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Showing posts from May, 2010

Forgetting to Remember

Today we honor those who have died in their service to our country. Many of them did not volunteer for such duty and few, if any, planned to die in the process; after all, most of those buried in our military cemeteries were killed in their late teens or twenties, having missed out on at least 2/3 of their expected life span.

While these courageous individuals did not intend to sacrifice their lives, the government that sent them into harms way, including those who have supported its policies, condoned and justified their sacrifice. Throughout history, all wars, declared and conducted by presidents, prime ministers, kings and self-appointed despots, have used human fodder to achieve their desired goals.

Few would argue that military power is, unfortunately, necessary for the purpose of defense. But, too often, it has been used in a misguided attempt to force other nations to comply with the demands, policies and beliefs of the invading government; during these crusades, which often f…

Prothonotary Warblers

Eagle Bluffs Conservation Area, southwest of Columbia, hosts spectacular congregations of waterfowl during the spring and fall migrations. During the summer, the refuge is a more tranquil place but still harbors a superb variety of wildlife. Among these are prothonotary warblers, attractive insectivores that inhabit the Midwest from late April through mid September; at Eagle Bluffs, they are especially common along the levee trail that parallels the Missouri River.

Favoring bottomland forest and riparian woodlands, prothonotary warblers are rarely found far from water. The brilliant gold plumage of the males, contrasting with their blue-gray wings and tail, makes them easy to spot among the flooded timber; females are adorned with a duller version of the same plumage but are also attractive birds. If not immediately seen, their loud, ringing song (a series of tweets) heralds their presence and the warblers soon come into view, hunting for insects and larvae.

Unlike other warblers, proth…

Natural Stress Management

This has been a long and difficult week; numerous demands at work and a malfunctioning air conditioner at home have been the primary culprits. Then there was the backdrop of catastrophe across the globe, from the Gulf of Mexico to Wall Street to the Korean Peninsula.

As a physician, I have come to realize that recurrent periods of stress, even if relatively mild, play a major role in the pathophysiology of human disease. While some stress is unavoidable, we often augment its effects by dwelling on factors over which we have no control. This allows a sense of helplessness to pervade our daily existence, magnifying the minor troubles that are an unavoidable part of life.

Faced with an unusual amount of turmoil at work, I choose to unload my free time by putting off duties that are not of immediate concern. In addition, I tune out the global crises by ignoring television and newspapers, content to check in every few days to get an update on our tumultuous planet; music, painting and books …

Summer Settles In

Though the summer solstice is still a month away, hot, humid air has moved into central Missouri. These summer-like conditions are forecast to stick around for the rest of the week but, for all practical purposes, we can expect them to dominate our weather through mid September.

Down at our local nature preserve, it could be June. The greenery is luxuriant, insects have reclaimed the land, the summer songbirds have all returned and the wetlands are alive with various frogs, water snakes and aquatic turtles. Only the lack of summer wildflowers belies the season.

For those of us who are not thrilled by hot, sticky weather, this early taste of a Midwestern summer is a bit unsettling; hopefully, an occasional Canadian front will come to our rescue. If not, I'll confine my outdoor jaunts to the early morning and evening hours and be glad (at least for the next few months) that I have an indoor job.

South Wind

It arrived in Metro Denver during the night, sending a roar through the trees and rattling the windows of our Littleton farmhouse; on this strong, southwest wind, downsloping from the Front Range, the morning temperature had climbed into the mid sixties F, a good ten degrees warmer than usual. The culprit was a potent storm system, centered over Wyoming, and its cold front, trailing through western Colorado; ahead of the system, southerly winds were racing toward the central low, raking the High Plains with gusts to forty miles per hour.

Setting out for Missouri, we fought these winds almost all the way to Columbia. In Denver, the winds were southwesterly, over the Great Plains they were directly from the south and, in eastern Kansas and Missouri, they came from the southeast, all indicating that the central low had not progressed very far to the east; indeed, as of this evening, the center of the storm sits over the Wyoming-Nebraska border, igniting thunderstorms in the western Dakota…

Colorado's Geophysical Provinces

Seventy million years ago (MYA), as the Cretaceous Sea was retreating to the southeast, future Colorado was a relatively flat layer cake of Mesozoic and Paleozoic sediments, overlying the Precambrian basement rocks. Then, about 65 MYA, pressure within the North American craton caused the basement rocks to crumple upward, producing the Rocky Mountain chain. Over time, as rivers drained both sides of the mountain range, the overlying sedimentary rocks were eroded away, aprons of debris were spread to the east and west and the numerous streams carved valleys and canyons throughout the mountains and adjacent plains.

During the Eocene, some 50 MYA, great inland lakes covered the Utah-Wyoming-Colorado tristate region and would deposit the famous Green River shale (now uplifted as the Roan Plateau). Near the end of the Eocene, about 38 MYA, volcanic activity developed in southwest Colorado, initiating the formation of the massive San Juan Mountains. About the same time, grass was evolving on …

May in the South Platte Valley

As May arrives in the South Platte Valley, significant changes are underway. Wintering waterfowl have left the river, dispersing to northern breeding grounds, while summer residents, including cormorants, white pelicans, waders and songbirds are arriving from the south. At the same time, melting of the mountain snowpack is beginning to peak and the river's flow increases dramatically.

As a consequence, much of the "action" shifts from the river to the woodlands, lakes, fields and wetlands that cloak the valley floodplain. A rapid, deep river does not appeal to many water birds and nesting species, such as Canada geese, mallards, cormorants, great blue herons and black-crowned night herons, spend most of their time on or along the calmer waters of adjacent lakes and marshlands. Permanent woodland residents, such as flickers, magpies and great horned owls, are now joined by a host of insectivores, including yellow warblers, western wood pewees, house wrens, northern orioles…

Colorado's Rivers

Possessing the highest average elevation of any State, Colorado is bisected by the Continental Divide and is the origin of many important rivers. The west side of the Divide, known as the West Slope, is entirely drained by the Colorado River and its many tributaries; the East Slope, on the other hand, is composed of four major watersheds: the North Platte, the South Platte, the Arkansas and the Rio Grande.

The Colorado River rises along the Continental Divide in Rocky Mountain National Park. Snaking toward the WSW, this famous stream takes in flow from many other rivers, including the Fraser River at Granby, the Blue at Kremmling, the Eagle at Dotsero, the Roaring Fork at Glenwood Springs and the Gunnison at Grand Junction. The White, Yampa and Green Rivers, which drain the high plateau and mesa country of northwest Colorado, join the Colorado River in eastern Utah while the San Juan River, which heads on the south side of the San Juan Mountains, in southwest Colorado, joins the Colora…

Western Tanagers

May is a colorful month along the Colorado Front Range, as it is in most parts of our country. Here on our Littleton farm, color is provided by lilacs, blue flax, choke cherries, Oregon grape, a variety of roses and, of course, dandelions. And, during the middle of the month, we are visited by western tanagers, among the most colorful of our native birds.

Stopping by the farm on their way to the coniferous forests of the foothills and mountains, these songbirds are reliable and attractive visitors. The breeding males, decked out in a striking suit of red, yellow and black, are easy to spot as they move among our larger trees, chasing insects in the company of yellow-rumped warblers; they also feast on berries later in the season. Within a week or two, they will be off to the high country, where they and their olive-colored spouses, construct a nest of twigs, usually near the top of a spruce, Douglas fir or ponderosa pine.

Though the great majority of western tanagers winter in Central A…

Escape to Dryness

After a week of heavy rains, chilly mist and boggy landscapes throughout the American Midwest, we have escaped to the relatively dry, sunny refuge of our Littleton, Colorado, farm. En route, we crossed the flooded Missouri River, which has spilled across its floodplain, and the Kansas River, which is lapping the top of its banks. On my side trip to Ohio, I had also encountered flooding along all of the major streams, including the Kaskaskia, the Wabash, the Kentucky and the Ohio River itself. Leaving the luxuriant but soggy landscape in central Kansas, we gradually climbed into the semi-arid province of the High Plains; nearing Limon, we endured one final onslaught of precipitation as a massive supercell crossed our path.

Though numerous broken limbs and a sluggish start to leafing attest to the recent snows and cold weather along Colorado's Front Range, the dry air and sunny skies are a welcome change. We may have to dodge afternoon thunderstorms over the coming week but the stead…

Journey along the Ohio

Heading for Cincinnati, I left Columbia this morning and traveled in the wake of a storm system that rumbled through Missouri during the preceding hours. By the time I caught up with the storm, in St. Louis, it was clearly moving on to the northeast and I elected to take the southern route to Ohio, using Interstates 64 and 71.

After crossing the broad, floodplain of the Mississippi, I-64 climbs into the rolling farmlands of southern Illinois; cropfields and wooded stream channels characterize this region which, this morning, was brightened by scattered fields of yellow mustard. The swollen Wabash River marked my entry into Indiana, where the Interstate begins to parallel the Ohio River, some 10-15 miles to the south. Just beyond the outskirts of Evansville, the highway climbs into the Shawnee Hills, which have eroded from a thick layer of Carboniferous sandstone and limestone; the southern section of this geophysical province dips into north-central Kentucky where Mammoth Cave penetrat…

Baldcypress Swamps

Symbols of the Deep South, baldcypress trees are native to the Coastal Plain, from the Chesapeake Bay to Texas and grow along the Mississippi and Ohio Valleys, from southwest Indiana to Louisiana. These majestic trees, which may live for more than 1200 years, are related to California redwoods; though conifers, they are deciduous, dropping their feathery needles (and becoming bald) during the colder months of the year.

Since their seeds must germinate in moist soil, baldcypress favor freshwater, riparian areas, where they form vast swamps with other water-loving trees such as red maple, sweet gum and sycamore. Towering up to 150 feet and achieving a trunk diameter of up to 10 feet, they are easily recognized by their fluted base, which is surrounded by "cypress knees;" originally thought to assist with gas exchange, these knobby projections of the root system are now thought to stabilize these massive trees in the boggy soil. Baldcypress are often festooned with Spanish moss …

Death Valley Heat

Death Valley lies within the Mojave Desert of southeastern California and in the southwestern arm of the vast Basin and Range Province. The latter, which stretches from western Utah to the Sierra Nevada and from southern Idaho to the Sea of Cortez, is characterized by numerous fault-block mountain ranges (running north to south), separated by long, flat valleys. The crust of this region has been under tension for the past 16 million years, stretching it from east to west and causing it to rupture along numerous fault lines; this process (which continues today) has produced the basin and range topography. Filled with lakes during the cool, wet climate of the Pleistocene, the valleys now harbor vast salt pans and stark desert landscapes.

During the above process, Death Valley has dropped lower as its surrounding mountains have risen and, despite a thick layer of erosional debris, its floor still dips to 282 feet below sea level at Badwater Basin, the lowest point in North America. Cut of…

Natural Peacemakers

Throughout human history, wars have raged across this globe, usually waged in the pursuit of territory or power. Fueled by testosterone and endowed with the physical traits for conflict, men have declared and fought the vast majority of these battles, expanding their natural roles of protector and provider.

Women, more inclined toward discussion and compromise, stayed in the background until very recently, concentrating on their nurturing duties as mothers and confidants. Their battles were fought at home, dealing with unruly children, molding the behavior of headstrong teens and appeasing their needy spouse. Mothers, now a growing force within political and corporate circles, have long been the glue that holds families and societies together.

Their invaluable contribution to our lives is celebrated on this day and humans would do well to elevate their stature in our increasingly fragmented civilization. Long devoted to the welfare of their children, mothers, as political leaders, would…

October Drops By

A week into balmy, verdant May, October has paid a visit. Cool, dry air has pushed in behind a Canadian cold front and it feels more like football than baseball season. The sun it too high for October but, if you close your eyes, you can easily picture the painted leaves and smell the wood smoke.

This minor hitch in the progression of spring is certainly not unusual in the American Heartland but it is a bit of a shock when your high temperature is suddenly lower than the recent lows have been. The wildlife, of course, are unfazed; the house wrens sing just as loudly, the garter snakes lounge in the flower beds and the common nighthawks zigzag across the evening sky, confident that their season has not betrayed them.

Only we humans, focused on the calendar, take note of this unseasonable chill. But, if it means that the hot, muggy weather of our Midwest summer will be delayed, I'm all for these autumn-like interludes. In fact, I'd welcome October anytime.

Polite Visitors

Our large tulip tree is in bloom and, over the past few days, flocks of cedar waxwings have stopped by to feast on the showy, yellow and orange flowers. Unlike the bickering mobs of starlings and grackles, waxwings glide in silently and take their place across the canopy. Amiable, mild mannered and neatly groomed in their attractive plumage, they are the perfect dinner guests.

Common but nomadic, cedar waxwings travel about in large flocks but might go unnoticed were it not for their thin, high-pitched whistles. During the colder months, they congregate near berry producing trees where they often share the bounty, passing the fruit from one to another. Last October, I observed a lone cedar waxwing in a large western cedar on our Colorado farm; known to occasionally overindulge or to become inebriated from fermented berries, this fellow was in no condition to fly. Whatever his problem, he eventually recovered and flew off to join his comrades.

Like human societies, bird populations are c…

The Prairie Tern

Most birders remember their first year of "hunting" for new species with a special fondness. Every discovery was exhilarating and the growing list of observations produced a sense of accomplishment. Over the years, having seen these same birds on numerous occasions, the repeat encounters lose their luster and we constantly search for new quarry. But, for many of us, there are some species that occupy a special place in our birding memory and each sighting takes us back to that first discovery; in my case, black terns are on that list.

I first observed a flock of black terns at the Murray Dam on the Arkansas River, just northwest of Little Rock; according to my oldest field guide, it was May 16, 1980. Since these birds winter along the coasts of Central and South America and since I have never travelled to their favored breeding grounds on the vast prairies of central Canada and the north-central U.S., I have rarely encountered these birds since that first sighting. In fact, I…

The Energy Season

The great majority of life on earth is dependent upon the sun; solar radiation is converted into edible carbohydrates by plants (via photosynthesis), these feed the primary consumers and they, in turn, become prey for animals higher on the food chain. Exceptions to this sequence are organisms deep within the earth or on the sea floor that feed on nutrients released by geothermal processes.

Across the Northern Hemisphere, the peak of energy transfer from the sun to the Earth occurs during the months on either side of the summer solstice, which falls on or about June 21. However, when it comes to the efficient transfer of energy to plants and animals, this period begins and ends a few weeks earlier (i.e. from early May to mid July). It is during this period when moisture is still abundant, leafy plants are exploding and the insect swarms have yet to do much damage. Taking advantage of this natural abundance, most herbivores and their predators give birth in May and June.

By mid July, exce…

Man's Divorce from Nature

Ever since man became aware of his superior intelligence, his divorce from nature began to unfold. Fueled by the rise of religious philosophy and our capacity for imagination, we convinced ourselves that we possess spiritual traits that set us apart from other creatures and that give us the right to mold this planet.

Of course, man would not have survived without preying upon plants and animals. But it was the evolution of human culture, some 10,000 years ago, characterized by the rise of cultivation and domestication, that sealed our role as the chosen species. And, as time marched on, the industrial and technologic revolutions widened the gap between man and his natural environment.

Like the modern, human divorce, our separation from nature was initially exhilarating. We sensed the freedom to choose lifestyles without regard to our natural origin. Alas, pretending to be independent of nature and assuming the capacity to control her, we have placed our species at risk. Until we acknowl…

The Patience of Snakes

Late yesterday morning, we noticed a garter snake coiled between two clumps of day lilies. Apparently, he had emerged from the rock wall behind the garden and was attempting to warm up in the fleeting sunshine. I checked on him over the next few hours and he barely moved; at one point, a small beetle actually crawled along his winding torso and, for a few minutes, rested on the snake's head. It would be mid afternoon before my wife's crusade against lawn onions spooked him into the rock wall; perhaps he attempted another hunt in the evening.

Many people, especially those afraid of snakes, imagine that these "dangerous and menacing" creatures slither across the landscape, snaring helpless victims in their path; after all, the serpent is the image of the devil himself! In fact, most terrestrial snakes hunt by stealth; camouflaged amidst foliage, rocks or forest debris, they wait for unwary insects, frogs, birds or small mammals to wander by and, depending on the species…

Oblivious of Nature

One need not live in a college town, as I do, to appreciate the fact that a large segment of our population is oblivious of their natural surroundings. This group, spanning the general age range of 12 to 35, are fixated on their portable, electronic devices and, for the most part, pay little attention to the environment through which they move. When not required to focus on work or school, they are talking on their cell phones, texting one another or tuning into their music; between these activities, they often stare at their smart phones, checking emails and waiting for the next human encounter.

Perhaps I exaggerate, but the connected generation seems to have little interest in the living, natural world. There are some, of course, who plan careers in the fields of biology or ecology, that harbor a true enthusiasm for the great outdoors but, sadly, they are a small minority. Most others, even when jogging or power-walking through our nature preserves, are focused on their headsets and …

Waiting on Nighhawks

Like the migration of snow geese in February and the bugling of elk in October, the arrival of common nighthawks, in early May, is another event by which I mark the natural year. Their arrival signals the onset of a sustained period of warm days and balmy nights and, though I am not a big fan of summer heat, these birds appear with those cherished, mild, fragrant evenings of late spring.

I had thought that the strong, southerly winds of the past two days might have swept a few into mid Missouri but these finicky travelers, unlike the swallows and swifts, will not risk the occasional cold spells of a Midwestern April. Rather, they bide their time, feasting on swarms of insects as they follow the changing arc of the sun.

Within a few days, they will arrive in the Heartland and their sharp peents will echo across the evening sky. Watching them tilt and flap overhead, I will realize, once again, why I am so fond of these common summer residents. It is not the warm weather that they bring; r…