Central Oregon’s bats love caves — and both share fragile ecosystem

(Update: Adding Part 2 of report, full video)

'It's actually one of the most fragile ecosystems that we have'

BEND, Ore. (KTVZ) -- It's pretty well-known that bats like to hang out in caves, but experts say the ecology of Central Oregon's caves also depends on bats, in ways you may not have thought about.

Central Oregon is home to more than 700 caves, and most are homes for the bat population, including 14 of the 15 known bat species in Oregon.

"You may look at a cave and think it's just rocks and dirt in there but it's actually one of the most fragile ecosystems that we have," Deschutes National Forest wildlife biologist Brock McCormick said during a recent save visit.

Lauri Turner, wildlife program manager for the forest, noted, "Ours are lava tube caves. So they were formed when the hot lava went through, and solidified as they cooled."

Cave ecosystems are considered by scientists to be among the most fragile on the planet. Caves are a non-renewable resource, and they take millions of years to form, which makes protecting them from vandals or other negative impacts even more important.

"If we do something inside a cave, that is going to be there forever, unless we go in and remove that piece of trash or graffiti or whatever we might take into a cave," Turner said.

There is no natural process in place to restore damage done to a cave, like we see above ground with sunlight and other forms of energy.

"The impacts you're having on that site aren't going to be obvious," McCormick said. "It's not like walking through a wildflower meadow and trampling the flowers, where you can definitely see the effects of your actions."

That's why bats are crucial for caves.

"Bats are incredibly important to our cave ecology," McCormick said, "because they bring in nutrients into the cave environment, and those nutrients are what feed some of the other flora and fauna that are within the cave."

McCormick told NewsChannel 21 all of our Central Oregon bats eat insects.

"They spend their summers eating as many insects as they can," he said. "Some bats, like little brown myotis, which is a really common bat we've got -- they are capable of eating 1,000 bugs in one hour."

The living creatures in deep parts of the cave require animals like bats to go above ground, collect nutrients and bring them back into the cave.

Turner said, "They bring in this energy system with their guano (poop) that feeds centipedes and spiders and sometimes salamanders that live their whole life time in a cave. And so they have to get their nutrients from somewhere, and bats help provide that.".

Turner told NewsChannel 21 they're working with Oregon State University's Bathub to monitor any changes in bat population, with a system called NABat.

Turner explained, "It's an acoustic monitoring protocol that they follow to determine if there are increases or decreases in bat populations. The findings of those surveys, or that monitoring thus far, is that many of our species are in decline."

NewsChannel 21 asked what the impacts would be if the population continues to decline.

Turner replied: "Our pest population, our insect pests, things like that -- they start to increase. And then so how we deal with that is that we have to use more pesticides, insecticides, things like that.

"So it's kind of a vicious circle, and we would rather have it done naturally than us put chemicals out on the landscape,"

The increase in population and recreation in Central Oregon is having an impact on this delicate ecosystem.

Jean Nelson-Dean with the Deschutes National Forest said, "This last year, with COVID and more people getting outside we've saw a 40% increase of visitation on the Deschutes National Forest -- and that's on top of what we already have documented, 5 million visits to the Deschutes National Forest every year."

McCormick added, "Which is a great thing -- people getting outside enjoying what Central Oregon has to offer. But we have seen that come at a cost, especially to places that are fragile, like caves."

If we don't understand the cave ecology, and the fragility of a cave environment, we could actually harm the cave. Bats rely on caves for hibernation in the winter.

"They are on a really tight energy budget to survive through the winter on the fat they've built up over the summer," McCormick said. "And if they are disturbed too often, even just a handful of disturbance events through the winter could be a matter of life or death for these bats."

And raising their pups in the summer.

"Another thing about bats is they are very slow to respond to disturbance," McCormick said. "Bats produce one pup per season. When you impact that bat population, that effect takes a long time to rebuild those numbers."

Nelson-Dean said it's important to be respectful, and remember that caves are the home to wildlife, too.

"One of the terms we like to use is respectful recreation," she said. "We want our visitors to enjoy, experience, but also learn and take care of these resources for us. Everyone that comes and visits and enjoys these are also stewards."