When bat researcher Leonel Ayala invited me to visit a cave he
had found overlooking Lake Chapala, I figured it had to be
typical of every other cave I’ve seen in the area: a closet-size
hole which only gets dark at night. However, when he casually
added that he’d appreciate my help in surveying and mapping the
place—which he called La Cueva de Toscano—I figured his cave
might even turn out to be two or three closets long. Well, I was
in for a big surprise.
One day Leonel and I picked up caver Luis Rojas and drove off
towards the town of Jamay, which is located at the eastern end
of Lake Chapala. We parked in front of a lakeside restaurant and
Leonel went off to talk to the owner of the land on the other
side of the highway. “We have permission to visit the cave,” he
announced a little while later and off we went.
After working our way through a grapefruit orchard, we came to a
high promontory overgrown by a giant amate fig tree whose
tendril-like roots formed a bizarre kind of Chinese string
The trail took us to a higher point from which we could see the
lake in all its glory. Yet a little higher, at an elevation of
1650 meters, we came to a fissure in the rock, two meters wide.
“This is it,” said Leonel.
Aha, I thought: just a crack. That’s about all you can expect in
volcanic conglomerate like this. But we took out our tape,
compass and clinometer and began surveying.
Well, the floor of this crack was slanted upward at an angle of
about 49 degrees and when we got up to the very top we found
ourselves standing in the doorway of a big room eight meters
high with horizontal passages going off in two directions.
“What?” I gasped. “Leonel, this looks like a real cave—why
didn’t you tell us?” Leonel, however, was too busy watching the
screen of his video camera to answer me. He had lit up the roof
of the big room (which was in total darkness) with invisible
infrared light and was watching the antics of the many bats
roosting there. Zooming in on two of these playful creatures, we
could see every one of their whiskers in perfect focus. Not only
that, Leonel has a device which lowers the frequency of the
bats’ voices to within human range, so we could all hear the
chattering, twittering and whistles of the socializing,
quarreling and love-making which was going on above us. What a
World's Fastest Bats
We learned that there are two kinds of bats living in this cave,
both rather remarkable. One of them is Pallas’s Long-Tongued Bat
(Glossophaga soricina), famous for having the fastest metabolism
of any mammal in the world, similar to that of a hummingbird.
The other is the Jamaican Fruit Bat (Artibeus jamaicensis), one
of the world’s most efficient mammals in terms of food
digestion. It processes its food in about 15 minutes. “I read
about this cave in a book on Mexican bats,” said Leonel. “The
author visited this cave decades ago.”
Leonel’s bat book is called Los Murciélagos de México by
Bernardo Villa (UNAM 1966). So far this book has successfully
led us to two caves we knew nothing about, so I would say the
cavers of the world should look into sources like this for
rediscovering long-forgotten caves!
While Leonel took notes on the bats’ behavior, Luis and I went
off to survey the passage on the left, whose walls were slanted
at a 51-degree angle. Here we spotted several flat spiders of
the sort you’re more likely to find crawling on the rocks
alongside Río Caliente.
also discovered a Chinche Hocicona on
the wall, a blood-sucking “vinchuca” or Vampire Bug. This is the
dreaded Triatoma infestans, which transmits trypanosomiasis or
Chagas Disease, the infirmity which laid Charles Darwin in his
tomb. These bugs have radar-like heat sensors in their antennae
and subsist on a diet of blood. They’re most common in South
American where they typically glide into your bedroom on air
currents, inject a quarter-inch long needle into your neck and
suck out up to seven times their body weight in blood. Then,
uncouth visitors that they are, they defecate on your skin, thus
depositing a parasite (Trypansoma cruci) which up to twenty
years later, might give you a heart attack. As there is no cure
for Chagas Disease, according to the University of Texas, I
recommend you avoid sleeping “under the good old stars” in
Mexico and that goes for sleeping in caves too. Believe it or
not, we put up tents when we do sleep underground.
Chinche Hocicona doesn’t bother people who are
wide awake and moving around, so we weren’t worried and carried
on our survey.
As soon as we crawled into the right-hand passage, we knew this
cave was something out of the ordinary. We found ourselves in an
almost square-shaped tunnel 75 centimeters wide by 85 high and
perfectly straight. Normally this means you are in a man-made
passage inside a mine, but this tunnel in Toscano’s Cave showed
no sign of chiseling or chopping. We followed it for 12 meters
to a room where you had to walk above a deep crack half filled
with water, supporting your weight on nubs sticking out of a
wall. That’s where I turned around, but climbers Luis and Leonel
took over the survey.
On the other side of the water were passages heading left and
right, and once again they were square-shaped crawlways like the
first. The left branch ended abruptly after 27 meters, while the
right-hand one curved around toward the cave’s entrance and
actually passed underneath the entrance fissure, only to end at
the foot of a nine-meter-high tube about a meter in diameter.
I was standing outside of and above the cave entrance when I
suddenly saw Leonel’s head pop up right out of the ground. A
weird cave indeed it turned out to be, with a total of 118
meters of passages, most of them nearly square in shape and
about a meter high and wide…mighty suspicious, eh? Well, we are
waiting for the experts to explain it all to us.