Sunday, November 28, 2010

South of Town

North of Columbia, the landscape soon gives way to the relatively flat terrain of the Glacial Plain that covers much of the Midwest, from central Ohio to the eastern Dakotas. But south of town, one encounters the rolling hills, bluffs and floodplain of the Missouri River Valley; it is a landscape of wooded slopes, hilltop meadows and valley farms, all sloping toward a broad, flat swath of cropfields, wetlands, bottomland woods and the River itself.

On this bright, cloudless morning, I journeyed through this landscape, winding along graveled roads and stopping now and then to observe the changing scenery. Mourning doves and eastern bluebirds huddled on the powerlines, blue jays, mockingbirds and cardinals flashed across the roadways and mixed flocks of juncos and winter sparrows scattered from the roadside thickets. Red-tailed hawks circled above the frosted fields and an occasional red-shouldered hawk patrolled from a barren tree. Though common in this habitat, wild turkeys had not yet left their forest retreats, leaving the meadows and corn stubble to herds of livestock and flocks of Canada geese.

Down on the floodplain, noisy killdeer raced along the mudflats, crows foraged in the crop fields and a lone bald eagle surveyed the scene from a riverside grove. A steady south wind negated my opportunity to observe migrant snow geese but distant, high clouds, off to the northwest, foretold of an approaching storm. That front, due tomorrow, will reinforce the winter season and another wave of snow geese will ride its northerly wind across the Heartland.

Friday, November 26, 2010

Swans over the South Platte

Not inclined to join the mob scene at area malls and presented with another mild, sunny morning along the Front Range, my wife and I decided to take a hike along the South Platte River. A series of cold nights have coated many of the smaller ponds with a sheet of ice and wintering waterfowl are now congregating along the river and its adjacent lakes.

Joining the permanent residents (mallards, gadwalls, Canada geese, wood ducks, northern shovelers, American wigeon and common mergansers) were an excellent variety of winter residents and visitors; these included buffleheads, common goldeneyes, American coot, hooded mergansers, lesser scaup, green-winged teal and ring-necked ducks. On our walk through the South Platte Valley we also encountered belted kingfishers, northern flickers, red-tailed hawks, a lone rough-legged hawk, black-billed magpies, great blue herons, ring-billed gulls, song sparrows, red-winged blackbirds and an industrious muskrat.

But the highlight of this November morning was a flock of tundra swans, winging their way toward Chatfield Reservoir. All eight were in full adult plumage and were unusually silent on their graceful flight above the South Platte. After breeding on the Arctic tundra of Alaska and northern Canada, most tundra swans winter on estuaries along the mid Atlantic and Pacific Coasts; smaller numbers migrate through the interior, heading for the marshlands of New Mexico and Texas.

Thursday, November 25, 2010

A Global Thanksgiving

On this American holiday of Thanksgiving, most of us will give thanks for our human possessions and relationships. But our lives, our health and our society are dependent upon the background support of Earth's natural ecosystems.

Those who do focus on the benefits of nature are likely to mention spectacular sunsets, beautiful scenery, wondrous night skies and the inspiration of our magnificent diversity of wildlife. In referring to the latter, there will be reference to eagles, whales, wild horses and other creatures that humans hold in high esteem. Few will give thanks for fungi or beetles or earthworms, yet, their presence and activity is as vital to our welfare as any other life forms that share this planet.

Indeed, all life on Earth is interdependent. Diverse human cultures, while prone to disagreement and conflict, must learn to cooperate if our species is to survive. And we humans, inclined toward self importance, could not survive without the support of our planet's "lowest" plants and animals. It is thus appropriate that we give thanks for life itself, in whatever form it may exist, and dedicate ourselves to its protection and conservation.

Wednesday, November 24, 2010

The Colorado Piedmont

When the Rocky Mountains first crumpled skyward, 70 million years ago, the adjacent plains rose with them, producing a gradual rise from the High Plains to the eastern flank of the central uplift. Streams meandered eastward from the modest summits which were gradually eroded to the level of the sloping plain. A second uplift of what is now the Colorado Plateau and Rocky Mountain corridor began about 25 million years ago, significantly augmenting the elevation of the mountains and increasing the erosive power of the streams that flowed from the high country.

These streams and subsequent Pleistocene glaciers sculpted the mountains and foothills, removing overlying sediments and cutting numerous canyons through the ancient, Precambrian core. Rumbling onto the plains, the streams merged to form two primary channels, the South Platte and the Arkansas Rivers, their watersheds split by the Palmer Divide; this high, broad ridge, which rises between Denver and Colorado Springs, still connects the High Plains with the east edge of the Front Range. The Rivers and their numerous tributaries have molded a scenic terrain of valleys, low ridges, mesas and hidden canyons along the base of the Rockies, extending eastward along the channels of the primary streams; lower than the adjacent mountains and High Plains, this landscape is known as the Colorado Piedmont.

The great majority of Coloradans live on the Piedmont and its valleys of Cretaceous Pierre Shale support a large portion of the State's agricultural production. The numerous lakes and reservoirs of the Piedmont attract bald eagles and migrant waterfowl while the wooded streams and canyons host the greatest concentrations of eastern Colorado wildlife. Basking in the rain shadow of the Rockies, the human and wild residents of Colorado's Piedmont enjoy a spectacular climate while dodging most of the severe thunderstorms and blizzards that plague the High Plains.

Tuesday, November 23, 2010

Canadian Sunsets

As the sun sets behind the Colorado Front Range, lines and Vs of Canada geese take to the skies. Common across the urban corridor throughout the year, these large waterfowl are especially abundant from November to March, when the permanent residents are joined by their migrant cousins.

After feasting on natural grasslands, golf courses and the manicured lawns of parks and cemeteries throughout the day, the geese return to our lakes and reservoirs to spend the night. There, surrounded by water or ice, they are protected from the coyotes, fox and feral dogs that prowl the Piedmont; unless taken by surprise, Canada geese are large and aggressive enough to protect themselves from these predators.

Having lost favor due to their abundance and their habit of fouling our pristine lawns, Canada geese do not inspire the average citizen (or even the average birder); but one must admire their tenacity, their cooperative instincts and their powerful flight. Backed by the Rockies and the spectacular Front Range sunsets, their wildness and beauty are easy to appreciate.

Monday, November 22, 2010

Snows in the Clouds

Heading to Colorado for the Thanksgiving Holiday, we left Columbia shrouded in moist, balmy air, courtesy of a stiff southerly wind; the latter was produced by an advancing cold front, still in Kansas at the time of our departure. Once we reached Kansas City, the location of the front was obvious as low, gray clouds formed a dense wall across the western horizon.

Passing through the front, the temperature dropped from the sixties to the forties and the wind shifted from the south to the northwest. Layered cloud decks replaced the blue sky and sunshine of our Missouri leg and it looked like our trip across the Great Plains would be far from appealing. Then, in Central Kansas, flocks of snow geese appeared amidst the clouds and my concern about the weather was soon forgotten.

Catching a ride on the strong, northwest winds, these vocal migrants were surely on their way to the Gulf marshes of the Texas Coast. They will probably make another stop in the Arkansas or Red River Valley before pushing on to their wintering grounds and we were fortunate to observe a small segment of their journey from the Arctic. The encounter may have been relatively brief, but the memory will invoke wanderlust in my soul for years to come.

Sunday, November 21, 2010

Marriage: an Unnatural Union

Marriage is not a natural human relationship. Rather, our society has collectively decided (and most of us would agree) that children are best reared in the setting of a monogamous commitment. Unfortunately, our natural traits tend to undermine and disrupt these good intentions.

The romantic, "can't get enough of each other" phase of marriage is often fleeting and, in some cases, is over before the vows are exchanged. It is followed by the "what have I done?" phase, when we begin to pay more attention to annoying traits of our partner and come to resent our loss of independence. The arrival of children usually rescues the marriage, as parental pride and the shared responsibilities of nurturing our kids rekindle the romance. Once they are teens or young adults, however, other threats emerge, including discipline issues, Oedipal jealousies and nostalgic yearnings for the freedom that our progeny enjoy.

Perhaps the greatest threat to the stability of marriage occurs when the children are finally independent, often coinciding with the boredom of our middle age lives. Men, naturally attracted to fertile females, have a tendency to stray while many women, having sacrificed careers for their children and now facing entrenched societal discrimination, come to resent the advantage that their spouse has enjoyed; if not rescued by communication, compromise and the trust to extend individual freedoms, the relationship often disintegrates. Those couples who make it through this stage have generally learned to respect the human need for personal space and, if luck holds, they finish out their lives together.

Saturday, November 20, 2010

Winter's Assault

As of this morning, a potent winter storm was spinning over the Great Basin and its associated cold front stretched from San Francisco to Maine. Pulling in moisture from the Pacific Ocean, the storm is expected to drop heavy snow from the Sierra Nevada to the Rocky Mountains.

North of the front, frigid air is pouring into Montana and the Dakotas, the vanguard of winter's sweep through the country. Here in Missouri, the temperature will push into the sixties over the next few days, as southerly winds develop ahead of the front; by Tuesday, winter should arrive.

Summer's feeble jabs are weakening and, like a light-weight contender facing the heavy-weight champion, it is at risk of a knock-out blow. Winter is gaining strength with each shortening day and its grip will tighten as summer retreats to the south. For all practical purposes, the battle has been won.

Thursday, November 18, 2010

Ringing in the Season

On this first cold evening of the season, I was surrounded by the tinkling song of juncos as I walked home in the fading twilight of dusk. Down from the great Northwoods, these small, attractive songbirds are a fixture of the Midwest winter, thrilled to spend the cold, dark months in our relatively balmy climate.

Feasting on weed seeds, they scavenge our brushy fields and woodlots, scattering into shrubs and thickets if danger is sensed; as they do, their white outer tail feathers unveil their identity. Dark-eyed juncos are hardy survivors, christened "snow birds" for their seeming indifference to the challenges of winter weather.

Those who place feeders in the yard can observe these birds at close range; both slate-colored and Oregon races visit the Heartland. Unlike many of our residential songbirds, they shun the feeder perches, preferring to search for seed that has fallen to the ground. We'll enjoy their company until early April, when the weather gets too warm for their taste; it is then they'll escape to their homeland, the vast coniferous forests of Canada.

Wednesday, November 17, 2010

Autumn Rain

Unlike recent cold fronts, our current trough has tapped a fetch of Gulf moisture and cold rain is falling across central Missouri. Though the rain will be short-lived and modest in quantity, it has temporarily doused our image of a crisp and sunny Midwest autumn.

Such bands of rainfall, caused by the same atmospheric clash that brings early spring showers, are more common in autumn than we care to admit. An unruly jet stream characterizes both seasons, mixing chilly air from the north with a warm, moist flow from the south. The result, raw days with cold rain and shifting winds, is perhaps the least favored weather of nature's year.

While spring showers are often welcomed, ushering in the season of growth and renewal, autumn rains are recognized as the vanguard of a deeper chill. The wet leaves and muddy fields that they leave behind offer little promise of brighter and warmer days ahead. Rather, these autumn rains lead toward the dark, cold realm of winter where, in time, they will convert to a seasonal mix of sleet and snow.

Monday, November 15, 2010

Exorcism 2010

Born of fear and scientific ignorance, religions have retained significant influence thoughout the course of human history. Early man, facing the many threats of prehistoric life, developed beliefs and rituals which, over time, have morphed into the religions that we know today. Ingrained in childhood, reinforced by clergy, imposed by governments and maintained by social pressures, they continue to govern our lives.

Modern man tends to ridicule the "pagan" rituals of prehistoric "savages" while defending the mysticism that still pervades our culture. This week, Catholic bishops are convening in Baltimore to review and update the Church dogma related to exorcism, the ritualistic treatment of persons who are "possessed by demons." Despite the advances and revelations of modern neuroscience, the bishops cannot relinquish their conviction that mental illness may be induced by evil spirits!

While some are amused by this exorcism conference, many of us see it as another sign that the talons of religious indoctrination still grip human society. We are embarrassed for our species and view Exorcism 2010 as an insult to human intelligence.

Sunday, November 14, 2010

Red-tail Highway

Red-tailed hawks are common on the farmlands of the Midwest and are especially conspicuous during the colder months of the year. It is then that they congregate along our country roads and Interstate highways, hunting for small rodents that inhabit the grassy medians and berms.

On my travels to and from Ohio this weekend, the red-tails were abundant, perched on fenceposts, tree limbs or power poles if not soaring high overhead or rising from the grass with a victim in their talons. Their bulky frame is easy to spot in the barren woodlands and their pale, red tail feathers aid identification as they flap and glide above the fields. Though outnumbered by starlings and (perhaps) turkey vultures, these buteos are readily observed by anyone who traverses the open country of America's Heartland.

Indeed, when scouting birds for the annual Audubon counts, one often hears the retort that "it's just another red-tail." But their common occurrence does not detract from the power and grace of these magnificent raptors and should not minimize their role in controlling the rodents and cottontails that might otherwise decimate our vital croplands.

Wednesday, November 10, 2010

A Polarized Nation

As if our political polarization was not bad enough, the jet stream has now divided our country. This afternoon, a broad dip in the jet has brought winter conditions to the western U.S. while the eastern half, protected by a dome of high pressure, basks in summertime warmth. The dividing line between the trough and ridge runs north to south across the Central Plains; on either side of this cold front the temperature varies by 20 degrees F.

Such potent contrasts set the stage for severe weather and, once the trough moves into areas primed with Gulf moisture, thunderstorms will ignite. Meanwhile, within the trough, an upper level low is spinning from the northwest to the southeast, producing mountain snows and bringing the first significant upslope snow to Front Range cities.

Over the next few days, the protective dome will shift eastward, summer will retreat and a taste of winter will invade the Heartland. Here in Missouri, we'll escape the western snow but chilly rain and blustery weather will deliver a reality check; it is, after all, November.

Tuesday, November 9, 2010

Jurassic Parks

The Colorado Plateau of the Western U.S. harbors one of the most extensive exposures of Jurassic strata on our planet. Stretching from 200 to 135 million years ago, the Jurassic Period covered the heart of the Mesozoic Era, the Age of Dinosaurs.

A number of our National Parks and Monuments are famous for their Jurassic deposits and, by extension, their cargo of dinosaur fossils. Dinosaur National Monument, in northwest Colorado and northeast Utah, is a showcase for the Morrison Formation; deposited in a long, shallow basin, from Canada to New Mexico, this layer cake of mudstones, siltstones, coal and sandstone is famous for its late Jurassic fossils. A bit older, the Entrada Sandstone, deposited in the mid Jurassic, is highlighted at Arches National Park, in eastern Utah, where it has been sculpted into a spectacular array of fins, natural bridges and arch formations.

Perhaps most famous of the Jurassic sedimentary rocks is the Navajo Sandstone, deposited about 190 million years ago when a vast desert covered the region. Relatively soft and heavily jointed, this sandstone forms the upper cliffs of Canyonlands National Park, the scenic domes of Capitol Reef National Park and the towering walls of Glen Canyon, now drowned by Lake Powell. Separated from the Navajo Sandstone by the Kayenta Formation, the Wingate Sandstone yields the middle cliffs of Canyonlands and the majestic, sheer walls of Colorado National Monument; though officially dated from the onset of the Jurassic, some geologists argue that, based on its fossil contents, the Wingate was deposited near the end of the Triassic.

Monday, November 8, 2010

Summer takes a Round

After a week of frosty mornings and the sense that winter was taking control, summer got off the mat and reclaimed mid Missouri today. Its victory may be brief but we'll enjoy a few days in the seventies before the next cold front pushes through the Heartland.

Any thought of raw, gray, November weather has vanished, as coeds stroll across campus in shorts and t-shirts. A steady, southerly wind has the flags rippling atop the ROTC building and has coaxed a trio of vultures into the air. If not for the long shadows and the fading colors of autumn, one might think it was early September.

Such gyrations in our Midwest weather are typical of autumn as a restless jet stream undulates across the country. While songbirds, attuned to the light cycle, are not fooled, the waterfowl will slow their migration until heavy snows and frozen ponds drive them south. As much as I look forward to those wavering flocks of snow geese, this mild interlude is a welcome setback. After all, in due course, winter will win the battle.

Sunday, November 7, 2010

The Great Oceanic Plates

When Earth's Continents merged into Pangea, some 250 million years ago, the vast intervening ocean stretched across two oceanic plates, the Pacific and the Farallon; spreading out from a mid-oceanic ridge, the Pacific Plate lied beneath the western half of the sea while the Farallon occupied the eastern half, abutting the future Americas.

Pangea began to break up during the Triassic, as the Tethys Sea opened from east to west. Later, in the Jurassic, the Atlantic began to open, shoving the American Plates to the west. As this occurred (and continues to occur), the Farallon Plate was forced to subduct beneath the American Plates and, in doing so, added a cargo of sub-continents to western North America, crumpled up the Rockies and created a broken chain of subduction volcanoes from the Andes to southeast Alaska. Today, only remnants of the Farallon persist, including the Nazca Plate along the west coast of South America, the Cocos Plate west of Central America and the Juan de Fuca Plate (and a few smaller remnant plates) off the west coast of the Pacific Northwest.

The Pacific Plate, devoid of major continental masses continues to form along its ridge with the remnants of the Farallon and along its younger ridge with the Antarctic Plate. Inching to the northwest, the Pacific Plate scrapes through Southern California along the San Andreas Fault and eventually subducts beneath or overruns the North American, Eurasian, Philippine and Australian Plates in a broad arc, from the Aleutians to New Zealand. For now, only hotspot volcanic islands disrupt its vast expanse of open sea; eventually, this great oceanic plate will also disappear as new oceans open, our current continents rift apart and the Pacific subducts into history. Just like the Farallon and its many other predecessors, the Pacific Plate is a transient feature of Planet Earth.

Saturday, November 6, 2010

Morning Chill at Eagle Bluffs

Arriving at Eagle Bluffs Conservation Area this morning, it was clear that winter had taken charge of the refuge. Flocks of horned larks and meadowlarks moved across the frosted fields while smaller groups of crows foraged amidst the brown corn stubble. Kestrels surveyed the scene from roadside powerlines and red-tailed hawks soared overhead, scouting for mice or cottontails on the cold, yellowing grasslands.

As expected, most of the preserve is closed for duck hunting but there were a fair variety of waterfowl on accessible lakes and waterways. Mallards and wood ducks cruised through the flooded timber while shovelers, gadwall and coot gathered in the shallows; pied-billed grebes were especially common, diving amidst the reeds and aquatic vegetation that rimmed the ponds.

This placid scene was disturbed only by the shotgun blasts that rang through the valley. Watching the ducks in the safe zone, one wanted to warn them of danger just to the south; they, of course, were oblivious to the threat and showed no response to the distant explosions. It was, in some ways, a disturbing experience, watching these potential victims that, later in the morning, might venture across the killing fields.

Friday, November 5, 2010

Claron Lake

When the Rocky Mountain chain began to rise, some 70 million years ago, the crust to its west was stretched, producing a mosaic of ridges and broad basins. Drainage into the basins created large inland lakes, including the Green River Lakes of the Utah-Colorado-Wyoming Tristate and Claron Lake of southwest Utah. All of these lakes gradually filled with sediments of the Paleocene and Eocene Periods (60-50 million years ago); the deposits in the Green River Lakes would eventually yield the famous oil-shales of the Roan Plateau while deposits in Claron Lake would become prized more for their natural beauty.

Compacting into layers of limestone, dolomite, siltstone and conglomerates and capped by volcanic tuff from the Oligocene Period (30 million years ago), the Claron Formation was lifted with the rest of the Colorado Plateau during the Miocene-Pliocene Uplift, some 25-10 million years ago. Erosion and faulting would eventually expose the Claron beds along the edge of regional plateaus; Cedar Breaks National Monument, a spectacular natural amphitheater on the west edge of the Markagunt Plateau and Bryce Canyon National Park, on the east edge of the Paunsaugunt Plateau, protect the most scenic exposures.

Rich in iron oxides and manganese oxides, the colorful limestones and dolomites have eroded into striking rock formations, known as hoodoos. These pinnacles, capped by more resistant rock layers have been split apart by stream erosion and freeze-thaw fracturing. Once lying beneath an ancient lake, they now gleam in the bright Utah sun and adorn calendars across the globe.

Thursday, November 4, 2010

Tardy Canadians

Perhaps our balmy October weather kept them at bay. Or perhaps they arrived under the radar and I've been too busy to notice their presence. For whatever reason, I saw the first white-throated sparrows under our feeder this afternoon, a sign that they have escaped the harsh winter of Canada to spend the dark season in the mild confines of central Missouri.

Two weeks behind schedule, their appearance is always a welcome sight and their plaintive song will brighten the long, dreary months of winter. That tune will build in urgency during the waxing days of early spring and, by mid April, they'll depart for their homeland, never to endure the sticky weather of a Midwest summer.

Watching them beneath the feeder, one wonders if they would stay put if they knew about the mild conditions along the Gulf Coast. If informed, would they pull up stakes and head for the sandy pinelands of that southern clime? I tend to doubt it; after all, these hardy birds have adapted to the cool climate of the Great Northwoods and our Missouri winters, however taxing, pose little threat to their survival. On the other hand, a few months in the heat and humidity of the Gulf Coast, while inviting to many humans, might sap their energy and hasten their demise. I, for one, would never encourage them to leave; their stoic presence, especially on those frigid winter mornings, is an inspiration to all of us who cannot escape.

Wednesday, November 3, 2010

The Nature of Politics

The elections are over. The Republicans control the House, the Democrats will likely retain the Senate and, in the end, nothing will change. At least the obnoxious commercials and recorded phone messages will stop for a while.

American politics is all about power, celebrity and perks. During campaigns, the candidates parade their families before the camera, visit local merchants, extol the values of middle America and promise to restore our faith in Government. Once elected, it's politics as usual: pompous rhetoric, cable TV appearances, travel junkets, celebrity galas, golf tournaments, extra-marital affairs and deal-making legislation to ensure that constituents get what they want. After all, their primary goal is to be re-elected. Meanwhile, wars drag on, the economy stagnates, the wealth gap widens, individual rights are threatened and a commitment to environmental protection is but an empty promise.

The concept of term limits surfaces now and then and, in my opinion, deserves serious consideration. Professional politicians argue that they understand the logistics of government and that a regular turnover of Congress would diminish their effectiveness. The evidence, however, suggests otherwise.

Tuesday, November 2, 2010

The Heart of Volcanism

The great majority of Earth's volcanoes are found along subduction zones, where one tectonic plate is dipping beneath another; the lower plate begins to melt as it approaches the mantle, magma rises and a chain of volcanoes develops near the edge of the overriding plate. The famous Ring of Fire refers to the numerous subduction zone volcanoes that have developed along the Pacific Rim; these include the Andes, the volcanoes of Central America, the Cascades, the Aleutian Islands, Japan, Taiwan and the Philippines, among others.

But the most concentrated and active swath of subduction volcanoes lies along the western and southern edge of Indonesia, where the Australian Plate is subducting beneath the Eurasian Plate. Having developed within the past 15 million years, the volcanic islands of Sumatra, Java, Bali and others harbor more than 150 active volcanoes and have been the site of some of the most powerful volcanic eruptions in Earth's history: Krakatoa, Toba and Tambora. Over the past week, Merapi, on Java, has begun erupting for the 27th time since 1930, the most active and, in light of the regional population, one of the more deadly volcanoes on our planet.

This concentration of volcanism in Indonesia is, of course, merely a reflection of Earth's current geography and topography. Since it formed, 4.6 billion years ago, our planet's surface has undergone constant change; oceans have opened and closed, continents have merged and rifted apart and the sites of active subduction have shifted across the globe. The intense volcanism in Indonesia and elsewhere is evidence that the evolution of Planet Earth continues to unfold.

Monday, November 1, 2010

The March of Autumn

November, like March, can be a fickle month in the American Heartland; though known for blustery weather and gray skies, both months offer a fair number of mild, sunny days. But an unsettled jet stream, tugged by summer and winter, produces intermittent showers and storms, some of which harbor snow.

Many prefer the stability of January or July but, for the naturalist, these transition months have much to offer. The weather patterns, themselves, can be fascinating, prompting adaptation by a wide variety of creatures, including humans. And, for birders, these months host the peak of the waterfowl migrations, offering some of the true spectacles in nature's year.

Following the splendid month of October, November has a rougher edge and generally brings the first significant round of winter weather; for those who dread the cold and snow, its value is redeemed only by the prospects of football and the beloved Thanksgiving holiday. But, for the rest of us, November offers crisp, invigorating weather, active and conspicuous wildlife, the inspiration of migrant geese and the reassurance that nature's cycle will stay the course.