Every evening in summer and early fall, a half million Mexican free-tail bats exit Carlsbad Caverns in a black wave in their daily search for insects.

The nightly bat flight was discovered in the late 1800s by local cowboys who noticed “smoke” coming out of a cave.  Jim White is credited as the first “explorer” of Carlsbad Caverns in 1898.  In Jim White’s Own Story he wrote: “…any hole in the ground which could house such a gigantic army of bats must be a whale of a big cave.”

But what you see in this early November photo are not Mexican free-tail bats, which had already migrated south for the winter.  Park rangers believe this was a few hundred thousand brown bats using the caves on their migration south.

Park regulations prohibit photographing the bats during their nightly exit because the bright flash and infrared focus mechanism on most modern cameras can disrupt the bats’ sonar capabilities.  However we shot these photos from far away in the parking lot and used a telephoto lens so as not to disturb the bat flight.

With such a thick concentration of bats, it’s amazing there are not many more mid-air collisions.

This mass bat migration from Carlsbad Caverns lasted over two hours and continued after sunset.  We couldn’t see the bats anymore, but we could hear their wings flapping overhead.

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