life cycle within the great cave.

But when did man first visit the Caverns? That question is indeed problematic and may never be definitely answered. The early Folsom people have been traced to an encampment site some fifteen miles south of Clovis, New Mexico, which they occupied some time between 10,000 and 15,000 years ago. Chipped stone dart points associated with a post-glacial species of bison have been found imbedded in the earth in rock strata going back that many years.

These wandering hunters were known as "Bison Nomads" and it is not at all improbable that they knew of the cave and frequented it. They could have been the first humans to have entered it.

Then, approximately 2,000 years ago, or at about the beginning of the Christian era, the Basket Maker Indians began to roam this southwest area of the continent. They may have been the physical descendants of the early hunters, but from a standpoint of culture they are credited with having brought agriculture from some focal point in Mexico much further south.

The Basket Maker Indians lived in this area for some eight centuries, and archæologists mark three distinct periods of their civilization. The Basket Maker I people did much hunting and probably roamed the hills and valleys while the maize was growing, moving on to new areas after each harvest. The Basket Maker II group built simple dwellings, lived in caves, and grew numerous vegetables, including squash and beans. The Basket Maker III group established permanent villages, fired pottery, and elaborated on weavings established by both of the earlier groups.

The Basket Maker Indians are definitely known to have visited the cave, for their pictographs have been found on the entrance walls. What is more, skeletons have been found in the cave, some buried in baskets! These were found on shelves in the walls. Other skeletons were found buried beneath piles of guano far back in the cave, together with bits of pottery and broken arrow points.

As to how much the Indians used the cave remains speculative. Some archæologists believe the cave was used mostly as a tomb, while others think the Indians may have lived in the cave for a certain length, basing this observation on the bits of pottery and other remains found along ledges within the walls. These, they point out, definitely were not buried with a body.

Most likely the cave was used for both purposes, for it served the Indian well as a place of refuge and defense, and it appears that the living quarters were located within a close radius of the entrance. Any more extensive use of the rest of the cave would have left more evidence, archæologists say.

But that was well over a thousand years ago. How about recent times?

Several authorities mention the fact that the existence of some form of bat cave or hibernation den was known to ranchers in the Carlsbad area as early as 1880-90. Great swarms of bats would rise out of a mound in the earth at dusk and go winging their way into the horizon. At sunrise they would return.

Was this the present Big Cave? Southern New Mexico contains numerous bat caves and many were known at this time. The existence of a new one didn't seem to overly excite the ranch hands, for exhaustive research has failed to reveal any positive knowledge of the existence of this particular cave as such prior to the time my father noticed the bats.

Millions of pounds of guano had been taken out of the various bat caves in this area by late 1900, and if anyone had stumbled onto this particular cave prior to my father's discovery, they would most certainly have immediately taken out a claim and proceeded to mine the guano, for there was so much of it that it assumed gold mine proportions.

The fact that my father was the first to take out a claim seems proof enough that he was the first to actually find the cave and,realizing its economic potential, did what any other person would have done, simply, take out a claim. It was the first ever recorded for this particular 20 acres and his claim may be seen today on pages 149 and 152 of Book I in the Eddy County Courthouse at Carlsbad.

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