(EDITOR'S NOTE:) Most scientists spend quite a bit of time on the road, and Texas A&M University Center for Mathematics and Science Education (CMSE) researcher Dr. Craig Wilson is certainly no exception. From time to time, he emails us about his travels, regaling us with salient snippets as well as exquisite photographs from the journey.

Anyone who has had the pleasure of meeting (much less working) with Craig will attest that to know Craig Wilson is to learn from him -- a delightful process definitely worth sharing. But don't take our word for it -- read for yourself and enjoy the vicarious experience as he chronicles his encounter earlier this week with Mexican free-tailed bats near San Antonio, courtesy of Bat Conservation International (BCI):

# # # # # # # # # #

23 April 2012

Thanks to Fran Hutchins (BCI), yesterday afternoon and evening I was privileged to witness the emergence of millions and millions of mainly female Mexican free-tailed bats (Tadarida brasiliensis) from Bracken Cave just north of San Antonio, owned and managed by Bat Conservation International. It was awe-inspiring.

The scent of ammonia from the hundreds of feet of bat guano on the cave floor greets you as you approach the cave mouth. A raccoon is ambling around the opening, not innocently, and a hawk circles overhead, both anticipating a bat supper.

A little after dusk, a few solitary fliers appear, but then a swirling vortex of bats becomes visible at the opening, moving counter-clockwise, gaining momentum, until at some unspecified point, the group moves from below the canopy of overhanging rock and swells larger. The amphitheatre at the cave entrance is suddenly full of darting bodies circling higher and higher before a squadron breaks loose and heads upwards and east away from the setting sun. It turns southeast as if gaining its bearing and heads off to feed on emerging insects at altitude. Then the mass of swirling dervishes continues unabated, with swarms breaking off at regular intervals at some unseen signal as the exodus continues, building in frenzy until millions of bats are leaving each hour, until many millions have taken flight. By then it would be completely dark.

At Fran's suggestion, I cup a hand behind each ear and face my head in the direction of the cave entrance. The sound is like raindrops landing on the leaves of a forest canopy and increases in intensity as more bat wings flutter with occasional mid-air collisions until it resembles the cacophony of a Texas thunderstorm. Talking of Texas: When the millions of females each has one pup, the colony swells to twice its size, reportedly making it the largest inhabitation of mammals on Earth. Where else but in Texas!

I sat speechless and tried to absorb everything that I could. What a privileged memory to share, spreading the word that spectacles such as this need to be protected to maintain the richness and diversity of life.

Note: One of the bats' preferred foods is the corn earworm moth (Helicoverpa zea), the insect that forms the focus of the USDA/HSINP Future Scientists Program [which Wilson oversees through the CMSE].


Contact: Shana K. Hutchins, (979) 862-1237 or shutchins@science.tamu.edu

Hutchins Shana

  • Grand Entrances

    Cave entrance (sorry, I could not resist getting in the photo).

  • On a Wing and Prayer

    A few bats emerging low down, where they are prey for raccoons, skunks and snakes hiding in the grass.

  • In-Flight Meals

    Up, up and away. Squadron after squadron headed east and then southeast, deciding at which altitude to feed.

© Texas A&M University. To request use of any of our photographs for educational use or to view additional options from our archive, please contact the College of Science Communications Office.

College of Science
517 Blocker
TAMU 3257 | 979-845-7361
Site Policies
Contact Webmaster
Social Media