bats

Bat colony checks in to hotel; 200 guests check out, unaware of rabies scare

Health officials in Wyoming are sinking their teeth into a meaty task.

Over 200 people who stayed in a hotel in Grand Teton National Park between May and July may have unknowingly been exposed to rabies, according to Wyoming Public Radio.

In an announcement on Friday, the National Park Service reported finding evidence of a bat colony in the attic. The discovery was made after there had been at least eight incidents in which guests encountered winged mammals inside the hotel.

Now, the Wyoming Health Department is trying to contact all guests who stayed in a block of rooms under the bat’s lair. Specifically, they’re reaching out to the over 200 who stayed in rooms 516, 518, 520, 522, 524, 526, 528, and 530 at the Jackson Lake Lodge between May 15 and July 27. It was on July 27 that the eighth bat run-in occurred and the hotel closed the eight rooms.

“Although there were a lot of people exposed in this incident, one positive about it is that we know who 100 percent of those people are,” Travis Riddell, director of the Teton County Public Health Department, told Wyoming Public Radio.

In Wyoming, bats are one of the two main carriers of rabies, the other being skunks. But bats are of particular concern because—unlike an extremely obvious skunk attack—people might not be aware of bat exposures.

Inconspicuous risk

The rabies virus generally transmits through saliva via bites and scratches, and bat bites and scratches are easy to miss. The most common bat in Wyoming is the small brown bat, which weighs less than half an ounce on average—though they can look larger due to their wide wings. These teeny bats, with their wee teeth, can leave bites and scratches that are not visible, do not bleed, and are not painful.

Bats use echolocation to make mental maps for navigation

bats, Behavioral science, Biology, echolocation, navigation, neurobiology, Science / Mike M. / November 1, 2024

Bat maps

To evaluate the route each bat took to get back to the roost, the team used their simulations to measure the echoic entropy it experienced along the way. The field where the bats were released was a low echoic entropy area, so during those first few minutes when they were flying around they were likely just looking for some more distinct, higher entropy landmarks to figure out where they were. Once they were oriented, they started flying to the roost, but not in a straight line. They meandered a bit, and the groups with higher sensory deprivation tended to meander more.

The meandering, researchers suspect, was due to trouble the bats had with maintaining the steady path relying on echolocation alone. When they were detecting distinctive landmarks like a specific orchard, they corrected the course. Repeating the process eventually brought them to their roost.

But could this be landmark-based navigation? Or perhaps simple beaconing, where an animal locks onto something like a distant light and moves toward it?

The researchers argue in favor of cognitive acoustic maps. “I think if echolocation wasn’t such a limited sensory modality, we couldn’t reach a conclusion about the bats using cognitive acoustic maps,” Goldshtein says. The distance between landmarks the bats used to correct their flight path was significantly longer than echolocation’s sensing range. Yet they knew which direction the roost was relative to one landmark, even when the next landmark on the way was acoustically invisible. You can’t do that without having the area mapped.

“It would be really interesting to understand how other bats do that, to compare between species,” Goldshtein says. There are bats that fly over a thousand meters above the ground, so they simply can’t sense any landmarks using echolocation. Other species hunt over sea, which, as per this team’s simulations, would be just one huge low-entropy area. “We are just starting. That’s why I do not study only navigation but also housing, foraging, and other aspects of their behavior. I think we still don’t know enough about bats in general,” Goldshtein claims.

Science, 2024. DOI: 10.1126/science.adn6269

Bats use echolocation to make mental maps for navigation Read More »