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10 ORDER CARNIVORA Carnivores

David M. Armstrong University Press of Colorado ePub

Carnivores are native to all continents but Australia, and there they were introduced (in the form of the dingo) by early humans. The order Carnivora includes both terrestrial representatives and an impressive array of marine species (the seals, sea lions, and walruses). There are about 285 species of carnivores in some 125 genera. A broad spectrum of the extant diversity of terrestrial carnivores occurs in Rocky Mountain National Park, where these mammals participate in the “top layer” of the food web in most biotic communities. The list of carnivores in Rocky Mountain National Park is dynamic, “a work in progress.” Two carnivores—the gray wolf and the grizzly bear—were extirpated from the area in the early twentieth century. Wolves may eventually restore themselves to the park. River otters disappeared a century or more ago but are being restored. If the black-footed ferret ever occurred here, it is gone now. The status of the wolverine here and elsewhere in Colorado is poorly known. The Canada lynx has been rare or absent through the last century but is being restored in Colorado and eventually may re-inhabit Rocky Mountain National Park. The raccoon has come to occur in the park in rather recent years, and the ringtail is of possible occurrence. Hence, as many as twenty species of carnivores representing six families may have occurred in Rocky Mountain National Park in the past century.

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Letter to a Reader

Scott Russell Sanders Indiana University Press ePub

Since you ask for an account of my writing, I will give you one. But I do so warily, because when writers speak about their work they often puff up like blowfish. Writing is work, and it can leave you gray with exhaustion, can devour your days, can break your heart. But the same is true of all the real work that humans do, the planting of crops and nursing of babies, the building of houses and baking of bread. Writing is neither holy nor mysterious, except insofar as everything we do with our gathered powers is holy and mysterious. Without trumpets, therefore, let me tell you how I began and how I have pursued this art. Along the way I must also tell you something of my life, for writing is to living as grass is to soil.

I did not set out to become a writer. I set out to become a scientist, for I wished to understand the universe, this vast and exquisite order that runs from the depths of our bodies to the depths of space. In studying biology, chemistry, and above all physics, I drew unwittingly on the passions of my parents. Although neither of them had graduated from college, my father was a wizard with tools, my mother with plants. My father could gaze at any structure—a barn or a music box—and see how it fit together. He could make from scratch a house or a hat, could mend a stalled watch or a silent radio. He possessed the tinkerer’s genius that has flourished in the stables and cellars and shops of our nation for three hundred years. My mother’s passion was for nature, the whole dazzling creation, from stones to birds, from cockleburs to constellations. Under her care, vegetables bore abundantly and flowers bloomed. The Great Depression forced her to give up the dream of becoming a doctor, but not before she had acquired a lifelong yen for science. When I think of them, I see my father in his workshop sawing a piece of wood, my mother in her garden planting seeds. Their intelligence spoke through their hands. I learned from them to think of writing as manual labor, akin to carpentry and farming.

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7. Water, Predators, and Pen-Raised Bobwhites

Hernández, Fidel Texas A&M University Press ePub

Figure 7.1. This map shows where annual precipitation averages 20, 30, and 40 inches. Although soils, length of growing season, and severity of winter affect bobwhite management, annual rainfall is the most powerful influence on much Texas rangeland. Management practices for bobwhites must be fit to rainfall zones.

IN THIS CHAPTER we discuss common practices other than food management that generate just as much interest in the bobwhite world: water, predators, and pen-raised bobwhites.

All animals need water to survive. Laboratory experiments tell us that a 160-gram bobwhite in the wild needs about 18–22 milliliters of water/day to survive. Some of this water, about 3–5 milliliters, can be obtained during the metabolism of food (metabolic water). The rest has to be obtained from outside (exogenous) sources.

Exogenous sources of water may include preformed water (water in food), free water, and dew. The amount of preformed water in food depends on the item. Preformed water may range from as low as 3% of the food-item mass (e.g., dry seeds) to as high as 90% (e.g., green vegetation). Free water may be obtained from a variety of sources such as stock ponds, puddles, and water troughs.

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4. Forest Lands

Jr John O Whitaker Indiana University Press ePub

The main natural habitat of Indiana has always been deciduous forest (Figure 4.1; Map 4.1). Prior to settlement by colonists from the young United States, some 20 million of the state’s 23 million acres were probably forested. Indiana is part of the vast temperate deciduous forest biome of eastern North America, though near the western edge of it: Illinois was “the prairie state.” As elsewhere in the biome, climate and soils dictate the forest and its predominant leaf type. Indiana’s annual rainfall of 36–44 inches (91–112 cm) and a 5- to 7-month growing season favor trees and forest over other vegetation, and the state’s mid-temperate latitude and rich soils favor deciduous broadleaf over evergreen needle-leaf species.

Forests are only superficially monotonous. The knowledgeable observer can catalog regional and local diversity in tree species associations almost endlessly. Only a subset, typically 20 to 30 species, of Indiana’s “101 trees” (Jackson 2004) are present in a given forest parcel of 10 hectares or so. Species occurrences and relative abundances differ between upland and floodplain, between 38 and 41 N latitude, and are influenced by soil type, fire frequency, and other factors. Second, there is a structural diversity associated with forest age. Many forests begin with tulip (Liquidambar) saplings in an old field, and go through a characteristic series of vegetative phases: from old field to seedling/sapling, to pole stage, and finally to mature or high-canopy forest. This also happens constantly within mature forest when gaps are created. The early and mid-successional habitats are as important to certain wildlife groups as mature forest is to others.

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3 First Elk

Bruce L. Smith Utah State University Press ePub

Two weeks after arriving in Wyoming, I saw my first reservation elk from a Cessna 182 airplane. Dick Baldes cobbled together the dollars for six hours of flight time over winter ranges in the Wind River Range and Owl Creek Mountains. The new wildlife program’s budget made no allowance for such niceties. For the remainder of fiscal year 1978 it was spartan.

Typically, wildlife surveys are flown during winter or early spring, when snow restricts big game to limited areas. As a further advantage, the snow background makes animals stand out like Winnebagos in a parking lot. Well, not quite that clearly, as it turns out.

Besides counting observed animals, biologists classify them by sex and by age—sometimes distinguishing just young of the year and adults, and sometimes including additional age classes depending upon the species and objectives of the survey. From these classifications, we determine sex ratios (expressed as adult males per 100 adult females) and recruitment (number of young per 100 adult females). Wildlife managers then estimate the size and makeup of populations, charting trends over time like financial planners gauging the past and future performance of an investment portfolio. Later in my career, I would use computer-based population models to do the math. In minutes they would churn out predictions of population growth and harvestable surplus that I had to painstakingly derive from simple calculator computations while at WRIR.

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