timber rattlesnaketimber rattlesnake

June 1, 2020

The rattlesnakes have emerged, but there is no need to worry!  Every spring we watch for the several large timber rattlers that sun themselves on a big rock down the road, while others take up temporary residence under piles of drying lumber in one of the solar kilns.  The truth is that only one human fatality has resulted from timber rattlesnake venom across its entire range during the past century, and only two or three bites are reported each decade. We also understand that less than half of all bites to humans by poisonous snakes contain venom, as rattlesnakes can control the amounts injected when biting. We treat our rattlesnakes with considerable respect, but find them to be interesting and relatively docile neighbors despite their forbidding unblinking glower.

Wisconsin has two poisonous snake species, the massasauga and the timber rattler but only the timber rattlesnake lives among our rugged open bluffs of southwestern Wisconsin.  It is a heavy-bodied snake with a broad triangular head, a narrow neck and a thick black tail tipped with a tan rattle.  Adults average about 40 inches in total length and have dark cross bands extending along yellow, brown or rust-orange backs. Fear and misunderstanding has resulted in many being killed, which is the primary reason that it is listed as a protected wild animal.

The timber rattlesnake feeds primarily on small mammals and typically coils alongside a trail and waits for prey to come to it.  The snake's heat-sensing pits, located between the eye and the nostril on each side of the face, warn of an approaching rodent., and snake bites it injecting venom that kills it almost immediately, and then swallows it whole. Timber rattlesnakes breed near the den site before moving into the woods for the summer.   A female often mates only a few times during her life, requiring at least seven years to become sexually mature and then reproducing only every third or so year.  In Wisconsin, litters of 6-15 young are born from late August to mid-September but their mortality is high.
Snakes appeared in the fossil record 100 million years ago and vipers evolved during the Miocene period, some 35 million years ago, and they are not the only organisms at the farm that have ancient predecessors.

Long before dinosaurs walked the earth, there were horsetails. Perhaps you have never noticed this rather unassuming plant, but it is found locally in swampy areas, heavy soil, in ditches, and along the edges of farm fields. Fertile stems emerge first, resembling jointed, leafless tubes and topped by a yellowish, club-shaped, spore-bearing head. The green, sterile shoots develop later, by which time the fertile stems usually have wilted. These are jointed, hollow shoots, bearing up to 20 whorls of slender branches with insignificant leaves, and terminating in a long, naked point. Common horsetail grows a foot or two tall while giant horsetail may stretch up to seven feet. A major problem is its far-ranging root system that produces thick stands of shoots that can choke out other plants.

Horsetail is a plant left over from prehistoric times when it grew to the size of our present-day fir trees and there were huge forests full of them. It does not flower but reproduces from spores, as do ferns. The whole plant has a hard grainy texture, and when crumpled in the hands makes a good scour, like fine-texture sandpaper. In the Middle Ages it was used as an abrasive by cabinetmakers, to clean pewter, brass, and copper, and for scouring wood containers and milk pans.

Some people cook and eat the young fertile shoots as a sort of asparagus substitute, but this seems risky as livestock have been poisoned by consuming the gritty weed. It is an interesting fact that horsetail picks up compounds such as selenium, mercury and gold from the soil in which it grows. In some areas, it has been found to accumulate up to 4.5 ounces of gold per ton of fresh plant material, but its value is primarily as an indicator plant rather than as a commercial source of gold. Early Romans wrote of using the plant to staunch bleeding in wounds, and at various times it was even employed as a folk remedy for kidney and bladder troubles, arthritis, bleeding ulcers, and tuberculosis.

There are other primitive plants in our woods and fields. One is lichen, which consists of two life forms, a green algae or blue-green bacteria that is photosynthetic, and a fungus. Others are liverworts and moss that lack true roots and must absorb water and nutrients through their surfaces. Club moss, which is not a true moss, also had ancient predecessors that included giant tree-sized plants and contributed to the coal deposits then being formed.

Ferns were known to live as early as 300 million years ago, and cone bearing plants, which today include pine, cypress, spruce, cedar, juniper, and redwood, were more diverse when dinosaurs roamed the earth.  A fern does not have stems but the leaves arise directly from a below ground rhizome or very short vertical stem near the soil surface. Those in Wisconsin may be as small as one inch long, or as large as three feet long in other species and most die back at the end of each growing season while the stem overwinters below the soil surface. The frond may be undivided divided into smaller parts and perhaps each part is again divided, etc.  Ferns do not produce flowers or seeds, but rather reproduce by spores,  minute, typically one-celled, reproductive units capable of giving rise to new individuals without sexual fusion. 

The structures of all these plants have changed little through the centuries, and our woods and hills are full of organisms-- both animal and plant--that are fascinating in their diversity.