To the FWGNA group:
I was born and raised in Waynesboro, Virginia, where the Chamber ofCommerce likes to advertise that “The Skyline Drive meets the BlueRidge Parkway.” The SkylineDrive runs 105 miles north from Waynesboro through the ShenandoahNational Park to Front Royal, generally at 1-2,000 ft. elevation. South from Waynesboro the BlueRidge Parkway extends another 412 miles through the mountains toAsheville, North Carolina, at elevations rising to 6,000 feet.
I spent many a lazy summer day in my youth picnicking with family onthe SKD and the BRP, and not a few warm evenings at the overlooks withmy girlfriend. One of my favorite spots was the visitor center atHumpback Rocks (BRP mile 5.8), where latter-day pioneers live in anauthentic log cabin and farm the rocky hillside (Fig. 1). The tiny, hand-hewn springhouse on that property must have stoodunchanged for 200 years (Fig. 2).
No surface water enters or leaves the springhouse at BRP mile5.8. Water seeps up through the rocks, travels in completedarkness for about 3 feet, then seeps back into the earth anddisappears. (A narrow PVC pipe has been installed to keep thepath from becoming muddy.) But if you crawl through the door,grab a wet rock, pull it out into the sunlight and turn it over, youmay be lucky enough to discover a scattering of tiny white hydrobiids, Fontigens orolibas (Hubricht), thespring snail of the Blue Ridge.
My attention was first called to this remarkable animal by thewonderful 1990 monograph of Hershler, Holsinger, and Hubricht, “Arevision of the North American freshwater snail genus Fontigens” (Smithsonian Contrib.Zool. 509). To tell you the truth, I don’t know which is moreamazing – the fieldwork of Leslie Hubricht, the scholarship of BobHershler, or the biology of the snails they have teamed up todocument. The authors reviewed nine Fontigens species in their work,including four species from the Commonwealth of Virginia, meticulouslydocumenting hundreds of remote and scattered populations.
So one fine morning not too long ago I set off up the Skyline Drive inmy pickup truck, HH&H monograph in my lap and topo maps on the seatbeside me, determined to visit as many populations of F. orolibas as I could before thesun went down. The habitats I sampled ranged from proper springswith good water flow down to wet seeps in grassy or marshy high meadowsmany miles from the nearest permanent water. Figure 3shows a typical spring, at a visitor cabin operated by the NationalPark Service down the mountain below SKD mile 81. I found snailsonly on the underside of rocks very near such springheads, never in anyabundance.
The animals themselves are typically no more than a couple millimeterslong and essentially colorless. Figure 4shows a 2.9 mm F. orolibas(below) crawling with an individual F.nickliniana, a widespread species found throughout the easternU.S. in valley springs and spring runs. Fontigens nickliniana does notshare the retiring habit of F.orolibas, and seems unafraid to crawl about quite brazenly onthe open streambed. The body color difference is striking.
I was ultimately able to visit seven of the sites listed by HH&H ashabitats for Fontigens orolibas– a pretty full day, but only 20% of the total sites theyrecorded. And I’m pleased to report successful collections of F. orolibas from five ofthem. The other two sites had been capped and the waterdiverted. But given the ephemeral nature of natural snailpopulations and their habitats, I think the confirmation of 5/7ths ofany list of historical freshwater snail records is reassuring.
The little boy from Waynesboro who played hide-and-seek in thespringhouse at Humpback Rock forty years ago knew, even then, that hewanted to be a professional biologist when he grew up. I’m notsure why, but a combination of “Wow, how interesting!” and “Man, that’spretty!” played a big role. Spending a warm summer day huntingtiny populations of mysterious animals, scattered across the crest ofthe ancient Blue Ridge, it’s not hard to feel the wonder again.
Keep in touch,
Rob
Figure Captions
Figure 1. The pioneer cabin at the Humpback Rock Visitor Center, BRP mile 6.
Figure 2. The old spring house at the Humpback Rock visitor center. Fontigens orolibas inhabits cracksunder rocks inside.
Figure 3. Spring at Doyle River Cabin, SKD mile 81. Fontigens orolibas is localizedunder rocks directly beneath the spring outlet.
Figure 4. The lightly-colored individual is Fontigensorolibas (2.9 mm) from a spring on the Blue Ridge, the darkeranimal is F. nickliniana fromCoyner Springs in the valley near Waynesboro, Va.
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