North America's bats are in trouble. Even before millions began falling victim to the fungal disease known as white-nose syndrome, many species were already losing valuable habitat to humans. And now, with fewer bug hunters in the skies at dusk, many humans are also losing the long-overlooked value of neighborhood bats.
Fortunately, there are ways for almost anyone to help. Setting up a bat house is a popular option, offering bats a safe place to roost while also encouraging them to hunt insects in our habitat. Bats have very specific housing needs, though, often refusing to occupy a bat house with the wrong dimensions, materials or location.
And that's why two friends from Kentucky came up with BatBnB, which starts an Indiegogo crowdfunding campaign today. Their goal isn't to reinvent the bat house, but to solve common problems with cheap or DIY versions. BatBnB has three models so far — all optimized for picky bats with help from Merlin Tuttle, the ecologist and bat expert who founded Bat Conservation International (BCI) in 1982 — and sleek designs meant to help people embrace bats as a blessing, not a curse.
"Most cheaper models on the market aren't designed well to the specifications that experts recommend," says Christopher Rannefors, who started BatBnB with friend Harrison Broadhurst. "Also, the aesthetics — most models on the market aren't that pretty. They're just plain pine boxes that people tuck deep in their backyard."
"As part of rebranding bats," he adds, "you have to bring bats back to the front of the conversation. It's not something you hide, but that you put up proudly at the front of your house or your barn. You want to show it to people. A person's home and yard are a reflection of themselves, so if a person cares about conservation and protecting their family from mosquitoes and other pests, BatBnB does that."
Ruling the roost
The dynamic duo behind BatBnB say their mission is to help humans and wildlife "live together in mutual benefit." Rannefors grew up building bat houses with his dad, although neither co-founder has formal bat expertise. (Rannefors handles marketing and operations for BatBnB; Broadhurst designs and builds the houses.)
So they turned to people who are bat experts, namely Tuttle — whose work at BCI popularized bat houses in the U.S. decades ago — and conservation biologist Rob Mies, executive director of the Michigan-based Organization for Bat Conservation.
No one can guarantee where wild bats will choose to roost, Tuttle says, but there are many ways to maximize the appeal of a bat house, which is what he helped BatBnB do. "Initially there were problems that I pointed out, and they were very responsive in correcting those," he tells MNN. "I believe the product they have now is outstanding."
The houses have precise dimensions based on bats' known preferences, and resist moisture leakage with caulk, tongue-and-groove connections and a sealant that's applied before shipping. They're also vented, and tall enough to provide a full thermal gradient, which Tuttle says can be critically important. And while many bat houses aren't properly roughened, BatBnB models are cross-cut every half inch, making it easier for bats — especially babies — to cling onto surfaces and maneuver.
"I see bat houses routinely that are basically put together with staples, not pre-treated, not painted, they warp and leak," Tuttle says. "And no bat wants to live in a leaky house any more than we do."
The hero Gotham needs
Despite their spooky reputation, bats are hugely beneficial. North America has dozens of small, insect-eating species like the little brown bat, just one of which can eat 60 medium-sized moths or 1,000 mosquito-sized flies in a single night. Bats also save U.S. corn farmers about $1 billion per year by eating crop pests, and their value to U.S. agriculture overall ranges from $3.7 billion to $53 billion per year.
Many insect-eating bats roost in trees during summer, seeking security in tight spaces like gaps between the bark and trunk. Bat houses are designed to mimic those narrow roosting spaces, which have grown less common with the loss and fragmentation of native forests. Combined with the scourge of white-nose syndrome, Tuttle says "there's never been a time when bats needed help more."
"Bats are largely roost-limited, and we've cut down the ancient forests that included lots of trees with hollows," he says. "A lot of those bats now are pretty desperate for homes, and bat houses do provide a pretty good alternative."
BatBnB's houses will later sell for $275, but they're initially available at discounted rates through the crowdfunding campaign to help the company get off the ground. Rannefors and Broadhurst also don't discourage people from building their own bat houses, and are even thinking about making their plans available for download.
They hope to attract customers who already have a bat house, too, since research shows bats are more likely to occupy one if others are located nearby. That's because their natural roosts under loose bark can be damaged or destroyed by a storm, Tuttle explains, potentially forcing the bats to abruptly find a new roost. So bats have learned to instinctively prefer housing options that are clustered together.
"They're looking for multiple roosts available," he says. "In one study, we found that by putting up two or more bat houses in a single area, we could double the occupancy rate just because bats felt secure in knowing they had alternatives."