DAY 5 (24 August 2007) Last day of August 2007 Fieldwork on the North Rim
After the sun slowly rose, Kyle and I did also. We didn’t have much on the agenda for today, so the work was going to be light. We needed to pull traps and temperature sensors from Lizard Cave, collect the ANABAT detector from Lizard Cave, and then travel across the rolling grassland to Fat Man Cave to collect water and bacteria samples in hopes that they would contain tardigrades. I will submit a lab blog in coming weeks regarding our success in our search for cave-dwelling water bears.
While we were having breakfast, I saw a deer approaching the water tank. We were camped near a corral and water tank maintained by local ranchers. This deer was most impressive and was a strapping eight point buck. He cautiously approached, stopping every few steps and looked towards us, once he determined we were not a threat, he walked to the water’s edge. This gave me ample time to capture several photos of him. As goes the luck of photography, only one of these photos came out, which is the one featured here.
After breakfast, we broke camp and headed for Lizard Cave. Upon arriving there, the “cave guardian,” our friend the crevice lizard was perched on the ledge above the entrance. After greeting our old friend, we twisted, crawled and pulled our way into the cave. Much as we expected, Lizard Cave was the antithesis of DryBone Cave. Most of our traps were replete with arthropods. However, the most abundant critter trapped was the cave cricket.
On both trips to this cave, we observed crickets mating. This picture depicts two individuals reproducing.
As I was processing the contents of each trap, I continued to note the large amount of guano deposited by the crickets within the trap. While there is evidence of past porcupine activity in the dark zone, packrat activity in the entrance, and infrequent bat use, cave crickets are fueling this entire ecosystem. They are the primary nutrient input into this cave. They bring in nutrients from the outside environment via guano, and the nymphs (baby crickets) provide food for carabid beetles and spiders. I also suspect the guano provides food for psocopertan, who in turn, are a food resource for pseudoscorpions. Upon our forth visit to this cave, the web of life here is slowly becoming more apparent.
From this cave, we trapped and/or collected, cave crickets, beetles (at least three species), Psocopterans, and possible two spider species. From our work to date in northern Arizona, this cave is by far one of the most biodiverse. Perhaps if more diverse is Fat Man Cave – our next stop of the day.
Upon completion of our work at Lizard Cave, we hiked back to the trucks and began our drive to Fat Man Cave. The roads up here are marginal at best. These roads are all dirt, infrequently maintained and quite bumpy. Consequently, it can take a long time to get to where you are going. It took us over an hour to drive 30 miles to Fat Man Cave.
Fat Man Cave involves a nuisance drop of about 20 feet, which requires the use of a cable ladder to gain access. Kyle is in the process of securing an anchor line to ‘bineer our ladder onto.
While standing at the entrance, I observed owl pellets on the ground. Owl use at caves is quite common in this region. While we cannot ascertain exactly what species of owl left behind this pellet, we do have confirmation that an owl was here.
Fat Man Cave is a large cave system characterized by a 300 foot crawl from your hands and knees to a full belly crawl before it opens up into walkable passage. Once you reach this point, it was about 60 feet further before you reach several sulfur rich pools. Beyond the pools, there’s about 900 feet of walkable passage. This is a large and neat cave.
But today we are going no further than the sulfur rich pools. Navigating the crawl will be a lot of fun. This cave floods substantially during the late summer due to monsoon rains, so we expected to get muddy. Once we arrive at the pools, we will collect bacteria and water samples in hopes that we’ll collect tardigrades as well. We have to be careful in this area because we don’t have our gas meter today. The sulfur levels can get high, and this can be dangerous. We will not be spending much time at the pools, so Kyle and I both agreed this was an acceptable calculated risk.
This cave is also one of three caves to contain our new cave-limited millipede genus. Once we reached the walkable passage, Kyle found these two millipedes caught in the reproductive act. This is the first photo documenting reproduction of this new millipede genus. You can find more information about the new millipede genus by going to my Media page on my website.
After the long belly and hands and knees crawl we reached the sulfur pools. I collected several vials of bacteria and water in hopes of finding tardigrades. Tardigrades or “water bears” as they are commonly known occur anywhere there is water. They can withstand being chilled for days at -200°C; can be subjected to ~ 570,000 rads of x-ray radiation (1000-2000 rads can be fatal to a human); it’s suggested they can survive in the vacuum of space, and can withstand up to 6000 atmospheres pressure ( ~6x the pressure of water in the deepest ocean trench); and, can survive extended periods of dehydration (I read a report indicating a piece of 120 year old moss from a museum collection was hydrated, and tardigrades were observed within – they successfully recovered after +100 yr of dormancy!). All of the factors combined make this organism one of the, if not the, most extremophillic organism on the planet. While this is somewhat outside the purview of my dissertation research, cave-adapted Tardigrades interest me greatly from a Mars analogue perspective.
I’m collecting water and bacteria samples using a pipit. We’re collecting four vials of bacteria and water. I’m extracting as much bacteria as possible using the pipit. Because tardigrades are known to feed on bacteria, this is the most promising area to sample for water bears.
As we were leaving the sulfur pools, Kyle observed a spiders walking across the floor. It had pale legs and a pale cephlathorax and abdomen. Note the light color and lack of any markings of this individual in the image. I realized at once this was our best candidate to date for a cave-adapted spider in northwestern Arizona. We collected this first individual and then continued to search the sulfur pool room and the room adjacent to the sulfur pools. We saw several spiders, but collected only four more. I will be sending these spiders, as well as the others collected during this work to my friend and colleague Dr. Pierre Paquin. He is a North American spider expert, and specializes in cave dwelling spiders.
We then began our crawl to the entrance. This trip did not go off without a hitch – at least not for me. As I arrived at the entrance, and I was so ready to climb out, hop in the truck and head back to Flagstaff, I stood up quickly and banged my head against a large boulder. This was done perhaps as hard as one could possibly hit their head against a rock. The impact was such that it put me on my butt and the rim of the helmet cut the bridge of my nose. Yes indeed, this did not feel very good. Not to mention, when one does this, it really makes you feel smart. In addition to being humbled by the cave, it also showed me that I was not paying as much attention as I should have been. This is the lesson that I took with me out of the cave.
I am normally incredibly vigilant while working in caves. I pay attention to my foot and hand placement, and always look at where I’m going and thinking “is this rock/ boulder stable enough for me to climb over or under. Caves are very dangerous, and one dumb move could lead to an early checkout time. Fortunately, the helmet buffered my otherwise hard head from direct contact with that boulder – I was even more fortunate the big boulder chose to stay put after I crashed into it.