Participants – Bill Gee (trip leader)
Martin Carmichael
Mike Kovacs
Candace Kovacs
Sarah Peterson
Daisy Dabbs
Jarrett Whistance

Time in = 9:10am
Time out = 5:45pm

Photos and videos at the bottom of this post.

Every year at the end of October I run a bat census trip. The goal is to count bats and other critters in the section of cave between the Lunch Room and the Mountain Room. This year we had a few other small goals which I will bring out in the narrative.

For several days before the trip it rained heavily in Kansas City. Radar reports showed no rain at all at Carrol Cave, so we went ahead with the trip. The weather turned sharply colder on Friday, going from highs near 80 to highs in the mid-40s.

I drove to the campground Friday afternoon and spent the night. It was nice to have electrical power to run the camper. Saturday morning people started showing up around 8:30. We were all there by 9:00. The only new person to Carroll was Daisy. I helped her get on a loaner seat harness, and Martin provided a rescue eight to use for rappel. Just before we started down the rope, I showed Daisy how to use the cable safety sleeves. Jarrett and Sarah both watched as a refresher.

Martin was the first person down the shaft at about 9:10. He helped everyone else get off the rope as they landed. I was the last person down at about 9:45.

The first thing I did was set out an air quality monitor. This is a device I built around an Arduino microcontroller. It measures temperature, relative humidity, barometric pressure, carbon dioxide and VOC content once per minute. The numbers are saved to a memory card. We left the device at the ladder for pickup on our return.

Unfortunately the memory card file system got scrambled, probably because the battery ran low. There was no usable data from the air quality monitor.

We left the ladder about 10:00 heading for the Water Barrier. After passing the water barrier we stopped at the first riffle to count and measure isopods. The water level was a fairly low and we only saw a half-dozen. That is less than half of what is usually seen at this location.

Moving on, we arrived at the first set of guano piles about 11:00. Guano gauge 3, which in past years has never had more than a dusting on it, was mostly covered this time. There was a lot of fresh guano on the ground around it. We counted several salamanders in this section of the stream.

The remaining guano piles did not have any surprises, except there was more guano than usual on the ones that get regular use. We arrived at the Lunch Room shortly after 12:00 and had lunch. The waterfall in the lunch room was not flowing, not even a drip.

After lunch we began the bat count at 12:20. This year we saw more bats than in past years. There were still not very many, but it was noticeably higher. We noticed far more salamanders than in previous counts, and almost no sculpins. Indeed, we did not see a sculpin until we got to the Mountain Room.

In past years we have seen a cluster of bats around the 500 foot marker. I brought along a bat detector hoping to get some recordings of them. It was very disappointing to see no bats whatever in that area. For the entire trip we saw no clusters of bats. Everything we saw was lone individuals. I did not get an opportunity to use the bat detector.

We arrived at the Mountain Room at 3:30pm. Mike and Jarrett checked the stream for critters while I went around and checked the guano guages in the room.

We were all very pleasantly surprised to hear Sarah sing a verse of “Ave Maria” from atop the tall mound in the middle of the room. She has a wonderful operatic voice and the reverberation in the room was perfect. That should happen more often! A very short video is at

The return trip began at 4:20. We hightailed it to and through the Turnpike in about an hour. At guano piles 14 and 15 we picked up the Anabat Roost Logger for return to Vona Kuczynska of U.S. Fish and Wildlife Service. We also picked up some PVC that was used as a stand when the Anabat was in the Mountain Room. The Anabat has been on loan to us for three or four years. It has provided data about when bats move into the cave (late April) and confirmed that they are not there over the winter. Vona wants to use it in another cave, so we pulled it and will return it to her.

We arrived at the ladder about 5:15. I took Daisy and Jarrett over to see Thunder Falls while the others geared up and climbed out. We were at Thunder Falls for only a few minutes. It was flowing but at a rather low rate.

Everyone was out of the cave by 5:45pm. The weather was gloomy, as forecast. It was raining lightly and temperature was in the middle 40s. The rain gauge at my camper showed about 1/4 inch during the day. Mike and Candace and I planned a cave trip nearby for Sunday so we intended to camp Saturday night. Mike and Candace decided the weather was too cold and damp for them. They drove home for the night.

I was the only one to stay the night. It rained all night, off and on, not very heavy, about 0.6 inches by morning. About midnight the power failed at the site. Everything was out. It was not just a tripped circuit breaker. I left the campground at 7:30am.

Judging by the log files, the Anabat Roost Logger ran for less than one month. It was started on March 18 and the last log file is on April 4. That is extremely disappointing. A set of batteries is $30 and is supposed to run four to six months. Vona will confirm the runtime once she has the data.

Overall the Anabat Roost Detector was mostly a failure. We had it for three years and in that time got only 2 months of good data. The rest of the time it either detected no bats or had dead batteries. At $30 for a set of batteries and two sets per year, that is a fair bit of money spent for very little return. The two months of good data we got show the bats moving into the area around the guano piles starting about the last week of April. A visit to the area in July 2021 proves the bats were still there.

=========== Data Section ===============

Bat and critter counts:
Lunch Room to 6000 foot: 12:32pm – Zero bats, 2 salamanders.
6000 to 5000: 1:00pm – 28 salamanders, 1 bat, 1 isopod 12mm.
5000 to 4500: 1:12pm – 3 bats, 27 salamanders.
4500 to 4000: 1:26pm – Zero bats, 11 salamanders.
4000 to 3500: 1:40pm – 5 bats, 5 salamanders.
3500 to 3000: 1:50pm – 1 flying bat, 7 salamanders.
3000 to 2500: 2:00pm – 2 flying bats, 3 salamanders. 7 isopods on stream bedrock, not measured.
2500 to 2000: 2:10pm – 3 bats, 5 salamanders.
2000 to 1500: 2:20pm – 3 bats, 3 salamanders.
1500 to 1000: 2:26pm – 1 bat, 4 salamanders.
1000 to 500: 2:33pm – No bat cluster. 1 bat, 5 salamanders.
500 to Mountain Room: 2:42pm. 2 bats.
Mountain Room: 6 sculpins, 3 other surface fish, zero bats, zero crayfish, zero frogs.

Isopod count:
4mm = 1
5mm = 3
6mm = 2

Guano gauges:
Guano gauge 1 = Completely clean.
Guano gauge 2 = 40% coverage 2mm.
Guano gauge 3 = 90% coverage 4mm.

6 salamanders and 2 fish in the stream. One salamander on the number 3 guano pile.

Guano gauge 4a = 25% coverage 2mm.
Guano gauge 4b = 25% coverage 3mm.
Guano gauge 5 = Completely clean.
Guano gauge 6 = 100% coverage 6mm.
Guano gauge 7 = Two turds.
Guano gauge 8 = Thin film of guano.
Guano gauge 11 = One turd.
Guano gauge 12a = 100% coverage 5mm.
Guano gauge 12b = 95% coverage 4mm.
Gauno gauge 13 = One turd.
Guano gauge 14a = Completely clean.
Guano gauge 14b = Completely clean.
Guano gauge 15a = 100% coverage 6mm, fresh fungus.
Guano gauge 15b = 100% coverage, dripping over the edge, 12mm.
Guano gauge 16 = Completely clean
Guano gauge 30 = Completely clean.
Guano gauge 31 = 10% coverage 1mm.
Guano gauge 32 = Thin film of guano.

Between guano pile 15 and the Lunch Room – Three grotto salamanders in the stream. 1 at 12 cm, two at 9cm. Two fish.

A sculpin in the stream by the Mountain Room. Photo by Candace Kovacs.

Unknown non-cave fish in the stream near the Mountain Room. Photo by Candace Kovacs.

A grotto salamander in the stream near guano pile 3. Photo by Candace Kovacs.

A ring-neck snake at the base of the ladder. Photo by Candace Kovacs.