As we arrived at Eagle Bluffs Conservation Area this morning, a large flock of snow geese passed overhead, shimmering in the bright morning sun; it was 12 degrees F. Most of the shallows had frozen over but open pools attracted a mix of wintering ducks, including mallards, gadwalls, coot, green-winged teal, ring-necks and lesser scaup; scattered flocks of Canada geese rested on the ice and a group of pied-billed grebes dove for their breakfast.
Several more flocks of snow geese crossed the refuge during our visit, moving north along the Missouri River Valley, as did a large flock of greater white-fronted geese. Five sandhill cranes had gathered on a wooded island and at least fifty American white pelicans huddled on a sandbar near the south end of the preserve. Ring billed gulls swirled above the open pools, northern harriers zoomed across the dormant crop fields, great blue herons perched in the morning sun and an immature bald eagle soared overhead, oblivious of the frigid air.
Silence ruled this winter scene, broken only by the occasional flocks of noisy geese and the distant calls of headstrong crows. How ironic that the season's first blast of Arctic air should coincide with the first wave of migrant geese. Winter may be strengthening its grip but my money is on the geese; despite this brief setback, the tide of spring has begun.
Saturday, February 11, 2012
Friday, February 10, 2012
From Snow to Snows
As we left the snowy landscape of Metro Denver yesterday morning, a full moon gleamed above the Front Range. Once past the Palmer Divide, the snow cover gradually diminished and, except for residual drifts along the highway, had disappeared by the time we entered Kansas. However, as I discussed on February 6, the snow blanket reappeared near Wakeeney and then steadily vanished as we descended toward Hays.
For the remainder of our journey, a brown landscape and gray sky set the scene; only the aerial ballets of starlings, the agile swoop of harriers and the reliable presence of red-tails broke the monotony. Then, just east of Russell, Kansas, my first glimpse of snow geese during this "spring" migration season erased my boredom as a wavering flock crossed the bleak winter sky, headed toward their Arctic breeding grounds. A second flock appeared near Salina and a third, much larger flock graced the sky in eastern Kansas.
Darkness negated any sightings in Missouri but, over the next six weeks, I'll hear and see many more flocks of these vocal travelers, the vanguard of our gathering spring. While the season of snow has yet to run it course, snow geese carry the hope of warmer, fragrant and colorful days ahead.
For the remainder of our journey, a brown landscape and gray sky set the scene; only the aerial ballets of starlings, the agile swoop of harriers and the reliable presence of red-tails broke the monotony. Then, just east of Russell, Kansas, my first glimpse of snow geese during this "spring" migration season erased my boredom as a wavering flock crossed the bleak winter sky, headed toward their Arctic breeding grounds. A second flock appeared near Salina and a third, much larger flock graced the sky in eastern Kansas.
Darkness negated any sightings in Missouri but, over the next six weeks, I'll hear and see many more flocks of these vocal travelers, the vanguard of our gathering spring. While the season of snow has yet to run it course, snow geese carry the hope of warmer, fragrant and colorful days ahead.
Wednesday, February 8, 2012
Flying with Pterosaurs
Since heavy snow still covers most of the Front Range trails, we opted for a visit to the Denver Museum of Nature & Science today. Long famous for its wildlife dioramas, this magnificent institution has recently received kudos for its recovery of numerous Pleistocene fossils from a lake bed near Snowmass, Colorado; the skeletal remains of mammoths, mastodons, ancestral camels, ancestral bison and numerous other animals were unearthed last summer before the reservoir was refilled.
Today, we arrived just in time to see an IMAX film produced by National Geographic and narrated by the renowned naturalist, David Attenborough. Given the odd title of The Flying Monsters, apparently chosen to attract young visitors, this 3-D film covered the natural history of pterosaurs, from their initial appearance in the Triassic, some 200 million years ago, until their disappearance at the end of the Cretaceous, 65 MYA. Thought to have evolved from lizards that used webbed limbs to glide between trees, pterosaurs had an elongated digit on each forefoot which was connected to the ipsilateral leg by a thin membrane. Early pterosaurs were not much larger than lizards while giraffe-sized pterodons had appeared by the late Cretaceous; through the course of their evolution, pterosaurs lost their long tails and developed a limited ability to walk on their hands (located at the bend of each wing) and feet, offering some capacity to feed on land as well as in the air. Some pterodons, equipped with a large head fin, also may have preyed on fish, sailing across the surface of the sea.
While pterosaurs disappeared with terrestrial dinosaurs, at the end of the Cretaceous, the film suggested that their demise may not have been solely related to a massive meteor strike; rather, the rise of birds, more agile on land and in the air, may have sealed their fate. Though pterosaurs were extinct for almost 65 million years before humans appeared, the film provided a splendid introduction to those fascinating creatures and, through the magic of 3-D photography and computer animation, allowed the audience to fly with them.
Today, we arrived just in time to see an IMAX film produced by National Geographic and narrated by the renowned naturalist, David Attenborough. Given the odd title of The Flying Monsters, apparently chosen to attract young visitors, this 3-D film covered the natural history of pterosaurs, from their initial appearance in the Triassic, some 200 million years ago, until their disappearance at the end of the Cretaceous, 65 MYA. Thought to have evolved from lizards that used webbed limbs to glide between trees, pterosaurs had an elongated digit on each forefoot which was connected to the ipsilateral leg by a thin membrane. Early pterosaurs were not much larger than lizards while giraffe-sized pterodons had appeared by the late Cretaceous; through the course of their evolution, pterosaurs lost their long tails and developed a limited ability to walk on their hands (located at the bend of each wing) and feet, offering some capacity to feed on land as well as in the air. Some pterodons, equipped with a large head fin, also may have preyed on fish, sailing across the surface of the sea.
While pterosaurs disappeared with terrestrial dinosaurs, at the end of the Cretaceous, the film suggested that their demise may not have been solely related to a massive meteor strike; rather, the rise of birds, more agile on land and in the air, may have sealed their fate. Though pterosaurs were extinct for almost 65 million years before humans appeared, the film provided a splendid introduction to those fascinating creatures and, through the magic of 3-D photography and computer animation, allowed the audience to fly with them.
Tuesday, February 7, 2012
Snow on Snow
Leaving a nearly snowless winter in Missouri, we arrived at our Littleton farm and found it adorned with more than 15 inches of white powder; fortunately, my Tacoma pickup was able to navigate the long, uphill driveway and it was just a short trudge to the backdoor.
Out on our property, Townsend's solitaires, robins and bushtits feasted on juniper berries while chickadees, flickers and house finches moved among the bare deciduous trees, undaunted by the heavy snow. Our resident fox and raccoons may den up for a few days but we'll soon see their tracks across the blanket of white. Down on the South Platte, ducks and geese crowded the river, feeding along and beneath the relatively warm, open waters.
Another cold front passed through Colorado overnight and, though only a dusting was expected, five more inches were left behind. Enjoying a snowy winter landscape for a change, my wife and I took a walk through the residual flurries as the clouds began to dissipate and patches of blue opened above the Front Range. Milder, sunny weather is forecast for the rest of this week and the intense Colorado sun will soon take a toll on our beautiful gift of the season.
Out on our property, Townsend's solitaires, robins and bushtits feasted on juniper berries while chickadees, flickers and house finches moved among the bare deciduous trees, undaunted by the heavy snow. Our resident fox and raccoons may den up for a few days but we'll soon see their tracks across the blanket of white. Down on the South Platte, ducks and geese crowded the river, feeding along and beneath the relatively warm, open waters.
Another cold front passed through Colorado overnight and, though only a dusting was expected, five more inches were left behind. Enjoying a snowy winter landscape for a change, my wife and I took a walk through the residual flurries as the clouds began to dissipate and patches of blue opened above the Front Range. Milder, sunny weather is forecast for the rest of this week and the intense Colorado sun will soon take a toll on our beautiful gift of the season.
Monday, February 6, 2012
High Plains Upslope
On my frequent travels between Missouri and Colorado, I have often noticed that, following a snowstorm, the Wakeeney, Kansas, area receives more snow than areas to its west or east on I-70. Assuming this must represent an upslope phenomenon, a reflection of the local topography, I examined a map of the region after yesterday's journey reinforced my past observations.
In fact, Wakeeney sits on the east edge of the High Plains at the west end of a topographic wedge in which the elevation is gradually rising from east to west. A prominent ridge just south of Hays, Kansas, is an erosional remnant of the High Plains, dividing the watersheds of the Smoky Hill River, to its south, from that of Big Creek to its north. In similar fashion, though not as visible from I-70, another eastward extension of the High Plains divides the Big Creek watershed from that of the Saline River, to the north of that ridge. Both of these ridges merge near Wakeeney and the rolling terrain between them climbs from 2000 feet at Hays to about 2450 feet at Wakeeney, yielding an upslope terrain that concentrates its orographic precipitation near the latter city; this scenario develops whenever easterly winds sweep Gulf moisture westward toward the High Plains.
Upsloping air cools and condenses, dropping its cargo of rain or snow. Such orographic weather events are common along mountain ranges, producing vital snowpacks in many regions and moist, forested retreats in the "sky islands" of desert areas. The upsloping terrain near Wakeeney is repeated at many other sites across the Great Plains, where a series of escarpments produce stair-like transitions from the lower, tallgrass zone on the east to the higher, shortgrass ecosystem of the High Plains. In addition, similar escarpments border the High Plains to the north, west and south, yielding upslope funnels in those regions as well; examples include the Pine Ridge Escarpment of western Nebraska and the Palmer Divide in eastern Colorado.
In fact, Wakeeney sits on the east edge of the High Plains at the west end of a topographic wedge in which the elevation is gradually rising from east to west. A prominent ridge just south of Hays, Kansas, is an erosional remnant of the High Plains, dividing the watersheds of the Smoky Hill River, to its south, from that of Big Creek to its north. In similar fashion, though not as visible from I-70, another eastward extension of the High Plains divides the Big Creek watershed from that of the Saline River, to the north of that ridge. Both of these ridges merge near Wakeeney and the rolling terrain between them climbs from 2000 feet at Hays to about 2450 feet at Wakeeney, yielding an upslope terrain that concentrates its orographic precipitation near the latter city; this scenario develops whenever easterly winds sweep Gulf moisture westward toward the High Plains.
Upsloping air cools and condenses, dropping its cargo of rain or snow. Such orographic weather events are common along mountain ranges, producing vital snowpacks in many regions and moist, forested retreats in the "sky islands" of desert areas. The upsloping terrain near Wakeeney is repeated at many other sites across the Great Plains, where a series of escarpments produce stair-like transitions from the lower, tallgrass zone on the east to the higher, shortgrass ecosystem of the High Plains. In addition, similar escarpments border the High Plains to the north, west and south, yielding upslope funnels in those regions as well; examples include the Pine Ridge Escarpment of western Nebraska and the Palmer Divide in eastern Colorado.
Saturday, February 4, 2012
Human Hybridism
While evangelicals will surely stick to their Adam and Eve story, DNA technology has greatly advanced our understanding of evolution and, in recent years, has uncovered the fact that most humans are hybrids. The last (to date) in a long line of hominids to walk the Earth, our species appeared in Africa about 130,000 years ago and began to disperse from that Continent about 80,000 years ago. However, earlier hominids had colonized Eurasia long before we left our homeland.
About 600,000 years ago, the lineage that would lead to humans split from one that would culminate in Neanderthals and their close cousins, the Denisovans. Based on DNA studies, these hominids diverged genetically and geographically about 350,000 years ago as Neanderthals spread into Europe and Western Asia while Denisovans occupied Eastern Asia, from Siberia to Indonesia. The latter group was unknown until a few fossils were discovered in a Siberian cave just two years ago; cool conditions within the cave served to protect DNA within the two bones and one tooth and subsequent studies demonstrated their close relationship to Neanderthals.
Of even more interest, DNA analysis of various human populations has demonstrated that early human migrants interbred with Neanderthals and Denisovans as they dispersed from Africa. While the latter two hominids became extinct about 30,000 years ago, we continue to carry some of their genes; 5% of the genome in humans of Eurasian descent is of Neanderthal origin and various populations of Southeast Asia, Melanesia and Australia have genomes that contain 4-5% Denisovan genes. The persistence of these genes in our DNA indicate that they conferred some benefit to early humans and were thus retained through the process of natural selection; only humans who are descendants of African populations do not possess this hybridism. Racist, white evangelicals may be interested to know that African Americans are pure Homo sapiens while they, themselves, are part Neanderthal.
About 600,000 years ago, the lineage that would lead to humans split from one that would culminate in Neanderthals and their close cousins, the Denisovans. Based on DNA studies, these hominids diverged genetically and geographically about 350,000 years ago as Neanderthals spread into Europe and Western Asia while Denisovans occupied Eastern Asia, from Siberia to Indonesia. The latter group was unknown until a few fossils were discovered in a Siberian cave just two years ago; cool conditions within the cave served to protect DNA within the two bones and one tooth and subsequent studies demonstrated their close relationship to Neanderthals.
Of even more interest, DNA analysis of various human populations has demonstrated that early human migrants interbred with Neanderthals and Denisovans as they dispersed from Africa. While the latter two hominids became extinct about 30,000 years ago, we continue to carry some of their genes; 5% of the genome in humans of Eurasian descent is of Neanderthal origin and various populations of Southeast Asia, Melanesia and Australia have genomes that contain 4-5% Denisovan genes. The persistence of these genes in our DNA indicate that they conferred some benefit to early humans and were thus retained through the process of natural selection; only humans who are descendants of African populations do not possess this hybridism. Racist, white evangelicals may be interested to know that African Americans are pure Homo sapiens while they, themselves, are part Neanderthal.
Friday, February 3, 2012
A Spring Storm in Mid Winter
Here in central Missouri, we awoke to clear skies and temperatures in the low 40s (F), with light southeast winds. But to the west, a wall of dark clouds stretched across the horizon, the leading edge of a massive storm system that is centered over the Southern Plains. Ahead of the storm, Gulf moisture is flowing northward across the Heartland and, as the system approaches, bands of rain will move in from the west, a product of lift, atmospheric moisture and the clash of air masses. Rain should develop in central Missouri by early afternoon and is expected to persist for 24 hours or more, a welcome development for our parched landscape.
On the northwest side of this storm, the Gulf moisture is being whipped toward the Front Range as counterclockwise winds swirl around the central low. These upsloping winds cool as they rise in elevation and heavy snow is falling across Metro Denver, the foothills and the adjacent plains; up to 20 inches are expected in the city with higher amounts on the east slope of the Front Range. Since the primary jet stream remains up in Canada, the air will not be extremely cold (remaining in the 20s F) but the associated strong winds are producing blizzard conditions and parts of several Interstates have been closed.
As the storm pulls on to the east, this upslope effect will be lost and snow will be very limited in the Upper Midwest; here in Missouri, all precipitation is expected to arrive in the form of rain. Once again, the high riding jet stream will spare most of the U.S.; while we enjoy a mild winter, Alaska, eastern Europe and Russia, caught above the jet stream, have been dealing with heavy snow and frigid air. Indeed, our mild winter has nothing to do with global warming but, rather, reflects a stagnant weather pattern across the Northern Hemisphere.
On the northwest side of this storm, the Gulf moisture is being whipped toward the Front Range as counterclockwise winds swirl around the central low. These upsloping winds cool as they rise in elevation and heavy snow is falling across Metro Denver, the foothills and the adjacent plains; up to 20 inches are expected in the city with higher amounts on the east slope of the Front Range. Since the primary jet stream remains up in Canada, the air will not be extremely cold (remaining in the 20s F) but the associated strong winds are producing blizzard conditions and parts of several Interstates have been closed.
As the storm pulls on to the east, this upslope effect will be lost and snow will be very limited in the Upper Midwest; here in Missouri, all precipitation is expected to arrive in the form of rain. Once again, the high riding jet stream will spare most of the U.S.; while we enjoy a mild winter, Alaska, eastern Europe and Russia, caught above the jet stream, have been dealing with heavy snow and frigid air. Indeed, our mild winter has nothing to do with global warming but, rather, reflects a stagnant weather pattern across the Northern Hemisphere.
Thursday, February 2, 2012
Natural History of Elephants
Sixty million years ago (MYA), a common ancestor gave rise to three orders: Sirenia (represented today by manatees and dugongs), Hyracoidea (represented by the hyrax) and Proboscidea, which encompasses all extinct and living species of elephants and their close relatives. Moeritherium, a pig-sized mammal that lived in North Africa about 50 MYA, is the earliest known proboscidean and the Deinotherium line diverged 10 million years later; this lineage culminated in a massive elephant-like creature that spread throughout Eurasia and Africa during the Miocene and became extinct by the onset of the Pleistocene (2 MYA).
The Paleomastadon line emerged in North Africa about 34 MYA; Gomphotheriums split from this primary lineage about 25 MYA, giving rise to the Mastadon line about 20 MYA. The main group of Gomphotheriums died out by the end of the Pliocene (2 MYA) but the mastodons lived through the Pleistocene, occupying Africa, Eurasia and North America. Primelephas, the first member of the Family Elephantidae, appeared in North Africa about 7 MYA and this lineage would eventually give rise to mammoths and our modern elephants. The African and Indian elephant lines diverged very early in the history of this family; African elephants would then split into savannah and forest species (some say subspecies since they can interbreed) about 4 MYA and, during the same period, mammoths would split from Indian elephants. While the latter split occurred in North Africa, both species would leave their home Continent; Indian elephants spread across southern Asia (giving rise to Indian, Sumatran and Sri Lankan subspecies) while mammoth species colonized Eurasia and, during the Pleistocene, North America.
Here in North America, our elephant heritage is limited to mastadons and woolly mammoths that crossed the Bering land bridge during the glacial periods of the Pleistocene (2 MYA to 10,000 years ago). Like our ancestral bison, they were pursued by human hunters who likely colonized our Continent by 20,000 years ago. This predation, combined with the warming climate of the late Pleistocene and early Holocene led to the demise of our North American elephants; the last woolly mammoths are thought to have died out in the Arctic about 8000 years ago. Though we have lost the company of these large, sociable and intelligent creatures, we still have the manatees, their very distant cousins.
The Paleomastadon line emerged in North Africa about 34 MYA; Gomphotheriums split from this primary lineage about 25 MYA, giving rise to the Mastadon line about 20 MYA. The main group of Gomphotheriums died out by the end of the Pliocene (2 MYA) but the mastodons lived through the Pleistocene, occupying Africa, Eurasia and North America. Primelephas, the first member of the Family Elephantidae, appeared in North Africa about 7 MYA and this lineage would eventually give rise to mammoths and our modern elephants. The African and Indian elephant lines diverged very early in the history of this family; African elephants would then split into savannah and forest species (some say subspecies since they can interbreed) about 4 MYA and, during the same period, mammoths would split from Indian elephants. While the latter split occurred in North Africa, both species would leave their home Continent; Indian elephants spread across southern Asia (giving rise to Indian, Sumatran and Sri Lankan subspecies) while mammoth species colonized Eurasia and, during the Pleistocene, North America.
Here in North America, our elephant heritage is limited to mastadons and woolly mammoths that crossed the Bering land bridge during the glacial periods of the Pleistocene (2 MYA to 10,000 years ago). Like our ancestral bison, they were pursued by human hunters who likely colonized our Continent by 20,000 years ago. This predation, combined with the warming climate of the late Pleistocene and early Holocene led to the demise of our North American elephants; the last woolly mammoths are thought to have died out in the Arctic about 8000 years ago. Though we have lost the company of these large, sociable and intelligent creatures, we still have the manatees, their very distant cousins.
Wednesday, February 1, 2012
Nature & Government
While I am a social liberal, I am a fiscal conservative and I actually agree with many Republicans that our government is bloated and inefficient. I support simplification of the tax code, elimination of earmarks and enforcement of term limits. Unlike many conservatives, I also favor an end to corporate welfare and strongly support efforts to cut our outrageous defense budget.
On the other hand, history is replete with evidence that the federal government plays a crucial role in the protection of both civil rights and the health of our natural environment. Big business, driven by greed and focused on profits, has not demonstrated the capacity to protect either the consumer or the environment without oversight by federal agencies. From a naturalists point of view, governmental regulations have been vital to the welfare of natural ecosystems throughout this country and across the globe.
Too often, Americans jump on the bandwagon of anti-government rhetoric without giving proper consideration to the consequences. It is not until they are personally affected by mining disasters, oil spills, polluted water or tainted food that they recognize the need for federal mandates. If we let the corporate world run our environmental policy, we place the health of our citizens and that of our vital natural ecosystems at significant risk.
On the other hand, history is replete with evidence that the federal government plays a crucial role in the protection of both civil rights and the health of our natural environment. Big business, driven by greed and focused on profits, has not demonstrated the capacity to protect either the consumer or the environment without oversight by federal agencies. From a naturalists point of view, governmental regulations have been vital to the welfare of natural ecosystems throughout this country and across the globe.
Too often, Americans jump on the bandwagon of anti-government rhetoric without giving proper consideration to the consequences. It is not until they are personally affected by mining disasters, oil spills, polluted water or tainted food that they recognize the need for federal mandates. If we let the corporate world run our environmental policy, we place the health of our citizens and that of our vital natural ecosystems at significant risk.
Tuesday, January 31, 2012
Winter Thaw at Eagle Bluffs
Entering Eagle Bluffs Conservation Area this morning, the windows down on my pickup, it looked like January but felt like April. The brown vegetation and barren trees evoked an image of winter but the mild air, scented with the fragrance of moist soil, spoke of early spring. A rosy dawn backlit the hills to the east, augmenting the feel of an April morning.
Mallards were abundant on the ponds and wet fields, joined by sizable flocks of coot, gadwall, pied-billed grebes and Canada geese; small flocks of shovelers, lesser scaup and ring-necked ducks also graced the scene. As is typical for mid winter, ring-billed gulls swirled above the wetlands, northern harriers strafed the crop fields, red-tailed hawks patrolled the grasslands and an immature bald eagle circled overhead, spooking the ducks. Great blue herons stalked the shallows, sharp-shinned hawks darted through the woodlands and, surprisingly, a quartet of American white pelicans gathered along a marshy shoreline, satisfied to stay up north for this mild winter season.
Parking in a remote lot, I got out to enjoy the spring-like conditions; since the waterfowl hunters have departed and the spring birding crowd has not yet arrived, I was treated to the peaceful solitude of the winter season, minus the blowing snow and frigid air. Though a freight train rumbled west of the Missouri, all other sounds were natural, including the raucous call of crows, the muted chatter of waterfowl, the rustling of sparrows in the dry grass and the drumming of woodpeckers in the riverside forest. A special treat was the distant howl of a coyote, yet another sign that the season of renewal will soon invade the floodplain; I could almost see the purple haze of henbit on the barren fields.
Mallards were abundant on the ponds and wet fields, joined by sizable flocks of coot, gadwall, pied-billed grebes and Canada geese; small flocks of shovelers, lesser scaup and ring-necked ducks also graced the scene. As is typical for mid winter, ring-billed gulls swirled above the wetlands, northern harriers strafed the crop fields, red-tailed hawks patrolled the grasslands and an immature bald eagle circled overhead, spooking the ducks. Great blue herons stalked the shallows, sharp-shinned hawks darted through the woodlands and, surprisingly, a quartet of American white pelicans gathered along a marshy shoreline, satisfied to stay up north for this mild winter season.
Parking in a remote lot, I got out to enjoy the spring-like conditions; since the waterfowl hunters have departed and the spring birding crowd has not yet arrived, I was treated to the peaceful solitude of the winter season, minus the blowing snow and frigid air. Though a freight train rumbled west of the Missouri, all other sounds were natural, including the raucous call of crows, the muted chatter of waterfowl, the rustling of sparrows in the dry grass and the drumming of woodpeckers in the riverside forest. A special treat was the distant howl of a coyote, yet another sign that the season of renewal will soon invade the floodplain; I could almost see the purple haze of henbit on the barren fields.
Monday, January 30, 2012
Dividing Humanity
We have long become familiar with Christian colleges, Christian bookstores and, more recently, Christian dating services. Now, as advertised on TV last evening, there is a Christian insurance company that, according to their ad, only welcomes nonsmoking Christians. One wonders if they are willing to insure morbidly obese Christians; how about Christians who abuse alcohol or use injectable street drugs? Why not take a chance with Jewish tri-atheletes or Muslim vegetarians?
While they publicly espouse tolerance, religious organizations, zealously self-righteous, are among the most divisive forces in human society. If businesses can restrict access to members of one religion, why not discriminate based on race, ethnicity, sexual orientation, gender or socioeconomic status?
Perhaps this company is just testing the waters, trying to determine how sensitive America might be to such policies. Perhaps they are blind to the sectarian strife that pervades many other nations across this globe. Or perhaps they are just simple-minded zealots who place their narrow-minded views above any concern for the welfare of human society. Regardless of their motivation, their message of intolerance must be challenged if our country is to uphold the freedoms that we so vigorously defend.
While they publicly espouse tolerance, religious organizations, zealously self-righteous, are among the most divisive forces in human society. If businesses can restrict access to members of one religion, why not discriminate based on race, ethnicity, sexual orientation, gender or socioeconomic status?
Perhaps this company is just testing the waters, trying to determine how sensitive America might be to such policies. Perhaps they are blind to the sectarian strife that pervades many other nations across this globe. Or perhaps they are just simple-minded zealots who place their narrow-minded views above any concern for the welfare of human society. Regardless of their motivation, their message of intolerance must be challenged if our country is to uphold the freedoms that we so vigorously defend.
Sunday, January 29, 2012
White-throat Serenade
Every winter evening, as the sun begins to set behind a woodland to our west, a flock of white-throated sparrows returns to our backyard feeder. Filtering in as pairs or small groups, they scour the ground for fallen seed; often joined by northern cardinals, they are polite birds, not inclined to squabble over the handouts.
After a period of silence through early winter, they have begun to sing during the past week, a response to the lengthening daylight. Their distinctive, homesick tune will increase in intensity over the next several months and, by mid April, they will depart for Canada to breed in the vast Northwoods.
Accustomed to chilly, gray conditions, white-throats are also among the first birds to become active on winter mornings and their song is a welcome serenade on my walk to work. More importantly, it offers reassurance that winter is loosing its grip and that the mild, fragrant days of early spring are on the horizon.
After a period of silence through early winter, they have begun to sing during the past week, a response to the lengthening daylight. Their distinctive, homesick tune will increase in intensity over the next several months and, by mid April, they will depart for Canada to breed in the vast Northwoods.
Accustomed to chilly, gray conditions, white-throats are also among the first birds to become active on winter mornings and their song is a welcome serenade on my walk to work. More importantly, it offers reassurance that winter is loosing its grip and that the mild, fragrant days of early spring are on the horizon.
Saturday, January 28, 2012
The Purpose of Life
Throughout human history, man has pondered the purpose and meaning of life. Endowed with a large brain, we have convinced ourselves that the ecosystems of planet Earth were created for our benefit and human cultures have imagined a wide range of gods that facilitate and govern that process. The fact that life evolved almost 3.6 billion years before our own species appeared is ignored or rejected by most religious persons; after all, they believe that this earth-bound life is preparation for a more significant, eternal existence.
If we strip away the cloud of human mysticism, we find that life has the single purpose of sustaining itself and has "learned" that diversification is the best means to accomplish that goal. In the words of that thoughtful scientist in the film Jurassic Park, "life will find a way."
Unfortunately, the mysticism of human society often impedes the purpose of life, as religious and sectarian wars decimate populations and as the culture of human superiority encourages the exploitation of our natural resources. If we truly support the purpose of life, we humans need to end our futile conflicts, devote ourselves to protecting the natural diversity of this planet and ensure that our own unbridled population growth does not threaten the sustainability of Earth's ecosystems.
If we strip away the cloud of human mysticism, we find that life has the single purpose of sustaining itself and has "learned" that diversification is the best means to accomplish that goal. In the words of that thoughtful scientist in the film Jurassic Park, "life will find a way."
Unfortunately, the mysticism of human society often impedes the purpose of life, as religious and sectarian wars decimate populations and as the culture of human superiority encourages the exploitation of our natural resources. If we truly support the purpose of life, we humans need to end our futile conflicts, devote ourselves to protecting the natural diversity of this planet and ensure that our own unbridled population growth does not threaten the sustainability of Earth's ecosystems.
Friday, January 27, 2012
American Gators
Crocodilians, now represented by crocodiles, alligators and caimans, split from other reptiles and early dinosaurs back in the Triassic Period, some 200 million years ago. Modern alligators are limited to two species: the American alligator and its smaller cousin in southern China; our gator, the largest reptile in North America, inhabits the Southeast Coastal Plain, from North Carolina to Texas.
Up to 15 feet long and weighing as much as 800 pounds, adult males bellow in mid spring to attract a mate. Once impregnated, the female builds a nest mound of rotting vegetation and deposits 20-50 eggs before covering them with more vegetation. Staying close by until they hatch (usually in August), the mother protects her young, digging them out and carrying them to open water in her mouth; she will continue to watch over her offspring for their first year of life. Those eggs that incubate at temperatures above 90 degrees F produce males while those below 86 degrees produce females; nest temperatures in between these parameters yield a mix of genders.
Young alligators may fall victim to a variety of predators, including snakes, large fish, snapping turtles, raccoons, bobcats, bald eagles and other alligators; once fully grown, however, American gators are threatened only by human hunters and habitat loss and may live 50 years or more in the wild. Nearly driven to extinction by overhunting and swamp drainage during the first half of the 20th Century, these large reptiles are now common in freshwater marshlands (and some brackish areas) of the Coastal Plain; they are especially numerous in Florida and Louisiana. Adults feed on a wide variety of fish, reptiles, birds and mammals and can pose a threat to humans if harassed or startled; they have been known to grab pets or even young children on rare occasions. American gators are also raised in captivity for their meat and leathery hide and, unfortunately, are victims of the tourist carnival industry across the Deep South.
Up to 15 feet long and weighing as much as 800 pounds, adult males bellow in mid spring to attract a mate. Once impregnated, the female builds a nest mound of rotting vegetation and deposits 20-50 eggs before covering them with more vegetation. Staying close by until they hatch (usually in August), the mother protects her young, digging them out and carrying them to open water in her mouth; she will continue to watch over her offspring for their first year of life. Those eggs that incubate at temperatures above 90 degrees F produce males while those below 86 degrees produce females; nest temperatures in between these parameters yield a mix of genders.
Young alligators may fall victim to a variety of predators, including snakes, large fish, snapping turtles, raccoons, bobcats, bald eagles and other alligators; once fully grown, however, American gators are threatened only by human hunters and habitat loss and may live 50 years or more in the wild. Nearly driven to extinction by overhunting and swamp drainage during the first half of the 20th Century, these large reptiles are now common in freshwater marshlands (and some brackish areas) of the Coastal Plain; they are especially numerous in Florida and Louisiana. Adults feed on a wide variety of fish, reptiles, birds and mammals and can pose a threat to humans if harassed or startled; they have been known to grab pets or even young children on rare occasions. American gators are also raised in captivity for their meat and leathery hide and, unfortunately, are victims of the tourist carnival industry across the Deep South.
Thursday, January 26, 2012
Mixing Oil & Wetlands
Since I drive a car and heat my home, it would be hypocritical of me to renounce oil production in the U.S. or elsewhere across the globe. Nevertheless, the oil industry has a tendency to minimize its potential impact on wetlands, the most productive ecosystems on our planet.
Sabine National Wildlife Refuge, in extreme southwest Louisiana, is the largest wetland preserve along the Gulf Coast, renowned for its large flocks of wintering waterfowl, its wide variety of wading birds and its resident population of American alligators and wetland mammals. Yet, oil production continues on this preserve despite a significant spill during the winter of 2002-2003 and the devastation of Hurricane Rita, in September, 2005, which spread more than 1400 barrels of toxic chemicals across the refuge. More recently, shortcuts in the startup of BP's Deepwater Horizon inundated coastal marshlands with crude oil, the worst man-made disaster in the history of the Gulf of Mexico. Now, despite concerns for potential damage to wetlands and groundwater across the unique sandhills ecosystem of western Nebraska, conservative politicians and their oil company supporters are attempting to push through the Keystone Pipeline Project before appropriate environmental studies are complete. And, of course, conservationists have been battling proposals to drill in the Arctic National Wildlife Refuge for decades.
While we cannot replace fossil fuels with "green" sources of energy overnight, it is equally short-sighted for the oil industry to minimize its impact on fragile and vital ecosystems across our planet. Oil and wetlands will not mix and we destroy those crucibles of life at our own peril.
Sabine National Wildlife Refuge, in extreme southwest Louisiana, is the largest wetland preserve along the Gulf Coast, renowned for its large flocks of wintering waterfowl, its wide variety of wading birds and its resident population of American alligators and wetland mammals. Yet, oil production continues on this preserve despite a significant spill during the winter of 2002-2003 and the devastation of Hurricane Rita, in September, 2005, which spread more than 1400 barrels of toxic chemicals across the refuge. More recently, shortcuts in the startup of BP's Deepwater Horizon inundated coastal marshlands with crude oil, the worst man-made disaster in the history of the Gulf of Mexico. Now, despite concerns for potential damage to wetlands and groundwater across the unique sandhills ecosystem of western Nebraska, conservative politicians and their oil company supporters are attempting to push through the Keystone Pipeline Project before appropriate environmental studies are complete. And, of course, conservationists have been battling proposals to drill in the Arctic National Wildlife Refuge for decades.
While we cannot replace fossil fuels with "green" sources of energy overnight, it is equally short-sighted for the oil industry to minimize its impact on fragile and vital ecosystems across our planet. Oil and wetlands will not mix and we destroy those crucibles of life at our own peril.
Wednesday, January 25, 2012
Harney Basin
Harney Basin is a geologic and topographic basin in southeast Oregon; while it sits adjacent to the northwest corner of the Great Basin, it is separated from that province by the massive fault-block of the Steens Mountain ridge. On its north side, the Harney Basin is bordered by the southern edge of the Blue Mountains while a high lava plain separates the basin from the watersheds of the John Day and Klamath Rivers to the northwest and southwest, respectively.
During warm interglacial periods of the Pleistocene, glacial meltwater from the adjacent highlands filled the Harney Basin, spilling northeastward into the Malheur River, a tributary of the Snake River. Today, as the climate has warmed through the Holocene, the floor of Harney Basin has become a high desert, receiving only 6 inches of precipitation each year; a low divide along the basin's northeast edge, formerly a spillway, now completes the basin topography and all streams flow inward toward Harney and Malheur Lakes, on the basin's floor. Burns, Oregon, is the only sizable town in this remote, high desert basin.
While most of the basin floor is high and dry, with elevations between 4000 and 5200 feet, Malheur Lake, fed by the Silvies River from the Blue Mountains and the Blitzen River from Steens Mountain, provides a rich and welcome oasis for migrant waterfowl, shorebirds, white pelicans and sandhill cranes. Home to many other species as well, the lake and its wetlands are protected as the Malheur National Wildlife Refuge; during seasons with heavy precipitation or snowmelt, Malheur Lake spills west toward Harney Lake, an ephemeral, salt pan lake that is the topographic sink of Harney Basin.
During warm interglacial periods of the Pleistocene, glacial meltwater from the adjacent highlands filled the Harney Basin, spilling northeastward into the Malheur River, a tributary of the Snake River. Today, as the climate has warmed through the Holocene, the floor of Harney Basin has become a high desert, receiving only 6 inches of precipitation each year; a low divide along the basin's northeast edge, formerly a spillway, now completes the basin topography and all streams flow inward toward Harney and Malheur Lakes, on the basin's floor. Burns, Oregon, is the only sizable town in this remote, high desert basin.
While most of the basin floor is high and dry, with elevations between 4000 and 5200 feet, Malheur Lake, fed by the Silvies River from the Blue Mountains and the Blitzen River from Steens Mountain, provides a rich and welcome oasis for migrant waterfowl, shorebirds, white pelicans and sandhill cranes. Home to many other species as well, the lake and its wetlands are protected as the Malheur National Wildlife Refuge; during seasons with heavy precipitation or snowmelt, Malheur Lake spills west toward Harney Lake, an ephemeral, salt pan lake that is the topographic sink of Harney Basin.
Tuesday, January 24, 2012
Mt. Shasta
Towering above the landscape of Northern California, at the southern end of the Cascade Range, Mt. Shasta is a composite of four volcanic cones, the first of which began to form just 600,000 years ago; with a summit elevation of 14,179 feet, it is second only to Mt. Ranier among the Cascade volcanoes.
The current summit crater of Mt. Shasta, 600 feet across, tops the Hotlum Cone, which formed about 8000 years ago and has been erupting every 600-800 years; the last significant eruption was 200 years ago. Mt. Shastina, topping out at 12,330 feet, is an older cone that now appears as a prominant satellite peak to the west of Shasta's primary summit; the Whitney Glacier, one of five glaciers that grace Mt. Shasta, lies between the two peaks. Tributaries arising from Shasta's ice sheets feed the Klamath River to the north (primarily via the Shasta River) and the Sacramento River, to the south.
Since Mt. Shasta rises almost 10,000 feet above its immediate surroundings, this magnificent massif can be seen from up to 150 miles away. Though classified as a dormant volcano, Shasta is not extinct, as indicated by active fumeroles along its flanks. Another explosive eruption is expected within a few hundred years....if not next month!
The current summit crater of Mt. Shasta, 600 feet across, tops the Hotlum Cone, which formed about 8000 years ago and has been erupting every 600-800 years; the last significant eruption was 200 years ago. Mt. Shastina, topping out at 12,330 feet, is an older cone that now appears as a prominant satellite peak to the west of Shasta's primary summit; the Whitney Glacier, one of five glaciers that grace Mt. Shasta, lies between the two peaks. Tributaries arising from Shasta's ice sheets feed the Klamath River to the north (primarily via the Shasta River) and the Sacramento River, to the south.
Since Mt. Shasta rises almost 10,000 feet above its immediate surroundings, this magnificent massif can be seen from up to 150 miles away. Though classified as a dormant volcano, Shasta is not extinct, as indicated by active fumeroles along its flanks. Another explosive eruption is expected within a few hundred years....if not next month!
Sunday, January 22, 2012
Return to Winter
Ah, the wonders of modern travel. Strolling on a sun-drenched beach one day and trudging through an icy fog the next. No roseate spoonbills to brighten our morning, just the bulky form of a red-tailed hawk, hunched on a roadside limb. No noisy chatter from those carefree gulls and terns, just the raucous, indignant calls of our jays and crows.
Many humans, true to our tropical heritage, would love to spend their lives in the balmy climate of South Florida. But some of us, including most naturalists, I suspect, favor life in the Temperate Zone, with its broad seasonal fluctuation; variety, as they say, is the spice of life and those of us at middle latitudes surely experience a great deal of variety (annual if not weekly). While nature has her cycle in the Subtropics as well, her patterns are more dramatic in northern climes; besides, those of us who endure the hardships of winter are more likely to appreciate the steady, if not even, advance of spring.
So, while our splendid respite was all too short, I welcome our return to winter, with its raw, somber days and clear, frigid nights. What we really need is a good snowstorm, an event often envied by those from the land of perpetual summer.
Many humans, true to our tropical heritage, would love to spend their lives in the balmy climate of South Florida. But some of us, including most naturalists, I suspect, favor life in the Temperate Zone, with its broad seasonal fluctuation; variety, as they say, is the spice of life and those of us at middle latitudes surely experience a great deal of variety (annual if not weekly). While nature has her cycle in the Subtropics as well, her patterns are more dramatic in northern climes; besides, those of us who endure the hardships of winter are more likely to appreciate the steady, if not even, advance of spring.
So, while our splendid respite was all too short, I welcome our return to winter, with its raw, somber days and clear, frigid nights. What we really need is a good snowstorm, an event often envied by those from the land of perpetual summer.
Saturday, January 21, 2012
Along the Myakka
The Myakka River, in southwest Florida, one of only two rivers designated "Wild & Scenic" by the Sunshine State, rises in northern Manatee County and flows southward for 60 miles to Charlotte Harbor. Along the way, it passes through the lakes and marshlands of Myakka River State Park, east of Sarasota, and encounters little human development for much of its course; indeed, Sarasota County has been especially committed to protecting its natural channel and three preserves offer access to southern portions of this ecosystem.
Having enjoyed a week along the Gulf Coast, we decided to head inland and explore the lower Myakka corridor. Jelks Preserve, about two miles south of I-75 on North River Road (via the North Port/Englewood Exit), provides an excellent overview of natural habitats along the river as well as scenic views of the Myakka itself; oak hammocks, festooned with Spanish moss, border slash pine flatwoods, marsh-lined ponds and scrub meadows. Armadillos were abundant along the sandy trails, black vultures and bald eagles soared overhead and American alligators, though unseen on our visit, haunt the shallow pools and wetlands. Myakka River State Forest, about 5 miles south of U.S. 41 via River Road, offers an extensive network of trail loops through these same habitats; it was there that we encountered a massive flock of wintering tree swallows, surely numbering in the thousands, and watched a trio of Florida sandhill cranes drift across the bright blue sky. Finally, Myakka Islands Point, a Sarasota County preserve west of North Port, provides access to pine flatwoods (dominated by slash pine, cabbage palm and saw palmetto) which overlook broad swaths of riverside marsh.
South of these preserves the Myakka becomes increasing brackish as it receives tidal inflow; in concert, the river leaves its meandering, tree-lined corridor and open marshlands stretch across its broad floodplain. Alligators that bask along the River's more northern shores avoid these salty waters but manatees, moving in from the bay, now inhabit the Myakka. As expected, wading birds are abundant across this vibrant tidal zone, roosting in tree islands that rise above the marsh.
Having enjoyed a week along the Gulf Coast, we decided to head inland and explore the lower Myakka corridor. Jelks Preserve, about two miles south of I-75 on North River Road (via the North Port/Englewood Exit), provides an excellent overview of natural habitats along the river as well as scenic views of the Myakka itself; oak hammocks, festooned with Spanish moss, border slash pine flatwoods, marsh-lined ponds and scrub meadows. Armadillos were abundant along the sandy trails, black vultures and bald eagles soared overhead and American alligators, though unseen on our visit, haunt the shallow pools and wetlands. Myakka River State Forest, about 5 miles south of U.S. 41 via River Road, offers an extensive network of trail loops through these same habitats; it was there that we encountered a massive flock of wintering tree swallows, surely numbering in the thousands, and watched a trio of Florida sandhill cranes drift across the bright blue sky. Finally, Myakka Islands Point, a Sarasota County preserve west of North Port, provides access to pine flatwoods (dominated by slash pine, cabbage palm and saw palmetto) which overlook broad swaths of riverside marsh.
South of these preserves the Myakka becomes increasing brackish as it receives tidal inflow; in concert, the river leaves its meandering, tree-lined corridor and open marshlands stretch across its broad floodplain. Alligators that bask along the River's more northern shores avoid these salty waters but manatees, moving in from the bay, now inhabit the Myakka. As expected, wading birds are abundant across this vibrant tidal zone, roosting in tree islands that rise above the marsh.
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