Posts

Showing posts from March, 2013

Nature's Advance Man

This morning, an eastern phoebe flitted across the restored prairie at Forum Nature Area, in Columbia. Moving through chilly, moist air under gray skies that might rain or snow, the flycatcher seemed out of place.

Yet, this is his annual calling card.  Nature's advance man often arrives by mid March, six weeks ahead of many northern flycatchers.  Among the earliest signs of spring, eastern phoebes are generally found alone, flicking and spreading their tail as they alight on a sapling or dead wildflower stalk.  Until the insect supply catches up with their energy needs, they feast on berries and soft seeds as well; once the weather is reliably warm and hordes of insects fill the air, eastern phoebes pair off, nesting on cliff ledges, beneath bridges or along the eves and beams of barns and other out-buildings.

The hardiness of this flycatcher is also apparent in the fall, when they stop to winter along the southern tier of the U.S., well north of their cousins that head for the ba…

Denial in Boston

Devout Catholics, like almost everyone else, favor efforts to minimize the need for abortion; eliminating unwanted pregnancies offers the most direct route toward that goal.  One assumes that they also support the prevention of sexually transmitted diseases, such as  HIV, Hepatitis B, Hepatitis C, gonorrhea and chlamydia, among others.

Nevertheless, officials at Boston College, a Catholic institution, oppose a student program to improve access to condoms on campus.  Apparently convinced that this project will shed a negative light on their University and encourage premarital sex, they announced their intention to shut down the program; they softened their position by citing the availability of condoms at retail stores or through public health services.

This antiquated stance, surely taken to appease older alumni and donors, is just the latest attempt by conservative religious organizations to deny the nature of human sexuality.  Whether they admit it or not, sexual activity is widespr…

Avian Drones

Driving back to spring, we left the wintery landscape of northeastern Ohio and headed WSW across the Glaciated Plain of the American Midwest.  While we enjoyed clear skies and mild weather, wildlife observations were rather limited.  Turkey vultures were the lone exception, soaring above the snow speckled farmlands from Ohio to Missouri.

These avian drones, unlike their military counterparts, are not predators; rather, they keep an eye (and, more importantly, a nose) on the rolling fields below, searching for carrion.  Roadkill is readily available along and near the highway and many small mammals, especially young cottontails, likely succumbed to our recent storm which left a heavy blanket of snow across the Heartland, now melting in the late March sun.

Terrestrial animals, including humans, tend to focus on the horizontal.  While we enjoy a colorful sunrise or sunset and glance at the night sky now and then, our daily chores keep us focused on our personal landscape; the heavens are…

The Seams of Life

Yesterday, facing another cold, gray, snowy day in northeastern Ohio, we opted for a visit to the Rock & Roll Hall of Fame, in Cleveland; it proved to be a very rewarding decision.  The Hall has created a fabulous review of rock history, from the late forties through the present, and the visit reinforced my view that music, more than any other human endeavor, keeps us tethered to the people, places and events of our life.

Music connects us with our past, with other persons of our generation, with those who influenced our lives and with world events that shaped our personal philosophy.  While many other factors are vital to our development as human beings, music is closely intertwined with memory, giving our life historical perspective.  Indeed, in the quilt of life, music provides the seams.

Some might argue that I am placing too much emphasis on the importance of music; after all, some cultures place strict limits on its use, concerned that its influence is too potent.  If anythi…

Horned Grebes

This morning, a pair of horned grebes rippled the calm, gray waters of Sandy Lake, southeast of Kent.  While the landscape of northeastern Ohio retains the look and feel of winter, these avian visitors were evidence that spring is gradually unfolding, however reluctant it may seem.

Indeed, horned grebes summer on freshwater streams, ponds and wetlands from southern Alaska to east-central Canada, including the northernmost tier of the American Great Plains.  Come fall, they head for saltwater bays and brackish rivers of the Pacific and Southeastern Coasts; a minority may also be encountered on southern freshwater lakes.  There and during their migrations, they are adorned in their black and white winter plumage, molting to their more colorful breeding plumage once back in their northern homeland.  Like pied-billed grebes but unlike western and eared grebes, horned grebes are rarely found in sizable flocks; rather, these small, stocky birds are usually seen alone, in pairs or in small g…

Spring Postponed

A broad atmospheric trough, dipping through much of the U.S., has put spring on hold for the next few days.  Allowing cold Canadian air to plunge across the Great Plains and Midwest, this southern dip in the jet stream is steering the latest winter storm across central latitudes of North America, a region that is often well into spring by late March.

A swath of snow, from the Rockies to the Mid-Atlantic, now coats the early spring landscape, masking the greenery that began to spread over the past two weeks.  The cold air has also put a halt to the emergence of flowers and leaves across our woodlands, prolonging the barren look of winter.  Even the hardy tree frogs, which were calling from chilly pools and lakeshores have been silenced by this late blast from the north.

Visiting relatives in northeastern Ohio, we have escaped the heaviest snow but are left with the cold, gray shroud of a Great Lakes winter.  Five days into the astronomical spring, signs of the season are limited to lon…

Sports Heroes

In March, as coverage of the NCAA basketball tournament blankets the airwaves, we are reminded that, more than any other field of human endeavor, sports provides our heroes.  As early as grade school, star athletes emerge as our most admired peers and, by college, rabid fans wear the jersey of their favorite player, signaling both their infatuation with that athlete and their personal identification with his or her accomplishments.

Indeed, unlike members of other professions, athletes enjoy a fan base that is emotionally invested in their success or failure.  While the fans of musicians or actors may admire their work, extending both the gift and curse of celebrity, fans of athletes often sense a partnership with their heroes; in their minds, they are members of that player's team, sharing in the joy of victory and the agony of defeat.  Through their cheers, rituals and energy, fans actively participate in the contest and, as a consequence, become emotionally connected with the at…

Dramatic Route to the Rockies

Back in the early 80s, when we lived in Arkansas, we usually took a southern route to the Rocky Mountains.  After following I-40 through Oklahoma and northern Texas, we would either head northwest, from Amarillo to Raton or, in a few cases, took a more dramatic route.

Leaving the Interstate at Tucumcari, New Mexico, we would follow New Mexico 104, passing or camping at Conchas Lake, on the Canadian River; the latter rises on the east slope of the Sangre de Cristo Range, in north-central New Mexico, and then angles SSE across the High Plains, carving a stark canyon through the Kiowa National Grassland before reaching Conchas Lake (elevation 4200 feet).  From the lake, Route 104 heads southwest and then northwest, passing a host of low mesas before reaching a prominent escarpment; climbing 1100 feet (from 5500 feet at its base to 6600 atop the cliffs), the traveler is suddenly treated to a spectacular view of the snow-capped Sangre de Cristo Range, from its southern end above Santa Fe t…

The Maumee Torrent

Toward the end of the Pleistocene, a lobe of the Wisconsin Glacier pushed southwestward into northeast Indiana.  Its maximum extent was reached about 22,000 years ago and, as it retreated toward Ohio and Canada, it left a series of terminal moraines in its wake.  The last of these in Indiana was the Ft. Wayne Moraine, which curved through the present day city of Ft. Wayne, extending northward and southeastward from that site.

As the Ice Sheet melted from the region, Glacial Lake Maumee formed behind the Ft. Wayne Moraine. West of the Moraine, the ancestral St. Joseph and St. Marys Rivers merged to form the Little River, which flowed southwestward to join the Wabash just west of Huntington, Indiana.  Then, about 14,000 years ago, Lake Maumee breached the Ft. Wayne Moraine, sending a torrent of glacial meltwater through the Little River Valley and thence down the Wabash to the Ohio River.

As the Wisconsin Glacier continued to retreat into Canada and the St. Lawrence Seaway opened, the G…

Cambrian Rock Exposures

Unlike strata from the other Paleozoic Periods, Cambrian rock exposures are relatively rare throughout the United States.  Deposited from 542 to 488 million years ago (MYA), when the variety of shelled and soft-bodied marine life was exploding on Planet Earth, Cambrian sediments lie deep beneath most regions of our country and are exposed primarily in association with ancient Precambrian basement rocks.

Where Precambrian domes or ridges have pushed up through overlying Paleozoic, Mesozoic and Tertiary strata, Cambrian sediments, usually metamorphosed by heat and pressure, may be found along the primary uplift.  Examples include Cambrian strata ringing the Black Hills, St. Francois Mountains (southeast Missouri) and Adirondack Mountains and seams of Cambrian deposits along the Blue Ridge of the Carolinas and northern Georgia; scattered Cambrian exposures are also found in the Rockies and throughout the Great Basin where fault blocks ranges brought deep basement rocks to the surface (e.…

Pure March

Classic March weather has settled across the American Heartland this week.  Chilly, humid air, gray, breezy skies and intermittent rain, sometimes mixed with sleet or snow, envelop the landscape.  We humans, native to the tropics, retreat to our dry, heated homes while nature conducts her slow transition from winter to spring.

In the countryside, livestock plod through soggy fields, hawks patiently cling to damp, barren limbs, crows and starlings swarm across dreary farmlands and pickups leave muddy tracks on the graveled roadways; even our beloved bluebirds, perched on icy powerlines, reflect drab silhouettes in the filtered sunlight.

Yet, the fields and lawns are slowly greening, migrant waterfowl grace the ponds and lakes, the first dandelions glow along roadside sloughs and robins pick their way across the thawing soil.  Hyacinths, daffodils and early tulips brighten our flowerbeds and a purple haze of henbit will soon spread across the floodplains.  The dingy, wet, raw days of Ma…

Singles Day at Eagle Bluffs

Yesterday, enveloped in chilly air and shrouded by a low overcast, Eagle Bluffs Conservation Area, on the Missouri River floodplain, was loaded with ducks.  Mallards, gadwall, shovelers, coot and blue-winged teal filled the shallows while flocks of lesser scaup, ring-necked ducks and ruddy ducks gathered on the deeper pools.  They were joined by scattered pairs of Canada geese, a few pied-billed grebes and the occasional great blue heron, stalking the shorelines.

Of special interest were one snow goose, resting in a flooded woodland, a single white pelican, lounging on a mudflat and a lone trumpeter swan, feeding in a shallow channel.  All three of these species are generally found in sizable flocks and the combined presence of these solitary visitors was unusual, especially during the spring migration.

When a flocking species is found alone, it is often a sign that the bird is sick or injured.  If so, these white-feathered visitors, conspicuous in the brown, March landscape, will soo…

The Nature of Discrimination

This week, a Conservative U.S. Senator reversed his position on gay marriage.  The reason?  His son announced that he is gay.

The Senator's personal decision crystallizes the nature of human discrimination.  Planted in the minds of children and sustained by fear and ignorance, negative feelings toward persons of another race or culture persist.  So too do we learn to discriminate against those with physical or mental disabilities and those who manifest atypical behavior.  Homosexuality, derided as a mental illness or a sinful indulgence throughout human history, remains a target of discrimination, even in light of scientific evidence that sexual orientation is a genetic trait.

Once ingrained, intolerance of those unlike ourselves tends to persist until we are forced to confront those attitudes through personal experience or intimate relationships.  Those who remain sheltered from such interactions retain their zealous intolerance while those who develop a close association with pa…

Detour to Wilson Lake

On my frequent trips between Colorado and Missouri, I often take short detours or side trips that offer relief from the monotony of the Interstate highway.  Yesterday, under warm, sunny skies dotted with flocks of migrating cranes, I opted for a visit to Wilson Lake, northeast of Russell, Kansas.

Created by damming the Saline River in 1964, Wilson Reservoir is renowned for its clear, blue water and good fishing.  Initially constructed for flood control, water supply and recreation, the lake's waters were found to be too salty for irrigation or home use and debate continues whether desalination or mixing in fresh aquifer water would be feasible; indeed, the use of this reservoir represents just one of many controversies regarding water rights throughout the Western U.S.  And, like many other water projects, its creation disrupted a natural river ecosystem to "produce wildlife habitat", a beautiful but unnatural oasis amidst a dry landscape.

Looking past these issues, Wils…

Arctic Ice

As one might expect, the extent of ice cover on the Arctic Ocean waxes and wanes with the seasons, reaching its annual maximum in March.  Of course, as global warming progresses, the ice cover will continue to diminish and, by 2040, the Arctic Ocean is expected to be ice free during the summer months.  Indeed, as the Arctic ice gradually disappears, less solar radiation is reflected into the atmosphere, accelerating the rate of Arctic warming.

Following the breakup of Pangea and the opening of our "modern" oceans, the northern Continents had drifted into their current positions by the end of the Cretaceous Period, some 70 million years ago (MYA).  Since the global climate remained relatively warm through the early Tertiary Period, Arctic Ocean ice did not begin to form until the late Eocene (about 47 MYA), reaching its maximum extent during the glacial periods of the Pleistocene (2.2 MYA to 10,000 years ago); during warm interglacial periods of the Pleistocene, the Arctic ic…

The Uncompahgre Plateau

At the beginning of the Miocene Period, some 25 million years ago (MYA), the Colorado River and its tributaries were cutting their way through a layer cake of Tertiary and Cretaceous sediments (top to bottom) in western Colorado; colorful Jurassic and Triassic rocks lay beneath these sediments, not yet uncovered by the river.

Then, as the Miocene-Pliocene Uplift began, a block of Precambrian granite began to rise; 100 miles long (NW-SE) and 25 miles wide, this block caused the overlying Mesozoic and Tertiary sediments of western Colorado to warp across it, forming the Uncompahgre Plateau.  Eventually rising more than 6000 feet above the surrounding terrain, the plateau has also been whittled by erosion, removing its Tertiary veneer and exposing layers of Cretaceous, Jurassic, Triassic, and Precambrian Rock (top to bottom); all Paleozoic sediments had been eroded from the top of the Precambrian block during the Pennsylvanian and Permian Periods, some 300-225 MYA, producing the unconfor…

The Desert Hawk

Zone-tailed hawks inhabit the Desert Southwest, from Southern California to southwest Texas, and range southward through Mexico, Central America and semiarid regions of South America; most of those that breed in the U.S. winter in Mexico.

A large but slender buteo, zone-tailed hawks resemble turkey vultures when in flight and often soar with flocks of those scavengers; indeed, some ornithologists believe that this behavior is an effort to deceive their prey (small mammals, birds and reptiles) that tend to ignore the harmless vultures.  Preferring desert and semiarid grasslands with nearby trees and cliffs, zone-tailed hawks are best found near desert ranges where they roost and nest in wooded canyons.  After engaging in spectacular mating flights, characterized by steep dives, these raptors construct a nest of sticks in a tree or on a rock ledge; two or three eggs are generally produced.

Easily identified by their black plumage, yellow legs, banded tail and vulture-like flight, zone-t…

The Nature of Comets

Comets are small astronomical bodies composed of rock, ice and frozen gases; they range in size from 1000 meters to 30 miles or more in diameter.  Almost 5000 comets are known to science though they likely represent a tiny fraction of the actual number.  Short period comets, defined as those with a period of less than 200 years, are thought to originate in the Kuiper Belt, beyond the orbit of Neptune, which contains countless icy objects and planetoids (including Pluto).  Long period comets, which have periods exceeding 200 years (up to many thousands of years) are assumed to arise from the Oort Cloud, at the outer edge of our solar system.

In either case, the comet is likely drawn from its original orbit by gravitational effects from the large gaseous planets, sending it toward the sun.  As it approaches the sun, ice, gases and dust from the comet are vaporized by the solar wind, producing a "coma" envelope around the rock nucleus and a tail that points away from the sun.  …

Upslope Slop in Colorado

As predicted, a typical upslope snowstorm is underway in Metro Denver.  Most common in March and April, these storms develop when the central low pressure of a Pacific system passes south and east of our region, sweeping Gulf moisture counterclockwise and "uphill" toward the Front Range.  As the air is forced to rise across the High Plains, Piedmont, foothills and mountains, it cools below its dew point and, depending upon the air temperature, precipitation falls as rain or snow.  The highest snow totals in Denver generally result from storms that move east along the Colorado-New Mexico line, producing an upslope flow from the northeast.

Today's storm is centered over western Kansas and our wind direction is more from the north, reducing the snow potential.  In addition, the air temperature is hovering in the low thirties (F),  producing a heavy, wet snow that is melting on our roadways (still warm from recent mild, sunny weather).  As a result, the storm has created a s…

March on the South Platte

Yesterday's sunny, mild weather sent me down to South Platte Park for a hike along the river.  Since the valley ponds and lakes are beginning to open, many of our wintering waterfowl have dispersed from the river but most species were still represented.  However, the large, mixed flocks have given way to scattered pairs, a sign that spring fever has taken hold; pairs of common goldeneyes, buffleheads and green-winged teal were encountered, joining pairs of our common, permanent residents.  The large flocks of wintering Canada geese have begun their journey to the north, leaving pairs and small, family groups scattered throughout the valley; nesting should commence within a week or two.

The distinctive calls of white-breasted nuthatches and the hysterical cries of northern flickers echoed through the cottonwood groves, where downy woodpeckers, chickadees, house finches, magpies and blue jays were all especially vocal.  In the riverside marshes, male red-winged blackbirds delivered …

River Connections

Rivers connect us with distant ecosystems, sculpt our landscape and provide vital water and nutrients to areas far from their source.  In effect, rivers give us a sense of place while highlighting our dependence on the health of their entire watershed.

On my regular visits to the Missouri River, west of Columbia, I often ponder the varied sources of the water that passes through our region.  Much of the water is derived from snow that fell on the eastern flank of the Rocky Mountains while some was dropped by blizzards and thunderstorms across the Great Plains.  A small but significant percentage bubbled from hot springs at Yellowstone National Park or was squeezed from prairie air as it rose along the rugged slopes of the Black Hills.  In most cases, the water first flowed through tributaries of the Missouri, including the Milk, the North and South Platte Rivers, the Yellowstone and streams of the Great Plains, such as the Cheyenne, White, Niobrara, James, Big Sioux and Kansas Rivers.

Australia's Largest River System

Most of Earth's Continents are known for their major river systems; there is the Amazon Basin of South America, the Mississippi Watershed of North America, the Nile and Congo systems of Africa, the Rhine of Europe and the Ganges-Brahmaputra and Yangtze of Asia, among many others.  When it comes to Australia, however, a nation Continent known for its vast desert landscapes and sunny climate, rivers do not immediately come to mind.

The Murray-Darling River System of southeast Australia is the largest on that Continent.  The Murray River, which rises on the western slope of the Great Dividing Range in New South Wales and Victoria, is Australia's longest river; flowing westward to form the border between those two States, it then angles to the southwest across the southeastern corner of South Australia, entering the Southern Ocean south of Adelaide to complete its 1476 mile course.  The major tributary of the Murray is the Darling River, which merges with the Murray in western New…

Snow-stressed Snow Geese

Heading west this morning, I saw numerous flocks of snow geese between Columbia, Missouri, and Lawrence, Kansas; most were not heading north.  In fact, the flocks were moving in all directions, clearly looking for potential feeding sites amidst the snow-covered landscape.  In a few areas, I saw small groups that alighted on parcels of grassland cleared by wind or sun exposure but most flocks remained in flight, circling above the thick blanket of snow.

While Mississippi Flyway snow geese generally follow the Mississippi and Missouri Valleys, they rely on wetlands, grasslands and crop fields for nourishment on their "spring" journey to the Arctic.  Facing the widespread snow cover, they will likely congregate along the major rivers, where floodplain marshes, side channels and oxbow pools offer access to aquatic vegetation; the backwaters of large reservoirs, if not frozen, might also be utilized.

West of the Flint Hills, in eastern Kansas, I encountered several flocks that we…

Sparrow Month in the Heartland

Like small sandpipers and Empidonax flycatchers, sparrows are often difficult to identify, especially for the beginning birdwatcher.  Across the American Heartland, March is the best month to compare our sparrow species since permanent, winter and summer residents may all be encountered.

Common permanent species include song, field and house sparrows (the latter are actually introduced weaver finches but tend to be grouped with native sparrows); vesper and savannah sparrows may also be encountered throughout the year.  Common winter residents, present throughout March, include white-throated, white-crowned, fox, swamp and American tree sparrows; they may be joined by rare winter residents such as Le Conte's, Harris' and Lincoln's sparrows.  By late in the month, summer residents, including Henslow's, chipping, lark and grasshopper sparrows begin to appear in the Heartland.

House (permanent), white-throated (winter) and chipping (summer) sparrows are common in residenti…

The Nature of Sinkholes

The unfolding tragedy in southwest Florida demonstrates the unpredictable nature of sinkholes, which can swallow roads and buildings as they suddenly form and expand.  These geophysical landforms develop in karst regions, where a layer of soluble bedrock (limestone or dolomite) lies near the surface.

Channelized by underground streams, the sheets of porous bedrock are penetrated by a network of tunnels and caverns which surface as springs.  Eventually, as a cave enlarges and its ceiling thins, it may collapse from the weight of the overlying soil, vegetation and/or structure, producing a sinkhole.  Depending upon the depth and width of the collapsing cavern or tunnel, the sinkhole may be small or massive and stress on the adjacent ceiling might produce an unstable collapse, prone to further expansion.

The Florida Platform, composed of limestone (deposited during periods of high sea level) overlying older basement rock, makes the Sunshine State especially prone to sinkhole development.…

March & Wednesday

Since many humans live for weekends, Wednesday, often referred to as hump day, represents the last hurdle before our downhill slide toward better days.  While it is welcomed as a sign that we have survived the first half of the work week, it is also a reminder that two more days of stress and tribulation stand between us and our weekend rewards.

March, the first calendar month of the northern spring, arrives before winter has thrown in the towel.  While the darkest and coldest months are behind us, the fickle weeks of March are not always as spring-like as we might prefer.  Indeed, in the American Heartland, this month is renowned for its raw weather, muddy landscape and all-too-slow progression.  The days may be longer and the greenery may be advancing but the glory of spring has yet to arrive.

March is a wonderful month for waterfowl watchers and college basketball fans but, for many in the Midwest, it is just a damp, gray, chilly interlude between the stark beauty of winter and the…