The Arctic Nearby

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There is a conversion meteorologists use called the Adiabatic Lapse Rate. What it says is that for every thousand feet of gain in altitude the temperature drops three degrees Fahrenheit.  Biologists employ a corollary equating a thousand foot gain in altitude with 600 miles of latitude, meaning that going up a mountainside a thousand feet is the climatic equivalent of traveling 600 miles north. So if you are in Ohio or Virginia at an altitude of 700 feet above sea level and you drive to Cranberry Mountain in West Virginia -- at 3575 feet -- you barter a hundred-mile drive for a trip to the boreal forests of Canada, 1600 miles to the north. That's the theory and in practice it is probably not far off. 

One way to confirm the altitude-latitude conversion is to look at the range maps of some of the birds which journey from the tropics to breed in the boreal conifers. Many observe a breeding range across Canada from the approximate latitude of Hudson's Bay to the U.S. -Canada border, a clean and regular band -- except for a dangling appendix down the spine of the Appalachian Mountains. If we pick a couple of boreal breeders such as Northern Waterthrush and Mourning Warbler we see that their breeding ranges reflect this Appalachian peninsula. As a result, we in the eastern or mid-western U.S. can drive a relatively short distance into the Appalachian highlands and enjoy a fair chance of finding these two northerly warblers on their breeding grounds. Cranberry Glades 15 miles west of Marlinton, West Virginia is the place to do it.

Cranberry Glades are a relic of  the Wisconsin glaciation; they constitute a botanic community of reindeer moss and red spruce which developed when the wall of Wisconsin ice bulldozed northern Ohio and Pennsylvania, pushing an arctic climate into our now-balmy realm. The ice retreated but the altitude and boggy soils permit Cranberry Glades' boreal botany to persist in glorious isolation, ours to savor on a day's jaunt.

Of course, sorting through the birds' calls when we get there is another challenge. The attached video offers a comparison of the songs of Northern Waterthrush and Mourning Warbler filmed at the Glades this morning and to complete the confusion we add a shot of the Louisiana Waterthrush, a much more accessible bird breeding along wooded streams at the lower elevations most of us occupy. All three (they are all warblers) sing in a burst of whistles followed by a dropping inflection, and because we rarely get to see and hear the northern worthies, we might find it useful to make the comparison with our more familiar lowland waterthrush.

Caveat:  this video won't help a bit when you get to Cranberry Glades. If your experience is like mine the overlapping chorus of echos and harmonies will leave you befuddled. But go anyway to enjoy this tiny nugget of the north in our midst.

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River Beings

May 2, 2013, Middle River, Swoope, Virginia.

The Middle River runs through this cattle farm.  We are about twelve water miles downstream of the highest gathers, a series of springs on a farm at the hamlet of McKinley,  and the trickles and tributaries give the flow a thirty-foot channel through Wheatlands, as this farm has been called since 1813. Downstream, the River merges with the North and that combined flow takes on the South at Port Republic to laze and loop northward under the name of South Fork, Shenandoah River, merging with the North Fork at Front Royal to make the main stem of the Shenandoah for its 65-mile run to the grand conjoining with the Potomac at Harpers Ferry.  Much of the nation’s history, tranquil or tragic, is written in that storied drainage washing the feet of official Washington.  Here in the high headwaters, too, we see our share of the sinister.  

What began this morning as a hike to greet the River’s spring arrivals -- a Solitary Sandpiper, a Spotted Sandpiper skimming the flow on stiff wings, a Great Egret, two Black-crowned Night-Herons – took a cloak-and-dagger turn.  A muskrat crossed the river to vanish under the bank at my feet, peculiarly close to an obvious intruder it seemed.  Then came strange scuffling sounds and a red streak shot away across the river, the early sun a neon pulse in its fur.  It humped up the bank and the bushes shook with squalls of protest.  A desperate contest thrashed the grasses until a muskrat tumbled down the river’s bank and swam upstream, dragging (or driven by?) a snaking tail. A noisy melee continued in the brush for some seconds. Then quiet resumed, leaving only a string of unanswered questions, like a Congress adjourned.  Did the escaping muskrat fight off the mink? Or did it leave behind a sacrificed family member? What happened in the hole in the bank under my feet? And are minks really foxy red or was that just a tricky light?  The river beings guard silence.