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Showing posts from April, 2015

A Handsome Visitor

Over the past few days, a chipping sparrow has visited our Littleton, Colorado, farm.  Easily identified by their slender form, bright rusty crown and light, unstreaked chest and abdomen, these summer residents are rather common along the Front Range urban corridor in mid spring; however most end up nesting in the open ponderosa parklands of the foothills, joining western and mountain bluebirds, pygmy nuthatches, Williamson's sapsuckers, mountain chickadees, Steller's jays, Townsend's solitaires and other montane species.

There they feed primarily on the ground, feasting on both seeds and insects.  Nests, which are placed in shrubs or small trees, consist of dry vegetation and an assortment of man-made and natural materials; chipping sparrows often use animal hair in their nest and were once known as the "hair bird" when horses were our prime mode of transportation and plowing-power.

By late summer, chipping sparrows become less territorial and gather in modest s…

Reassurance from SeaWorld

Facing a public backlash arising from a trainer's tragic death and accusations stemming from a highly publicized documentary, SeaWorld has launched emotional ads prior to the summer tourist season.  In these commercials, employees of the company stress their commitment to the killer whales, placing emphasis on their high level of medical and nutritional care; they also indicate that none of their orcas have been taken from the wild in recent decades and that the longevity of their captive killer whales matches that of their wild relatives.

Of course, the commercials do not mention the fact that most captive animals, removed from the stresses imposed by predation, malnutrition, disease and natural disasters, tend to live longer than they do in the wild.  Neither do they acknowledge that these large, intelligent creatures are confined to giant bathtubs for the course of their lives.

While modern zoos and aquariums play an important role in public education and place emphasis on cons…

Flycatcher Days on the Farm

Flycatchers generally arrive on our Littleton, Colorado, farm in late April or early May.  Western wood pewees (summer residents) and willow flycatchers (migrants) are regular annual visitors and Say's phoebes turn up on occasion, as one did today; all are generally found alone.

Returning from Central or South America, the willow flycatchers often hunt on our property for a week or two before heading to mountain meadows for the summer.  Say's phoebes winter in the Desert Southwest and Mexico; erratic visitors to our farm, they soon head for open, dry shrublands of the lower foothills. Western wood pewees, having wintered in South America, are common summer residents across the Colorado Piedmont; though they often visit our farm, they are best observed in cottonwood groves along the South Platte River and its tributaries.

More risk averse than many avian insectivores, flycatchers time their migrations to insure that prey will be available.  Of course, nature does not offer guar…

Exotic Bird of the Southern Plains

Birders who travel across the Southern Plains will usually observe a wide variety of raptors and grassland songbirds; in spring and fall, they may also find migrant flocks of waterfowl, sandhill cranes, American white pelicans and shorebirds.  One species, however, is often noticed by non-birders as well.

Looking like they belong in the tropics rather than on the semiarid plains, scissor-tailed flycatchers are easily identified by their long, thin, forked tail (which is longer in adult males than in females and juveniles).  After wintering in Mexico, Central America, southern Florida or the Bahamas, these exotic-looking birds summer from central latitudes of Kansas and western Missouri to South Texas and northernmost Mexico.  Often seen flycatching from barbed wire fences in open country, pairs are highly territorial during the breeding season; nests, which usually contain a mix of native vegetation and human-made materials, are placed in shrub lines or tree groves adjacent to grassla…

Earthquake in Nepal

Unlike many earthquakes, which develop along hidden faults beneath oceans or featureless plains, today's magnitude 7.8 quake in Nepal is easy to understand, even for the novice geologist.  The Indian Subcontinent, which broke from Antarctica and Australia some 80 million years ago, has been plowing into southern Asia for the last 50 million years, crumpling up the Himalayas, the highest range of mountains on Earth.

The tectonic force responsible for this ongoing collision is sea floor spreading in the western Indian Ocean, triggered by mantle currents beneath the ocean crust.  Inching to the NNE, India has fused with Asia and the intervening ocean crust is now incorporated within the mountain massif; indeed, Mt. Everest, the highest point on our planet, is capped with marine limestone.

Today's earthquake in Nepal, coupled with new eruptions of the Calbuco Volcano in southern Chile, remind us that the surface of our planet remains in flux, its tectonic plates rifting, colliding…

Andes Volcanism

The eruption of the Calbuco Volcano in southern Chile this week is that peak's first significant activity since 1972 and the most recent eruption in the Andes Chain, a volcanic range that began to form during the Mesozoic Era (the Age of Dinosaurs).  As Pangea broke apart and the Atlantic Ocean began to open (some 150 million years ago), the North and South American Plates were shoved westward, a tectonic process that continues today.

Along the western edge of the Americas, the oceanic Farallon Plate was forced to subduct beneath the advancing continental masses.  Now represented by smaller remnant plates (the Juan de Fuca, Cocos and Nazca Plates, north to south), the eastern edge of the subducting oceanic plate melted (and continues to melt) beneath the western edge of the American Plates, producing the Cascades, the Mexican and Central American Volcanic Belt and the Andes, respectively.  In southernmost South America, the Antarctic Plate is subducting beneath South America, prod…

A Riot of Life

In late April, wetlands across the Temperate Zone of North America harbor a riot of sound and color; the Garth Wetlands, in north Columbia, Missouri, are no exception.  Characterized by a mosaic of ponds, meadows, cattail marshes and riparian woodlands on the Bear Creek floodplain, this urban refuge is accessed by a fine network of graveled paths.

Today, wild mustard, purple phlox and the brilliant bloom of redbud trees complimented the varied shades of greenery.  Additional color was provided by indigo buntings, northern cardinals and American goldfinches that flashed among the meadows and woodlands.  The calls of red-winged blackbirds produced a steady background din, broken by the calls of cricket and leopard frogs, the chatter of belted kingfishers, the squawk of a great blue heron, the musical trill of house wrens and the varied tunes of wetland songbirds. Painted turtles and red-eared sliders basked in the warm April sun, attentive Canada geese escorted their downy youngsters al…

Noisy Intruders

By late April, some songbirds, such as robins and mourning doves, are already nesting.  Their parental activity will soon be mimicked by summer residents arriving from the south.  Indeed, birdsong is beginning to peak, reflecting the mating behavior of our many avian neighbors.

Joining this chorus are the varied tunes, squeaks and rattles of brown-headed cowbirds.  Settling in suburban shade trees, these noisy visitors survey the activity of other songbirds but do not construct nests themselves.  Rather, after mating, the female cowbird lays her eggs in the nests of other birds, generally leaving one egg in each parasitized nest; she is then free to mate again and may produce several clutches before late summer.  Unfortunately, the young cowbirds are often larger and more aggressive than the offspring of their adoptive parents, garnering much of the food and sometimes shoving their hapless cohorts from the nest.

In light of this behavior, many birders despise cowbirds; after all, it&#…

The Preacher Returns

The preacher has returned to our central Missouri neighborhood.  Dressed in his cinnamon-brown suit, he chooses a conspicuous location to deliver his message; as if to emphasize the importance of his words, each phrase is repeated and the volume of his sermon does not waver.  Though I am not a religious person, I welcome his arrival each spring.

The brown thrasher, as this preacher is known, is a vocal summer resident who generally appears in mid April and announces his arrival with a long musical banter; consisting of two or three note lines, each delivered twice, it is a composite of birdsong, natural sounds and human-related noises.  When not singing, this bird skulks in the woodland understory and feeds primarily on the ground, consuming a variety of invertebrates, seeds and berries.  Nests are generally placed in shrubs or thickets and both parents take part in raising the young.

Come fall, the brown thrashers of central Missouri move to southern parts of the State, into Arkansas…

Railing at Eagle Bluffs

By late April, waterfowl migrations are beginning to wind down at Eagle Bluffs Conservation Area, in central Missouri.  Nevertheless, there were a large number of ducks on the refuge when I visited yesterday morning; American coot, blue-winged teal and northern shovelers were most abundant, joined by hooded mergansers, wood ducks and lesser scaup.  Other sighting included great blue herons, American white pelicans (about 30), double-crested cormorants, Canada geese, belted kingfishers, yellowlegs, spotted sandpipers and two immature bald eagles.

But my goal on that cool, cloudy morning was to find rails, secretive residents of dense cattail marshes and other wetland habitats.  In Missouri, king rails and soras are summer residents while Virginia rails are primarily migrants through the State; though yellow rails and black rails might be encountered, they are very rare migrants in Missouri.  Most rails are best observed at dawn or dusk but they might also leave their vegetative cover o…

Cedar-Apple Rust

Yesterday, after a steady morning rain, my wife called me outside to look at strange, gelatinous growths in our eastern red cedar trees.  Bright orange, tennis ball sized and characterized by numerous tendrils, these alien ornaments had not been observed in previous years.

Cedar-apple rust is a unique fungus that utilizes both eastern red cedars and a tree from the rose family (primarily apples) to complete its life cycle.  Spores infect the red cedars in summer, forming small galls by the following spring.  Often called "cedar apples," the galls enlarge over the next year and spawn the gelatinous tendrils after spring rains; these odd structures release spores that, spread by the wind, infect nearby apple trees.  Spores released by lesions on the apple leaves then reinfect the cedars during the summer months, completing the cycle.

In retrospect, we recently lost a diseased crabapple tree that had grown near the red cedars.  In addition, our hawthorne tree has been losing li…

A Welcome Invasion

I have returned to central Missouri just in time for the annual invasion of summer and migrant songbirds, which should unfold over the next month.  Having wintered along the Gulf Coast, in Mexico or even in South or Central America, these fair weather species are generally those that rely on nectar, flowers and live insects for their nutrition.

While tree swallows and eastern phoebes arrive in March, the primary invasion begins in mid April and extends through most of May.  House wrens, gray catbirds and brown thrashers often lead the incursion, followed closely by indigo buntings, ruby-throated hummingbirds, chimney swifts, swallows (barn, cliff, bank and rough-winged) and northern orioles.  Of most interest to avid birders are the challenging mix of warblers, vireos and flycatchers that arrive or pass through over the next few weeks.

Long a keen observer of this welcome invasion, I wander our property during the morning or evening hours, hoping to spot those species that are but tra…

Travel by Radar

Heading east on the High Plains yesterday afternoon, we knew that our journey involved some risk.  After all, the massive spring storm that brought heavy snow to much of Colorado had also been igniting tornadic thunderstorms on the Great Plains; in fact, as we drove east from Limon, northeast Colorado and almost all of Kansas were under a tornado watch.  As the driver of our pickup, I scanned the horizons for worrisome cloud formations while my wife intermittently checked the regional radar and weather reports via her I-phone.

From Limon to Burlington, white puffy clouds dotted the clear blue sky, consistent with a relatively low dew point in that region; by contrast, two massive thunderheads rose far to our north which, we later learned, had spawned tornadoes near Akron, Colorado.  As we crossed into Kansas, it appeared that we had also crossed the Dry Line, an atmospheric boundary between dry air to the west and warm, humid air to the east.  In concert, the cloud formations began to…

Detour to Scenic Terrain

Planning to head back toward Missouri today, we learned that Interstate 70 was closed east of Denver due to dense fog and multiple accidents.  We thus took an alternate and far more scenic route.

Colorado 86 runs west to east between Castle Rock, on I-25, and Interstate 70, a few miles north of Limon.  From Castle Rock, the road climbs eastward through the mesa dominated topography south of Metro Denver before dropping through the broad valley of Cherry Creek; the latter stream rises along the Palmer Divide and flows NNW to join the South Platte in downtown Denver.  East of that valley, Colorado 86 undulates across a scenic landscape of pine covered escarpments and short-grass prairie on the northern flank of the Divide, passing through Elizabeth and Kiowa en route; nearing Interstate 70, the route drops across the south side of the Palmer Divide. leaving the higher, pine studded terrain.

The rustic farms, hilly topography and ponderosa pine parklands were a welcome change from the br…

Colorado Spring Breaks

Contrary to the image in the minds of Americans from other States and, perhaps, the citizens of other countries, Front Range cities are not enveloped in snow and ice for most of the year; indeed, periods of warm, sunny weather generally develop during every month.  Then again, measurable snowfall may occur from September to June; only July and August are reliably free of snow.

The general spring warm-up usually begins by late February and continues into mid summer along the Front Range urban corridor.  However, this seasonal process is often interrupted by upslope snowstorms, especially in March and April; in fact, March is, on average, the snowiest month for the Front Range cities.

The latest spring disruption began last evening as a cold front dropped across the Rockies and an upslope flow developed, dropping the temperature from the mid 60s (F) to the low 40s within a few hours.  This morning, steady snow is falling across Metro Denver, coating the colorful blossoms and green lawns…

Wild Plum

By mid April, stands of wild plum are readily observed along the Colorado Front Range.  Their clusters of white flowers, appearing before the leaves, adorn the barren limbs; favoring relatively moist soil and full sun exposure, this native shrub (or small tree) grows along streams and in sunny areas of foothill canyons.  Spines often appear on the rigid stems and the leaves, which begin to unfold as the flowers fade, have a finely serrated edge.

The reddish plums appear by early summer and are consumed by a wide variety of birds and small mammals; mule and white-tailed deer also brows on their leaves and stems.  Like other shrubs of the Colorado Piedmont and Front Range foothills, wild plum is drought and cold tolerant and is spread across the semiarid landscape in the droppings of wildlife that feed on its fruit.

Fortunately, developers and homeowners along the urban corridor have utilized wild plum in decorative plantings.  By choosing native plants that are well adapted to the Fron…

The Hardy Lilac

Lilac shrubs, renowned for their beauty and fragrance, are blooming on our Littleton farm, a couple weeks ahead of schedule; two weeks of summer-like weather have triggered the early flowering.  Native to the Balkan Peninsula of Eastern Europe, these attractive shrubs have been planted across the globe and adapt well to the sunny, semiarid environment of the Colorado Front Range.

Indeed, our scattered lilac hedges require very little maintenance and no supplemental watering; cutting out dead limbs is the extent of our intervention.  Since they spread by suckering, lilacs form colonial clumps which favor full sun exposure and well drained soil; found on rocky hillsides in their native range, long-lived lilac stands often mark the past sites of abandoned homesteads in other regions of human habitation.  On the negative side, these hardy shrubs tend to crowd out other vegetation; on our property, two forsythia bushes have recently succumbed to aggressive lilac expansion.

While we humans …

Compost Bin West

A year after constructing a compost bin for our Missouri property, I have begun to build a larger one for our Littleton, Colorado, farm.  While we have owned the farm since 1990, we have resorted to using an open compost pile in a wild corner of the lot; since a variety of creatures roam the farm, including red fox, skunks and raccoons, we have been reluctant to add fruit and vegetable scraps to the yard "waste," knowing that remnants would soon be scattered by those scavengers.

But my decision to build Compost Bin West was also motivated by the positive experiences derived from the Missouri project.  While we have we become more diligent about recycling kitchen leftovers, the bin has also been an effective teaching project for our grandsons; more than learning about the importance of conservation and the use of natural compost to fertilize our gardens, they have enjoyed adding scraps to the rotting pile and often report on the variety of "bugs" that they observed …

A Tradition of Exclusion

The 79th Masters Tournament begins today at Augusta National Golf Club, in Georgia.  Many Americans will tune in, attracted by the regular ads (airing since January), the drama of the tournament, the manicured landscape, the brilliant azaleas and, for birders, the calls of great-crested flycatchers ringing behind the hushed voices of the broadcasters.

But the tradition at Augusta National has a dark side as well.  Established in 1933, the organization did not admit African American members until 1990 (26 years after the Civil Rights Act) and did not offer membership to women until 2012 (an internationally famous woman and a local female business leader were accepted).  The Club might respond that blacks have been essential participants on the pristine course since its inception.....as caddies; indeed, Augusta National required Masters participants to use their African American caddies through much of the Tournament's history, highlighting the racial disparity at the Club.

Too ofte…

Squirrel Siesta

On the south side of our Littleton farmhouse is a large catalpa tree, its massive branches extending in all directions.  Every day, just after noon (snowy weather excluded), a fox squirrel stretches out on one of those limbs; if it is warm, he chooses a shady spot and, if it is cool, he lounges in the sun.

While I enjoy a close-up view of this squirrel siesta, I know that such behavior is repeated all across our farm and, no doubt, all across the global range of tree squirrels.  Between feeding throughout the morning and their late day foraging activity, the squirrels, like many other animals, need time to rest and digest their food.  Though this afternoon nap represents instinctual behavior, I am convinced that it is  a pleasurable experience for an animal that spends most of its day scouring lawns, climbing trees, chasing cohorts and escaping predators.

Indeed, any experienced naturalist knows that wildlife viewing is most productive during the morning and late day hours.  By early …

Bullsnake Bravado

On my visit to Waterton Canyon yesterday, I took a side trail down to the South Platte, hoping to spot a dipper.  My effort was in vain but, as I returned to the graveled roadway, I was startled by a loud hissing sound near the path.  Looking down, I saw the front half of a large bullsnake, protruding from a burrow.  After a threatening twist of its thick body, the snake disappeared beneath the ground.

Bullsnakes, often called gopher snakes in the Western U.S., range from the Midwest to the Pacific Coast and from southern Canada to northern Mexico.  These heavy-bodied, non-poisonous constrictors may reach six feet or more in length and are identified by brown markings on a yellowish background.  After emerging from their winter dens in April, bullsnakes begin to feed on small mammals, birds and lizards while also searching for a mate.  Once impregnated, females lay an average of 12 eggs in sun-exposed sand where they will hatch by late summer.

Often mistaken for rattlesnakes, which th…

Eastern Phoebe at Waterton Canyon

At the base of Waterton Canyon, southwest of Denver, groves of cottonwood trees and a rich understory of shrubs and junipers line the South Platte River.  I often visit this area, especially during the warmer months, since it attracts a wide variety of Front Range songbirds; in addition, dippers may be found in the river and golden eagles often soar along the edge of the foothills.

This morning, I was surprised to encounter an eastern phoebe, a species that I have not previously observed in Colorado.  Back in Missouri (and across the eastern and central U.S.), this bird is common and is among the earliest summer residents to arrive in the spring.  While its cousin, Say's phoebe is a common summer resident along the base of the foothills (favoring open shrublands), only sporadic sightings of eastern phoebes have been reported in recent years.

Like northern cardinals and white-throated sparrows, eastern phoebes seem to be expanding their range into Colorado.  In such cases, human al…

The War on Diplomacy

Now that a framework for the Nuclear Deal with Iran has been released, militarists on all sides have condemned it; in their minds, enemies are meant to be annihilated, not respected.  The fact their their own countries have a history of supporting dictators and occupying other nations does not seem to cross their minds.  No doubt, some will stop to condemn the peace plan as they leave Easter services today.

Of course, we humans have a long history of settling our differences with regional conflicts or broader warfare.  Though we are the only species to have both the cerebral and laryngeal traits to communicate effectively, we have preferred spears, guns and bombs.  Our evolutionary survival has depended as much on military power as it has on creativity and cooperation.

By now, one would think that we would be tired of the cycle of warfare, with its needless suffering and ruthless carnage.  Unfortunately, our divisive tribalism and religious zealotry foster hatred and distrust, deraili…

Blood Moon over the Rockies

Looking west from our Littleton farm this morning, I saw a darkened, reddish moon with a bright, bluish rim along its top edge; the time was 5:50 AM, about an hour before dawn.  In fact, I was witnessing a total lunar eclipse, as Earth's shadow temporarily blocked sunlight from illuminating the moon.

This morning's total lunar eclipse, best observed in the western U.S., will be the briefest this Century, lasting about 5 minutes.  While partial lunar eclipses are relatively common, total lunar eclipses are rare; for any given location on our planet, only 4-5 can be observed each decade.  The term "blood moon," describing the reddish appearance of the lunar surface, results from the scattering of sunlight by Earth's atmosphere; during a total lunar eclipse, only the longer wave lengths of the light spectrum (i.e. red light) reach and are reflected by the moon's surface.

Observing such astronomical spectacles, now explained by our knowledge of planetary motion a…

April in the Foothills

April is an excellent month to visit the Montane Forest of the Front Range foothills.  Composed of open ponderosa pine parklands (on sunny, south-facing slopes) and a mix of Douglas fir and Colorado spruce (on shaded, north-facing slopes), this aromatic forest cloaks elevations between 7000 and 9000 feet, attracting a distinct population of wildlife.

Permanent residents of the Montane Forest include mountain lions, black bear, mule deer, Abert's squirrels, Colorado chipmunks, wild turkeys, mountain chickadees, pygmy nuthatches, hairy woodpeckers, northern pygmy owls, Steller's jays, Townsend's solitaires and red crossbills, among more widespread species.  Joining them during the warmer months (and usually arriving in April) are dusky grouse, Williamson's sapsuckers, mountain and western bluebirds, violet-green swallows, broad-tailed hummingbirds, black-headed grosbeaks, western tanagers and chipping sparrows.  Elk winter on meadows of the Montane Zone; other winter vis…

The Laramie Basin

North of Ft. Collins, Colorado, US 287 angles northwest, climbing into the Front Range foothills.  It then turns northward, passing through a scenic landscape of hogbacks, ridges, rock spires and domes; initially crossing foothill shrublands, it cuts through ponderosa parklands as it nears the Wyoming border.  Just beyond that border, the highway crosses a low pass, leaving the watershed of the Cache la Poudre and descending into the Laramie Basin (also called the Laramie Plains) which has an average elevation of about 8000 feet.

The Laramie River rises near Cameron Pass, in Colorado, flowing northward along the eastern base of the Medicine Bow Mountains.  Entering Wyoming, the river veers northeastward across its broad basin,  cuts northward through Laramie, enters Wheatland Reservoir and then turns eastward once again, carving a canyon through the Laramie Mountains before joining the North Platte River.  The latter mountains form the eastern wall of the Laramie Basin and outcrops of…

A Failure to Evolve

We humans have inhabited Earth for at least 130,000 years.  In the course of our history we have spread across the planet, established vibrant cities, developed effective means of global transportation, created technologies to advance communication, healthcare and agriculture, harnessed energy from wind, sun, rivers, uranium and fossil fuels, explored near space and sent probes toward distant planets and galaxies.  While much of our activity has threatened the welfare of Earth's natural ecosystems, we have, in many cases, been able to utilize the same scientific discipline to repair the damage.

Unfortunately, while most humans benefit from the achievements of mankind, only a small minority understand the science that underlies that progress.  Worse yet, the great majority of humans retain mythologic belief systems that cause them to question the validity of science; furthermore, those beliefs tend to foster zealotry and tribalism which impede cooperation and incite conflict.

As a …