World's Largest Bat Colony Saved from Land Developer

The world's largest bat colony has just recently been saved from a San Antonio land developer thanks to efforts from conservation groups, Nature Conservancy announced Friday, ensuring the protection of vital habitat, including the well-known Bracken Bat Cave.

As part of a $20 million deal that took place on Halloween, a 5,000-acre swath of land was taken out of the hands of the development company Galo Properties and placed into the protective care of the non-profit group Nature Conservancy. Perhaps the most important part of the exchange was that it secured San Antonio's famous Bracken Bat Cave, home to 150 million bats and unofficial maternity ward for pregnant females returning from wintering in Mexico.

"Bracken Cave is the largest colony of bats in the world, somewhere between 15 and 20 million Mexican free-tail bats," Nature Conservancy spokeswoman Laura Hutchins told NPR. "So they deposit the baby in what we call the nursery section of the cave, which is just millions of hairless baby bats, so when you look at it, it's a ceiling of pink, hairless baby bats."

The gestation period of a female bat, according to Defenders of Wildlife, can range anywhere from 40 days to six months. And during that time, nursing moms are gaining their weight in milk as well as eating their body weight in insects every day.

"So this colony alone, that's 100 tons of bugs every night," Hutchins explained to NPR.

Not only is this food frenzy necessary to produce healthy pups, which will only weigh up to 25 percent of its mother's weight at birth, but as a bonus it also serves as natural pest control. Nationwide, a press release says, bats save farmers $23 billion annually in reduced crop damage and pesticide use.

So thanks to Nature Conservancy, along with Bat Conservation International (BCI), those walking down Texas trails in the countryside known as Crescent Hills will still come upon the Bracken Bat Cave's gaping 60-foot-wide mouth, instead of 3,500 homes like the developer planned. (Scroll to read on...)

[Credit: Bat Conservation International]

"We would have had hundreds of bats congregating on the porches, around street lights, around swimming pools," BCI Executive Director Andy Walker told NPR. "Baby bats that were either resting or sick, or older bats that were sick, might be found by family pets and brought into houses."

Not to mention that health officials were worried about potential rabies incidents with so many bats displaced.

Almost 1,000 bat species can be found worldwide, Defenders says, and while some like those in San Antonio number in the millions, others are dangerously low or in decline. This can possibly be attributed, at least in part, to the deadly bat disease known as white-nose syndrome, which spread to half of US states back in April. It affects hibernating bats, causing them to behave uncharacteristically like flying during the daytime. Bats' precious energy reserves are then drained, leading to their death in the winter months.

Past reports indicated that at least six million cave-dwelling bats had perished due to white-nose syndrome (WNS), but luckily for little brown bats in Vermont, things seem to be looking up. A small colony that hibernated in a Dorset cave last winter slept easy, showing no signs of WNS.

At least for the Bracken Bat Cave bunch, which fortunately hasn't been devastated by this disease, it seems that mothers and pups can sleep soundly, safely nestled in the Texas hillside.

"The emergence of these millions of bats, as they spiral out of the cave at dusk for their nightly insect hunt is an unforgettable sight," Walker added. "The protection of Crescent Hills helps ensure this centuries-old wildlife habitat will continue to provide a safe home for one of the region's most unique and important inhabitants."