Here in Austin, we coexist with 1.5 million Mexican free-tail bats that live near the Congress Street bridge over Ladybird Lake. It sounds big because it is: Austin is home to the largest urban bat colony in the world.
Every night from March through November, hundreds of spectators gather to watch the bats’ nightly exodus, and we even hold a massively popular bat festival every year that attracts folks from all over the world and shuts down an entire section of Congress Avenue, one of the busiest streets in town.
Even though Austin’s bats are largely accepted and even celebrated, many of us still only tolerate the furry aerialists. Or, if we do like them, we often misunderstand their behaviors and benefits. To clear the air, here are ten astonishing reasons to should love Austin’s bats…
10. Bats help protect you from Zika & West Nile Virus
It’s commonly known that bats eat bugs, but do you know which bugs bats prefer? Or how many of those little beasties they devour in a single evening? Bat Conservation International (BCI) says that free-tail bats enjoy a nommy diet of flying ants, moths, dragonflies, wasps, gnats, beetles, and — importantly — mosquitoes, which can carry West Nile Virus and even nastier diseases like Zika. Texas Parks & Wildlife Department (TPWD) adds that Austin’s free-tail colony collectively eats about 30,000 pounds of insects every night, with each bat consuming up to two-thirds of its body weight in bugs. Take that, deadly germs!
9. Bats are actually adorable
Just look at that face. Is that the face of a terrifying, blood-sucking demon? No. Adult Mexican free-tailed bats have oversized ears and little wrinkly faces, not unlike those of terrier puppies. In fact, baby bats are actually called “pups.” When grounded, Mexican free-tails behave a lot like rodents, sniffing at the air and intelligently surveying their surroundings. Once airborne, they squeak! You just think they’re ugly flying beasties. We promise, they’re not.
8. Bat guano is your best friend and you just didn’t know it
Stinky as it may be, bat guano is incredibly useful to humans. Mexican free-tail guano has long been used in the production of environmentally-friendly fertilizers and insecticides. Confederate soldiers fighting in the Civil War also harvested guano to produce saltpeter, the key ingredient in gun powder, after their ports were blockaded. Additionally, Bat guano is an important indicator to scientists working to measure pollution and the effects of climate change. It also helps microbiologists and biotechnologists by giving them bacteria and enzymes that help produce things like detergent and antibiotic drugs. Guano is even used to convert industrial waste and its byproducts into safer materials.
7. Bats are really good at mothering
Mexican free-tailed bats are incredible at the whole mom thing. Each female bat gives birth to one pup per year, which is an amazing feat in itself since baby bats weigh one-third of their mother’s body weight. (To put that into perspective, just imagine birthing a 40-pound human infant!) Even cooler: Baby bats roost together in impossibly tight clusters of up to 500 pups per square foot. Although every pup is nearly identical, mama bats can can locate their babies by keying in on their unique cries and scents.
6. Bats are super-great team players
Mexican free-tailed bats have a lot of natural predators. Since their nightly feeding frenzies happen like clockwork, it’s not uncommon to witness red-tailed hawks and great horned owls swooping in and out of bat streams looking for a quick meal. This is precisely why bats emerge in groups: That whole “strength in numbers” paradigm. Larger concentrations of bats make selecting just one bat to swoop in and grab much more difficult for raptors on the prowl. Bats understand that there’s no “I” in team and that definitely makes them awesome.
Playing host to the world’s largest urban bat colony makes Austin an appealing tourist destination. An estimated 100,000 out-of-towners travel to the state’s capital every year to see our bats, and they bring their wallets and bank accounts with them. In fact, a 1999 study by BCI attributes $8 million in annual tourism spending just to the bats — and newer estimates push that number above $10 million. That’s a big haul for such little guys!
4. They make Bacardi’s business — rum — possible
If you’re a drinker, you know the name Bacardi. You’re also probably just now connecting the dots and remembering that the Bermuda-based company’s logo is a bat (as is the logo of San Antonio’s Freetail Brewing Company). The reason is that Mexican free-tailed bats consume agricultural pests that often specifically target sugar cane. By having Mexican free-tailed bats around, Bacardi’s sugar cane is able to flourish, driving down the production costs of rum and thousands of other sugar-infused products. If you’re sipping a stout cup of rum, a hearty toast to the bats is clearly in order.
3. Bats are crazy-awesome athletes
Mexican free-tailed bats are built for aerial prowess. Their streamlined, webbed bodies make them amazing athletes, allowing them to reach impressive flight speeds and distances, and fly higher than any other bat species on record. According to Merlin Tuttle of BCI, Mexican free-tails often ascend two miles to snack on bugs or to catch tailwinds, and they’ve been clocked flying at over 60 miles per hour. Moreover, TPW reports that free-tailed bats travel as much as 100 miles in a single evening hunting for prey. Some people still complain about driving down the street to the grocery store. Not these guys!
2. They have built-in GPS and night vision
As it turns out, the phrase “blind as a bat” isn’t exactly true. Bats can actually see fine, but they navigate most effectively at night using a unique type of sonar technique called echolocation. As they fly, Mexican free-tails emit a number of differing “calls” at frequencies between 25 and 75 kHz. The sound waves bounce off of nearby objects, namely bugs and obstacles, and travel back to the bats, providing them with the information that they need to be masterful hunters and navigators in the dead of night. That’s pretty dang slick.
1. Bats were almost (sort of) war heroes
During World War II, Mexican free-tailed bats were the subject of a top-secret research program called “Project X-Ray” that aimed to destroy Japanese military capabilities without the use of a single, massive device. The goal of Project X-Ray was to use bats as carriers of tiny little incendiary devices that could be triggered simultaneously, creating seemingly spontaneous fires over a wide area. These “bat bombardiers” were actually on the brink of going operational, but when escaped bats set fire to a friendly barracks and blew up a general’s car during the final testing phase, Project X-Ray was canceled and the nuclear bomb took center stage. However, if you watch the bats at the Congress Bridge, you’ll find that they’re still dropping payloads… Thankfully, these days they just stink and won’t light you on fire.
As an honorary 11th reason why the Congress Bridge bats deserve your affection, we’ll leave you with this:
Bats are just weird! Whatever your opinion of these furry flyers, you’ve got to give ’em at least that. Being uniquely weird is key to making nice with the rest of us endearing oddballs here in Austin. Maybe that’s why they seem to fit in here so well.
To learn more about Mexican free-tailed bats, visit Bat Conservation International’s website or read this incredibly insightful article by bat expert and conservationist Merlin D. Tuttle. All listed facts were pulled from these sources, as well as Texas Parks & Wildlife and the Journal of Comparative Physiology.
Featured photo: Rebecca L. Bennett.