Ever since we discovered that we live within a few hours' drive of the largest bat colony in the world, we have been meaning to make the trip to the outskirts of San Antonio to see it. Bracken Cave is home to millions upon millions of Mexican Free-Tailed Bats. Just how many is hard to say, but some estimates claim 20 million plus!
Our first planned trip was flooded out after extreme rains at the end of May, but we were able to reschedule and make the mid-June overnight camping event. The cave is on private property, owned by Bat Conservation International, but a very affordable membership includes a "member night" viewing. I was quick to snap up the night which had camping included, as I was eager to see not just the bats' exodus into the night, but their dawn return as well. We borrowed a tent from one co-worker and a few sleeping bags from another, and we were in business. Finding the cave was not as straight forward as we had expected ... so we arrived slightly later than the others, but still with plenty of time to join in the nature walk before the bats' exit.
We passed by the cave in the late afternoon sun on our walk, to return later in darkness. We were pleased with how close we could sit.
The wildflowers are beautiful!
The old guano mine still stands on the cave's roof. Bat poop has a secret ingredient once used in making gunpowder: potassium nitrate, aka saltpeter.
We me this impressive crab-like spider on our nature walk.
As the sky darkened, our group gathered around the cave. One of the tour guides - with opportune timing - found a walking stick and let everyone take a look. I had never seen one outside of an aquarium before. He's huge!
Soon we could see the bats swarming around the mouth of the cave, preparing for their nightly feast. Eventually, their circle widened until they were looping the entire area outside the cave, and they finally took off in a wide stream of tiny winged bodies, heading out and behind the cave to catch tons (literally) of mosquitoes, moths and other pests.
Due to the darkness, my photos aren't that great, but it's enough to get an idea of the sheer number of bats. Bracken is more than just the largest bat colony - it's the largest known concentration of mammals. The bats roost here from about March to October, where each mother gives birth to one pup, then migrate 1000 miles to the south to winter in Mexico. As many as 500 bat pups can huddle together on one square foot of the cave.
After a short time, we walked to the other side of the cave and watched them fly just a little ways above our heads. Misha and Sebby caught grasshoppers and tossed them upwards, convinced they were feeding the bats. We could hear the soft hum of their wings as they continued to pour out of their cave. It takes hours for the cave to empty.
Once it was too dark to see, we returned to our camp, where the guides so generously provided not only a toasty campfire, but s'mores as well!
It was so hot and stuffy in our tent that we left the rain fly off for the increased circulation. And that was how I came to be dashing around in my underwear outside of my tent in the middle of the night as the rain hissed down while I tried to attach the fly, only to have it snap back in my face. Repeatedly.
Eventually I must have fallen back asleep on our dampened blankets, because all too soon our guide was calling us gently to wake up. It was still pitch black out, about 5 a.m. And still raining. Misha and Sebby wouldn't budge, and Josh was content where he was. Though waking up wasn't what my body wanted to do, I was determined to get what I had come for, so I straggled along behind a small group of the other early risers. The rain was not intense, but it was enough that I was completely soaked in a fairly short time, as I had not thought to bring even so much as a long-sleeved shirt.
Slowly at first, then in great numbers, the bats swooped in. I had been hoping to get better pictures in the morning, but by the time the rain stopped, most of the bats were already home. You can see the ghost-like wings palely outlined in the mouth of the cave.
With only the occasional bat straggling home, I started back to the tent, where I met Misha and Josh. Misha hadn't even realized that I had tried to wake him up earlier. Though disappointed we had to pack up and leave so quickly, the kids enjoyed seeing the bats.
Rather than go into San Antonio, we decided to head straight home and relax with the last bit of our Sunday, especially since we were in sticky, dirty clothes. Besides, we felt like we had seen the best part of San Antonio already - the bats!