Day 3 (21 August 2007)
This day in the field got off to a slow start. First thing this morning, we went to DryBone Cave to retrieve the Anabat detector. We already surveyed all caves on our list located at the higher elevations of the monument (DryBone, Lizard and Rattlesnake Caves), and now we have to wait until Thursday and Friday to retrieve our traps.
We wanted to optimize our time in the field and decided to sample one additional cave further north. We had a few options for our forth sample cave of this trip. After a lengthy discussion last night, we decided to visit and sample a cave that contained year round dripping water, and periodically flooded bringing detritus into the cave. This is one of the only caves in northern Arizona that contain year round water. Because caves are nutrient starved environments and we know the combination of water and nutrients input into a cave can result in higher biodiversity, this seemed like an appropriate candidate. Also, from our knowledge of two caves that contain cave-limited millipedes, this cave had the added benefit of being an excellent candidate to search for millipedes.
It took about an hour and a half to drive across the monument on unimproved dirt roads to reach this cave, a cave we are now calling “Coyote Bowl Cave.” We assigned this cave this synonym because of what happened upon our approach to this cave. Once we arrived at the entrance, we observed, one, then two coyotes bolt from the cave entrance and disappear into the hills of rolling sagebrush. After following them with our eyes, our gaze returned to the cave entrance and we saw a third coyote. The third one was rather reluctant to leave. He/she was perched upon a rock with its hair standing up on its back and its ears lowered. We were about 20 feet from the coyote, and I didn’t think it was going to attack. This coyote was smaller than the other two, and we think it may have been a pup. However, it was possible there were two females and one male using this cave. If this was the case, perhaps there were pups within the cave.
This mummified pallid bat was found between the entrance and the second room of CoyoteBowl. Photo Credit: Kyle Voyles.
We searched the entrance and two small passages near the cave entrance, which I thought may contain pups if they existed. One of these passages likely contained a porcupine. There was a strong smell of porcupine within the entire entrance and it became stronger as I went into one passage. There was fresh scat leading to where it narrowed to about porcupine width. The passage was too narrow for me to proceed. It would have been great to have a shot of a porcupine within a cave, but this wasn’t going to happen today. The other passage I searched yielded no pups. This does not mean there were no pups in this cave -- it means were unable to locate them. Perhaps the coyotes were “pup-less” and simply did not want to leave their den, or maybe the third coyote exhibited defensive behavior because it felt cornered.
Upon pondering this, I realized deploying traps in this cave would be a nightmare. Regardless whether they have pups in this cave, or if its used as a den site, this cave contains year-round water. Consequently, the coyotes would be back. It takes between three to four hours to deploy traps within a cave. I suggested to Kyle that it was quite likely we’d go through all the trouble to deploy traps only to return to find our traps uprooted by coyotes. Coyote Bowl Photo Credit: Kyle Voyles.
We decided to evaluate the cave and decide whether we should deploy traps. We explored throughout this cave looking for evidence of coyotes. We found several large holes apparently dug by coyotes. We also found one drip pool within gypsum that was dug out so the coyotes could access the water. Based on this observation, we decided we weren’t going to trap in this cave -- at least not on this trip. When we do decide to trap this cave, we’re going to need to camp out in front of it for the four day window to prevent the coyotes from using it during the trapping period.
A yet to be identified caterpillar found within the cave entrance of Coyote Bowl Cave. Note the porcupine quill and the possible owl down feature also within the frame. Photo credit: Kyle Voyles.
This cave is dissolation gypsum and likely limestone. It has two plunge holes at the back of the cave where the water goes when this cave floods.
We did take note of at least three beetle, one psocopteran, one collembolan and a moth species. It is near impossible to identify arthropods to species visually. Thus, this very general information is of limited value. It is informative in that this information aided us in deciding we would future sampling.
Interestingly, we did not observe any millipedes within this cave. There were large detritus banks with fungi decomposing the detritus. This is a similar habitat to the two nearby caves supporting millipedes. Why are there millipedes in these two other caves, but not in Coyote Bowl? Is Coyote Bowl too wet? Does the cave flood with such intensity that the millipedes would be scoured from the cave? I also noticed that cows were heavily using the area surrounding this cave. There was considerable dung littered upon the surface. It may also be possible that the high input of nitrogen into this cave was too much for the millipedes, and they were extirpated from this cave due to the high nutrient input. These are some of the questions we hope to address in future research.
This image was taken several years ago from one of the north rim caves containing the cave-limited millipede. Photo credit: Kyle Voyles.