Thursday, September 28, 2017

The Changing Face of Earth

Since forming from molten stardust some 4.6 billion years ago, the face of our planet has been constantly changing.  The earliest Continents had no resemblance to those we find today and have changed their size, shape and position as they have been rifted apart and sutured together by the opening and closing of oceans.  Of course, that process continues today but is too gradual to be noticed during our short life spans; hints of that relentless activity are offered by observable rift zones and the earthquakes that result from the collision, lateral scraping or subduction of Earth's tectonic plates.

Today's surface geography has only settled into place over the last 50 million years or so, a very brief period in Earth's natural history.  While volcanic islands continue to appear and Continental shorelines expanded and contracted throughout the Pleistocene (2 million to 10 thousand years ago), humans did not have the technology to adequately map and view our planet's surface until the last few centuries.

Indeed, the coming generations will be the first in human history to directly observe the changing face of Earth as our climate warms, sea levels rise and coastal geography changes dramatically.  Hopefully, that reality will ignite a more fervent commitment to minimize human impact on both the atmosphere and the natural ecosystems of our home planet.

Wednesday, September 27, 2017

A Mountain Visitor

Anyone who has traveled through the mountains of Western North America has likely encountered Steller's jays.  Represented by several subspecies, these conspicuous birds are adorned with a black head and crest, contrasting with the blue plumage of their body and wings.  Their loud, raucous calls often bring attention to their presence.

Along the Colorado Front Range, Steller's jays are common residents of subalpine forests across the mountains and of the ponderosa pine-Douglas fir woodlands of the upper foothills.  While they are occasionally observed along the base of the foothills, these noisy omnivores seldom venture onto the adjacent Piedmont except when heavy winter snows blanket the higher terrain.

Yesterday, a lone Steller's jay appeared on our Littleton farm, feeding with a group of blue jays; he was the first to turn up here during the non-winter months.  Perhaps the first mountain snows of the season forced him down or maybe he's just an adventurous individual.  Whatever the cause for his visit, he was more than welcome, reminding me that attentive naturalists are often rewarded with unexpected sightings. 

Tuesday, September 26, 2017

Out of the Gloom

After several days of a low, gray overcast, chilly air and intermittent showers, the clouds have pulled away from the Front Range this morning, revealing the first thick blanket of snow across the higher peaks.  Down here on the Piedmont, the sunshine and mild temperatures were inviting after the gloomy period and the precipitation had softened the landscape.

Surveying the farm this morning, I encountered the usual mix of avian residents but also came across a rock wren, foraging on one of the woodpiles; he was the first I have seen on the property since we purchased it in 1990.  Of course, his presence only added to the joy that the pleasant weather had brought.

The atmospheric trough that produced our cool, rainy conditions is pushing eastward across the Great Plains and warmer, drier air will soon move in from the Southwest.  On the backside of the trough, those air masses will clash and thunderstorms are forecast for tomorrow afternoon.  By the weekend, however, we expect sunny skies and highs in the seventies (F). 

Sunday, September 24, 2017

Leadership by Bullhorn

Donald Trump has little respect for anyone but himself.  Wallowing in his pool of self importance, he sends out tweets deriding his staff, fellow Republicans, foreign leaders, civil rights advocates and, this week, professional athletes.  Still campaigning in regions of the country that adore his in-your-face style, Trump attacks critics and opponents with zeal, shunning the decorum expected of American Presidents.

This leadership by bullhorn is both divisive and ineffective, as evidenced by his near total lack of achievements to date.  Limited to signing executive orders, Trump remains at the mercy of the Legislative and Judicial Branches which, hopefully, will keep this bombastic narcissist from destroying America's image across the globe.  Why the Republican leadership has not been more vocal in criticizing this wayward President is almost as disturbing as Trump's behavior itself.

Of course, The Donald could care less what the rest of us think.  He is all about himself and speaks only to his poorly educated, provincially-minded, racist base.

Wednesday, September 20, 2017

The Chill Alarm

The first chilly weather of late summer or early autumn certainly catches the attention of humans and wildlife alike.  After months of hot weather, it is a welcome reprieve for both but it is of more significance to our wild neighbors.

Though animal behavior is most closely tied to the daylight cycle, the cool weather is an instinctive alarm that the harsh months of winter lie ahead and that harvesting is now especially important.  That may mean putting on a layer of fat for hibernation, fueling up for migration or storing food in dens or natural cavities for the lean months.  In response to this seasonal alarm, wildlife species become more active and conspicuous, delighting many humans who are also invigorated by the chill.

Last night, our low temperature dropped into the mid forties (F), kicking on the furnace for the first time since April; the first prolonged run of chilly weather is expected to arrive by this weekend.  This morning, I toured the farm, taking in the cool fresh air and watching our resident birds and mammals as they began their initial preparations for winter.

Tuesday, September 19, 2017

Hurricanes send a Message

After enduring widespread destruction from Hurricanes Harvey and Irma, North Americans and residents of the Caribbean now face Hurricane Maria, churning toward the Virgin Islands and Puerto Rico.  Just upgraded to a category 5 storm, Maria has become the third major hurricane to threaten the region within the past month.

While much of our focus has centered on evacuation and recovery, the elephant in the room is global warming which may not increase the frequency of hurricanes but will surely augment their intensity.  Tropical storms and hurricanes are heat machines, fueled by warm ocean waters and the hot, humid air into which they move.  Global warming will increase all three factors as sea temperatures rise and a warming atmosphere retains more water vapor.

Unfortunately, while many industrialists and politicians appreciate the technology that predicts the path and intensity of hurricanes, they reject the science of climate change.  Few cities are planning for a warmer climate and politicians continue to fight over funding for infrastructure.  The message sent by these powerful storms should resonate across the globe; few if any regions of the planet will be immune to the effects of a warming climate. 

Monday, September 18, 2017

Apache Jumping Spiders

Sitting on a railroad tie along one of our flower beds, I looked down to see a small group of jumping spiders in the dry, weedy grass.  Yellow-orange patches on their cephalothorax and abdomen indicated that they were female Apache jumping spiders, a species common across central latitudes of the U.S.

Like all jumping spiders, they have excellent vision, provided by four pair of eyes (including a large, dominant pair).  Foraging in the bright sunshine, they search for a wide variety of small insects and will return to their den if clouds role in.  Unlike many spiders, jumping spiders do not spin webs but do use silk to create a nest for their young or a cozy retreat for themselves; the nest is typically placed in a protected crevice among rocks or logs.  The life span of these small, active arachnids is generally about one year; Apache jumping spiders overwinter in their immature stage.

It is always interesting to come across small creatures that, if not for sheer luck, might otherwise go unnoticed.  Some landscapes, such as our weedy, dry "lawns", would not seem attractive to many species of wildlife; but, if we stop and look, we are often surprised to discover an amazing diversity of fascinating creatures.  Backyard safaris are often rewarding.

Sunday, September 17, 2017

Borrowing Genes

All life forms on this planet, from fruit flies to humans, borrow genes that determine their physical and behavioral traits.  Having received half of their genome from each parent via sexual reproduction (or all of it in lower forms that are asexual), the genes are a blueprint for our structure and the biochemical processes that sustain life.  Many human genes date back to ancestral primates, having persisted through natural selection during 60 million years of evolution.

Unfortunately, some genes are harmful or corrupted, producing disease or failing to block disease processes; most of these bad genes were inherited while some mutated from good genes during our lives.  We have long used medication and surgery to deal with the effects of this "malware" in our chromosomes and are just now beginning to use gene therapy to correct the defects in our genome.

In the course of our lives, we may pass along some of our genes to biologic children, including some that may threaten their health.  As the saying goes, "we cannot choose our parents" and we are subject to any deleterious genes that we inherit.  Finally, upon our death, a sizable fragment of our genome persists in our biologic children; the rest is removed from the genome of our species, never to be returned.

Saturday, September 16, 2017

Engaging North Korea

Despite the saber-rattling and bombastic threats from the two narcissistic leaders, neither North Korea nor the United States has anything to gain from a military confrontation.  Though some war hawks in Congress are pushing for a tough stance, diplomatic engagement is the best answer in the long run.

It may be difficult to demonstrate respect for a dictator who brain washes and oppresses his citizens but we cannot encourage change by isolating and ridiculing Kim Jong Un.  Efforts to bring North Korea into the world economy will produce opportunities to shine light on the inequities that exist in that country and better introduce its population to the freedoms enjoyed in Western Society.

If Kim Jong Un is granted a more significant role on the world stage and if other major players initiate diplomatic relations with North Korea, we should be able to avoid military conflict and eventually bring that country into the international community.  Warfare, on the other hand, will lead to the death of thousands (if not millions) of innocent civilians.  See also War and Speech.

Thursday, September 14, 2017

The Second Coming of Man

Earth formed about 4.6 billion years ago, some 9 billion years after the Big Bang.  Life would appear on our planet a billion years later but would not emerge from the sea until 440 million years ago.  Primates evolved about 60 million years ago and the first hominins appeared about 5 million years ago; finally, modern man graced the scene about 150,000 years ago.

While our species had a limited effect on natural ecosystems for most of our history, we began to significantly pollute the planet over the last few centuries.  Fouling the air, water and soil, we have also altered the climate through our widespread use of fossil fuels.  There is a reasonable probability that Earth may become uninhabitable within a few more centuries unless we make major strides in the areas of population control and pollution curtailment.  Of course, supervolcanic eruptions, asteroid strikes and nuclear war could also play a role in our extinction.

Many humans envision that we will escape to other planets or other solar systems before our species is annihilated.  More likely, it seems to me, we will fall victim to our lack of stewardship, perhaps aggravated by natural catastrophe, and, in our absence, nature will heal herself.  Hundreds of millions of years later, assuming the sun has not yet begun to die, we may re-evolve from "lower species" that managed to survive the turmoil on Earth.

Saturday, September 9, 2017

Irma's Fury becomes Personal

As I write this post, Hurricane Irma is still meandering WNW along the northern coast of Cuba.  The most recent computer models suggest that it will soon turn north, slamming the Florida Keys, hugging the west coast of Florida and sparing Metro Miami.  In concert, celebrity reporters and weathermen are racing across the peninsula to be close to the action.

Anyone who has read this blog, even on a casual basis, likely knows that my wife and I own a condo on Longboat Key, off Sarasota.  It now appears that it will incur significant damage but we are fortunate that we have other homes and that none of our family members are currently using that property.  Since purchasing the condo, in 2003, we and our relatives have repeatedly enjoyed Longboat Key with nothing more serious than chilly weather to taint our vacations.

Of course, we always knew that the purchase was a risk and have never believed that public funds should be used to bail out those who choose to occupy barrier islands, river floodplains, volcanic slopes or other high risk zones.  Nature is not cruel but neither is she sentimental; if we do not respect her power or acknowledge the processes that culminated in her beautiful landscapes, we cannot complain when we suffer the consequences.  And when it comes to hurricanes, human-induced global warming will likely make them more frequent and more powerful.

Friday, September 8, 2017

Mexico's Subduction Quake

While the attention of most North Americans has been focused on Hurricane Irma, about to unleash her fury on Florida, a strong earthquake struck off the Pacific Coast of southern Mexico yesterday.  The magnitude 8.2 quake occurred along a subduction zone, where the Cocos Plate (a remnant of the massive Farallon Plate) is dipping beneath the North American Plate; unfortunately, at least 58 persons were killed by the earthquake.

In such subduction zones, the edge of the over-riding plate is pulled down by friction with the subducting plate.  Eventually, this edge rebounds upward, displacing a massive amount of seawater and often triggering a tsunami.  Fortunately, in this case, the latter did not develop.

As the North and South American Plates continue to drift westward in concert with the opening of the Atlantic Ocean, subduction of the Farallon remnants (the Juan de Fuca, Cocos and Nazca Plates, north to south) will continue, igniting volcanic ranges (the Cascades, Mexican volcanoes, Central American volcanoes and the Andes) as they melt and triggering earthquakes offshore that spread across the mainland.

Thursday, September 7, 2017

A Record-Setting Hurricane

Hurricane Irma, churning its way toward Florida, has pulverized a few Caribbean islands along the way.  Since it formed, in the tropical Atlantic, this storm has maintained a symmetrical structure and has not encountered obstacles to its development (wind shear, dry air, cold water or mountain ranges).  As a result, the massive hurricane achieved category 5 status and has retained that strength for more than twice as long as any Atlantic hurricane in recorded history.

Expected to pummel the Turks and Caicos today, the storm's center remained north of Puerto Rico and the Dominican Republic and will likely miss Cuba as Irma continues to track to the WNW.  The Bahamas will soon feel its leading edge and a hurricane warning has now been posted for Southeast Florida and the Florida Keys.

An atmospheric trough to the north, combined with a large dome of high pressure over the mid Atlantic, will eventually steer Irma northward.  When and where it makes that turn will make all the difference to residents of Florida, southern Georgia and the Carolinas.  We should know within 48 hours. 

Wednesday, September 6, 2017

A Pumpkin Moon

Over the last few days, as the waxing moon approached its full stage, our lone natural satellite has taken on an orange hue here in Metro Denver.  Looking like a giant pumpkin, it has hovered over the Eastern Plains in early evening and loomed above the Front Range peaks at sunrise.

The cause for its beautiful yet mysterious appearance is simple.  The moonlight is shining through a smoky haze that has settled across the Colorado Piedmont.  Extensive wildfires in Idaho and Montana are the source of the smoke, which moved southward within an atmospheric trough.  While the latter brought welcome, cooler air to the urban corridor, the smoke has greatly diminished the visibility and has produced a significant health risk for those with pulmonary disease.

While the wildfires continue to burn, winds are expected to shift back to the southwest in the coming days, bringing heat back to the Front Range but clearing out the smoke.  Of course, our pumpkin moon will then lose its colorful tinge.

Tuesday, September 5, 2017

Scrub Jay visits the Farm

Woodhouse's scrub jays are common, permanent residents of the Mountain West, from Nevada to Mexico.  Here along the Colorado Front Range, they are primarily found on the shrublands of the lower foothills and, until yesterday, I had not observed one on our Littleton farm.

While reading at the edge of our driveway, I was startled by the jay as he wandered out from the shrub-lined "lawn," picking at the asphalt in search of food.  After a minute or so, he flew off to our grove of pinyon pines and then headed south.

Like most jays, scrub jays are noisy, aggressive and omnivorous birds; unlike some species, they are usually found alone or in pairs.  They lack the distinctive crest of blue jays (a common permanent resident on the farm) and Steller's jays (an occasional winter visitor here).  Perhaps, like red-breasted nuthatches and lesser goldfinches, they'll become new, year-round residents on our property.

Monday, September 4, 2017

Laborers in America

American laborers generally come from the lower and middle classes; their income is but a small fraction of those in the upper class.  Many laborers have more than one job and few can afford to have their spouse stay home with the kids.  They don't belong to fitness clubs and rarely eat out.

Laborers work at country clubs and resorts but cannot afford to use those facilities.  Some work at professional sports stadiums but could never afford to attend the games.  Laborers avoid toll lanes and reserved parking lots.  They often use mass transit and, while they may load your plane or cruise ship, they could not afford the journey.

Many laborers are guest workers.  They pick our crops, repair our highways, cut our lawns and build our homes.  They take on jobs that more affluent Americans would never consider.  And when they're done, we send them back.  Happy Labor Day!

Sunday, September 3, 2017

September Heat

By September, the longer nights bring chilly mornings to the Front Range cities and, in most years, afternoon highs drop into the 70s F.  In fact, the first snow of the season often dusts the urban corridor before September ends.  This year, however, summer heat is slow to abate.

A ridge of high pressure, the same that blocked Harvey from moving inland, remains in place over the American West.  Deflecting Pacific fronts across the Northern States and blocking the Southwest Monsoon that usually brings rain in August and September, this atmospheric dome is prolonging the summer season and putting the cool, crisp days of autumn on hold.

For those of us who relish the invigoration that autumn brings, this static pattern is less than welcome and may portend a seasonal change that global warming will bring.  Until the jet stream dips across our region, we'll have to rely on migrant songbirds to provide reassurance that the seasons are changing; as in recent years, the waterfowl will likely be in no hurry to come south.  We can only hope that chilly air will arrive in time to spark the glorious colors of October. 

Saturday, September 2, 2017

Rock Wrens

This morning, on my regular birding walk at South Platte Park, I encountered a rock wren, foraging on a spillway.  While these small songbirds are common in canyons and on rock outcrops and boulder fields of the Front Range foothills and mountains, I rarely see them down on the Piedmont.

Found throughout western North America, from southern Canada to Mexico and from the High Plains to the West Coast Ranges, rock wrens are identified by their pale gray coloration (except for a light, rusty wash on their lower abdomen), a long, thin bill, a barred tail and short legs.  Almost always found on rocky slopes or boulder fields, they hunt for insects and spiders, bobbing over the rocks, searching the crevices with their bill or springing into the air to snare their prey.  As one might expect, these vocal birds place their nest within rock crevices, using dried vegetation, sticks and bark chips to build a shallow cup; of interest, they also construct a "patio" of pebbles at the entrance to the crevice.

Come autumn, rock wrens depart the northern half of their summer range (including Colorado), heading for the Central Valley of California, the Desert Southwest or Mexico.  I suspect this morning's visitor at South Platte Park was beginning that biannual trek.