Sunday, April 29, 2018

A Secretive Visitor

As I walked to our barn yesterday afternoon, I caught a brief glimpse of a medium-sized songbird that scurried into one of our shrub lines, its cocked olive tail my only clue.  I immediately suspected that it was a green-tailed towhee, yet another first sighting on our Littleton farm.

Birders who live along the Colorado Front Range know that this bird is a common summer resident of the foothill shrublands, often heard but seldom observed.  Scratching for insects and seeds, it spends most of its time under the cover of shrubs and thickets; though males may sing from a perch to defend their territory, green-tailed towhees are less conspicuous than their spotted cousins.  After nesting and raising their young in foothill canyons or on sun-drenched slopes below 8000 feet, these towhees head for the Desert Southwest or Mexico for the winter months.

Today, I waited for our visitor to emerge from the shrubs but he remained partly concealed.  A flash of his rusty orange crown confirmed my identification but the summer may come and go before I get a good look at one of these secretive towhees.

Saturday, April 28, 2018

Just Down River

Just downstream from South Platte Park, where the river has not been "restored" (channelized for fish), the South Platte flows through braided channels, broken by sandbars and marshes.  This morning, I wandered along 1.5 miles of that attractive ecosystem and was rewarded with a fine diversity of wildlife.

Among the birds were three seasonal firsts: a black-crowned night heron, three snowy egrets and a dozen or more cliff swallows.  Other avian highlights included a large number of blue-winged and cinnamon teal, two American avocets, a couple Say's phoebes, several great blue herons and the usual mix of raptors.  A coyote hunted along the opposite bank and a muskrat plied a calm stretch of the river.

This morning's walk was both a pleasant change from my usual birding route (within the Park) and a nostalgic return to the "old South Platte." The wildlife seemed to share my preference for a more natural ecosystem, however hemmed in it might be by human development.  See Restoring the South Platte

Friday, April 27, 2018

Nesting Cooper's Hawks

The Cooper's hawks that have been cavorting about our farm for the past couple of weeks are now preparing to nest in one of the large Siberian elms.  Actually, the male is building the nest, piling sticks atop one of several squirrel nests in that tree.  Stopping to rest or to hunt for himself, he spends most of his day on the farm.  Meanwhile, the much larger female departs for extended periods of time, letting her mate handle the construction work.

Sources disagree on this point, some reporting that both partners construct the nest while others confirm my observation.  In either case, it will take a couple of weeks to finish the nest and another month of incubation before the fuzzy chicks appear.  The female will provide most of the incubation and the male will do the hunting during that period.  Since Cooper's hawks feed primarily on mid-sized songbirds, the local doves, pigeons, flickers, jays and robins may be in for a harrowing summer.  Large females are also known to take rabbits and squirrels, a practice that might offer some balance to their populations on our farm.

For now, there is no panic among the songbirds and rabbits and squirrels continue to use the nest tree.  That may change in the coming weeks, especially when the raptors have hungry chicks to feed!

Wednesday, April 25, 2018

Spooked by a Bittern

As I circled Eaglewatch Lake at South Platte Park this morning, I accidentally flushed an American bittern and was spooked myself by his sudden rise from the marsh.  A medium-sized heron, this bittern has a thick torso and neck, making him appear quite large at close range; a long bill adds to his menacing appearance.

Foraging near the water's edge in both freshwater and brackish wetlands, American bitterns feed on fish, amphibians, lizards, large insects and small mammals.  When threatened, they assume a classic pose with their bill pointed skyward and their streaked plumage blending with the reeds and tall grasses.  This morning's encounter was too acute to permit that camouflage routine and he took off across the lake.

Wintering primarily in coastal marshes of the southern U.S. and Mexico, American bitterns way also utilize drier areas with tall grass.  Most nest in freshwater wetlands of southern Canada and the northern U.S. while smaller numbers summer in lakeside marshes of the Great Plains, Mid-Atlantic region and the Central Valley of California.  Solitary for most of the year, males are highly territorial during the breeding season, announcing their presence with loud "booming" calls.

Tuesday, April 24, 2018

The Appeal of Birding

Most birdwatchers begin their hobby due to the influence of a relative or friend who is already a devotee.  They soon learn that there are far more local species than they had realized and enjoy the hunt for more.

While some eventually lose enthusiasm, many continue birding throughout their lives, fascinated by the large variety of birds that reside in or visit their community.  Some begin traveling to regional wildlife refuges to augment their "life list" while others actually plan vacations to birding meccas.

But beyond the enjoyment and challenge of finding and recording species, birding appeals to conservation-minded individuals because birds connect us with distant regions of the planet, bearing witness that Earth's far-flung ecosystems are interconnected and interdependent.  The migrants that we attract with our landscaping and feeders are both welcome visitors and messengers from afar, temporarily taking advantage of our hospitality.  In return, we come to appreciate their beauty and their fortitude and are inspired to protect their natural habitat, wherever on Earth that might be. 

Sunday, April 22, 2018

Earth Day: Not Enough

Today is Earth Day, an annual celebration of our planet's many resources and of our commitment to protect them.  There will be speeches, festivals, marches, fun-runs and other human activities, designed to highlight the threats to our environment and to educate attendees how to minimize their personal impact on natural ecosystems.

Of course, those efforts will be ineffective unless they challenge the financial power of industry and the political forces within our government that strive to derail the work of conservationists.  It is good that many humans will "show their green" on Earth Day but they must followup that demonstration by making "green choices" when they shop, as they manage their own property and at the ballot box.

It is fun to gather on a warm, sunny day to taste organic foods, buy natural trinkets and accept free trees and bumper stickers but it is harder to join community action groups, support conservation organizations and take part in the political process.  What better time to make those commitments than during the reign of King Trump, a man devoted to plundering Earth's bounty.

Saturday, April 21, 2018

Relentless Evolution

We modern humans are the products of 3.6 billion years of evolution, governed by genetic mutations, genetic recombination (through sexual reproduction) and the overriding process of natural selection.  Even among the global human population, differences have developed as tribes have adapted to their environment (e.g. darker skin in those native to the Tropics and more adipose tissue in those native to the Arctic region).

Today I came across an article in the New York Times which reports on a study from the journal Cell.  It describes an anatomic alteration present in the Balau people of Southeast Asia, a coastal culture that has long sustained itself by deep diving to spear fish and to collect mollusks from the sea bed.  Known for their ability to remain underwater for prolonged periods of time, members of this tribe were found to have enlarged spleens (an organ that is also enlarged in other diving mammals such as seals and which plays an important role in the diving reflex observed in all mammals).  Of particular interest is the fact that all Balauns have enlarged spleens, even those who do not engage in diving; this suggests that it is an inherited trait, emplaced by natural selection.  Researchers suspect that this diving culture developed as sea levels rose at the end of the Pleistocene, forcing islanders to rely on marine creatures for their sustenance.

Many humans, especially those inclined toward mysticism, believe that we humans are the pinnacle of creation, the Chosen Species.  In fact, we have evolved from other primates and continue to evolve.  Hundreds of thousands of years from now, if we have not destroyed our planet, we may well have evolved into a new species.

Friday, April 20, 2018

A Colorado Low

During the spring, an upper level low often develops over the Four Corners region and moves eastward onto the High Plains.  In concert, its cold front bows southeastward from the central zone of low pressure, separating dry air, to its west, from warm, humid air, to its east.

Known as the Dry Line, this frontal boundary often ignites supercell thunderstorms across the Southern High Plains, from eastern New Mexico to West Texas and Oklahoma.  North of the low, counterclockwise winds push moisture toward the Front Range, producing cold rain or snow as the air is forced to rise by the terrain.

This scenario is playing out this evening.  The Dry Line and its attendant thunderstorms stretch along the New Mexico-Texas line and are moving eastward; hail is expected and tornadoes may develop.  Here in Metro Denver, chilly rain is falling which will likely change to snow overnight.  Since it has been very warm along the Front Range, significant accumulation is unlikely and the precipitation is more than welcome.

Thursday, April 19, 2018

The Avian Spring Migration

Across central latitudes of North America, the avian spring migration extends from February through May.  During this time, summer residents are arriving from the south, winter residents are leaving for their northern (or mountain) breeding grounds and other migrants are merely passing through, on their way from wintering areas (to our south) to breeding areas (to our north).

Migrant snow geese, northern white-fronted geese and American white pelicans are among the early migrants, often heading north by February.  During March, the duck/loon/grebe migrations begin to heat up and hardy summer residents appear; the latter include American woodcocks, eastern phoebes, mountain bluebirds and tree swallows.  Early shorebirds may also turn up in March though the number and variety of shorebirds usually peaks in mid-late April.  Mid April is an interesting time for birders since the wave of summer residents begins to increase and the last of the winter residents begin to depart; among the former are house wrens, hummingbirds, chipping sparrows, a host of swallows, chimney swifts, rails, migrant gulls and terns, gray catbirds and yellow-rumped warblers while the latter include white-crowned and white-throated sparrows and dark-eyed juncos.  Late April through early May brings the peak wave of migrant warblers, flycatchers, common nighthawks, rose-breasted grosbeaks, tanagers and migrant thrushes, among others.  By mid May, the migration show is over but fall migrants (i.e. early shorebirds) will be turning up in July.

Here on our Littleton, Colorado, farm, the migration schedule is unfolding right on schedule.  The dark-eyed juncos have all but disappeared and both house wrens and broad-tailed hummingbirds have appeared this week.  Our lone Townsend's solitaire has yet to depart but his days on the farm are numbered.  The next few weeks will be especially interesting. 

Tuesday, April 17, 2018

Seasonal Firsts at South Platte Park

Those of us who have been birding for many years rarely encounter a "new species" unless we travel to a new region of the country (or of the planet).  To compensate, we generally look for birds that are "the first of the year" or "the first of the season."  Of course, these species are either migrants or season residents.

This morning, despite a gusty southwest wind, I headed down to South Platte Park, hoping to see some "seasonal firsts" and I was not disappointed.  The first of these firsts was a male yellow-headed blackbird, lounging on a beach of Eaglewatch Lake; perhaps tired from his journey, he was basking in the bright sunshine, oblivious of the strong wind.  The second was an American avocet, foraging in the residual pool of Bufflehead Lake (where the water level remains low); joined only by six green-winged teal, he is on his way to ephemeral pools of the Northern Plains.  Finally, two ospreys graced the scene, cavorting in the gusty wind; though I saw many in Florida this past winter, they were seasonal firsts (for me) in the South Platte Valley.

Strong winds rattled our windows through the night and, when I awoke this morning, I almost canceled my plan to visit South Platte Park; as I have discussed in the past, strong winds are one of the weather factors most likely to keep birds inactive and inconspicuous.  Having encountered these "new" spring birds (and 28 other species as well), I'm glad I ignored my own advice.

Monday, April 16, 2018

A Sage Thrasher visits the Farm

On this cloudy but warm afternoon, a sage thrasher visited our Littleton farm; it is the first one I have seen on the property since we bought it, 28 years ago.  Since this small thrasher prefers dry grasslands with nearby shrubs or pinon pines, I'm not surprised that he stopped by.

Spending most of their time on the ground, sage thrashers often chase grasshoppers and other insects, climbing into shrubs to feast on berries.  They breed across the sage flats of the Great Basin and Colorado Plateau, wintering on the Southern High Plains or in the Desert Southwest of the U.S. and Mexico.

Primarily migrants along the Front Range, these thrashers are identified by their yellow eyes, their relatively short and slightly down-curved bill, their dull gray upper plumage and their boldly streaked or spotted chest and abdomen.  When disturbed, as our visitor was by my close inspection today, they retreat to shrubs or thickets and repeatedly flick their tail.

Sunday, April 15, 2018

Can Scientists be Religious?

The answer to this question, it seems to me, depends on how we define scientist.  Those who use scientific facts in a practical way (e.g. teachers, lab technicians, flight engineers, medical practitioners) can likely balance their scientific knowledge and their religious beliefs without facing a philosophical crisis.  Basic scientists, however, especially those delving into the mysteries of the Universe and the nature of life itself, are less likely to accept the tenets of religious faith.

Indeed, organized religion has attempted to derail the validity of science since the days of Galileo and Copernicus.  Since that time, our scientific knowledge has expanded tremendously as theories have been proven or disproven using the scientific method.  Meanwhile, religious beliefs, not subject to scientific analysis, remain unchanged, a source of pride for most true believers.

But scientists can be just as kind, just as charitable and just as committed to human rights as any of their religious friends and colleagues.  In fact, I suspect that they are less likely to be intolerant or to engage in discrimination.  Science seeks truth through proven facts and truth is the path to human enlightenment and peaceful coexistence. 

Saturday, April 14, 2018

A Muted Protest in Denver

Despite the sunshine, the turnout at Denver's March for Science was underwhelming this morning.  Those who did participate were enthusiastic but, for a city as large and liberal as Denver, the message from here was muted.

Even the number of booths was disappointing and most were devoted primarily to recruiting members; I gravitated toward those that had a philosophical edge, such as organizations promoting freedom from religion.  While there was certainly a good deal of anti-Trump sentiment during the March itself, the displays and speakers were relatively apolitical.

Having come of age in the sixties, I've participated in my fair share of protest marches.  But the anger and fervor of that period was not matched today.  Perhaps we've become immune to Trump's daily tweets and executive orders, hoping to wait out the term of his dysfunctional Administration.  Unfortunately, they are doing a great deal of damage in the meantime and we will need a revolution to change the mindset in America.  Today's modest assembly in Denver will have no effect, even at the local level; let's hope the March for Science received more zealous support in other cities.

Thursday, April 12, 2018

March for Science

What are you doing this Saturday, April 14?  If you are alarmed by the anti-science rhetoric of the Trump Administration and the Religious Right, consider taking part in the second annual March for Science that will occur in cities throughout our country and across the globe.

More than a protest rally, March for Science also highlights the importance of science education, scientific research and evidence-based policies related to human society and our stewardship of the planet.  Unfortunately, many industries, politicians and religious leaders have taken an anti-science approach to protect their own interests.

The Earth is not flat.  The evolution of life on our planet has been unfolding for 3.6 billion years and continues today.  The health of human society is directly related to the welfare of natural ecosystems.  Global warming is real and is primarily caused by our use of fossil fuels for more than a Century.  Tobacco use is a major health hazard.  These are scientific facts; to deny them or to ridicule other science-based evidence is to place the welfare of future generations at risk.  March for Science on Saturday!

Wednesday, April 11, 2018

Summer Crosses the Mountains

A high pressure dome over the Four Corners region, combined with low pressure over the Northern Plains, has produced strong WSW winds along the Colorado Front Range.  Warm air from the Desert Southwest is being swept across the Continental Divide and, as that air is forced to sink along the Eastern Slope, it warms up and dries out.  As a result, we reached 81 degrees F in Metro Denver this afternoon.

Working outside on our Littleton farm, the summer-like conditions were readily apparent and I had to retreat to the shade on a regular basis.  The birds were noticeably quiet on this hot afternoon but insects and arachnids were especially conspicuous, including bees, yellow-jackets, jumping spiders, cabbage white butterflies, a wide assortment of beetles and clouds of midges.  Due to the recent mild weather, the pear and crabapple trees are beginning to bloom and most of the shrubs are almost leafed out.

The warm weather is expected to continue through tomorrow but rain and/or snow is forecast for Friday.  As local residents know, Colorado's spring is usually a mix of summer and winter.

Tuesday, April 10, 2018

Caged Birds

On this warm, April afternoon, as I watched a flock of gulls soar above our Littleton farm, I, like most humans since the dawn of our species, wished that I could join them.  While a small minority of humans have a pilot's license and an even smaller percentage are capable of using some form of a glider, we will never match the experience that birds enjoy on a daily basis.

It is thus especially sad to encounter a caged bird, capable of soaring above the countryside but trapped behind bars for the amusement or "education" of humans.  As a child, I enjoyed the banter of my grandmother's parakeet and took part in its care; too young to understand the deprivation that I was witnessing, that caged bird may have actually played a role in my early development as a naturalist, interested as I was in its vocalizations and behavior.

Is there a more cruel sentence that humans impose on wildlife?  Certainly the physical abuse of animals and trophy hunting come to mind but to cage a creature that is capable of flight ranks very high on my list.  Other than for the temporary care of an injury (and even that is questionable if not human-induced), birds do not belong in cages.

Monday, April 9, 2018

Creativity & Substance Abuse

History is replete with authors, painters and musicians who used (and often abused) alcohol and/or illicit drugs.  One might question the reason for this association.

First of all, it seems that creativity is associated with manic-depressive tendencies.  It is for this reason that writers, artists and musicians often experience prolific periods that alternate with episodes of inertia (e.g. writer's block).  As a result, they may resort to the use of stimulants to augment their productivity or rely on alcohol to assuage their depression.  On the other hand, alcohol and certain drugs tend to diminish our inhibitions and may enhance creativity; one might argue that the secondary honesty or unique perspective may play a significant role in the success of the work.

Of course, there is a fine line between use and abuse and history is also replete with creative artists who died young due to their dependence on drugs and/or alcohol.  In some cases, the pressures associated with celebrity lead to the abuse while, in others, the inability to meet personal or public expectations is the trigger.  Creativity, an advantage in many professions, can be a health risk. 

Sunday, April 8, 2018

The Perching Tree

When we bought our Littleton, Colorado, farm in 1990, we noticed that a weeping mulberry tree, less than 10 feet from our picture window, was partly obstructing our view of the South Platte Valley and of the High Plains Escarpment to the southeast.  There was some discussion as to whether we should cut it down but, fortunately, it still stands.

During the warmer months, its dense clusters of curved branches are festooned with rich green foliage and, in early summer, it provides a copious supply of sweet red mulberries, enjoyed by humans and wildlife alike.  If one lives in the semiarid climate of the Front Range, anything that is green and provides tasty fruit is best left alone.

But it is during the colder months that I most appreciate this "ugly" tree.  It is then that a wide variety of birds perch on or within its net of barren branches.  Bathed in sunshine from dawn to dusk, the weeping mulberry attracts small songbirds such as juncos, finches, sparrows and bushtits but is also a favored resting spot for doves, jays, thrushes and woodpeckers; were I inclined toward wildlife photography, it would offer a steady supply of close-up subjects.  As it is, I'm content to merely enjoy their company, especially on cold winter days.

Friday, April 6, 2018

Sharp-shin in the Snow

Returning to the farm on this cold, snowy morning, I discovered a sharp-shinned hawk perched on the bird bath.  Oblivious of the blowing snow, he flew away when I stepped from my pickup.

Winter residents across the lower elevations of Colorado, sharp-shinned hawks return to the mountains or to the conifer belt of Canada to breed.  Throughout the year they prefer wooded areas where they hunt from a secluded perch or race through the trees to snare their prey.  Small to medium sized songbirds are their primary victims though they may feast on large insects and occasionally dine on snakes or amphibians.

I did not see the remains of a songbird near the bird bath and assume he merely stopped by for an icy drink.  But his unexpected presence in the swirling snow was both a special treat and a source of inspiration.  He was off to hunt in the April snowstorm while I grabbed the groceries and headed indoors!

Thursday, April 5, 2018

Who We Are

Most humans accept the fact that our physical body is a product of our genome, modified by our lifestyle and, perhaps, by disease or injury.  However, many reject the concept that our thoughts, emotions, memories and dreams are also products of anatomic and biochemical systems.

In fact, from fetal life to the time of our death, our body is bombarded with stimuli; received through our senses, the signals and interactions are recorded in our brain and become as much a part of us as our external features.  Molding our sense of self, these experiences, remembered or not, determine who we become.

While our genes govern the physical framework and biochemical mechanisms with which we respond to life's challenges, the events and relationships of life's journey are equally significant.  Indeed, we are also products of the joy or pain, the love or rejection, the kindness or criticism and the nurturing or abuse that we experience along the way.  

Wednesday, April 4, 2018

Flashback Post III

The first week of April is a great time for many American sports fans.  The Final Four reaches its exciting climax, the Masters Golf Tournament is held and the Professional Baseball Season gets underway.  It seems like an appropriate time to reflect on one of my posts from February, 2013.

See: Rooting for Champions

Tuesday, April 3, 2018

Wind Herding

As one who has been birding for many years, I know that strong winds and heavy rain are the two weather factors that most often keep birds inactive and out of sight.  On the other hand, a steady wind often concentrates our quarry, encouraging them to forage in sheltered areas.

This morning, at South Platte Park, a strong northwest wind raked the valley and I clearly noticed the herding effect described above.  The waterfowl congregated along the western and northern shores of Eaglewatch Lake, almost negating the need for binoculars.  Songbirds gathered in the same regions, sheltered from the wind by the reservoir levee and by a housing development north of the lake.  Of course, we birders find those areas more pleasant as well, bathed in sunshine yet protected from the chilling effect of the wind.

Among this morning's highlights were a common loon, two horned grebes (in breeding plumage), blue-winged teal (just beginning to populate the Front Range), a greater yellowlegs and a few yellow-rumped warblers.  Though I hoped to see double-crested cormorants, American white pelicans and an osprey or two, none were encountered on this windy morning.

Monday, April 2, 2018

Walking into Spring

After two weeks of raw weather in Missouri, I have returned to our Littleton farm.  As I walked onto the property, I noticed the effects of a recent spring snowstorm; several large tree limbs lay on the ground, one partially blocking the driveway.  On the other hand, it was 70 degrees F and it sure felt like spring.

Indeed, the recent snows have brought greenery to our "lawns" and a host of bulb plants are providing the color that we associate with April.  One of my favorite wildflowers, the common dandelion, adorns the farm and both the wild cherries and the apricot trees are in bloom, attracting hordes of bees.  Though some of the shrubs have begun to leaf-out, the larger deciduous trees remain barren, a sign that nights remain cold along the Colorado Front Range.

No doubt, more upslope snowstorms lie ahead (April is second only to March when it comes to snowfall in Metro Denver) and tomorrow will be 20 degrees colder than today after 40 mph winds rake the area overnight.  But it was nice to walk into spring this morning.

Sunday, April 1, 2018

Flashback Post II

On this Easter Sunday, I thought I would link back to a post from April of 2012 which describes a formative experience in my development as a naturalist.

See: Easter Awakening