Karine Aigner, wearing a facemask to protect herself from the high levels of amonia produced by the bat guano, sets up a photo shoot at the mouth of Bracken Cave. Photo © Karine Aigner

Outtakes: From Inside the World’s Biggest Bat Cave

October/November 2015

Contrary to the old saying, bats are not blind. So photographer Karine Aigner had to be careful when capturing images for a Nature Conservancy magazine story about protecting Texas’ Bracken Cave, home to 15 to 20 million Mexican free-tailed bats that make up the largest single colony of bats in the world. She worked with bat experts to find ways to take pictures of the animals while using lighting techniques that would not disorient them.

White lights were briefly permitted at the mouth of a nearby cave well before sundown, when the light would not affect the bats. And at Bracken Cave even more rigorous and non-intrusive tactics were required—only infrared and other sophisticated lighting techniques were used to capture the bats’ nightly exodus.

“It’s such a beautiful mass behavior,” Aigner says. “Once they start coming out of the cave, they fill the sky … I could watch this every night.”

Here, we’ve rounded up some of the best outtakes from the shoot. (See more photos and read the story from our October/November issue here).

Visitors at Bracken Cave shoot photos and video of the flight. Mexican free-tailed bats emerge in such large and dense concentrations that they appear as storm clouds on weather radar.
Visitors at Bracken Cave shoot photos and video of the early evening emergence. Mexican free-tailed bats exit the cave in such large and dense concentrations that they appear as storm clouds on weather radar. Photo © Karine Aigner
Bats arrive at Bracken Cave in March from Mexico, where they spend the winter. Before they arrive, they mate and the males form their own bachelor colonies. The pregnant females move between about a dozen caves within a 100-mile radius of San Antonio, with the largest colony inhabiting Bracken Cave.
Bats arrive at Bracken Cave in March from Mexico, where they spend the winter. The bats mate before they migrate, but the males depart to form separate bachelor colonies. The pregnant females move between about a dozen caves within a 100-mile radius of San Antonio, with the largest colony inhabiting Bracken Cave. Photo © Karine Aigner
Babies are born in early summer, and the mothers start to consume one-half to three-fourths their body weight in insects per night to feed them. Their formidable appetite provides a critical benefit to central Texas: wide-reaching insect control.
Babies are born in early summer, and the mothers consume one-half to three-fourths their body weight in insects per night to feed them. Their formidable appetite provides a critical benefit to central Texas: wide-reaching insect control. Photo © Karine Aigner
Once pups are born, the cave’s population balloons to upwards of 20 million bats. The babies cling to the rock—up to 500 pups per square foot.
Once pups are born, the cave’s population balloons to upwards of 20 million bats. The babies cling to the rock—up to 500 pups per square foot. Photo © Karine Aigner
Aigner says bats get a “bad rap” that they don’t deserve. “I’d never been this close to them and had that close up view of them,” she says. “They’re really cute...they’re really one of nature’s miracles.” Photo © Karine Aigner
Aigner says bats get a “bad rap” that they don’t deserve. “I’d never been this close to them and had that close up view of them,” she says. “They’re really cute…they’re really one of nature’s miracles.” Photo © Karine Aigner
Aigner uses sophisticated lighting techniques to capture an emergence at Bracken Cave, which happens each night at dusk from March through October.
Aigner uses sophisticated lighting techniques to capture an emergence at Bracken Cave, which happens each night at dusk from March through October. Photo © Karine Aigner
Millions of Mexican free-tailed bats flutter out of The Nature Conservancy’s Eckert James River Bat Cave Preserve, located about 100 miles northwest of San Antonio. The public battle for Bracken Cave elevated the understanding of bats, and their maternity caves, across central Texas.
Millions of Mexican free-tailed bats flutter out of The Nature Conservancy’s Eckert James River Bat Cave Preserve, located about 100 miles northwest of San Antonio. The public battle for Bracken Cave elevated the understanding of bats, and their maternity caves, across central Texas. Photo © Karine Aigner

— NCM

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22 comments

  1. Spectacular photos–and a rare chance to see something important that is rarely seen by human eyes. Thank you so much.

  2. Wow! What beautiful photographs. Such a close up look at one of my favorite animals. Stunning.

  3. Wonderful photos. How I’d love to see all that Karine has seen! I’ve always loved bats and it is very wonderful to see evidence to change people’s old fashioned ideas about bats. Thanks ever so much.

  4. These are some of the best images of bat activity I’ve seen. Did engravings of bats when I was in college, and bats come out at near dark during the summer in my yard and alley area. They deserve our reverence and protection.

  5. I have the utmost respect for bats and so am happy to see this article and the photos. What a sight to see that many bats at one time. Thanks to those who helped protect them. I have seen bats take flight in the evening and it is always a thrill. Years ago my cat actually brought one into the house. Luckily I caught her, she let go, and the bat flew to my bedroom where s/he spent the night with the door close and thewindow open for an easy escape the next morning.

  6. I was in a small rain forest in northern Madagascar from where we walked into a massive bat cave. Just the two of us had flashlights to enter the cave, and as the sun was beginning to disappear, my guide suggested we stop at a certain point in the cave and turn off our lights, asking if I were afraid of bats, “by the way”.

    I replied I wasn’t and so we were suddenly immersed in darkness. Then, whoosh, a sudden somewhat harmonious sound and bats were flying just past my neck, over my head , all around us, to get out of the cave to feed. It was an incredibly exciting couple of minutes that I will always remember.

  7. I love bats. Such wondrous creatures. They are so important to the natural ecology of this earth. It would be seriously detrimental if they no longer existed. These pictures are truly incredible. It’s not often that people can get to view their existence. And these pictures really provide a wonderful pictorial of a really unique little animal.

  8. Great story, but I have a question. What is the range of flight of the bats from the cave?

  9. Wonderfukl..my husband has been there and wanted to share it with me but haven’t made mit yet. These photos show the rest of us such a great close-up view. Thanks.

  10. Really great photos and data collected about these bats. And I enjoy learning of the research conducted. Thanks for the good work.

  11. I live on the central Oregon coast and have been facinated by the local bat population for years. My wife and I have done all we can to make our area very bird friendly and would now like embark on the same thing for bat. We are unsure how to start without messing up our relationship with our feathered friends. Any suggestions?

    1. Hi Jeff,
      Encouraging bats in your yard is a great idea! And I have never heard of any conflicts between bats and birds. Installing a bat house is probably the best thing you can do. Bat Conservation International http://www.batcon.org/ is an excellent resource for bat boxes (and bat box plans) and other ideas you can do to help bats. Thanks for your interest in conserving these great creatures!

      Matt Miller
      Cool Green Science editor

  12. love it! these look so good, wonder what the pics that were used look like.

  13. Nice story and wonderful images of what looks like a healthy colony of bats. Here in New Jersey our bats are in trouble with “white nose” disease and populations are way down. I used to have some living in my roof rafters but have not seen one in about five years or more. Let’s hope they can find a cure and bring back our New Jersey bats soon. The mosquitoes are having it too easy up here and there are too darn many of them in the summer in our neighborhood. Can we borrow some of yours from Texas?

  14. I’ve been listening to the news accounts about Zika virus and how they are discussing releasing a genetically modified mosquito– of the type that carries the virus– that cannot reproduce and they were projecting that would lower that particular mosquito population by over 80%. I’m wondering what affect that would have on the food source for birds and bats in the areas where those mosquitos are normally found?