Friday, February 26, 2010

Snowbird

The bluebird skies and brilliant sun in the morning betrayed us all. I thought the five degree morning would magically turn into a forty degree afternoon with all that bright heat beaming down into my bleary eyes during my chicken o'clock commute. But no, instead, after fording a creek, walking through an ankle deep cave stream for four hours, fording the creek again, my jeans, fire boots, and socks literally froze, thick ice forming on my clothing as soon as the eighteen degree air hit it. The warmth of the fifty six degree cave never reached my little feet; I honestly thought I was going to lose a toe to hypothermia, but I didn't. They didn't know the flowing creek was going to be so high this week, you see, but it was, so before entering the cave I was already soaked.

A small surface water stream courses through this Burlington-Keokuk limestone cave, one packed to the gills with crinoid fossils. The surrounding watershed includes a hog farm, a cattle farm, not a few septic systems, several homes, and a network of roads. My guide instructed me to "take a hot bath with lots of soap" to wash off the e.coli when I returned home, and warned us all to "take precautions" if we have open sores that have "made contact" with the cave stream water. Ick. My poor fire boots.

But forget about the bone-chilling cold, and the persistent dismay I maintained regarding the loud, disruptive noise level in the cave, I chalked up several new cave species to my life list. For what it's worth, I don't spend a lot of time in caves because I prefer sunlight to darkness, but I remain fascinated by their ecology and geology. Unlike some of our woodlands and glades, every cave is different, distinctive, no two caves are alike. They're fascinating places with often highly divergent faunal populations based on geography, hydrology, chemistry and other factors that contribute to distribution. For a crude example, some caves are devoid of salamanders while another cave located a mere 20 miles away is loaded with several species of the little amphibians.

But in recent weeks I've been introduced to a few species I've not encountered before. For example, the cave orb weaver, a relatively large olive and khaki spider, is one of the more common troglobitic species in the cave I visited this week. We even found a few pendant spun egg sacks belonging to these handsome spiders hanging from the cave walls. Hanging out with the spiders were small black flies with big red eyes, Heleomyzid cave flies. I suspect the latter provide necessary food to the vertebrates in caves like this one.

Of the species I've not seen in a Missouri cave before this week, the herald moth ranks as the most charismatic. A rather common moth, the herald moth feeds on willows and poplars as a caterpillar, but as an adult, they feed primarily on fruit (blackberries in particular). Beautiful, colorful moths, they were seen throughout the cave hanging onto the limestone walls. Herald moths have been recorded from caves in five counties in Missouri during winter months. I can't share a photo with you of my own because I don't take photos in caves. To see a lovely, colorful guide to Missouri cave fauna, see this guide that includes our esteemed cave biologist's photos and brief descriptions. Scroll to page 36 for photos of the stunning herald moth and red eyed flies.

Walking up slope (and breathing more heavily than I ever have before in an effort to warm myself) I wondered if the hog farmer and cattle farmer knew that their farming practices were undoubtedly negatively impacting the aquatic invertebrate populations in the cave stream. I felt confident that the noise caused by the rest of the party disrupted the hibernating bats, causing them to lose approximately 20% of their body weight because these novices didn't know how to shut up when they're in a cave. But the herald moths don't really care about the watershed, about the bats, about the fossils on the cave walls, or even about the countless people taking their photos. They're there for the warmth, for the constant temperature and shelter from the very cold weather that is hopefully on the way out to make way for fire season.

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