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Showing posts from May, 2015

A Trilling Reception

We returned to Columbia last evening, arriving just after the latest spring storm.  Stepping from my pickup, I realized that a full blown orgy was in progress.

Male American toads had staked out every pond, pool and transient wetland in the neighborhood, ready to mate with anything that moved in their small piece of heaven.  Generally successful, they will fertilize hundreds if not thousands of eggs; the small black tadpoles that hatch from those eggs will become ravenous toadlets within a few weeks, hopping into the verdant landscape, oblivious of its many dangers.

After a month in the dry air and chilly rains of Colorado, central Missouri felt like the Tropics and the frenzied trilling of toads only added to that illusion.  Cheers to the proud parents and their many offspring!

Texas: Land of Drought & Flood

Texas, second only to Alaska in size, lies in the south-central U.S.  To its west are the dry landscapes of Mexico and the Desert Southwest while, to its east, is the Gulf of Mexico.  Stagnant weather patterns, common across the Continental U.S., can trigger prolonged periods of drought or, as we have seen this month, episodes of abundant rainfall and severe flooding.

Persistent domes of high pressure often develop over the Southern Plains and play an important role in the annual Southwest Monsoon.  Under such conditions, Pacific storm systems are deflected across the Northern Plains and onshore flow from the Gulf of Mexico is shunted across Mexico and into the Four Corners region.  Deprived of Gulf moisture, Texas enters a period of drought which may last for months or years.

By contrast, persistent atmospheric troughs across the Western U.S., as has occurred this spring, direct Pacific storms across the Southern Plains.  Ahead of these systems, copious moisture is pulled northwestwa…

A Prodigal Sun

After weeks of cloudy, cool, wet weather, an intense morning sun lit the Front Range today.  Lasting through mid afternoon, the brilliant sunshine bathed the soggy landscape, lavishing its heat and light on a grateful assortment of plants and animals (humans included).

Unable to resist the reprieve, I spent much of the morning wandering our farm, checking the fences, trimming shrubs and surveying the vegetation, some of which is still suffering from the prolonged chilly upslope.  Yellow rose shrubs glowed in the bright sunshine and our usual mix of summer and permanent songbirds reveled in the welcome warmth; joining the latter was a Swainson's thrush, scouring the leaf litter for insects before heading off to the mountains.  Overhead, a lone white pelican soared in the clear blue sky while a great blue heron stroked his way toward a neighborhood pond.

The prodigal sun ruled the scene for much of the day, finally yielding to late afternoon thunderstorms that rose above the mountai…

Remembrance & Apologies

On this Memorial Day, Americans attend parades, visit cemeteries and enjoy picnics while honoring the men and women who served, or currently serve, in the U.S. Military.  Many of those soldiers now lie in graves while many more carry the physical and mental scars of combat.

While remembrance and appreciation are the primary purpose of this holiday, I feel that apologies are in order as well.  After all, much of the personal sacrifice that we honor occurred in wars that were ill-advised, undertaken by politicians who misinterpreted (or took advantage of) regional conflicts and over-hyped their international implications; Vietnam and the second Iraq War surely fall into this category.  Even today, hawkish members of Congress are pushing for more American involvement in Syria and Iraq, ignoring the sectarian hatred that, until abandoned, will fuel social unrest in those regions.

More than 400,000 gravestones grace the manicured lawns of Arlington National Cemetery.  Many more military ce…

Avian Sunshine

After almost a month of cloudy, cool, rainy weather along the Colorado Front Range, packets of avian sunshine arrived on our Littleton farm this afternoon.  Over a week late, these brightly colored birds generally stop by in mid May, on their way from wintering grounds in Central American to their breeding territory in the Colorado foothills and mountains.

Western tanagers are primarily insectivores, moving slowly through conifers and deciduous trees to snare prey from the twigs and branches; at other times, they flycatch from an exposed perch.  Usually observed in moderate sized flocks during migration, they pair off to nest in open coniferous woodlands of the Front Range, seeming to prefer the ponderosa parklands of the Montane Zone (7000-9000 feet in elevation).  Early and late in the breeding season, when chilly temperatures suppress the insect population, these colorful tanagers also feast on berries.

Always welcome on the farm, the brilliant travelers were a godsend after weeks …

Geologic History of Cuba

As the Atlantic Ocean began to open, some 160 million years ago (MYA), the North and South American Plates were forced westward, a tectonic process that continues today.  In concert, the Caribbean Plate was shoved between them.

The geology of Cuba, which lies along the southern edge of the North American Plate, is complex.  It appears that the largest Caribbean island began to form during the Cretaceous Period, some 100 MYA, as collision and subduction volcanism occurred along the margin of the North American and Caribbean Plates, creating a chain of islands.  Since that time, uplift, deposition, erosion, Tertiary volcanism and a prolonged period of submersion (from 35 to 5 MYA) have left behind Cuba's varied topography and geology; rock strata on the island range in age from Precambrian igneous rock (900 million years old) to late Tertiary marine limestone (less than 5 million years old).  During the Eocene Period, some 50 MYA, volcanism occurred in southeastern Cuba (then contig…

Stressed Swallows

The recent chilly, damp weather in Colorado has curbed the activity of flying insects and has stressed those birds that feed on them.  Swallows are among our most abundant aerial insectivores and their behavior has clearly been altered by the prolonged cold spell.

In recent days I have watched large mixed flocks of barn, cliff, tree and violet-green swallows strafing ponds and meadows in the South Platte Valley, apparently snatching insects that hover near these relatively warm surfaces and gleaning sluggish prey from the grass or water.  The frenzy of activity might also flush insects from the dense vegetation, making them more accessible to the swallows.

One wonders how these birds consume enough prey on such chilly days to balance the energy expended to catch them.  When their aerial efforts prove to been inadequate, swallows are known to snare sluggish insects from bridges, river banks or the walls of barns and other outbuildings.  Nevertheless, the persistent, chilly upslope alon…

The Nature of Trust

Trust is the sense that another person or human organization has integrity and will act in our best interest.  It is distinct from love and friendship; we place our trust in many who we do not love or befriend and, through the course of our lives, we love some individuals who we cannot trust.

Our ability to trust others is likely affected by our early childhood experience; if we are ignored, abused or abandoned by parents or caretakers, we may find it hard to trust other individuals.  In like manner, repeated episodes of misplaced trust may diminish our capacity to rely on other human beings.  For most of us, over the years, we come to trust a mix of individuals and organizations that earn our respect and rely on them repeatedly for their advice and support; among these are friends and loved ones with whom we share our passions, beliefs, hopes and fears.

Trust is not always permanent.  Some who earn our trust later prove to be deceitful or unreliable; examples are charitable, financia…

A Relentless Upslope

Over the past two weeks, a series of Pacific storm systems has produced a nearly continuous period of upslope flow along the Colorado Front Range.  Counterclockwise winds generated by low pressure centers and clockwise flow within atmospheric troughs have directed Gulf of Mexico moisture toward the Rocky Mountain corridor; rising with the terrain, the air cools and condenses, producing overcast skies, chilly temperatures and intermittent rain or snow (depending on elevation).

Indeed, it has felt more like March than May.  Though the greenery is especially lush for this semiarid landscape, the chill has slowed the leafing and flowering process for many trees and shrubs.  Despite flooding along the South Platte and its tributaries, the mountain snowpack has continued to build, threatening even greater runoff when seasonal warming resumes.

In a region renowned for sunny skies and dry air, it's hard to accept such a relentless period of chilly, damp weather.  Though the precipitation …

Denver Botanic Gardens Chatfield

Settled by Frank and Elizabeth Hildebrand in 1861 and by the Green Family in 1935, the lower Deer Creek Valley, southwest of Denver, was obtained by the Army Corps of Engineers in 1967 during the construction of Chatfield Reservoir.  Leased by the Denver Botanic Gardens in 1975, the land was first developed as the Chatfield Arboretum, which opened in 1990, and became the Chatfield Nature Area in 2000.  By 2005, a master plan was developed to establish a botanic gardens on the property, highlighting plants native to Colorado while preserving the historic structures and maintaining a working farm.

Accessed from Deer Creek Canyon Road, west of Wadsworth Blvd. and south of C-470, the Denver Botanic Gardens Chatfield is a mosaic of meadows, farm fields, wetlands, gardens and riparian woodlands along Deer Creek.  A network of paved paths, graveled trails and dirt/gravel roads lead the visitor through the varied natural habitats, past the historic structures and along the display gardens.  A…

The Nature of Avian Flu

Avian flu, commonly known as Bird Flu, is caused by a spectrum of influenza A viruses; many strains and subtypes have been documented and some are highly pathogenic to both wild bird and domestic poultry populations.  While past severe outbreaks of avian influenza have occurred primarily in Asia and Africa, the current North American outbreak (the first since 1983) began in December of 2014.

The spread of avian flu across the Continent is thought to result from infected migrant waterfowl though other regional carriers may be involved.  Once the virus infects individual birds at a poultry farm, it may spread quickly through the closely confined population and, potentially, to other local populations; some strains have been associated with a death rate of 90% or more.  As a result, when evidence of avian flu is documented on a poultry farm, the entire population of chickens, ducks or turkeys is culled and the facility must be disinfected.  The current outbreak is especially severe in Io…

Country Folk

On our recent trip to Flaming Gorge, my pickup blew out a tire.  Fortunately, we were at the exit for a small town when that random event occurred.

Flagging down a local resident, we learned the name of the town's towing service and placed a call.  The friendly owner arrived within five minutes and towed us to the town's only tire shop; en route, he gave us a brief rundown on his home town, including the opening of a Walmart and the town's second grocery store.  He also recommended a tour of the old, historic prison if time permitted.  Once at the tire shop, we were informed that, unfortunately, repairs might take an hour or more; to bide our time, we were advised to visit a popular coffee shop, run by two older women.  We took that advice and enjoyed both a tasty breakfast and friendly service.  Once back at the tire shop, we caught up on the clerk's family history while awaiting the final repairs.  Ninety minutes after the accident, we were back on the highway and he…

Crossing Southern Wyoming

After leaving the Green River Valley, we drove east on Interstate 80 this morning, headed for our Littleton farm.  Between Rock Springs and Rawlins, Wyoming, we crossed some of the most desolate landscape in the country, covered by a rolling sage grasslands and broken by stark ridges of Cretaceous sandstone.  Lone cows, pronghorns and oil pumps appeared to be the only residents.  For geography buffs, such as myself, there was some reward offered by the topography: we crossed the Continental Divide twice, dipping through the Great Divide Basin.

As we approached Rawlins, a spectacular view of the Bighorn Range unfolded to the northeast and, once past that city, more interesting terrain began to appear.  Far to the south, the Sierra Madre of Colorado poked above the horizon and off to the ENE, Laramie Peak towered above its range.  Further along, we crossed the North Platte River and the massive bulk of Elk Mountain loomed along the south side of the highway, backed by the Snowy Range an…

Flaming Gorge

The Green River of the Western U.S. rises on the northwest flank of the Wind River Range in west-central Wyoming and flows southward through its broad basin of Tertiary and Cretaceous deposits.  Approaching the Utah border, it has sculpted Flaming Gorge, named by Major John Wesley Powell for bright red Triassic rocks that adorn southern portions of the chasm; the scenic gorge now lies within the Flaming Gorge National Recreation Area.

Having initially established its course in Tertiary sediments (from the Green River Lakes, regional volcanism and mountain erosion) the Green River cut through the eastern end of the Uinta Range as it rose from below during the Miocene-Pliocene Uplift.  Today, the northern two-thirds of the Gorge is carved in Eocene deposits while the southern third is lined by a progression of Mesozoic, Paleozoic and Precambrian rock (north to south); along its 91 mile course in the Gorge, the Green River (dammed since 1964) has cut through strata representing at least …

Journey to Flaming Gorge

Though my wife and I have traveled extensively throughout the Western U.S., a visit to Flaming Gorge, on the Wyoming-Utah border, has eluded us.  Over the next few days, we plan to remedy that deficiency.

This afternoon, we'll head west on Interstate 70, climbing to the Continental Divide, dipping through the Blue River Valley, winding across Vail Pass and eventually merging with the Colorado River to snake through Glenwood Canyon.

After a night in Glenwood Springs, we'll leave Interstate 70 at Rifle, angling northwest across the Roan Plateau of northwest Colorado and the Uinta Plateau of northeast Utah, both of which are topped by Eocene sediments of the Green River Formation (see Green River Lakes).  From Vernal, Utah, we'll head north to Flaming Gorge, sculpted by the Green River over the past 30 million years and flooded by Flaming Gorge Lake since 1964; more on the Gorge tomorrow.

Caving to Big Oil

Despite the ecological disaster wrought by the Deepwater Horizon explosion in the Gulf of Mexico, five years ago, the effects of which have yet to be fully determined and addressed, the Obama Administration will allow Shell Oil to drill in the pristine waters of the Arctic Ocean off the coast of Alaska.  While the leases were initially granted by the Bush Administration, permission to drill was delayed until "stringent new regulations" were in place.

Though the Obama Administration has spearheaded efforts to reduce our use of fossil fuels, promote solar and wind energy and protect threatened wilderness areas, one wonders why they are caving to Big Oil at a time when there is a worldwide glut of gas and oil and when the tragic consequences of our dependence on fossil fuels (including transportation spills, groundwater and wetland pollution and global warming, among many others) are becoming more and more evident.  To assume that strict drilling regulations will protect the fr…

On the Storm's Cold Side

At our Littleton, Colorado, farm, the rain began to change to snow just after 7PM last evening.  A potent upslope flow on the backside (north and west) of the massive spring storm had dropped the air temperature into the mid 30s (F) and, over the next eight hours, five inches of heavy, wet snow accumulated on the grass and trees.

Fully leafed, the smaller trees and shrubs are bent toward the ground by their heavy white cargo while a few branches broke from the larger trees.  This morning, a winter wonderland envelops the farm and the temperature is hovering near 30 F.  Undaunted, the birds are singing as usual, sensing that May will soon re-emerge.

As the storm pushes northeastward, into Nebraska, the upslope flow is breaking down and the morning sun is peeking through the light gray overcast.  Snow showers should end by noon and the potent Colorado sun will bake away the winter glaze; we'll be back in the 70s by Tuesday.  Happy Mother's Day to all who qualify for that beloved…

Spring Bird Census

The annual spring bird count was conducted at South Platte Park this morning, a swath of ponds, meadows and riparian woodlands along the South Platte River in Littleton, Colorado.  Setting out from the Interpretive Center by 7AM, the groups endured chilly air and a dense gray overcast, hoping to complete our counts before more heavy rain descended on the valley.

My partner and I were assigned to woodlands and wetlands east of the river.  On our two hour tour, house wrens, tree swallows, American robins, mourning doves and red-winged blackbirds were the most abundant species, followed by mallards, Canada geese, great blue herons, northern flickers, yellow warblers, killdeer, western wood pewees, black-capped chickadees, western kingbirds and white-breasted nuthatches.  Individual sightings included an American kestrel, a spotted sandpiper, a wood duck, a northern oriole and a Say's phoebe.

Though the weather was threatening, the trails were muddy and the sightings were far from exc…

Downslope Drying

In the midst of a Front Range deluge, drier air is moving into Metro Denver this evening.  The moisture flow is currently from the south, moving northward along the mountain wall and the adjacent Piedmont.

To our south, heavy rain is falling in Colorado Springs and across the southern flank of the Palmer Divide.  North of that divide (which has an elevation of about 7500 feet), the air descends with the terrain; in concert, its dew point falls (the air is compressed and warms up).  North of Denver, the air rises out of the South Platte Valley and into the foothills; this upsloping air cools, condenses and drops its precipitation once again.

By tomorrow afternoon, the wind is forecast to shift back from the northeast, producing classic upslope conditions along the Front Range, primarily north of the Palmer Divide.  Afternoon thunderstorms will progress to widespread rain which will turn to snow by Sunday morning.  For now, we'll enjoy a brief period of downslope drying.

Water, Deserts & the Wealthy

In American society, the wealthy enjoy an increasing number of social perks, based on their ability and willingness to pay for them; close-in parking spots, toll lanes and rapid boarding privileges are but a few examples.  It was thus with dismay that I read an article in the NY Times outlining Santa Fe's move to base water price rates on the amount consumed; the report placed a positive spin on that decision, indicating that rates would not significantly rise for lower income citizens while the wealthy will pay heavily to fill their pools and water their lush landscapes.

In my opinion, such a solution to the Western water shortage misses the point and, once again, caters to the lifestyles of the rich and famous.  If one chooses to live in an arid or semiarid environment, one should be willing to forgo green lawns, parks and golf courses and live without private swimming pools.  If the cities must expand their populations to meet economic needs (a questionable premise), new reside…

The Mystery Legume

When we purchased our Littleton farm, in 1990, I discovered a healthy looking shrub beneath a pair of spruce trees east of the house.  Never much of a botanist, I could not identify the shrub but noticed that its leaves, while softer and paler in color, resembled those of our locust trees.  Small yellow flowers appeared by mid spring and, in mid summer, numerous small spindle-shaped pods hung from its branches, confirming that it is a legume.

Following years of failing to identify the shrub in field guides, the wonders of an internet search finally provided the answer; our lone, hardy shrub is a Siberian Pea Tree.  Native to Siberia, China, Mongolia and Kazakistan, this deciduous shrub has been used for windbreaks across northern regions of the globe; while its seed pods may be cooked for human consumption, the abundant seeds are favored by a wide variety of birds and small mammals, including domestic chickens.

Though our Siberian Pea Tree has adapted well to the Front Range soil and …

Trapped in a Trough

Over the past week, an atmospheric trough has enveloped the Front Range region and much of the Intermountain West.  Reinforced by a series of cold fronts, this dip in the jet stream has spread cool, cloudy, wet weather from the High Plains to the Pacific Northwest.

Low pressure centers, developing along the eastern edge of the trough, have swept Gulf moisture northward through the Heartland, igniting severe thunderstorms across the Plains and producing an upslope flow along the Front Range.  The latter, while studded with strong thunderstorms at times, has primarily brought overcast skies, cool temperatures and pockets of heavy rain.  This pattern, which is expected to persist through the coming weekend, is more reminiscent of the Pacific Northwest than the sunny, semiarid climate of the Front Range.

While this chilly, damp weather may not be ideal for outdoor activity, it is fueling the verdant growth of spring and, for now, eliminating the need for artificial irrigation.  In a dry r…

The Lonesome Towhee

Along the Colorado Front Range, both spotted towhees (permanent residents) and green-tailed towhees (summer residents) prefer the open shrublands of the lower foothills though smaller populations may be found in suburban or rural areas of the urban corridor.  Over the years, some have visited our Littleton farm for periods of time but have always moved on for the breeding season.

Last spring, however, a male spotted towhee appeared on our property and has yet to depart.  Intent on attracting a mate, he sings from dawn to dusk, from late winter to early summer; for the remainder of the year, he is rather quiet, skulking among the shrubs or scratching for insects and seeds beneath the junipers and pinyon pines.  Isolated from his cohorts, his incessant singing has been in vain and I have yet to discover a female spotted towhee on the property.

Social creatures, we humans tend to pity animals that lose contact with their flock or herd.  While I have no ability to relocate our lonesome to…

Axial Seamount, Iceland & Hawaii

Oceanic volcanic islands develop above mantle hotspots or along mid oceanic ridges where the sea floor is spreading.  The Hawaiian Ridge is an example of the former; its chain of islands, atolls and seamounts formed as the Pacific Plate moved northwestward above a mantle plume, a process that continues today.  Iceland, on the other hand, has formed (and continues to form) above the mid Atlantic ridge, between the North American and Eurasian Plates, where oceanic crust is forming.

Axial Seamount, 300 miles off the coast of northwest Oregon, is the product of both volcanic processes.  Sitting atop the Juan de Fuca Ridge, a spreading center between the Pacific and Juan de Fuca Oceanic Plates (the latter is a remnant of the Farallon Plate), this Seamount is also fed by magma from the Cobb Hotspot; indeed, the Axial Seamount is the youngest (and currently active) formation in a chain that leads northwestward to the Aleutian Trench.  Like the Hawaiian Archipelago, the Cobb-Eickelberg Seamou…

Transition in the Valley

Over the past week, there has been a significant transition in the South Platte Valley.  The last of the winter birds have departed for northern latitudes or for their summer range in the mountains; in concert,  an increasing variety of summer residents have returned to the Valley, having wintered well to our south.

Yesterday, only a few tardy female buffleheads remained on the ponds at South Platte Park, while double-crested cormorants, American white pelicans, western grebes and snowy egrets had settled in for the summer.  In the riparian woodlands, house wrens, yellow warblers, gray catbirds, northern orioles, western pewees and yellow-breasted chats joined the permanent residents.  On our farm, which sits on the west wall of the valley, broad-tailed hummingbirds, house wrens, Say's phoebes, willow flycatchers, mourning doves and chipping sparrows have all made an appearance and Swainson's hawks, back from Argentina, have rejoined our year-round raptors.

Late migrants, such…