The Piedmont Foothills of Pennsylvania contain a variety of habitats that harbor unique plant and animal communities. One of my favorite places to aimlessly wander are the dry ridge tops of these hills where forested grassland can often be found growing on thin, rocky soils. In fall, as the canopy thins and grasses begin to yellow, winds from the north drive out the heat of summer and receive the first waves of warblers and hawks. These high glades have experienced a range of human impacts in agriculture and logging, but with time they seem to have come full circle as productive forage patches.
These were natural high, dry pastures for cattle owned by early settler families who witnessed the last of the wild elk and bison to come through Pennsylvania to winter here. The Susquehannock people, too, were gone by the late 1700s, along with their carefully tended fire-managed blueberry balds. Without the seasonal migrations of elk and managed fires, forested grasslands not grazed by domestic cattle, goats, and sheep soon succumbed to weedy undergrowth. Some of that weedy growth harbored toxic plants that made life difficult if not deadly domestic animals and their farm families.
Back when families drank the milk from their own dairy cows, Snakeroot poisoning was common among those who pastured their cattle in wooded clearings. Tremetol, the toxin found in the plant can cause heart problems and severe tremors - even death. Before homogenization became standard practice in the dairy industry during the 1940s, tremetol was carried undiluted into dairy products like milk, cheese, and butter. Accumulation of toxins in the body could seriously sicken and even kill anyone who consumed enough dairy and meat from animals that grazed on Snakeroot. Young humans and calves nursing from their cow-moms were most at risk. It was so common among farm families in the Mid-Atlantic and Mid-West that it was referred to as "the trembles." As noted in a circular published by the University of Illinois in 1935, "the progress of the disease is usually rapid and mortality is high..." (see Notes).
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| Northern Cinnabar Polypore. |
Today there are no cattle left in this woodland pasture but the grasslands persist due to the heavy concentration of Whitetail Deer. They avoid the Snakeroot, so it grows in dispersed patches here and there. As I was exploring, two cautious bucks, each carrying heavy racks of antlers, kept a wary eye on me but did not leave the glade. A doe and two fawns of this year and a third, a yearling, grazed unconcernedly on the edge of the woods near a picnic site where the grass is cut and White Clover is abundant. Between me and the clover-eating deer stood a patch of highly invasive Beefsteak Plant with its small spikes of purple-pink blossoms and deeply veined leaves. This garden escape is a real problem in the D.C., Maryland, Pennsylvania area, readily displacing natives and easily reseeding via wind into dry sites. Like the native Snakeroot, it is toxic to grazing animals but it was pretty clear that these deer don't like it either. I wonder if next year this patch will reseed into the glade and displace the grasses preferred by the deer?
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| Beefstake Plant, Perilla frutescens. Invasive! |
I wanted to go much deeper into the dry glade but the deer were there and I felt it best to let them graze in peace. As I stood at the edge looking in, I was gifted with a Common Yellowthroat male still singing his "witchety witchety" song, decked out in his somewhat faded black mask. He'll be moving on tonight continuing his journey south. Not so the deer, which rely on these forested grasslands for fall and winter forage and I hope next fall it will not be a huge patch of Beefsteak Plant!
Notes:
University of Illinois, Extension Circular 436: "White Snakeroot Poisoning" (1935) https://www.ideals.illinois.edu/bitstream/handle/2142/32957/1057734.pdf?sequence=2
There is some thought that Abraham Lincoln's mother died of "milk Sickness" caused by milk containing white snakeroot's toxin.
ReplyDeleteBy the way, white-tailed deer normally don't eat grass, they prefer forbs, twigs of trees and shrubs, both green and dry leaves and seeds like acorns. Deer are browsers not grazers.