22 August 2007

My Return to Grand Canyon North Rim

Day 1 Cave Ecological Inventory Greater Grand Canyon Region (19 August 2007)

These entries were written while in the field and will be entered when I have internet access.

I am currently in the field in one of the most remote National Monuments in Arizona. I am sitting in my tent as my colleague snores in his tent about 10 feet from me (once I have completed this entry, I plan to move my tent).

My plan will be to blog nightly from my tent. The moths have been incredibly around our lantern and cook stove. So, although I’d prefer to blog underneath the star-filled sky, if I were sitting outside my tent, I would get nothing done for I’d be dealing with the incessant swarming and buzzing of kamikaze moths.

This week I’ll be working with one of my best friends and thunderous snorer, Kyle Voyles. Kyle and I have worked out here for the past three years, and have identified over 10 new species and two new genera of cave-dwelling arthropods in the early stages of our research in northern Arizona.

Our work out here began with more of a curiosity -- “To what extent are tiger salamanders using caves in northern Arizona?” In the Spring of 2005, Kyle, the late Dr. John Prather and myself came up here to collect data to gain insights into this question. This worked ballooned into cave-dwelling faunal inventory. Today, Kyle and I are continuing this very important work. Virtually nothing is known about the cave ecology in Arizona, and we are working to change this.

Day one in the field was marred by numerous kinks and bumps. This seems to always be the case for one’s first day in the field. First, while in St. George, UT and in the process of loading Kyle’s truck, we realized we had a flat. After spending an hour trying to find an open garage (the town of St. George is almost completed shutdown on a Sunday) we were unsuccessful. Realizing time was ticking and we needed to leave for the field, Kyle started searching for another field vehicle that he could take and about another hour passed. By the time we left St. George, it was well after 1200hr.

We headed south, and after almost being ran off the road by a speeding red utility truck, we arrived at our first study cave by 1400hr.

We were well aware our first cave would take a while to sample. Kyle and I had met for breakfast early this AM to finalize our methods for sampling cave-dwelling invertebrates. So, given this, we realized this would need a little tweaking for nothing applies perfectly from the office to the field. The first cave of the project will serve as our “test case.”

Geologically, DryBone Cave is characterized by dissolution gypsum with a limestone cap rock. The gypsum was dissolved by water and the limestone ultimately subsided into the void creating a jumbled labyrinth of breakdown including monolithic-sized boulders strewn throughout the cave. This made the job of applying our sampling techniques that much more challenging.

Pitfall trap: two cups placed within one another. Holes are punched in the bottom of the inside cup and the peanut butter is placed within the lower cup.

Given the dryness of this cave, I speculated we would not find many invertebrates. I was correct. After spending approximately three hours in this cave, and applying time-constrained searches at seven sampling stations, we did not encounter one invertebrate – not even a cave cricket. It is possible we will encounter collembolans and perhaps psocopterans within our baited pitfall traps. This will be determined on Thursday.

We believe the packrat activity may be paleontological in origin, for we did not observe any recent packrat activity. We observed extensive packrat activity throughout this cave. This was evidenced by pack rat midden throughout the entrance, twilight and dark zone and nearly a complete carpet of packrat scat on the cave floor. We also noted amber rat (crystallized and fossilized mixture of urine, scat and plant material) along many of the walls and floor well within the cave’s dark zone. We also noticed some porcupine scat within the cave’s dark zone. But perhaps most exciting was this cave was used by bear. From a fossilized carnivore scat collected several months ago by Kyle, NAU Paleontologist Dr. Jim Mead identified a specimen as “bear.” As I was chimneying down a stretch of vertical passage I noticed a small room below me and thought “if I were a bear, I would definitely catch a long winter’s nap there.” Sure enough upon closer inspection, I noticed a lot of large carnivore scat. While I do not know conclusively whether it was bear, it certainly looked like it. We plan to collect some additional specimens for identification.

Also noted was contemporary used by macrofauna. Owl pellets and feathers were found within both the entrance and dark zone. We also documented a light but apparently consistent distribution of bat guano throughout the twilight and light zone of the cave. Based on the appearance of the guano – most of the guano appeared to be Townshend’s big-eared bat. We will have further insights on this once we analyze the Anabat data. In addition to guano, we found three Myotis spp. bats roosting within this cave.

Our invertebrate traps will remain in situ for the next four days. However, I don’t expect our efforts in this cave will bear fruit, or bugs – for that matter. Now, I’m going to move my tent away from Kyle’s…

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