Viewing 10 Million Bats Will Take Your Breath Away
With childlike excitement, my friend, Sam, said "we're going to see the bats!" Sam has an acute fascination with flying mammals. His company, Cavi Consulting, supports Bat Conservation International (BCI) and goes on an annual company retreat to Bracken Cave. When he invited me to tag along this year, I realized that the adventure was too rare to decline.
Bracken Cave is a 30-minute drive from San Antonio. Our small caravan arrived at the gravel-road entry point, handed in our liability waivers, then waited patiently for direction. Once we learned the rules of the property, the BCI employees led us and the other participants to a small, outdoor seating area. BCI keeps their eco-tours small, so there were only about 25 people total in our cohort, including the five or six BCI representatives and volunteers who acted as guides and information hubs. A BCI employee addressed the crowd, sharing germane bat trivia and recounting how their organization and others teamed up to acquire and protect ~3500 acres of property surrounding the cave.
He explained that the colony we were about to witness is comprised only of females. These Mexican free-tailed bats mate in Mexico and travel north to Bracken to gestate and bare their young. As we were there toward the beginning of the summer when the females are pregnant, the colony was "only" 10-million strong. However, in late July when they give birth, the colony swells to about 20-million, making it the largest bat colony in the world.
Bats emerge from the cave at night for two primary reasons. First, as their diets consist of insects, they feed when their prey are most active. Second, since bats are mammals, it takes extraordinary effort for them to fly. The constant flapping of their wings to keep them airborne requires vast amounts of energy and, therefore, creates heat. The sunless evening enables them to remain cooler.
BCI then led us farther into the property, first to an old guano (bat poo!) mine and finally to the cave itself. The viewing area is several feet away from the mouth of the cave, and no one goes inside--not even BCI members. They explained that the 87+ feet of guano that has accumulated on the cave floor over the past several thousand years prevents visitors. If that weren't enough, the flesh-eating beetles crawling across the guano keep everyone out. The beetles wait for the baby bats unlucky or unfit enough to take their first flight successfully.
We all waited patiently and in near silence on large rocks, anticipating the rush of bats at an estimated 8:47 pm. Like clockwork, they emerged from their cave in streams, following the current of the wind.
My friend who had seen these bats before warned me that no camera could capture the majesty of the moment. This event has so much magnitude, it altars Doppler radar readings and reduces the insect population by 100 tons annually. A camera simply will not do it justice.
The bats exited the cave in a cyclone, slowly traveling skyward and across the light of the full moon. It's impossible to capture the feeling that washes over you as millions of tiny mammals rush over your head and swirl in droves with the undulation of the wind. If you cup your ears and listen closely, you can easily hear the flapping of millions of little wings.
The experience will dwarf you. Realizing that these bats have been following the same migratory and feeding patterns for thousands of years creates a clearer sense of time, reminding you of how small your footprint is on nature's timeline. This nightly feeding happens in perfect accordance with the environment. It happens en masse, and it happens with or without you.
Bracken Cave is a 30-minute drive from San Antonio. Our small caravan arrived at the gravel-road entry point, handed in our liability waivers, then waited patiently for direction. Once we learned the rules of the property, the BCI employees led us and the other participants to a small, outdoor seating area. BCI keeps their eco-tours small, so there were only about 25 people total in our cohort, including the five or six BCI representatives and volunteers who acted as guides and information hubs. A BCI employee addressed the crowd, sharing germane bat trivia and recounting how their organization and others teamed up to acquire and protect ~3500 acres of property surrounding the cave.
He explained that the colony we were about to witness is comprised only of females. These Mexican free-tailed bats mate in Mexico and travel north to Bracken to gestate and bare their young. As we were there toward the beginning of the summer when the females are pregnant, the colony was "only" 10-million strong. However, in late July when they give birth, the colony swells to about 20-million, making it the largest bat colony in the world.
Bats emerge from the cave at night for two primary reasons. First, as their diets consist of insects, they feed when their prey are most active. Second, since bats are mammals, it takes extraordinary effort for them to fly. The constant flapping of their wings to keep them airborne requires vast amounts of energy and, therefore, creates heat. The sunless evening enables them to remain cooler.
BCI then led us farther into the property, first to an old guano (bat poo!) mine and finally to the cave itself. The viewing area is several feet away from the mouth of the cave, and no one goes inside--not even BCI members. They explained that the 87+ feet of guano that has accumulated on the cave floor over the past several thousand years prevents visitors. If that weren't enough, the flesh-eating beetles crawling across the guano keep everyone out. The beetles wait for the baby bats unlucky or unfit enough to take their first flight successfully.
We all waited patiently and in near silence on large rocks, anticipating the rush of bats at an estimated 8:47 pm. Like clockwork, they emerged from their cave in streams, following the current of the wind.
My friend who had seen these bats before warned me that no camera could capture the majesty of the moment. This event has so much magnitude, it altars Doppler radar readings and reduces the insect population by 100 tons annually. A camera simply will not do it justice.
The bats exited the cave in a cyclone, slowly traveling skyward and across the light of the full moon. It's impossible to capture the feeling that washes over you as millions of tiny mammals rush over your head and swirl in droves with the undulation of the wind. If you cup your ears and listen closely, you can easily hear the flapping of millions of little wings.
The experience will dwarf you. Realizing that these bats have been following the same migratory and feeding patterns for thousands of years creates a clearer sense of time, reminding you of how small your footprint is on nature's timeline. This nightly feeding happens in perfect accordance with the environment. It happens en masse, and it happens with or without you.
