18 November 2007

Cave Life near the Ghetto in the Meadow

Ben Solvesky and I conducted reconnaissance of five caves west of Flagstaff. Our purpose for the site visits were to (a) identify bat use and (b) identify caves as potential study sites for intensive ecological sampling.

All caves were dissolution limestone with a volcanic stratum above. Fortunately, these caves are not well known. This was evidenced by virtually no evidence of human visitation.

Two of these caves were incredibly tight cork-screw passage that went back five to ten meters and then narrowed to the point where movement by any normal-sized human was impossible. We determined these two caves were not going to be further investigated. This cave was a three meter vertical drop where I had to chimney down. I learned it was much easier getting into this cave than it was getting out. I got stuck near the entrance, and had to cork-screw 360 degrees to get out.

This was one of the caves with a rather tight passage.

This is likely an historic graffiti signature.

Tree-stump Cave was the first cave we investigated. This was the largest of the five caves we visited. This is quite close to Flagstaff and has significant walkable passage. As a result, I was very pleased to see there was virtually no evidence of human visitation. The only evidence was some historic graffiti and a dig at the back of the cave. Cavers often dig in caves in hopes of finding major passage. Ben decided to investigate this dig and went in. It was a narrow belly crawl, and from what I could see (~ 3 meters beyond my vista), the passageway trifurcated and became somewhat of a labyrinth. Based upon Ben’s initial assessment, we decided this tunnel was chaucy, brambly muddy material that was not very stable. Furthermore, it did not appear very interesting from a biological perspective.

We did find three hibernating bats (Townsend’s big eared bats, Plecotus townsendii) within this cave. We also saw extensive but light bat guano throughout most of the cave, heavy porcupine use (not recent), and evidence of small carnivore use (possibly a ringtail cat). Additionally, there was an extensive network of root mats in the ceiling, which will be an excellent place to search for arthropods. I did a quick look within the root mats and didn’t see anything. Also of interest from an arthropod perspective was the cave was wet and contained a mud floor in many areas. We also encountered numerous crickets and hundreds of fungus gnats on the ceiling within the twilight zone of the cave. The combination of active hydrology and the resultant nutrient input (via vegetation from the surface), and the presence of arthropods and root mats, make this an excellent candidate for further research.

We also documented active actinomycete colonies (microbes) on the cave ceilings and walls.

The second largest cave we visited was Sediment Cave. This cave is located about one meter from an unimproved dirt road. This cave clearly receives considerable amounts of sediment runoff during the monsoons and snow melt. The cave was muddy in many areas and the mud was orange (the same color as the dirt road above). The most exciting discovery of the day were two tiger salamanders (Ambystoma tigrinum). These cute little critters were observed in the back of the cave in a small room with a mud floor. We also documented crickets, spiders and fungus gnats in the entrance and twilight zone of this cave.

Our final stop was Candycane Cave (aptly named with Christmas right around the corner). This was the third largest cave we visited. As we crawled into the entrance of this cave, we at once noticed thousands of fungus gnats. Several kamikaze gnats chose to meet their demise by flying directly into my mouth.

This cave was rather small and contained two rooms – one directly above the other. It was also muddy with the lower room likely flooding during monsoons and snow melt. The lower room contained a barren mud floor. From my experience of a cave in New Mexico, I know diplurans can occur in this habitat type, so I searched for them. During this trip, I did not encounter any arthropods in or on the mud floor.

Of particular interest were the filamentous bacteria that occurred on the ceiling. If I can get a microbial person in this cave, I’d love for them to collect samples. This cave contained extensive porcupine use, and we saw only crickets and fungus gnats.

Our one-day outing in western Flagstaff provided us with some interesting findings. Overall, our trip was quite successful. We identified one cave containing at least three hibernating Townsend’s big eared bats, one cave containing two tiger salamanders, two caves containing historic porcupine evidence, and all caves had evidence of packrat activity. Additionally of the five caves we visited, three caves contained dark zone and were hydrologically active and contained arthropods. I will be very interested in sampling these three caves intensively in the near future. With two new genera and 10 new species identified from work on the north and south rims of Grand Canyon, I’m looking forward to learning more about cave ecology in my backyard. I hope to begin survey of around 20 caves in the Flagstaff area this summer.