Sunday, July 29, 2012

Our Sense of Self

The human body, like that of all animals, is the product of our genetic code and its physical components are nearly identical to those of most mammals.  It is only our large and complex brain that sets us apart and it is that organ which gives us our sense of self.  Unlike most other animals, we are able to reason, theorize, calculate, imagine, anticipate and ponder; our level of conciousness is far more advanced than is evident in other higher mammals and it is this trait that deludes many humans into thinking that we have no direct connection with other species.

Our personal view of life, from our own body to our local environment to the vast Universe, is the current product of our genetics and all of our experience; the latter includes education (formal and otherwise), emotion-inducing events (positive and negative) and our personal interaction with other humans, other creatures and our environment.  All of this information and experience, like data fed into a computer, is acquired through our physical senses and molds our sense of self.

While many humans believe that there is also a spiritual component to our existence, such mysticism has no basis in science and is not necessary to explain our human capabilities, including our thoughts and emotions.  Dreams, which free our mental processes from concious control, arise from our life-long spectrum of experience and provide the best insight into the neurochemical processes that are responsible for memory and thought..  Once awake, our natural defense mechanisms take charge and we are less willing to accept the fact that we humans, as intelligent and creative as we might be, are merely self-aware, biochemical organisms.

Saturday, July 28, 2012

A Promising Darkness

After a month of intense sunshine, excessive heat and severe drought, we in the American Heartland are searching for signs of autumn.  Dry and leaf-lilttered lawns certainly evoke the image of fall but, in this case, result from dessicated vegetation and stressed trees; the latter are dropping their leaves to reduce transpiration and thereby conserve water for their more vital tissues.  Yet, a month past the summer solstice, there is a sign of hope.

A promising darkness is developing across the Northern Hemisphere, welcome evidence that we have begun our slide toward winter.  Sunrise is coming later and the twilight of dusk now provides earlier relief from the intense summer sun.  While the daytime heat will not abate for another month or so, the lengthening nights will gradually provide cooler mornings and more pleasant evenings; the latter, filled with the music of crickets and katydids, will tempt us outdoors after our long summer estivation.

Unfortunately, little rain and persistent heat are forecast for the coming week and our patience is wearing thin.  The subtle loss of sunlight is all too gradual at this point and we long for the refreshing air and sparkling snow of winter.  Of course, by then, the prospect of a hot summer day will sound inviting.

Friday, July 27, 2012

Memories of the Dead

As we age, the number of our dead relatives, friends and acquaintances expands dramatically.  Yet, some memories of those individuals, whether they died fifty years ago or just last month, remain sharp and continue to affect our lives.  Indeed, in my experience, there are usually a handful of events, traits or expressions that we associate with each of them; should someone mention their name, those specific memories flood our mind.

Like personal tags, these unique mental links will forever define each person; many, if not most, will shed a positive light while some may tarnish their image.  Since memories forged under the influence of intense emotion are most likely to persevere, we often recall the more joyous and more painful interactions above all others and those are the memories that, years hence, tend to shape our feelings about another individual.

Many believe that we will see them again, that we will have another chance to mend grievances or to express gratitude.  Others, including myself, suspect that death is final and that we live on through our genes, through our contributions to human society and in the memories of those who knew us.  We recognize the influence that the deceased had (and continue to have) on our lives and strive to ensure that our own lives inspire those who, some day, will remember us.

Wednesday, July 25, 2012

Five-lined Skinks

Attempting to rescue our plants from the brutal summer weather, I was watering last evening when I spotted a small lizard as it dashed from a clump of azaleas and disappeared into a crevice beneath our brick walkway.  With its distinct black lines and bright blue tail, I knew that it was a juvenile five-lined skink, one of the more widespread lizards in eastern North America, found from southern Ontario to the Gulf Coast; they are the only lizards to inhabit New England.  Juveniles are commonly known as blue-tailed skinks while adult males, which acquire an orange facial mask during the breeding season, have received a variety of titles.

Five-lined skinks are diurnal hunters, generally seeking insects, spiders, earthworms, other invertebrates and even newborn mice on the ground; however, they are capable climbers and may be found in trees, especially those infested with insects.  Favoring moist woodlands, these skinks emerge from hibernation in mid spring and soon mate; the female will deposit up to 18 eggs in a shallow depression beneath a rock or log and guards them until they hatch.  As noted above, the young have bright blue tails which fade with aging, though adult females often retain some bluish-gray coloration on their tail.  Like many lizards, five-lined skinks are able to discard their tail when pursued by a predator, distracting the hunter as they make their escape; the tail grows back but tends to be shorter than the original appendage.

Natural predators of five-lined skinks include snakes, shrews, opossums, raccoons, fox and a variety of raptors (especially barred owls, broad-winged hawks and red-shouldered hawks).  Adults may grow to a length of 8 inches and have a natural life span of 5-6 years.  Like garter snakes, these skinks often hibernate in colonies, choosing a sun-exposed rock pile, a hollowed log beneath the leaf litter or an abandoned den below the frost line.

Tuesday, July 24, 2012

The Long La Nina Summer

The extreme heat and drought across the Central U.S. this summer is courtesy of a La Nina atmospheric pattern that has been in place for almost two years.  Characterized by relatively cold waters across the tropical eastern Pacific and high pressure over that region, storm systems are shunted across the northern latitudes of North America, reducing snowpack in the western mountains (except for the Pacific Northwest) and bringing drought conditions to the central and southern Plains.

Having developed late in 2010, this La Nina strengthened by late 2011, producing spring-like conditions last winter and summer warmth that began by mid spring across the American Heartland.  Since the eastern Pacific high has diverted the jet stream across Canada, few Pacific storm systems have penetrated the central U.S., allowing a high pressure ridge to settle over our region; beneath this ridge, sinking air has produced hot, dry conditions and a devastating drought while torrential rains and floods have occurred around its rim (across the Upper Great Lakes, mid Atlantic and northern Gulf Coast).  This prolonged La Nina is also responsible for the intense tropical storms in Japan and China this summer, as warm Pacific waters are displaced to the west.

La Nina patterns generally develop every five years or so and back-to-back La Ninas occur 50% of the time.  The severity of their impact is likely to increase with global warming and the current two-year drought across the Southern Plains may be a harbinger of even worse events in the future.  On the positive side, the waters of the eastern tropical Pacific are beginning to warm and this prolonged La Nina is expected to break down by December. That forecast, if accurate, suggests little relief from our long, hot, dry summer in the coming months.

Sunday, July 22, 2012

Fame by Mass Murder

Following the most recent episode of mass murder in U.S. history, representatives from almost every news service in America have descended on Aurora, Colorado, to bring us excruciating details of the perpetrator's violent deeds and personal history.  In effect, his careful planning and ruthless action have achieved their intended goal.

Such events are, indeed, one of the more assured routes to celebrity in human society.  Deranged loners, seeking attention and fame, vent their anger on innocent victims and, in the process, become permanent fixtures in the recurring cycle of violence and tragedy.  America, of course, is the perfect setting for these mass murders, with its social freedoms, lax gun laws and competitive media industry.  Whatever fame is not endowed by the event itself will be assured during frenzied coverage of the trial and by the ongoing talk shows, documentaries and crime story programming that follow.

I do not wish to imply that the tragedy itself does not deserve appropriate coverage and scrutiny.  Sensitive remembrance of the innocent victims and discussion of how such events might be prevented in the future deserve the attention that they receive.  On the other hand, detailed coverage of the attack, deaths and injuries feeds a disturbing morbid voyeurism in human society and contributes to the devious goals of the perpetrator.

Saturday, July 21, 2012

Condoning Intolerance

Within the past few days, Boy Scouts of America has reiterated its policy that homosexuals are not welcome in their organization and Dan Cathy, the President of Chick-fil-A (and the son of its founder), renounced gay marriage as an offense to God.  While some might accept such pronouncements as freedom of speech, the use of prestige, wealth or power to foster discrimination against a segment of human society is, in my opinion, offensive and intolerable.  Though the action of such groups may not be strictly illegal, it illuminates the ignorance and rigid theology that often undermine freedom and social progress in this country.

Christian conservatives have a long history of imposing their beliefs on others and of restricting the rights of those who do not fit within their world view; the Inquisition, Adolf Hitler and the KKK all come to mind.  Their modern colleagues argue that homosexuality is a choice, not an inborn trait, and express concern that it might be ingrained in innocent children; they, of course, indoctrinate youth with their own zealotry and ignore the fact that 10% of humans are homosexual (including 10% of their fellow Church members).

Those of us who hope to counter this intolerance are left to effect change at the polls and in the marketplace.  To profess a commitment to human rights and equality while financing individuals and organizations that oppose or fail to enforce such rights is a hollow gesture.  Making donations to the Boy Scouts or buying dinner at Chick-fil-A condones their message.

Friday, July 20, 2012

Detour to Kirwin NWR

Heading back to Missouri yesterday, I decided to take a detour to Kirwin National Wildlife Refuge in north-central Kansas.  Though I realized that the season, the weather and the time of day would all work against my observation efforts, I had never been to that refuge and I knew it was sure to be more interesting than another journey along I-70.

I thus left the Interstate at Colby, Kansas, and headed east on U.S. 24, paralleling the South Fork of the Solomon River once I was east of Hoxie; the green swath of the river valley was a welcome change from the parched topography of the drought-plagued plains and a stop at Webster Lake provided both a scenic vista and a look at the Cretaceous chalk that underlies the thin soil of that region.  At Stockton, I turned north and crossed a low divide, leaving the South Fork Valley and entering the watershed of the North Fork of the Solomon.  Kirwin Reservoir, around which the 10,800 acre National Wildlife Refuge was established (the first in Kansas), sits at the junction of the North Fork and Bow Creek.  Despite the intense sunshine and an afternoon high of 106 degrees F, a large variety of birds were found on and along the lake.

American white pelicans, double-crested cormorants, Franklin's gulls, great egrets, great blue herons and killdeer were common; joining them were a smaller number of snowy egrets, wood ducks, blue-winged teal and ring-billed gulls.  While the refuge brochure indicates that cattle egrets and black terns nest at Kirwin, I did not encounter either of those species; perhaps they were out feeding on the pastures or, like many of the mammal and avian residents, taking a siesta from the mid day sun.  Though I saw plenty of meadowlarks, kingbirds (eastern and western), swallows (tree, bank, barn), dickcissels, kestrels and a few red-tailed hawks, I failed to locate the upland sandpipers and greater prairie chickens that inhabit the refuge.  Another visit, during the spring or autumn migration, is certainly in order; indeed, Kirwin NWR is especially well known for its large flocks of migrant cranes and waterfowl.

Thursday, July 19, 2012

Northern Pygmy-Owls

Favoring open forest of western mountains and foothills, northern pygmy-owls are found from southern Alaska to northern Mexico.  Among the smallest owls in North America, they resemble the elf owl of our Southwestern deserts but have darker plumage and a long, barred tail.  Like their desert cousin, they roost in cavities.

Northern pygmy-owls are crepuscular in their activity and are best observed at dawn or dusk.  Preferring to hunt from a perch, they may be spotted on the branch of a dead tree, atop a small conifer or on power lines along mountain roads.  Despite their small size, they are very aggressive raptors, often attacking prey twice their size; small mammals and songbirds are their primary victims but they also consume insects, lizards and small snakes.  Like many residents of mountain ecosystems, they cache food during the winter months and may descend to lower elevations if prey becomes scarce and their stock runs low.

Solitary for most of the year, northern pygmy-owls pair off in the spring and generally produce 3-4 young, nesting in natural or abandoned woodpecker cavities at least 10 feet above the ground; the family stays together until early autumn before dispersing.  Their natural predators include northern goshawks, larger owls, Cooper's hawks, merlins, ravens and snakes.  Unlike many owls, these mountain residents avoid consuming fur, feathers and scales; their pellets thus disintegrate quickly and are not helpful in locating their roost.  On the other hand, northern pygmy-owls are often mobbed by Steller's and gray jays, ravens and mixed flocks of mountain songbirds, calling the attention of hikers and birders to their presence.

Wednesday, July 18, 2012

Birth Control, Human Welfare & Conservation

A recent article in the New York Times reported that unwed mothers are the new face of poverty, often attempting to raise children on one meager salary; of course, the health, education and socialization of their children tend to suffer in concert.  Another report, on PBS, called attention to the alarming incidence of AIDS in African Americans, including heterosexual women in developed countries.  Finally, numerous studies have demonstrated an inverse relationship between the economic vitality and health of a population and its average number of children per household.

Beyond the impact of these economic and health problems on human society, uncontrolled population growth is having a serious and potentially irreversible impact on natural ecosystems.  Deforestation, pollution, overfishing, resource depletion, habitat destruction and, at least to some extent, global warming, are all consequences of our unbridled reproductive rate.  Of course, the welfare of human society is tied directly to the health of our natural environment.

Countering efforts to educate the populace about these issues and to provide condoms and other forms of birth control to those in need are conservative religious and political organizations that oppose the programs.  Catholic dogma associates sexual activity solely with procreation, implying that it is otherwise hedonistic and evil (despite the actions of its own clergy) while Conservative Republicans, want to eliminate public support for programs such as Planned Parenthood.  Unfortunately, the power and influence of these groups leads to unnecessary human suffering, places additional stress on the world economy and poses a significant threat to natural ecosystems across the globe.

Tuesday, July 17, 2012

Devils Tower

Near the end of the Cretaceous Period, some 75 million years ago (MYA), the landscape of eastern Wyoming and western South Dakota was flat, topped by shales and sandstones deposited within and along the Cretaceous Sea that had recently retreated to the southeast.  Successively older Jurassic, Triassic and Paleozoic sedimentary strata lay below this surface veneer, forming a layer cake above the deep Precambrian basement. Then, about 70 MYA, compression within the North American craton forced up the Precambrian core of the Rocky Mountains and, in concert, the Precambrian dome of the Black Hills, which  rose through the overlying sediments.  In areas surrounding the Black Hills Uplift, fissures developed in the sedimentary layer cake and magma pushed toward the surface, cooling within the Mesozoic and Paleozoic strata before reaching the surface.

One of these pillars of magma would become Devils Tower, which rises above a low ridge of the Bear Lodge Mountains of northeast Wyoming (northwest of the Black Hills).  Its summit elevation of just over 5100 feet is almost 1300 feet above the Belle Fourche River, which flows northeastward and then southeastward to join the Cheyenne River east of the Black Hills.  This river and its numerous tributaries dissected the Bear Lodge Mountains from a plateau of Mesozoic sediments and, in the process, freed Devils Tower from the layers in which it formed.  The vertical columns of the Tower resulted from cooling of its molten rock beneath the surface and its prominence, like other laccolithic formations throughout the American West, attests to the fact that its igneous rock is more resistant to erosion than the encasing Mesozoic sediments.  Most of this erosion occurred during the wet climate of the Pleistocene (2.0-0.01 MYA) but the relentless process continues today.

Long a source of human mysticism and the inspiration for America's first National Monument, Devils Tower, like the sediments in which it formed, will eventually erode to a flat surface and be carried off to the sea.  Until then, it will loom above the Belle Fourche Valley and stir the imagination of many future generations, perhaps until Close Encounters becomes a reality.

Monday, July 16, 2012

Birding Chatfield

Chatfield State Park surrounds a large reservoir at the confluence of the South Platte River and Plum Creek, southwest of Denver.  For sheer variety of species, this preserve is, in my opinion, the best birding location in the Metropolitan Area and one of the best along the entire Front Range.

The reservoir, itself, attracts cormorants, American white pelicans, western grebes, ring-billed gulls and a variety of waterfowl during the warmer months and, in winter, is known for attracting rare loons, gulls, scoters and other waterbirds.  Ponds, marshes and backwaters along the South Platte corridor provide nesting habitat for Canada geese, wood ducks, mallards, common and hooded mergansers, soras and pied-billed grebes and feeding grounds for great blue herons, snowy egrets and black-crowned night herons.
Grasslands west and south of the reservoir attract western and eastern kingbirds, western meadowlarks, grassland sparrows, magpies, kestrels, prairie falcons and other open country raptors; a prairie dog town along the south entry road may harbor burrowing owls.  Rich, riparian woodlands along Plum Creek and the South Platte offer nesting and feeding habitat for great horned owls and virtually any songbird that inhabits or visits the Colorado Piedmont while mudflats at the mouth of these streams are magnets for killdeer, spotted sandpipers and migrant shorebirds.

This morning's visit did not turn up any unusual sightings but one encounters a wide variety of birds just driving across this large refuge.  Of course, the beautiful scenery and sunny Colorado climate make a visit to Chatfield State Park worthwhile during any season of the year and not knowing what to expect fuels the enthusiasm of all birders and naturalists.

Sunday, July 15, 2012

Paterno & Human Sexuality

The Louis Freeh Report , released this past week, reveals that Joe Paterno and administration officials at Penn State University buried reports of child sexual abuse on their campus in order to protect the image of the institution and of the football program.  While this decision was deplorable, Paterno's willingness to participate in the cover-up was, to some degree, a reflection of his personal discomfort with sexual matters; indeed, his graduate assistant, Mike McQueary, testified that he didn't want to disturb the coach with the graphic details of what he had witnessed.

Joe Paterno came from a generation of American men who are/were not comfortable with the open discussion of human sexuality; this is/was especially true for those raised in Catholic or Conservative Christian families. Topics such as domestic sexual violence, homosexuality, premarital sex and aberrant sexual behavior were avoided, if not totally banished.  The sexual revolution of the sixties and seventies, which has had a significant impact on the views of their children, did not change human sexual behavior; rather, it brought this aspect of our lives into the open, forcing us to deal with the realities and ramifications of our nature.

This social shift has improved our understanding of human sexuality, including the natural incidence of homosexuality; while their rights are yet to be fully realized, gays now openly participate in all aspects of human society.  At the same time, our enlightenment regarding deviant behavior, such as pedophilia, allows us to deal with its threat and develop safeguards to protect the innocent.  Clearly, in the case of Penn State (as in the case of the Catholic Church), those safeguards failed.

Saturday, July 14, 2012

The Summer Sandpiper

Spotted sandpipers are the most widely distributed shorebird in North America, breeding throughout Alaska, Canada and most of the Lower 48 States (except for the Deep South).  Arriving on breeding grounds before the males, the larger and more aggressive females establish territories on which they often mate with a number of males; in fact these queens of the bird world leave incubation and child rearing duties to their male partners and, since she is capable of storing sperm, these hapless males may end up caring for a brood fathered by one of her other suitors.  Nest sites, also chosen by the female, are shallow, grass-lined depressions hidden by vegetation and placed near a freshwater stream, pond or lake.

Throughout the warmer months, spotted sandpipers are usually found alone, bobbing along the edge of a stream bank or shoreline.  When disturbed, they fly off on fluttering, stiffly held wings, dropping back to the ground within a short distance.  They are active feeders, snaring insects, other invertebrates and small fish from the vegetation, mudflats or shallows.  Best found along rocky streams, spotted sandpipers are easily identified by the above behavioral traits and by their spotted breast and abdomen; the distinctive spots are lost when they molt to their winter plumage.

Here in Colorado, spotted sandpipers are common along the South Platte and Arkansas Rivers and their  Piedmont tributaries but are also found along mountain streams and in the drier canyon country of the Western Slope; these adaptable birds are also among those species that inhabit wetland areas of the alpine tundra.  Come fall, spotted sandpipers head for southern coasts of the U.S., Mexico and Central America where they retain their preference for freshwater habitats.

Friday, July 13, 2012

Exercise Canyon

Waterton Canyon, which incises the foothills southwest of Denver, represents the South Platte's final journey through the Rocky Mountains before it rumbles onto the Colorado Piedmont.  Harboring a wealth of scenic rock formations and home to a wide variety of Transition Zone flora and fauna, the canyon has long been a popular destination for hikers, birders, fishermen and naturalists.  Over the past decade or so, it has also become a mecca for bikers and joggers, now comprising at least 75% of the visitors.

While these trail athletes surely enjoy the pristine landscape, at least in a holistic sense, I doubt they pay much attention to the varied plants and animals, focused as they are on distance and time.  As they trudge along, gasping and spitting, or whiz by on their trail bikes, I often wonder if they could identify even a handful of species that inhabit the canyon.  They surely notice the bighorn sheep, for which this refuge is well known, but a fleeting glance is probably sufficient.

In this age of obesity, I certainly have no objection to aerobic exercise.  But I suspect these bikers and joggers choose Waterton Canyon for its graded climb and known distance (6 miles to the Strontia Springs Dam); of course, they also enjoy group exercise and avoid the heavy auto traffic that occurs in other foothill canyons.  Some might conclude that I envy the youth and vitality of these athletes (which is surely true to some extent) but I am more inclined to pity their lack of interest in nature's bounty.  Dogs are not permitted in Waterton Canyon in order to protect the bighorn sheep; perhaps we should limit its use as an athletic training site in order to protect the natural milieu.

Thursday, July 12, 2012

The Kaibab-Coconino Plateau

As the Paleozoic Era gave way to the Mesozoic, some 225 million years ago (MYA), an ovoid upwarping of Earth's crust developed in what is now northern Arizona.  Reinforced during the Laramide Orogeny (the formation of the Rockies, 70 MYA), this broad ridge was eventually covered by layers of Mesozoic and Tertiary sediments (both erosional and volcanic).  Late in the Tertiary Period, the Miocene-Pliocene Uplift (stretching from about 15-5 MYA) lifted the entire Colorado Plateau and its rim of mountain ranges another 5000 feet, increasing stream erosion across the Province.  Rising on the west side of the Continental Divide, the Colorado River flowed westward and gradually southward to enter the Sea of Cortez; en route, it crossed northern Arizona, entrenched in the younger sediments that covered the Kaibab-Coconino ridge.  As the Colorado Plateau rose beneath it, the river was forced to cut down through this ridge of Paleozoic rock (and the upper layer of the ancient Precambrian basement that lies beneath it).  Augmented by the wet climate of the Pleistocene (2 to 0.01 MYA), the Colorado thereby sculpted the Grand Canyon, the most spectacular chasm on our planet.

The ridge itself, oriented NNW to SSE, has since been uncovered by erosion.  Streams from its eastern edge drain directly into the Colorado (or into the Little Colorado south of the Grand Canyon), while its northwest flank drains to the Colorado via Kaibab Creek and its southwest flank feeds the Cataract River, another tributary of the Colorado.  The exposed ridge is composed primarily of Kaibab limestone overlying Coconino sandstone; that portion north of the Grand Canyon is known as the Kaibab Plateau while its segment south of the Canyon is referred to as the Coconino Plateau.  The rock strata of the plateau, deposited during the Permian Period, form the upper layers of the Grand Canyon

The Kaibab Plateau rises to elevations that exceed 9200 feet, supporting a rich forest of fir, spruce and aspen, giving way to ponderosa pine and then pinon-juniper woodlands at lower elevations.  The Coconino Plateau is 7400 feet above sea level at the south rim of the Grand Canyon and gradually lowers toward the west, south and east; it is covered primarily by ponderosa pine parklands.  South of the Coconino Plateau, the landscape is dominated by the high peaks and scattered cones of the San Francisco Volcanic Field, including Humphreys Peak (12,633 feet), the highest point in Arizona.

Wednesday, July 11, 2012

Prairie Racerunners

Closely related to the six-lined racerunner of the Mid-Atlantic and Southeastern U.S., the prairie racerunner is found from northwestern Indiana and southern Wisconsin, westward to southern Wyoming and southward to Arkansas, West Texas and New Mexico.  Favoring dry, sandy soil and hot weather, these lizards inhabit prairie grasslands, abandoned farms, glades and rocky hillsides; attracted to disturbed areas, they are known to spread along power line swaths and railroad lines.  Here in Colorado, prairie racerunners are abundant from the High Plains to the shrub zone of the lower Front Range foothills.

Emerging from hibernation in late April or May, prairie racerunners are best observed during the morning and early afternoon hours of June and July, dashing across trails or clearings and disappearing into clumps of vegetation to snare prey or to avoid predators.  Their long tail, twice the length of their body, is thought to serve as a counter-balance as they zig-zag at speeds up to 18 miles per hour.  Mating occurs by late spring and five eggs are generally produced; as with most lizards, the hatchlings are miniature replicas of the adults and must fend for themselves.  While a second brood may be produced within a few weeks, adult prairie racerunners begin to hibernate by late August or early September; the young, needing more time to generate fat stores, wait until late September or October to settle in their winter burrows (depending on their home latitude).

Feasting on a wide variety of insects and other invertebrates during their brief season of activity, prairie racerunners may fall victim to grassland hawks, prairie falcons, burrowing owls, fox, coyotes, roadrunners, magpies and a variety of snakes.  Using shallow burrows during the warmer months, they dig a deeper channel with a terminal chamber for their prolonged hibernation; during that time, in sharp contrast to their frenzied life above ground, their metabolic rate falls dramatically and they rely on fat deposits to fuel their survival.  If they make it through their first winter, adult prairie racerunners are thought to have a natural life span of 4-5 years.

Tuesday, July 10, 2012

Front Range Oasis

While those of us who live along the Colorado Front Range enjoy abundant sunshine and a mild, semiarid climate, there is plenty of aquatic habitat along the urban corridor.  One of the best places to observe water-loving birds and mammals is South Platte Park, which stretches across the river's floodplain from the northern edge of Chatfield Reservoir State Park to the outskirts of downtown Littleton.  A mosaic of ponds, lakes, wetlands, meadows and riparian woodlands, the Park is accessed by a paved bikeway, its parallel walking path and a number of adjoining trail loops.  An Interpretive Center, west of Santa Fe Drive and north of Mineral, introduces visitors to the varied fauna and flora of the Park.

On this mild, clear morning, the refuge was teeming with birds, including many that non-Coloradans might not associate with our State.  A dozen American white pelicans moved among the lakes or fished in the shallows, joined by a large number of double-crested cormorants, scattered great blue herons, a pair of snowy egrets, a flotilla of common mergansers, noisy flocks of Canada geese and a varied assortment of ducks (primarily mallards, gadwall and wood ducks).  Tree and barn swallows swooped above the ponds, a Swainson's hawk circled overhead, belted kingfishers chattered along the river and a wide assortment of songbirds moved among the trees and cattails; these included yellow warblers, common yellowthroats, American and lesser goldfinches, western wood pewees, northern orioles, house wrens, northern flickers, downy woodpeckers and those ever-vocal red-winged blackbirds.  A lone black-crowned night heron, spooked from his shadowy haunt, was my final sighting of the morning.

Though represented only by fox squirrels, cottontails and black-tailed prairie dogs this morning, a variety of mammals also inhabit the Park and are best seen at dawn or dusk.  Among these residents are mule and white-tailed deer, red fox, coyotes, beaver, muskrats, raccoons, striped skunks,  meadow voles and deer mice; mountain lions and black bear are potential visitors but are rarely encountered.

Monday, July 9, 2012

Monsoon Relief

Returning to our Littleton, Colorado, farm today, I found that early monsoon rains have revitalized the landscape.  Indeed, over the past few days, heavy rains have moved northward across the Front Range, bringing much needed rain to the tinder-dry mountain forests and welcome moisture to the urban corridor.  While some flooding, mudslides and sinkholes developed, the storms have reduced the wildfire risk to some degree and, so far, have not ignited any new fires.

The annual monsoon rains of the American Southwest result from a southerly flow that brings in moisture from both the Gulf of California and the Gulf of Mexico.  The engine for this wind pattern is high pressure over the Southern Plains that generally develops by early July and persists through much of August; winds move clockwise around that atmospheric ridge, sweeping moisture northward along its western rim.  Showers and thunderstorms are usually confined to the Desert Southwest and Four Corners Region early in the season, reaching the Colorado Front Range by late July and August.  Thanks to the dome of drought that has plagued the south-central and southeastern U.S. for several weeks, the Monsoon got an early start and Colorado, caught in its own drought after a mild, snow-starved winter and a warm, dry spring, has received an early and very welcome gift.

Unfortunately, the monsoon flow will be shut off for the rest of this week as high pressure builds in from the West, bringing another round of hot, dry weather to the State and blocking the southerly stream of moisture.  When the Southwest Monsoon might generate more relief is anyone's guess but its typical arrival date is still a week or two away.

Friday, July 6, 2012

Colorado's Black Canyon

Near the end of the Mesozoic Era, as the Cretaceous Sea retreated to the southeast, Colorado was a relatively flat landscape of wetlands, sandhills and primitive forest.  Then, about 70 million years ago (MYA), pressure within the North American craton crumpled up the Rocky Mountains, pushing ancient Precambrian rock up through the overlying Paleozoic and Mesozoic sediments.

As soon as they formed, the forces of erosion began to act on these new mountains, filling the intervening valleys with debris.  About 35 MYA, volcanism developed in central and southwestern Colorado, lifting the West Elk and San Juan Mountains; the copious ash, pumice and lava from these eruptions also coated the valleys and basins of that region.  By 10 MYA, the Gunnison River had formed; rising on the west side of the Continental Divide, in the Sawatch Range, and receiving large tributaries from the West Elk Mountains, to its north, and the San Juans, to its south, this river flowed west to join the Colorado.  Entrenched within the erosional and volcanic debris that had settled across the broad, intervening basin, the Gunnison was forced to cut into a ridge of Precambrian gneiss and schist, east of present day Montrose, that was buried within the sediments.  Since that time, the river has sculpted the Black Canyon of the Gunnison from that ancient rock, a process that was augmented during the cooler, wetter climate of the Pleistocene.

Almost 50 miles in length, the Black Canyon is up to 2720 feet deep and 1100 feet across at its rim; at river level, it is much narrower, only 40 feet wide in one area.  The Painted Wall, on the north flank of Black Canyon, is named for the light-colored lava rock that laces its surface and is the tallest cliff in Colorado, dropping 2250 feet.  Within the canyon, the Gunnison River drops 43 feet per mile, a grade that is almost six times steeper than the Colorado River's course within the Grand Canyon.  Named for its shaded walls, hidden from the sun by its deep and narrow topography, the Black Canyon of the Gunnison is protected within a National Park that stretches along its middle (and most spectacular) 14 miles.  Farther west, the Gunnison is thought to have carved Unaweep Canyon through the Uncompahgre Plateau, later diverted northward by a landslide to join the Colorado west of Grand Junction (see my blog on 12-27-10).

Thursday, July 5, 2012

Looking at the Invisible

This week at CERN, the Organization for European Nuclear Research, near Geneva, Switzerland, nuclear physicists may have discovered the Higgs boson, first theorized to exist back in 1964.  Using the Large Hadron Collider, in operation for just two years, they smashed protons together at high velocity and found a particle that had never been observed with past forms of technology.  Based on their initial calculations, it is thought to be a transient manifestation of the cosmic soup that gives mass to the elementary particles.

If confirmed, this discovery will herald a new era in our understanding of the Universe, focusing on the dark energy and dark matter that, combined, make up over 95% of its content.  Indeed, the visible stars, planets, comets, asteroids and interstellar dust make up less than 1% of the Universe, with intergalactic gas accounting for 3.5% or so.  This week, we caught our first glimpse of the dark side and took our first step toward understanding the dark energy that is causing the Universe to expand at an increasing rate.

For most of us, the details of the Higgs boson discovery are difficult to understand.  Those who prefer to concentrate on the simplistic dogma of their chosen religion will dismiss the news as scientific heresay; after all, bosons are not mentioned in the Bible.  But for those hungry to understand the complex nature of our Universe, this discovery promises a new world of adventure.

Tuesday, July 3, 2012

A Stubborn Ridge

The dome of high pressure that has parked itself over the Heartland for the past two weeks shows no sign of abating.  Rather than drifting off to the east, it has backed into the Southern Plains; unfortunately, those of us in the lower Missouri and Mississippi Valleys remain within its grip.

Beneath this atmospheric ridge, the air is sinking and drying out, producing excessive heat and retarding cloud formation.  Storm systems are shunted along its outer rim, exacerbating drought within the dome while fueling violent weather at its periphery (as we saw in the Upper Midwest and Mid-Atlantic region last week).  On the positive side, this stubborn ridge may ignite the Monoon Season across the American Southwest, pulling in moisture from both the Gulf of California and the Gulf of Mexico as clockwise winds stream along its western rim.

Those of us caught within its boundaries can expect another week of hot, dry weather, with afternoon highs near 100 degrees F.  Beyond prolonging our personal discomfort, this dome of drought is taking a toll on forests and crop fields across the Heartland, stressing natural ecosystems and posing a serious challenge for farmers and ranchers.  Unless relief arrives in the form of a potent Canadian front, it may take a hurricane to dislodge this ridge.

Monday, July 2, 2012

The Heart of Champions

As the Olympic Trials wind down and national teams prepare for London, it is clear that there is something special about Olympic athletes.  Like others in their respective sport, they are talented and hard-working individuals who enjoy a good deal of support from family, friends and colleagues.  Yet, these Olympians seem to harbor traits that set them apart.

Despite their success and self-confidence, few (if any) are arrogant or egotistical.  Rather, their achievement reflects their competitive spirit, their courage in the face of adversity and, perhaps most importantly, an unwillingness to concede defeat.  This latter trait, which might be defined as heart, is found in all champions, from race horses to long-distance runners to heavyweight boxers.  When the margin of victory is razor thin or when endurance plays a major role, heart is especially vital.

Of course, this trait is not confined to sports.  While some owe their success to good fortune, most champions of human society possess this same competitive spirit; facing obstacles that discourage their rivals, they have the heart to persevere.  Heart is, indeed, a human trait which seems to require a delicate mix of genetic, familial and cultural factors.  Alas, in most individuals, it never reaches full expression. 

Sunday, July 1, 2012

The Season of Insanity

Humans, tropical creatures that we are, have a healthy respect for winter,  Not naturally equipped to survive its wrath, we take shelter from winter's storms and tend to hibernate for much of its course.  While the cold, dark season may be depressing for some and does induce its fair share of injuries, winter keeps us on our guard and, for the most part, out of trouble.

Summer, on the other hand, that carefree season of vacations, picnics and outdoor recreation, is welcomed by most humans and its dangers are too often ignored.  But, contrary to what many believe, the summer heat causes far more deaths than does the winter chill.  The elderly, stressed by excessive heat and too often housed in poorly ventilated apartments, are the primary victims; ironically, young, healthy athletes are the other group at risk.  Driven on by macho coaches and drill sergeants or by their own sense of immortality, they work out or engage in sports on summer afternoons and, as we observe every year, some fall victim to heat stroke..  There is a popular misconception that exercising in the heat, drenched in sweat, is a more effective way to lose weight or to get in shape than is exercising during cooler parts of the day.  This, of course, is false and such behavior invites disaster.

Despite these admonitions, repeated throughout the summer by news and weather reporters, many will ignore the warnings and our current heat wave will be the last for some young athletes.  We may be designed for the tropics but there are limits to our capacity to dissipate heat.  Staying well hydrated is important but common sense is our best means of protection.