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Showing posts from March, 2010

The Tide of Spring

Unless you are a committed astronomer, in which case spring always starts with the equinox, one's choice of a starting date for this beloved season is purely arbitrary. And, as most of us come to realize, conditions dictate a different date from year to year. This year, in central Missouri, I would choose yesterday evening.

After weeks of cold rain, wet snow and overnight temperatures below freezing, we have had several mild days in a row and, yesterday, we enjoyed the first, balmy, spring-like evening of the year. Following a late afternoon high near 60F, a gentle, southerly breeze continued through the evening and high cirrus clouds streaked the pale blue sky. The greenery of spring had spread from the grass to the shrubs, as small, olive bundles tipped the honeysuckle, forsythia and lilac bushes, periwinkle blossoms adorned the ground cover, clusters of daffodils brightened the lawns and our tardy magnolias had begun to bloom.

The mellow call of mourning doves wafted through the …

The Scourge of Ignorance

To the uneducated, this world can seem both daunting and mysterious. The complexity of our bodies, our culture and our surroundings, coupled with the seemingly random occurrence of catastrophe, leads to the assumption that spiritual powers manipulate our lives. As a result, these individuals are easy prey for those who espouse a simplified view of life and who, for a price, offer the key to their personal welfare.

Arguing that modern science and governments are a threat to individual freedom, the zealots of various religions and political movements appeal to these lost souls, swelling both the ranks and the bank accounts of their organizations. Spurred on by paranoia and fear, gullible followers find solace in the simple, narrow-minded message of these prophets and come to despise the views of others, especially the "intellectuals" of society.

Claiming to protect the beliefs and rights of their members, the zealots set out to disrupt and derail social progress, potentially den…

Tree of Water

After wintering on beaches, bays and marshes along the Gulf of Mexico, waterfowl and shorebirds stream northward from late February to mid May, heading for breeding grounds across the Great Plains and Arctic tundra. En route, they follow the branching streams of the vast Mississippi watershed; like a tree of water, the major rivers and their numerous tributaries guide these travelers northward, offering nutritious rest stops along the way.

Snow geese and swans lead the exodus, moving across the Heartland in late February and early March. The migrations of Canadian geese and most ducks peak in March while flocks of coot, blue-winged teal, shovelers, white pelicans and shorebirds dominate the waterways in April. May brings the late shorebirds, waders and tardy migrants such as black terns.

This morning, at Eagle Bluffs Conservation Area, southwest of Columbia, the Missouri River was in flood stage and shallow pools covered much of the refuge. American coot, blue-winged teal, shovelers and…

The Sound of Change

There are many sounds of early spring; the rising chorus of birdsong, the chirping of tree frogs and the questioning hoot of the barred owl all come to mind. But it is the rumble of thunder that most signifies a change in the season.

As the jet stream drifts northward, the flow of Gulf moisture opens across the Heartland. Combined with more intense solar heating, this fuel ignites thunderstorms as Pacific cold fronts march across the country. Beginning along the Gulf Coast, the thunderstorm season moves northward through the spring, peaking in April across much of the Midwest. This evening, a band of storms is pushing through Missouri and, after a long, frigid winter, the sound of change is more than welcome.

We'll endure some cool showers on the back side of the front tomorrow morning but, according to the forecast, the first significant heat of spring will invade our region through the coming week. The southerly flow that brings this heat will, of course, inject more humidity…

Cemeteries & Conservation

Landscaped to attract future "residents" and those who will visit them, cemeteries often harbor a wide variety of trees and shrubs. As a result, as birders know, they are often good places to observe our avian neighbors, especially during the spring migration.

But, like golf courses and suburban lawns, cemeteries are not natural environments. Their vast, green carpets are maintained by a toxic assortment of chemicals; after all, who would want their loved ones surrounded by the handiwork of dandelions, grubs and moles? Those of us who care about the accelerating loss of natural habitat are not fond of cemeteries and wonder why we all need our own plot in which to disintegrate after death. Would it not be better to have our ashes spread at one of our favorite haunts....along a beach, in a forest or on a mountainside where we would quickly re-enter the fabric of nature? Would our loved ones not prefer to visit us there than to stand over a grave marker, picturing us in a q…

Woodpecker Days

While tree swallows, waterfowl and eastern phoebes migrate northward in March, the tide of summer migrants will not get underway until mid-April and some of our winter visitors (juncos, white-throated sparrows) will enjoy a few more weeks in the balmy Midwest. But it is the woodpecker group that seems to dominate the March woodlands, drumming and calling as their breeding season gets underway.

Since the trees are still devoid of leaves, it is a good time to observe these carpenters of the bird world as they chisel new cavities or search for burrowing insects. Their territorial displays make them especially conspicuous during the early days of spring and, here in the Heartland, all of our resident and migrant woodpeckers can be found. Northern flickers and red-bellied woodpeckers, known for their hysterical calls, are impossible to ignore while downy woodpeckers, those small residents of suburban woodlots, have paired off and are reliable visitors at the backyard feeder. Hairy woodpecke…

Iceland & Rift Volcanism

There is no Atlantic Plate; rather, this Ocean covers a broad basin that opened (and is still opening) between the North American, Eurasian, South American and African Plates. The rifting process began about 160 million years ago and continues today along the Mid Atlantic Ridge.

In such rift zones, where continents are pulling apart, the crust thins, the Earth's mantle bulges toward the surface and volcanism develops. Volcanic rift zones are evident in some regions of our Continents today: the Rio Grande Rift of North America and the East African Rift are prime examples. Eventually, as happened with the Atlantic, ocean waters will invade these rift basins.

Iceland began to form above the Mid Atlantic Ridge during the Miocene and emerged from the sea about 16 million years ago; its northwestern half lies on the North American Plate while its southeastern half lies on the Eurasian Plate. Volcanism continues along and near the rift line, adding more land to this island nation as it exp…

Winter Sandwich

Though it is the spring equinox, a swath of winter stretches from Texas to the Great Lakes. The latest Pacific storm, which brought upslope snow to the Front Range earlier in the week, has pushed into the Southern Plains and, this morning, is centered over northeast Oklahoma. Along it cold front, a mix of cold rain and wet snow is putting a damper on spring through the center of the country; within the past few hours, heavy, wet snow has rapidly accumulated in central Missouri.

Meanwhile, the eastern and western sections of the U.S. are enjoying mild, spring weather, with afternoon highs near or above 70 F. As is typical in March and April, dramatic changes in weather conditions occur over short distances, creating the image of a winter sandwich, with chilly, moist ingredients trapped between warm, fragrant loaves of spring.

Of course, this weather sandwich is not static and, as it pushes eastward, Gulf moisture will sweep across the Eastern States. Fortunately, the higher sun and longe…

The Impatient Mammal

Yesterday, after enduring a long, cold, gray winter, we were rewarded with the first sunny and warm day of the new season. Walking home amidst throngs of cheerful college students, clad in shorts and T-shirts, there was a sense of relief in the air. Then, at the next intersection, someone did not turn quick enough and the blare of a car horn shattered the serenity. Impatience is, unfortunately, a common human trait and, as a consequence, we endure a great deal of self-imposed stress.

Wildlife, on the other hand, living by instinct and not capable of anticipating the future, are not crippled by impatience. While they do respond to the solar cycle, they are not governed by the minutes and seconds of human time. Indeed, they rely on patience for their own survival, a key to successful stalking and foraging.

Here in Missouri, human patience will be tested once again as two spring-like days yield to cold rain and snow over the coming weekend. While we grumble and resort to watching col…

March Misery

As much as we look forward to spring, the season often begins with the worst weather of the year: raw, windy days, cold rain, wet snow, floods and oscillating temperatures. Despite global warming, early spring has been especially cold and unpleasant over the past few years and, to date, the trend continues.

Here in Missouri, we are at least two weeks behind schedule when it comes to spring flora. Of course, when compared to the recent storms in New England and the threat of floods in the Upper Midwest, we have little to complain about. March is always a fickle month and has a reputation for bringing severe weather to various parts of our country; it drops the heaviest snows of the year across the Colorado Front Range, triggers tornado season along the Gulf Coast and ushers in the wildfire season of South Florida.

Unfortunately, despite our tidy image of the seasons, nature's cycles are gradual and uneven. Spring is an ill-defined transition from winter to summer and its clash of war…

The Mountains of Kansas

This morning, we left Denver under clear, blue skies and, out on the High Plains, the bright sunlight gave the drab, late winter landscape a clean, sharp-edged look. Across the grasslands, heifers tended to their newborn calves, pronghorn browsed the windswept hillsides and harriers cruised low above the shortgrass prairie, hunting for voles.

Then, approaching Goodland, we noticed a purple ridge that stretched across the eastern horizon; where it rose highest into the deep, blue sky, the ridge was topped with snowy domes and peaks. Had we not known better, we might have concluded that the highway had circled back to the west and that we were getting a distant glimpse of Colorado's Front Range. We finally caught up with the imposing wall near Colby, where its component cloud layers had become more obvious.

One can imagine that early explorers were often confused by such distant illusions, rechecking their compasses or, perhaps, offering a few choice words for those who published thei…

Karst Springs

Karst plains are characterized by a thick layer of soluble bedrock (limestone or dolomite), often topped by a veneer of sandstone. Cracks in this overlying roof allow rain water and snowmelt to percolate into the soluble bedrock; over thousands of years, the water opens channels in the limestone, eventually producing a network of caves and underground streams. In some areas, the cave roof collapses, forming a sinkhole at the surface, another source of entry for precipitation; indeed, in karst areas, much of the surface drainage is into these sinks and surface streams may be very limited.

The watershed of these underground stream networks is often very extensive; since they pass beneath surface divides, they may encompass the territory of several surface watersheds. Eventually, the underground flow discharges into a surface stream, usually as a spring along the walls of a river valley; in some areas, the discharge is via a vertical shaft, producing what is commonly called a blue hole.

Th…

The Season of Mud & Flood

By mid February, as the jet stream begins to oscillate and the sun creeps northward, alternating periods of cold and mild weather occur across the Heartland. During the warm interludes, Pacific storms often drop heavy rains on the frozen ground; augmented by snow melt and unable to penetrate the hard soil, this copious precipitation immediately drains into the numerous tributaries of our larger streams and rivers, eventually leading to floods.

March brings longer periods of mild weather, more frequent rains and a more rapid rate of snow melt. As the higher sun takes a toll on the frozen ground, the upper layer of the soil thaws and, saturated with precipitation, turns to mud; farmers and early spring hikers know these facts all too well. Of course, the production of mud uses only a fraction of the precipitation and the majority flows into our stream channels, increasing the flood risk as the month progresses. It is not until mid April, when leaves unfold across our woodlands, that …

Children & Nature: A Lost Connection

Today, children are heavily exposed to nature and are well schooled regarding the importance of conservation. Daycare centers and schools provide regular field trips to zoos, museums and nature centers and communities offer a host of volunteer programs related to recycling or environmental cleanup. Of course, many parents do their part by "living green" and by taking their children to parks, campgrounds and nature preserves.

On the other hand, I am concerned that many children (especially those living in urban and suburban areas) are denied the immersion in nature that past generations of children were able to experience. Memories of my early childhood are filled with exploration; my friends and I spent endless hours in the nearby woods, along the creeks and ponds or tramping through fields and farms. Such open space was readily available in those days and concern for our safety was relatively nonexistent. On summer days and on weekends throughout the year, we might disappea…

March along the Front Range

As the sun rose over the Colorado Plains this morning, the last clouds of yesterday's storm system stretched across the eastern horizon and clear skies extended westward to the Front Range. Downsloping, westerly chinooks were warming the urban corridor and, by mid morning, the temperature was approaching 50 F.

Along the South Platte, the hysterical call of flickers rang through the valley and the chorus of red-winged blackbirds was reaching a fevered pitch. Since the ponds and lakes of the Front Range have begun to thaw, the concentration of river waterfowl has diminished though a good variety, including a pair of hooded mergansers, still graced the scene. The flickers drummed away on dead limbs, magpies gathered sticks for their bulky nests and a pair of red-tailed hawks cavorted overhead. Spring has certainly arrived along the Front Range!

But, as locals know, the season of snow has not ended. March is the snowiest month in Denver (followed by April and November), thanks to Pacifi…

A Sight for Bored Eyes

On our journey across the Great Plains today, we saw a wide variety of migrating waterfowl. Flocks of snow geese were very common, wavering across the morning sky between Columbia and Topeka. In western Missouri, a large flock of greater white-fronted geese had settled in a shallow marshland and migrant ducks crowded the farm ponds all the way to the High Plains.

The highlight of our trip occurred near Lawrence, Kansas. Just south of the highway, a flock of small geese rose from the corn stubble and circled above our path; solid white except for their black primaries, they initially appeared to be snow geese. But, having observed thousands of those abundant migrants over the past few weeks, I realized that these birds were smaller, somewhat chunkier and flew in a tighter formation. They had to be Ross' geese, which, like the snow geese, nest on the Arctic tundra of northern Canada; while most winter in the Central Valley of California, Ross' geese have become more common across…

The Nature of Reason

Reason is the intellectual capability of humans to confront life's mysteries and, by adhering to the scientific method, to uncover their solutions. Throughout human history, the process of reasoning has greatly expanded our understanding of the Universe, including the structure and function of our own species. Of course, as our knowledge continues to advance and as our scientific tools become even more sophisticated, our current level of understanding will, eventually, come to be viewed as primitive.

Some aspects of human life, such as art and music are conduits for the expression of emotion and, despite their importance in our lives, are not governed by reason. Religion and mysticism, long ingrained in human culture, are not based on reason and, in fact, are threatened by man's intellectual curiosity; the more we understand about our Universe, the less influential these philosophies become. Of course, some argue that religion explores truths that man is not equipped to com…

The Siberian Traps

One of the great natural spectacles of the modern age has been the awakening of Kilauea, on the Big Island of Hawaii, which has continuously spewed lava since 1983. Yet, from the perspective of geologic history, this flow is but a momentary trickle. Consider, for example, the Siberian Traps.

In the late Permian, some 250 million years ago, vents opened in the crust of what is now north-central Russia and, over the next million years, a basaltic flood covered an area the size of our lower 48 States to a depth of 2 km; most geologists believe that the flow was triggered by a mantle plume which melted the overlying crust. The largest event of its kind in the history of our planet, the basalt and its associated volcanic debris extends from the Ural Mountains to the Lena River Valley. Today, this igneous province is named for the step-like terrain that erosion has left behind.

Having more than a spectacular effect on the landscape, this prolonged volcanic episode changed the climate of Earth…

Seasonal Setbacks

In a typical year (if there is such a thing), the temperature gradually rises as the days lengthen in spring and gradually falls as daylight wanes in the autumn. Average temperature charts reflect this pattern but, as we all know, nature is not focused on human records.

During many of our transition seasons, periods of excessive cold may disrupt expected trends. While these episodes are merely inconvenient and frustrating for impatient humans, they can be deadly for some species of wildlife. Early insectivore migrants, such as eastern phoebes and tree swallows, travel north in response the the lengthening daylight, only to find that their natural food has been suppressed by a prolonged, unseasonable freeze. In like manner, a late period of cold weather may destroy a variety of natural flowers, impacting both the creatures that feast on their nectar and those that rely on their fruit. Heavy spring or early autumn snows are notorious for culling newborn and aging mammals, thinning he…

The Danube Delta

Rising in the Black Forest of southern Germany, the Danube River, the second largest in Europe, winds southeastward for almost 1800 miles before emptying into the Black Sea. At its mouth, the River has created a vast delta, the largest and best preserved wetland on the Continent; covering 2200 square miles and still growing, the delta is a mosaic of braided channels, marsh, reed beds, lakes and riparian woodlands. Most of this vast wetland lies within Romania while its northern section is in the Ukraine; the entire ecosystem, much of which is protected in the Danube Delta Biosphere Reserve, is thought to harbor the 3rd greatest biodiversity on the planet (trailing only the Galapagos Islands and the Great Barrier Reef).

Plaur, floating islands of vegetation, make this delta especially attractive to nesting water birds, including 3500 pair of Egyptian white pelicans; of more than 170 birds that nest within the preserve are rare species such as pygmy cormorants, ferruginous ducks, red-cre…

Feral Cats

The cries outside our window last night indicated that the next generation of feral cats is in progress. We seem to have more than our fair share of stray cats in Columbia, perhaps a reflection of the large population of college students, prone to free-spirited pet maintenance and short-term living arrangements.

Archaeological evidence suggests that humans and cats have lived in close proximity for at least 10,000 years; initially, wild felines likely took advantage of the food sources that human habitation provided. The Egyptians are thought to have been the first civilization to domesticate the cat (approximately 8000 years ago) and, ever since, these creatures have become favored pets across the globe; their attractive appearance, low maintenance requirements and rodent-killing abilities have all played a role in this respect.

Unfortunately, as often occurs in human society, we can be lax about the responsibilities of pet ownership; failure to neuter these animals and a willingness t…

A Tardy Spring

On this first calendar day of spring, there are few signs of the season. While changes induced by the lengthening daylight, such as birdsong and waterfowl migration, are on course, those dependent on warming of the soil are far behind. By now, the crocuses are usually blooming, the grass is greening and robins have abandoned their wetland haunts to snare earthworms on our spongy lawns. Alas, the ground remains frozen and there is little color in the late winter landscape.

While, here in Missouri, the afternoon highs are creeping into the low forties (F), the overnight lows are still dropping into the mid twenties and the soil has yet to thaw. Out in the wetlands, the shallows remain ice covered and the tree frogs (spring peepers and chorus frogs), usually singing by late February, remain silent, still entombed in the cold, winter muck.

Yes, spring, when it finally arrives, will seem especially glorious this year. We humans, often apprised of the value of hard work and suffering, ex…