Bat Flight: Restoring Awe and Wonder

Sunday, August 14th, 2016

Last night I had the gift of one of those experiences that reminded me that the word "awesome" once meant to be filled with awe, a feeling my dictionary describes as "reverential respect."

I led a field trip to the Orient Mine in the northern San Luis Valley to see the evening out-flight of Brazilian Free-tailed Bats (Tadarida brasilensis). Some 230,000 to 250,000 male Brazilian Free-tails spend their summers roosting in the cool and safe confines of that partly collapsed underground mine, emerging each evening around sunset and flying 100 or more miles to catch tons of flying beedles and moths. 

The batchelor colony in the Orient Mine is unusual because it's all males, and it's the farthest-north and highest-elevation summer roost of this subtropical species (at least that we know now).

Brazilian Free-tailed Bats migrate north from the tropical forests of Mexico and Central America in spring, and congregate by the millions in maternity  roosts in caves in the southern Southwest. They are the bats of Carlsbad Caverns National Park in southern New Mexico, and of Bracken Cave in the Texas Hill Country. 

Our only large Colorado roost is small by comparison to those, but it's also hundreds of miles north and far higher, located in the Sangre de Cristo Mountains at about 9,000 feet elevation.

The view from the Orient Mine toward the distant San Juan Mountains across the San Luis Valley. 

The bats usually fly out for their night's feeding at about sunset, so when I planned the trip, I calculated that the group would need an hour to drive the 40+ miles to the trailhead--the last four miles on a steep two-track that is fairly rocky in spots, so it's slow, and another hour to do the mile and 700 feet of elevation gain to the viewing area for the bat flight at the mouth of the collapsed mine. 

I checked the time when the sun would set, and called the land trust that owns the mine to find out what time the bats were flying out. "Sunset," I was told. "Be there 15 minutes early to get settled in before the first scouts fly out." 

Okay. Subtracting the two-hour travel and hiking time and adding 15 minutes for good measure, I knew when we needed to hit the road. All seemed set. Until I got a frantic email on Thursday letting me know that the bats had changed their schedule and were flying out an hour earlier. I recaculated the departure time and sent out emails to the participants. 

Our caravan set off last night at ten to five; the first part of the drive went quickly. The two-track road turned out to be a bit more of a challenge, but we still made it to the trailhead only about ten minutes behind my target time. 

I gave a short talk on geology, the bats, and the mines, and then off we set up the old narrow-gauge railroad right of way, the gentlest part of the trail. I talked about plants and wildlife along the way, and then as we turned up through the town site of Orient, which sprang up in the late 1800s in the narrow mountain valley next to the mines and vanished as quickly as it had sprouted when they closed in 1940, we slowed as the grade steepened. 

By the time we reached the viewing area next to the collapse hole, it was very close to the time the bats had emerged the night before. We could smell the guano on the air coming out of the mine tunnels, and we gathered in hushed anticipation, along with a couple of dozen other visitors, and waited. 

And waited. Finally at just past seven-thirty, I spotted a bat fluttering overhead. And then another, and in moments a stream of bats began to pass overhead in a twisting current of flapping wings. 

Bats beginning to emerge from the "Glory Hole," as the collapsed portion of the mine is called. 

For the next twenty minutes, bats spiraled out of the mine and flew past in a noisesome current. They were so close that we could feel the wind of their passage and hear the sound of wings cupping the air with each beat. 

We stood spellbound, awestruck by the swirling vortex emerging from the cave, by the way the sun's rays struck and glittered on bare-skin wings as the bats flew downhill from the mine, by the precision of the swirling river of furred bodies, their writing column seeming never-ending. 

It was, as I told the trip participants later, far and away the best view I had ever experienced, because it was in daylight and we could see the dance of the bats' flight so clearly; usually by the time they emerge, the mine tunnels are in shadow and they vanish quickly into twilight.

 

We watched, silent, awed, until as suddenly as if someone had turned off a tap, the bat flight ceased. 

As we hiked back downhill to the trailhead at a more leisurely pace, we stopped often to admire the sunset, to talk about plants along the trail, to read and discuss the interpretive signs at the townsite of Orient, and, as darkness snuffed the day, to admire Jupiter, shining above the western horizon. 

A stunning sunset on the hike back

All the way back to Salida, down the trail and the old railroad grade to the trailhead, bumping down the rough road to the gravel county road and then speeding in a cloud of dust to the highway, then driving over the pass and dropping down into our own valley, pricked with clusters of lights in the darkness, I saw again that stream of bats spiraling out of the cave and flying in a twisting current over the valley, the air filled with the clapping sound of beating wings.

When I finally reached home, exhausted, at quarter past ten, I was still smiling, still awed by the wonder of seeing, hearing, and feeling the passage of hundreds of thousands of bats exiting an old mine on a Colorado mountainside to fly into the twilight in search of food.   

The root word for "awe" comes from a Middle English word that also meant "terror" or "dread," a recognition of the close relationship between opposing pairs of powerful feelings: awe and dread, love and hate, fear and joy. Last night's bat-flight provoked my awe, and restored my sense of wonder and gratitude at being part of this living world.