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This classic of twentieth-century nature writing, a landmark work that is still a joy to read, offers a stirring portrait of the Midwest’s endangered glacial marshland ecosystems by one of the most influential biologists of his day. A cautionary book whose advice has not been heeded, a must-read of American environmental literature, Of Men and Marshes should inspire a new generation of conservationists.
Earth has had its great climatic changes, its alternate advances and withdrawals of continental glaciers. Because of their recency, the evidences of Pleistocene ice sheets are conspicuously before us. Of the recognized glacial stages in North America, the latest, known as the Wisconsin, left some of the modern glacial marshlands of southern Manitoba, western Minnesota, northwestern Iowa, and the eastern Dakotas.
Prairie potholes and shallow sloughs and lakes with rush-grown fringes and bays, remnants of immense lakes lying in sandy or peaty or muddy or salty flats, waters of rocky moraines, waters surrounded by tamarack, spruce, white cedar, willow, alder, aspen, oak, waters surrounded by sedge and grass, waters covered by cattail, reed, bulrush, burreed, waters full of waterlily, pondweed, coontail, bladderwort, arrowhead, marsh waters over hard rock or soft muck—these we have where the ice made dams, big dams or little dams.
Wherever the ice sheets or the loads they carry obstruct drainage, there impoundments occur. Wherever ice sheets come and go, there we shall have renewed conditions for the formation of glacial marshes. As long as there be plants and animals adapted for living in marshes and as long as there be impoundments suitable for them to live in, this long may we expect the phenomenon of marshes, glacial or otherwise, to persist.
The over-all phenomenon of glacial marshes has been involved with Life for a long time, and, being linked with fundamental forces of the universe, will presumably continue for some time to come. It does not follow that the marshes of the future will retain all or even most of the plants and animals that we associate with the marshes of today. Changes may be expected that are quite independent of human intervention.
One winter day, I was working over the drought-exposed bottom of a marsh in north-central Iowa. At the surface of the peat, I saw the fore part of a small skull facing me. I gently dug it out with a knife, thinking that the specimen would interest my mammalogist colleagues but not expecting that it would be described in the National Museum as a new species of Pleistocene otter. Its nearest relative now lives in western Mexico, far from our otterless interior of Iowa!
Whatever that marsh may have been when that otter lived, or whatever kinds of other animals may have lived there then, the remains of a long-dead otter hint of continuities extending far beyond the short spans of human civilizations.
Yet, the identity of a glacial marsh is subject to geologically rapid change. Ernest Thompson Seton recounted an Indian legend in which the sun god assigned the muskrat to the "between-land" —that which is neither land nor water. As "between-land," a marsh represents a stage in the filling of a lake or pond with silt and vegetation, and, as the filling continues, the marsh tends to disappear. We might consider the duration of a marsh, individually, as but a geological moment, with moments recurring over and over again to produce geologically ephemeral new marshes.
The advent of modern man as a geologic agent has hastened the filling in of many glacial marshes. Indirectly, through his acceleration of soil erosion, he has brought about a premature filling even of marshes he has intended to preserve. Dust-laden air and silt-laden waters are not peculiar to the era of human domination, but they have become increasingly characteristic of it.
In a separate category from man's incidental effects on glacial marshes is his purposeful drainage. During my life, I have seen two major drainage movements in the glaciated north-central prairies.
One of these movements occurred in the first two decades of the century and took marshes that could be drained relatively cheaply and easily. It took the then-drainable ponds and marshes of the richer farmlands and many extensive marshy areas that offered, or seemed to offer, opportunities for agricultural development. The second movement gained impetus in the forties and was largely centered upon the Minnesota and Dakota potholes that previously had been too expensive or difficult to drain.
To one who loves marshes, the end effects of drainage are the same, in that marshes cease to be marshes, whether they turn into weed patches or cornfields. If we look for variations, we are more apt to find them in the details of pre-drainage enterprising, in what people say or do in order to contribute to the objective of getting marshes drained. There may be publicly owned wetlands, in plain view of someone who might profit from promoting drainage, someone who might profit from the drainage engineering, someone who might profit or hope to profit from working the drained land. Perhaps application of political pressures may be needed to make everything legal. Or, it may only be that someone has a little rush-grown duck pond on his property, and, if he wishes to drain it, nothing less than the laws of physics may prevent him from draining it.
And technology has found so many loopholes in the laws of physics that marshes formerly considered undrainable are now drained with the expectation of their long staying drained. Ditches are machine-cut to depths of fifteen feet or more through one glacial knoll after another, and, in these ditches, capacious tiles are laid and covered up so that soon all looks as before except that the marshes are gone. Nor, in areas having electric power and big pumps to take out the water, do the drainers even have to show the deference to gravitation that they once did.
Of course drainage, as a work of man, does not have complete permanence. Despite technology, there are ditches and tiles that may become so choked that, if man does not actively interfere, drained lands may again become marshes. Or marshes may be intentionally restored, as has already happened in the United States and Canada, sometimes at the cost of great effort and expense to undo what someone else did at the cost of great effort and expense.
To me, as an admitted purist, marshes with man-made dams or ditches do not have quite the undefiled look of marshes having ancient ice ridges or heaps of glacial rock and clay holding the water. They do not look quite as once looked so many of the marshes that I knew in my youth in eastern South Dakota, before so many people coveted the soil of the bottoms. But reverted or restored or artificial marshes still have their values as marshes, along with the naturally impounded ones remaining in the glacial basins. Whether thinking as a purist or not, I am encouraged by the knowledge that conservation of our wetlands and balanced programs for their use are becoming more of a public issue that can result not only in agitation but also in well-conceived action. Minnesota, for example, a state that is rapidly losing many of its marshes to drainage, has one of the most vigorous campaigns on the part of the public to buy up or otherwise safeguard threatened marshes.
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Astrophysical forces are surely working toward another ice age for our earth. I doubt if man, though he master atomic energy, will be able to circumvent the next glaciation and the erasure by glaciation of the outward manifestations of many of his drainage successes and failures. Whatever may then be left of the present forms of marsh life, I think that there will be glacial marshes on earth after man is gone as a species—that is, unless man destroys himself and all earth-bound life. If he continues to gain power without proportional responsibility, he could do exactly that.
Spring, to marshland life on the north-central prairies, comes any time from midwinter to hot weather.
Sometimes, it comes almost as a prolongation of a winter thaw. I saw migrating Canada geese in a wet eastern South Dakota in early February. I can still remember a small flock that appeared over a low hilltop, their clamor preceding and following them. Another year, a South Dakota spring came somewhat as a continuation of fall, with not enough winter cold to seal over the streams, and, when it should have snowed, it rained. That was not the way winter usually was in the Dakotas of my younger years. It was more usual to have snow when there should be snow and snow when there should be rain.
On the calendar, spring sometimes comes when the snow is as deep and the ice as thick and as hard and the temperature as low as in the severest part of the winter. Twenty below zero Fahrenheit or colder and a two-foot snowfall in April must still be considered winter in actuality. Snow on plum blossoms and June snowdrifts must still be classed as snow. But the tracks of the wide-ranging minks during their late-winter breeding season are laid down in powdery snow or in slush, on wet sand or on frozen mud or on dry soil. Restless skunks emerge from hibernation long before the weather could tell them to, and great horned owls incubate and brood their young right on through late February and March and April blizzards. As sexual awakening progresses in the muskrat populations living out of sight of human eyes in their lodges and burrow systems, more and more animals come out and sit on the ice on mild days, until, with the ice gone, the main dispersal away from crowded wintering quarters begins.
Spring comes for much aquatic life when surface waters pour over the ice and down underneath through cracks and holes. The floating ice rises, and vortices with foam-caps appear. The air-gulping bullheads of the muskrat channels and the ice ridges swim away, leaving behind them the bodies of those that died. Water insects and Crustacea float or are carried by wind or currents over the ice or in the eddies of the vortices, and some of them may move and some may not. Cracks widen, their edges become smooth, and the waters beneath invite small boys to peer and to stir and probe with poles.
As the floating ice melts and evaporates on top, the lower layers become upper layers. The winter-killed fish collect on the surface to soften or to dry, depending upon whether they lie in or out of the water. About this time, the gulls come and, together with the crows that were around all winter, eat on the fish remains and the remains of turtles, snails, crayfishes, young dragonflies, and the other dead creatures a marsh presents to scavengers in spring. If there were heavy winter-killing, windrows of dead bullheads, pike, sunfishes, perch, buffalo, or the introduced carp surround the open spaces, or thousands of their rounded bellies protrude like pale bald heads from the water amid the rush stems. Where the frost sank deep under the mud margins, the frozen layer beneath the surface may detach itself from the unfrozen mud beneath that, with the result that large areas of marsh bottom float exposed; and the gulls and crows work over this exposed mud for animal remains. The frozen mud melts and settles to the bottom again.
Dispersing muskrats travel along marsh and lake edge, along streams and up gullies. They may act like cautious and adaptive explorers knowing what they are doing as they do it. They may get started in footloose and hazardous wandering and show up on city streets or in farmyards or in any number of out-of-the-way places—if they live long enough. They may travel far or they may not. Living uncertainly or living securely, they behave like muskrats. They hide or fight, doing their best to stay alive, somehow.
Salamanders and garter snakes crawl out of large and small holes on the hillsides while ice can be seen within. Let spring come as a series of warm and rainy nights, and tiger salamanders seem to have inherited the earth. For a couple of days thereafter, about everything predatory that is able and disposed to do so kills salamanders, to eat them or not, until the run is over. Dogs sicken from mouthing them, children take them to school, and horned owls gorge.
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In spring, I always feel that the marshes belong to the ducks. There may be loons or the big white or gray herring gulls, flocks of pelicans or cormorants, or herons, grebes, coots, rails, terns, shore birds, swallows, blackbirds, and muskrats all over the place. There may be the mass song of toads and frogs, or countless turtles, or the wakes of fishes. Sometimes there is something special to see, such as whistling swans putting on a courtship display, or flights of calling geese passing overhead or their flocks resting on the water, or an eagle in a dead tree or an osprey in the air. But there must be ducks, too. A north-central marsh without ducks in the spring would not be the full equivalent of a spring without life, but it would be lacking in what belongs.
The spectacles afforded by the ducks in spring vary from year to year, from week to week, and even—but usually to a less pronounced extent at the height of migration—from day to day.
At first, a few flocks of mallards or pintails may be seen far overhead, or the birds may be alighting on the ice, next to patches of open water that are no more than big puddles on the surface. They sit around hunched or stand with heads up, looking twice as large as they are.
Instead of a few flocks in the air, the spring flight of the mallards and pintails may attain massive proportions like a great wave. I was working out on the still-safe ice of a northern Iowa marsh when the fore part of such a migratory wave appeared in the sky—mostly in large, wary flocks. In another half hour, a fog—allowing about twenty yards of visibility—settled over the marsh. I became aware of ducks by the thousands and thousands, flying all over and around me. As I moved, they veered a little, their bodies and the sounds of their calls and wing beats becoming of the fog again. When I stood still, trying to make out the landmarks of familiar muskrat lodges and rush and reed clumps, they hovered and dropped down. They sat and swam, and more came to hover or drop or pass by. The mallards and pintails were barely out of reach and their colors bright, or, farther away, their dim bodies faded into invisibility. Then, as late-afternoon fatigue warned me not to be caught by darkness wandering over more than a square mile of marsh, I headed for shore, and the ducks made way to let me pass.
Soon, the ice may start melting through in the vicinity of cracks or muskrat channels or spring holes or heating vegetation beneath, or at the places last to freeze over. Wind-blown surface waters nibble at the edges of the ice about these openings, and needles separate and fall into the water and drift against the next shelf of needles ready for falling. Wavelets become waves as the openings enlarge.
American or red-breasted mergansers appear in the spreading open patches, along with goldeneyes and the first flocks of ringnecks and bluebills. Buffleheads sit or dive pertly or engage in flurries of fights. The formal blacks and whites dominate the color patterns of spring dress, but greens and purples also stand out, and there are blends as well as contrasts. The diving ducks fly in pairs or small flocks from one open patch to another.
After a day or two of warm weather and strong winds, the ice may be ready to break up completely. More ringnecks and bluebills come, and among them may be canvasbacks. There may be groups of plain coots among the ducks. Many flocks of mallards are in the air, close by or flying high. There may be a few pairs or small flocks of green-winged teal, shovelers, baldpates.
Another warm, windy day may take out the ice, leaving the remnant of the melting needles in windrows along shore, together with drifting vegetation. Or, that last warm, windy day may not come just then; the weather is wintry again, and the open water seals except for the patches crowded with the ducks and coots.
As the snow blows over the frozen slush and the new ice thickens, crows start picking at dead coots. Other coots flutter where the spray froze, their wings or feathers caught. Still other coots walk on the adjoining land, looking for green grass under the snow. After a couple of days more, they start dying everywhere on the marsh. Minks drag the thin carcasses into holes, and foxes and skunks work the shores.
The ducks get along better than the coots during spring cold snaps. Mallards feed in the cornfields and rest on the ice or swim in the open places, and so do some of the pintails. Perhaps half of the diving ducks leave, and the others dive and usually get enough to eat so that they do not starve. The mergansers and goldeneyes, if they found fish or insect life to attract them to the first open waters, are likely to stay on. The peculiar whistle of goldeneye wings carries over the marsh as the birds search for more open water to drop into.
The weather changes once more, and soon the ice is gone. The ducks and geese reappear in mass movements. In a day's time, the marsh is covered and the air is full of them. Spring is truly spring.
Excerpted from Of Men and Marshes by PAUL L. ERRINGTON Copyright © 1957 by Paul L. Errington. Excerpted by permission of UNIVERSITY OF IOWA PRESS. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
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