Monday, December 31, 2012

Glorious End to a Tragic Year

A steady, wet snow has been falling in Columbia since early this morning and is expected to continue through most of the day.  Perfect for building a snowman, the white blanket now surrounds a dapper fellow in our front yard, constructed with the "assistance" of our grandson.

The beautiful winter scenery offers a tranquil end to an otherwise tumultuous year.  Thanks to our dysfunctional Congress, international strife, widespread social injustice (at home and abroad), an unwillingness to adequately address issues such as mental illness, gun control and global warming and an exceptional run of natural disasters, 2012 delivered more than its fair share of tragedy.

Of course, most of the problems that we face would dissolve in an atmosphere of respect, compromise and communication, traits that should define humanity.  Rather, greed, intolerance and mysticism stand in the way and the cycle of suffering continues.  Here's hoping that 2013 will bring a more enlightened approach to the welfare of human society and to the health of our natural environment.  Happy New Year to all!

Sunday, December 30, 2012

Hypertension: the Silent Killer

Hypertension, the medical term for high blood pressure, can lead to a wide range of health problems.  Unfortunately, this common condition is often asymptomatic and, unless diagnosed by routine screening, may cause end-organ damage before proper treatment is initiated.

Most individuals with high blood pressure have primary, essential hypertension, a familial condition that can be mild to severe.  If untreated, it may lead to cardiovascular disease (including coronary artery disease, myocardial infarction, congestive heart failure, stroke or peripheral vascular disease), kidney damage and visual impairment.  Secondary hypertension is blood pressure elevation resulting from another clinical condition such as kidney disease, hyperthyroidism, certain tumors, steroid excess (endogenous or exogenous), obstructive sleep apnea or drug abuse (especially the use of stimulants such as cocaine).

Fortunately, most forms of hypertension are easily treated once recognized.  Short of medication use, mild to moderate hypertension may resolve with weight loss, salt restriction, regular aerobic exercise, caffeine reduction, stress management and smoking cessation.  Of course, secondary hypertension will not resolve until the underlying condition is properly treated.  In the end, the most important step in the management of hypertension is its initial diagnosis; unless discovered early, this silent killer may produce irreversible (if not fatal) complications.

Saturday, December 29, 2012

Snowy Owls

Among the most easily identified birds on our planet, snowy owls breed on the Arctic tundra of Alaska, Canada and Eurasia.  Their dense plumage makes them the heaviest owls in North America and their wingspan may reach 5 feet.  Adult males are almost pure white with scattered, small black markings while females have black edging on their feathers; juveniles have more extensive black barring.  Snowy owls have black beaks, yellow eyes and small ear tufts that lie flat against their rounded head.

These Arctic owls feed primarily on lemmings and their population tends to fluctuate with the availability of that prey; on their breeding territory, they also hunt other small rodents and ptarmigan.  Nests are shallow depressions on the ground (usually on a low rise for visibility and dryness) and both parents cooperate in raising the young; depending upon food abundance, 3 to 12 eggs are produced.  While adults are apex predators and rarely threatened, young snowy owls are potential prey for gray wolves, arctic fox, golden eagles, skuas and gyrfalcons.

As the perpetual sunshine of the Arctic summer begins to wane, snowy owls head for wintering areas as far south as the Northern Plains and New England.  Like short-eared owls, they favor open areas, including prairie, ranchlands, broad floodplains, airports and coastal dunes and are active during the day.  Hunting from a low hill or fencepost, they may sit for hours at a time, springing into flight when prey is spotted.  Winter prey is highly variable and these owls are opportunists, taking small mammals, waterfowl, pheasant, quail, gulls and songbirds.  Veteran birders know that snowy owls are an irruptive species and look forward to their seasonal incursions; their winter population in the lower 48 varies widely from year to year and, during large irruptions, individuals have been found as far south as the Gulf Coastal Plain.

Friday, December 28, 2012

The Woodland Mouse

White-footed mice are common residents of woodlands from southeastern Canada to Mexico and throughout the eastern 2/3 of the U.S. (with the exception of Florida).  They inhabit forests, open woodlands and, on the Great Plains, riparian corridors.  Omnivorous, these mice feed on a wide variety of nuts, seeds, fruits, fungi and insects; they are agile climbers and often forage in shrubs and trees.

White-footed mice mate throughout the year and females may produce five or more litters, each with up to five young.  Nests are generally placed in hollow logs, wood piles, abandoned burrows or beneath outbuildings; old bird or squirrel nests and abandoned tree cavities may also be used.  The young are independent by one month of age and female offspring are capable of breeding within five months of birth.  Predators, including hawks, owls, fox, weasels, coyotes, skunks and snakes, serve to keep the population of these prolific rodents in check and the natural lifespan of a white-footed mice is generally less than two years.

While this mouse is a vital component of woodland ecosystems, it is known to be a vector for hantavirus and Lyme disease and close contact with the animals, their nest or their droppings should be avoided; as with all wildlife, it is best to view them from a safe and nonthreatening distance.  Since white-footed mice are primarily nocturnal, observation efforts are most productive at dawn or dusk.

Thursday, December 27, 2012

Calendar of Life

As we approach the end of the human calendar year, it seems appropriate to revisit the calendar of life.  Current scientific evidence indicates that life first evolved on Earth about 3.6 billion years ago, 10 billion years after the Big Bang and 1 billion years after the Earth, itself, formed.  If we were to condense this history of life into one human calendar year, each day would represent 10 million years, each hour would equal 417,000 years, each minute would amount to 7000 years and each second would cover 117 years.

Using this calendar of life, the first bacteria (chemoautotrophic and cyanobacteria) appear in Earth's primordial oceans at 12 AM on January 1.  By the beginning of June, eukaryotic cells (possessing intracellular nuclei and organelles) appear and, by October 15, shelled marine life and multicellular soft-bodied marine organisms (the Ediacaran fauna) inhabit the ancient seas.  Near mid November, life crawls from the sea and, throughout the last 10 days of November, sharks, boney fish, ferns, primitive amphibians, web-spinning spiders and flying insects evolve.  The first week of December brings horseshoe crabs, frogs, primitive reptiles and conifers to our planet.

Dinosaurs reign from December 8 until noon on December 25.  Crocodilians, turtles ancestral monotremes, shrew-like mammals, archaeopteryx and flowering plants all appear by mid December, followed by snakes, ants, social bees, marsupials and broadleaf trees during the third week of the month.  December 26-27 brings ancestral primates, ancestral elephants, cone snails, bats, canids, felines, rodents, early cetaceans (whales, dolphins) and ancestral horses, camels, mustelids, tapirs and sirenians (manatees and dugongs).  From December 28 into December 29, grass, ancestral pigs, mastadons and North American megafauna appear and, on December 30, giraffes, okapis, hippos, true elephants and pronghorn evolve as pinnipeds diverge from the bear line.  Cattle, bison, goats and sheep all turn up on December 31. At about 3AM on that last day, gorillas split from the hominid line and chimps do the same by 8 AM; Australopithecus appears just after noon.  Homo habilis evolves around 6 PM and Homo erectus follows by 8 PM.  During the last hour of the last day, Denisovans, Neanderthals, polar bears and arctic fox appear and humans finally grace the scene 18 minutes before midnight; no living human has been around for more than 1 second.

Wednesday, December 26, 2012

Natural History of Squid

Squid, like octopi, cuttlefish and nautilus species, are cephalopods, a branch of mollusks.  Ancestral squid, which had elongated, external shells, known as orthocones, arose in the Ordovician Period (about 500 million years ago-MYA) and their fossils appear in marine sedimentary rocks throughout the Paleozoic Era.  By the onset of the Mesozoic Era (225 MYA), belemnites, possessing a linear, internal shell, had evolved, sharing the seas with nautiloids.

As the Cenozoic Era dawned, 65 MYA, the belemnites diverged into the modern squid, octopi and cuttlefish lines; of the 800 species found today, the great majority are squid, ranging from less than 1 to almost 50 feet in length.  Like the Mesozoic belemnites, squid have an internal, chitinous "shell," known as a gladius, that supports the structure of the mantle.  Other anatomic features include a siphon for locomotion, a beaked mouth, eight arms and two long tentacles.  Squid have large, prominent eyes and those of giant squid species are the largest in the animal kingdom.  Like octopi and cuttlefish, squid have chromatophores on their external surface which allow the animal to change color and blend with its surroundings and an ink sac that releases a black cloud to confuse predators.

Squid are a diverse group of carnivorous invertebrates that occupy a wide variety of marine habitats, from warm, shallow seas to the deep, cold oceans; many deepwater species migrate toward the surface at night to feed on krill, shrimp and small fish.  The primarily predators of squid include whales, sharks, dolphins, large fish, sea birds and humans; indeed, their massive schools are an essential component of fisheries across the globe.

Tuesday, December 25, 2012

Christmas Storms

The latest winter storm system has dropped across the Southwest and, as of this morning, its central low is spinning just north of Lubbock, Texas.  Sweeping moisture in a counterclockwise direction, it is producing upslope snow across the High Plains and along the Front Range.

To its east, the potent storm is dragging copious moisture up from the Gulf of Mexico, igniting strong thunderstorms and unleashing torrential rains from eastern Texas to western Alabama.  Of special concern is the risk for tornadoes; this has developed due to the position of the low level jet stream which curves west and south of the low and then tracks across the Southeastern States.  Clashing with the southerly winds of the storm's circulation, this westerly jet is injecting energy and producing spin in the atmosphere, thus augmenting the risk of tornadic thunderstorms.

The greatest risk of tornadoes is across Louisiana and Mississippi this morning but will shift into Alabama, north Florida and Georgia later in the day.  North of these storms, a swath of ice and freezing rain is expected to impact the Ohio Valley in the coming days and the storm system will eventually bring snow to the mountains of New England.

Monday, December 24, 2012

Copahue Volcano Eruption

The Copahue Volcano, in the Andes on the border of Argentina and Chile, is erupting once again, sending a cloud of ash one mile into the atmosphere.  Chile has raised its volcano alert level to red, the highest category, but has not initiated mandatory evacuations.  Looking at photos on the internet, one wonders why they are not concerned enough to do so; beyond the volcanic ash fallout and the potential for pyroclastic flows, the mountains are covered with snow and, at the very least, flash flooding and mud flows (lahars) would seem to be significant threats.

Like all volcanoes of the Andes Range, Copahue is the product of tectonic plate subduction.  Along the west coast of South America, the Nazca Plate is being forced to dip beneath the South American Plate; this is partly due to the westward motion of the American Plates (as the Atlantic Ocean continues to open) and the eastward motion of the oceanic Nazca Plate (due to sea floor spreading along the East Pacific Rise).  As the Nazca plate dips toward the Earth's mantle, its leading edge melts, producing a chain of volcanoes above and along this melting zone.  Indeed, the entire Andes Range formed and continues to form from this subduction process.

Copahue, rising to an elevation of 9833 feet, is a stratovolcano that formed during the latter half of the Pleistocene, likely within the last 500,000 years.  This "modern" volcano, which has multiple craters, formed within the remnant caldera of a larger volcano that erupted earlier in Andean geologic history.  Though Copahue has a long history of mild to moderate eruptions (most recently in 2000), the region is a popular tourist destination due to the numerous geothermal springs that rise along its flanks.  Hopefully, the current conservative evacuation policy is devoid of economic considerations.

Sunday, December 23, 2012

The Evolution of Corals

Corals are a diverse group of marine invertebrates that first appeared in the Cambrian Period, some 550 million years ago (MYA).  Fossils of these primitive tabulate corals are found in sedimentary rocks throughout the Paleozoic Era; a second group of ancient corals, the rugose corals, arose in the Silurian (400 MYA) and both groups apparently died out during the Permian Extinction, 225 MYA.

Early Triassic rocks are devoid of coral fossils but they reappear during the mid-late Triassic, some 210 MYA.  These scleractinian corals are the ancestors of all modern corals, having undergone cycles of expansion and near extinction as well as major periods of diversification, especially during the Jurassic (150 MYA) and the Miocene (25 MYA) Periods.  It was during the latter Period that the Great Barrier Reef began to form off the northeast coast of Australia, now composed of almost 3000 reefs that harbor at least 500 species of coral.

Marine biologists have cataloged about 70,000 species of coral across the globe.  While the great majority of corals are found in shallow, clear, warm waters of tropical and subtropical seas, there are coral species that occupy deep water and cold water habitats as well.  Unfortunately, these diverse communities are significantly threatened by human activity, primarily due to pollution and the effects of global warming.  At least 10% of modern coral reefs are dead and an increasing concentration of carbon dioxide in our oceans, which acidifies the seawater, impairs the formation of calcium carbonate shells, thus threatening corals and other shell-forming marine life.

Saturday, December 22, 2012

The Northern Goshawk

The northern goshawk is the largest accipiter in North America and the most widespread accipiter on our planet, breeding in coniferous or mixed forests across northern latitudes of North America and Eurasia; various races occur across that range.  In North America, this powerful hawk is found from Alaska to Newfoundland and southward along the Cascade, Sierra Nevada and Rocky Mountain corridors; they also inhabit the Appalachian Chain as far south as West Virginia.

Favoring mature forest, goshawks typically hunt from a perch and chase down prey with a rapid, zig-zagging flight; they feed on birds and mammals, including grouse, ptarmigan, jays, woodpeckers, snowshoe hares and tree squirrels.  A bulky nest of sticks, lined with tender vegetation, is placed in a tree and vigorously defended; indeed, hikers are often assaulted by the attentive parents.  An average of 2-4 eggs are produced each year and both parents take part in feeding the young; the latter are independent by 10 weeks of age.

Northern goshawks are an irruptive species and may turn up across the Great Plains and Midwest during the winter months if prey levels fall in their native forests.  In open country, they often hunt pheasant, prairie chickens and rabbits in addition to large songbirds.  As with other irruptive species, their numbers in the Heartland vary widely from year to year.  On the other hand, despite habitat loss from logging operations, their overall population appears to be stable.

Friday, December 21, 2012

Feeding Birds

On this clear, cold morning following our first significant snowfall of the winter, I am paying close attention to our backyard sunflower feeder.  After all, the snow cover and overnight chill should send plenty of our local residents to the feeder and, perhaps, less common visitors as well.  So far, the feeding groups have included the usual mix of characters: chickadees, titmice, cardinals, white-breasted nuthatches, house finches, downy woodpeckers, juncos and white-throated sparrows; but I'll keep checking throughout the day.

Non-birders usually hang a feeder because they feel sorry for their avian neighbors, trying to survive in the cold and snow; to them, the little brown, red or gray birds are all the same.  Novice birders, on the other hand, begin to appreciate the wide variety of species that inhabit our residential areas and realize that feeders offer an effective way to attract them and to observe them at close range.  Veterans birders, of course, know that the birds would do just fine without our charity but we both enjoy their visits and hold out hope that rare winter species will be attracted by their activity.

As a longtime birder and bird feeding suburbanite, I still have mixed feelings about the use of artificial feeders and favor the use of native plant landscaping to attract wildlife.  After all, we admonish the general public not to feed the raccoons or deer or bears.  While birds do not pose the potential nuisance or danger that mammals might bring, are we not disrupting nature's cycle by this activity?  We know that feeders attract songbird predators (cats, accipiters) as well, concentrating their prey and distracting the hapless songbirds with our convenient handouts; are we not tipping the balance in the hunter's favor?  Perhaps this is all philosophical hogwash.  For now, I'll keep filling the feeder and watching for exotic visitors.  And I'll keep wondering whether I can abide my unnatural behavior.

Thursday, December 20, 2012

Tornadoes & Blizzards

As of 6 AM, the latest winter storm was centered over northwest Missouri.  Ahead of its cold front, it was 50 degrees F here in Columbia, with gusty southwest winds.  Behind the front, a blizzard was underway, stretching from Kansas City to southern Wisconsin.

Meanwhile, the counterclockwise winds of this potent winter storm were dragging Gulf moisture into the Southeast, igniting tornadic thunderstorms in southern Mississippi and Alabama.  A wedge of dry air, injected by the jet stream, pushed up the Mississippi Valley, separating the warm sector, with its heavy rain, severe thunderstorms and tornadoes, from the steady snow, cold air and brutal winds across the upper Midwest.

By 8 AM, the cold front crossed Columbia, the temperature dropped into the 30s and windblown snow filled the air.  Since the ground is warm, accumulation will be limited but steadily falling temperatures will likely produce icy roads by early afternoon.  As the storm moves to the northeast, our skies will gradually clear and an overnight low of 21 degrees F is expected.  In concert, the severe thunderstorms will push into Georgia and the Carolinas and blizzard conditions will track from the Great Lakes region into New England.

Wednesday, December 19, 2012

Humans, Empathy & Guns

Social creatures, we humans tend to be empathetic.  This trait, the capacity to recognize suffering and commiserate with those in distress, is essential to the health of our families, our communities and society as a whole.  Depending upon our personal level of comfort and capability, we are prone to offer assistance or, at the very least, to avoid comments and actions that might exacerbate their physical or emotional pain.

Unfortunately, there are some members of human society that have a limited capacity to experience empathy.  These individuals, victims of mental illness, personality disorders, post-traumatic stress disorder, organic brain pathology (tumors, strokes, dementia) or the toxic effects of certain medications and illicit drugs, may demonstrate little or no concern for the welfare of others.  Serial killers and, as we witnessed in Connecticut this week, mass murderers, generally fall into one of these categories and often feel no empathy for their victims.  Indeed, how else could one engage in such horrendous behavior?

Faced with a significant number of violence-prone, empathy-deficient individuals in our communities, it is imperative that we devote more resources toward the diagnosis and treatment of their conditions and develop effective programs to monitor and restrict their activity (including psychiatric commitment when necessary).  Friends, family members and co-workers must feel free to report their concerns to social service personnel or law enforcement authorities and mental health professionals must have the funding, manpower and legal authority to intervene.  Finally, the tools of mass murder must be removed from public access, despite the paranoid, self-righteous objections of survivalists and the gun lobby.

Tuesday, December 18, 2012

Snows over Illinois

We left Cincinnati this morning and headed west under low, gray clouds.  The overcast cleared as we crossed the Wabash River, in western Indiana, and, as we approached the broad floodplain of the Kaskaskia River, in west-cental Illinois, several flocks of snow geese shimmered in the bright blue sky.

Snow geese generally pass through the American Heartland from mid November through mid December but may linger if open water and plentiful food are available.  Those that move south through the Missouri and Mississippi Valleys used to winter only in coastal marshes, from western Louisiana to eastern Texas; in recent decades, however, they have begun to utilize croplands of the lower Mississippi Valley as well, expanding their winter range, improving their winter survival and increasing the number of geese that return to Arctic breeding grounds the following spring.  As a consequence, despite loosened hunting restrictions, their population has steadily increased and wildlife biologists are concerned that the abundant geese may threaten the health of the Arctic tundra ecosystem.

In addition to the effects of winter cropland utilization, global warming may affect the population and distribution of these vocal migrants; how it will impact their Arctic breeding habitat, the welfare of their predators, the rate of gosling survival, the timing and pattern of their migration and the extent of their winter range all remain uncertain.  For now, those of us who live in the Heartland will anticipate the sound and sight of these hardy travelers as they move across the sky in late autumn and early spring.

Monday, December 17, 2012

In Familiar Terrain

Growing up in Cincinnati, I came to know its varied neighborhoods, towns, parks and suburbs but paid little attention to its topography and hydrology.  Today, more than 40 years later, I recognize that this city, famous for its "Seven Hills," is draped across two broad ridges that rise along the Ohio River and merge north of the metropolitan area.  The Mill Creek Valley separates these uplands, receiving tributaries from both ridges; the western flank of the west ridge drains into the Great Miami River while the east slope of the eastern ridge drops into the valley of the Little Miami River.

These three major streams and their numerous creeks expose the Ordovician bedrock of Greater Cincinnati; deposited in shallow seas about 500 million years ago, the layers of shale and limestone harbor fossils of early marine life, including trilobites and bryozoans, that lived 300 million years before dinosaurs roamed our planet.  These ancient sediments remain near the surface since they overlie the Cincinnati-Kankakee Arch, a ridge of deep, Precambrian basement rock that forms the eastern rim of the Illinois Basin.

Understanding the geologic and natural history of any given region increases our appreciation of the evolutionary process and how it produced our modern landscape.  We also come to recognize the impact that humans have had on that natural landscape, highlighted in Cincinnati by the industrialized and channelized Mill Creek Valley.  Some disruption of nature is, of course, unavoidable, but, when we look beneath the veneer of roads, houses and buildings, we can still see nature's handiwork; it, in turn, inspires us to protect what remains of our natural heritage.

Sunday, December 16, 2012

Ohio's Glacial Lakes

According to the Ohio Department of Natural Resources, Ohio harbors at least 50,000 ponds and lakes and, of these, only 110 are natural.  The natural lakes are almost all glacial in origin, the product of moraine-dammed streams, glacier-scoured basins or kettle lake formation (see my post of 2-9-08) and are scattered across the Glaciated Appalachian Plateau of northeastern Ohio; a minority are oxbow lakes, which formed during meltwater floods, and are primarily found along large rivers in southern Ohio.  At the end of the Pleistocene, 10,000 years ago, there were many more glacial lakes which, in response to sedimentation and the warmer and drier climate of the Holocene, have become bogs and marshlands; others were drained by human settlers to expand their agricultural fields or to ease construction of roads and rail lines.

This weekend, while visiting family, we stayed in a cottage on Sandy Lake, southeast of Kent.  Covering 90 acres, it is 17th in size on the ODNR list of Ohio's natural lakes.  Like many other natural lakes across the country, this lake has been modified by humans; canals now connect Sandy Lake with other lakes to its north and south, ensuring an adequate water supply for nearby communities.

Though modern residential neighborhoods now encroach on Sandy Lake, it is still bordered by a wooded wetland and upland forest along its southern rim and a fine trail circles the lake, providing access to those wild areas for lakeside residents.  This weekend, flocks of Canada geese, mallards and wintering ducks settled on its calm waters, a bald eagle soared overhead, great blue herons fed in the shallows and a crescent moon reflected from a surface that, while constantly renewed, dates back to the Pleistocene.

Friday, December 14, 2012

Flat Terrain, Hidden Geology

Following I-70 eastward from central Missouri to central Ohio, as we did today, one crosses relatively flat terrain, broken only by creek and river valleys.  After all, the Pleistocene glaciers scoured the bedrock of this region and left a thick layer of glacial till as they retreated into Canada.  In Missouri, from Columbia to St. Louis, their effects were limited; as a result, the terrain is a bit more hilly and outcrops of bedrock are seen in some areas.  Columbia sits on a thick bed of Mississippian limestone which is evident at roadcuts and along stream beds throughout the city and its surrounding countryside; another prominent outcrop of bedrock is seen along the deep Loutre River valley, where a seam of Ordovician sandstone crosses the highway.

Once the traveler moves east of the Mississippi River, however, such outcrops all but disappear, primarily due to a thick layer of overlying glacial till.  While Carboniferous rocks underly I-70 throughout all of Illinois and western Indiana, narrow swaths of Devonian sediments run through Indianapolis, Indiana, and Columbus, Ohio, and the Interstate runs above Silurian bedrock through eastern Indiana and western Ohio, these basement rocks cannot be seen from the highway.  Indeed to catch a glimpse of the Paleozoic sedimentary rocks that underlie most of the Glacial Plain, one must visit deep river valleys and gorges (such as Clifton Gorge, near Springfield, Ohio).

Though geology stares us in the face across the American West, New England, the Upper Great Lakes and the Appalachian Chain, it hides beneath glacial till throughout most of the Midwest.  Of course, that till (and the rich soil that it produced) once supported a vast tallgrass prairie and now nourishes the Great American Cornbelt.

Wednesday, December 12, 2012

Evolution of Marine Animals

Life, itself, evolved in Earth's primordial oceans about 3.6 billion years ago; these initial unicellular forms of life were likely chemoautotrophic bacteria, that arose near deep ocean vents, and cyanobacteria, that evolved in warm, shallow seas.  Eukaryotic cells are thought to have developed by 2 billion years ago and, by the end of the Precambrian Era, 600 million years ago (MYA), complex, soft-bodied organisms (the Ediacaran fauna) and the first shelled marine life had evolved.

Based on fossil evidence, the diversity of shelled marine organisms exploded during the Cambrian and Ordovician Periods (550-440 MYA) and jawless fish had appeared by the end of the Ordovician; the first jawed vertebrates, including spiny fish and placoderms, appeared during the Silurian (440-400 MYA), when marine arthropods first crawled from the sea.  Primitive sharks, amphibians, lungfish and boney fish arose in the oceans of the Devonian Period (400-350 MYA), having since diversified into a vast array of species; some evolved to breed in freshwater streams while others, stranded in shallow, inland seas, became freshwater species.

Reptiles evolved from terrestrial amphibians late in the Paleozoic Era (some 300-250 MYA) and turtles appeared in the Triassic (225-190 MYA); some turtles, of course, have since returned to the sea.  In like manner, snakes evolved from lizards during the Cretaceous Period (about 70 MYA) and some became marine species. Primitive cetaceans (whales and dolphins) split from terrestrial ancestors and returned to the sea during the Eocene Period (about 50 MYA), as did sirenians (dugongs and manatees), the only marine mammalian herbivores.  Finally, pinnipeds (seals, sea lions and walruses) diverged from the bear lineage during the Miocene (25 MYA) and returned to the sea by the Pliocene (5 MYA).

Tuesday, December 11, 2012

Generation Labels

Thanks to Tom Brokaw, we all "know" that those Americans who guided us through WWII are "the Greatest Generation."  While we should not underestimate the cooperate spirit of that group, one wonders why the generation that founded our country did not earn the title.  And, with all due respect to Mr. Brokaw, what about that generation of humans that had the courage to leave Africa, some 80,000 years ago?

My own generation, often referred to as the Baby Boomers and derided by older Americans for our anti-war protests, race riots and tree-hugging tendencies, has achieved a great deal, especially in the areas of social justice and environmental protection.  Are we less patriotic for having focused on the futility of militarism, the vital importance of conservation and both the dangers and injustice of discrimination and intolerance?  Should we overlook the more prevalent racism, homophobia and careless environmental pollution of the "Greatest Generation?"

In fact, it is both misleading and inaccurate to label human generations (though that practice does sell books).  Every generation has its leaders and its followers, its producers and its consumers, its members who inspire humanity and those who tarnish our image.  Hopefully, with each generation, we become more enlightened as a species, discarding failed policies, expanding personal freedom, diminishing our impact on natural ecosystems and ensuring a better life for all segments of future generations.  If we learn to focus more on the rights and capabilities of the individual and less on the artificial divisions of human society, we will all reap the benefits.

Monday, December 10, 2012

The Muskox

Every year, when the first wave of Arctic air drops into the Heartland, I am inclined to consider those mammals that are able to thrive in such brutal conditions.  Of those that survived the Pleistocene and still inhabit the Arctic, the muskox always comes to mind.  Best known for their shaggy coats and defensive behavior, muskoxen are closely related to mountain goats and mountain sheep (as is evident from the permanent horns of both genders).

Having evolved in northern Asia, the muskox, like the woolly mammoth, crossed into North America during the Pleistocene when the Bering land bridge connected the two Continents.  While they died out in Asia and Alaska, these hardy animals survived across Arctic Canada and Greenland despite harsh conditions and determined predators (including wolves, bears and humans).  During the latter half of the 20th Century, muskox herds were successfully re-established in Russia and Alaska and others were transplanted to Scandinavia; most of these herds have been domesticated for their meat, milk and qiviut, among the finest wools on our planet.

Like American elk, muskox males gather harems during their breeding season, which occurs in August and September.  Depending upon food availability (grasses, herbs, mosses, willows), females generally breed by age three and do so every 2-3 years; a single calf is born in late spring.  While muskoxen are known to live up to 20 years in the wild, most succumb to predators, injuries or starvation at a much younger age.  When threatened, muskoxen form a defensive circle with the bulls and cows facing outward and the young in the center.

Sunday, December 9, 2012

Gray Days

A stationary front has draped itself across Missouri for the past few days, bringing classic December weather.  Separating cold air to its northwest from mild, humid air to its southeast, the front has produced chilly, damp conditions with a low, gray overcast.

Many of us likely welcome the early winter weather this year, coming as it does on the heels of an extended period of unusually warm, dry conditions that have severely exacerbated our prolonged drought.  On the other hand, few will venture outdoors in this raw weather, leaving the parks and trails for true naturalists who understand the benefits that such conditions bring.  In addition to the solitude, relished by the majority of nature-lovers, these cool, gray days stimulate our resident wildlife; mimicking the twilight of dusk, the low clouds, combined with the invigorating chill, make birds and mammals more active and, thus, more conspicuous.  Conversely, wildlife watching is generally least productive on warm, sunny afternoons.

As this front is forced to the southeast by a new, more potent cold front, the skies will clear but the temperatures will drop.  We expect an overnight low near 20 degrees F and a high tomorrow afternoon near the freezing point.  Though winter has clearly taken charge, pushing summer down to the Gulf Coast, a gradual moderation is expected through the week and, in concert, the benefits of our gray days will be lost.

Saturday, December 8, 2012

Compromise & Zealotry

Compromise is, in my opinion, the vital key to sustaining relationships, whether they be marital, political or economic.  It requires a certain degree of humility and generosity in both parties and a willingness to appreciate the other's views, needs and desires.

The enemy of compromise is zealotry, religious, political or otherwise.  Zealots, self righteous and intolerant of other points of view, live in a black and white world.  Zealotry, in turn, is fed by greed and ignorance, traits all too common in human society.

As we are currently witnessing in the U.S. Congress, infused with zealots on both the left and the right, compromise is despised and progress is stymied.  On the world stage, religious and political zealotry pose the greatest threat to peace and prosperity, fueling terrorism, intolerance, discrimination, evangelism, imperialism, dictatorships and national theocracies.  Education, communication and compromise are the antidotes.

Friday, December 7, 2012

North American Japan

The northeastern half of Japan lies on the North American Plate, which dips down from the Aleutian Chain, crosses the middle of Honshu (Japan's large central island) and then angles NNW across Siberia, west of the Kamchatka Peninsula.  The southwestern half of Japan lies on the Eurasian Plate.

Today's magnitude 7.3 earthquake, off the northeastern coast of Japan, was another subduction quake, like the massive earthquake in March, 2011, that produced the destructive tsunami; fortunately, today's quake resulted in a relatively small tsunami.  Both earthquakes occurred along a subduction zone where the Pacific Plate, moving northwest, is forced beneath the North American Plate; friction pulls the edge of the latter plate downward and, when it slips and rebounds upward, an earthquake results and displacement of the overlying sea water may cause a tsunami.  Off the southern coast of southwestern Japan, the Philippine Plate is dipping beneath the Eurasian Plate and similar subduction quakes and secondary tsunamis have and will continue to occur along that tectonic boundary as well.

It is interesting to note that the residents of northeastern Japan live on the North American Plate while those of southern California and the Baja Peninsula do not (they, in fact, live on the Pacific Plate).  Contrary to a popular assumption, the tectonic plates do not correspond to the contours of the Continents for which they are named and the Continents may be composed of land segments from multiple tectonic plates (Asia, for example, includes segments from the Eurasian, Arabian, Indian, Philippine and North American Plates).

Thursday, December 6, 2012

Pine Birds

Throughout the American Midwest, deciduous trees dominate our forests and riparian woodlands and the majority of resident birds favor those habitats.  During the colder months, however, birders may find that groves of pine and other conifers offer the best opportunity to observe visitors from the north.

Many irruptive, Canadian or mountain species, native to vast coniferous forests, favor similar habitat during their winter excursions; while most are less selective in winter, visiting mixed woodlands as well, they are usually best found in stands of conifers where their favored foods are available.  These pine-loving birds include red and white-winged crossbills, pine and evening grosbeaks, red-breasted nuthatches, golden-crowned kinglets, purple finches and pine siskins; northern saw-whet owls are also best found in dense coniferous vegetation.  While most of these species are erratic nomads, moving about in response to natural food crops, pine groves are magnets for those passing through our region.

Of course, well-stocked sunflower feeders provide another effective means of attracting these northern wanderers.  Once their attention is drawn to the feeders by mixed flocks of resident birds (cardinals, chickadees, titmice, house finches, white-breasted nuthatches and others), they join the feast and, if they like the handouts, they might stick around for a week or so.  Better yet, planting your own stand of conifers will diversify the landscape of your property and increase your chance of observing irruptive species in the future.

Wednesday, December 5, 2012

Red Wolf Controversy

When European explorers first reached North America, red wolves inhabited the southeastern quadrant of the Continent, from New England to the Ozarks of Missouri, southward to the Gulf Coast.  Smaller than gray wolves but larger than coyotes, they favored swamp forests and river valleys.  By the 1970's, habitat loss and predator control programs had eliminated them from almost all of that range and captive breeding efforts were initiated by the U.S. Fish & Wildlife Service in 1980.  The first reintroduction of red wolves occurred in eastern North Carolina, in 1987, and approximately 100 live in the wild today; a little over 200 remain in breeding centers.

Fossil discoveries have long suggested that gray wolves, red wolves and coyotes diverged from a common ancestor early in the Pleistocene (between 2 and 1 million years ago).  However, recent DNA studies revealed that 80% of the red wolf's genes are of coyote origin while 20% are from gray wolves, suggesting that red wolves are hybrids of the other two species; modern wolves and coyotes are known to hybridize with domestic canines and the geneticists theorize that red wolves arose when the natural range of gray wolves and coyotes had significant overlap, perhaps within the past few thousand years.

While this conclusion could have significant implications related to listing the red wolf as an endangered species, the U.S. Fish and Wildlife Service continues to regard that canine as a distinct species and some scientific organizations and environmental groups list the red wolf as a subspecies of the gray wolf.  Regardless of their official status, red wolves were apex predators through a large portion of North America and vital to those ecosystems before humans intervened.  In reality, hybridism plays a significant role in evolution and whether natural interspecies breeding occurred in the distant past or in more recent times should not affect our conservation efforts.  After all, non-African humans are hybrids as well, possessing a relatively small but significant contribution of genes (5%) from Neanderthals or Denisovans; see my post on 2-4-12.

Tuesday, December 4, 2012

Modern Gladiators

Few of us would condone a resurrection of the Roman Colosseum, where throngs of rabid citizens were entertained by the suffering and death of captive slaves, a tool used by the Emperors to distract the public from their own miserable lives.  We humans, after all, have evolved over the past twenty centuries and are now sensitive to both human rights and the welfare of each and every member of society.  We do what we can to protect the health of our gladiators.

Unfortunately, we humans are still entertained by public humiliation and suffering and our modern gladiators, in the form of boxers, cage fighters, hockey players and football stars, provide that service.  While medical studies continue to highlight the risk of repeated head injuries, eventually leading to traumatic dementia, we, in the interest of economics and entertainment, choose to overlook the evidence, satisfied with the preventive regulations and technologies offered by the power brokers of the sports industry.  The athletes, after all, choose to engage in their respective sport (just as soldiers, stuntmen and prostitutes accept the risks of their careers).

Like the Colosseum of ancient Rome, our modern stadiums offer a form of entertainment that many, if not most, members of society relish.  When one of the gladiators is injured and carried from the field, we stop to offer our collective thoughts and prayers; then, its back to the action, the punishing hit replayed on a giant screen for all to admire.  Meanwhile, less acute and more insidious injuries go unnoticed, at least until early dementia or suicide bring them to light.

Monday, December 3, 2012

Pascagoula River Basin

Of the many landscapes that we crossed on our trip back to Missouri from South Florida, the broad tidal marsh of the lower Pascagoula River was surely the most spectacular.  This river, the largest (by volume) unimpeded stream in the lower 48 States, rises as the Chickisawhay River, north of Meridian, and the Leaf River in the Bienville National Forest, north of Hattiesburg; its 9000 square mile watershed covers most of southeast Mississippi and a sliver of southwest Alabama and drains into the Gulf of Mexico at Pascagoula Sound.

Long utilized for its timber, water and natural food sources and more recently recognized for its spectacular diversity of plant and animal life, the Pascagoula River Basin has come under increasing protection thanks to the efforts of local environmentalists in cooperation with State agencies, the Nature Conservancy and the Audubon Society; the latter organization has established the Pascagoula River Audubon Center, in Moss Point, which introduces visitors to the rich ecosystem of the Basin, from upland oak-pine savannas, to freshwater cypress-tupelo swamps to the vast tidal wetlands along and south of Interstate 10.  A consortium of the above organizations formed the Pascagoula River Basin Alliance in 2001, devoted to the protection of the River's watershed and to the welfare of its native plants and animals, many of which are threatened or endangered.

Among the many seasonal residents of the Pascagoula Basin are brown and American white pelicans, Mississippi sandhill cranes, swallow-tailed kites, bald eagles, ospreys, American alligators and a wide variety of herons, egrets, gulls, terns and wetland songbirds.  Gulf sturgeon spawn in the river, which is also home to the endemic yellow-blotched map turtle.

Sunday, December 2, 2012

Waiting on Winter

It may be December 2 but it felt more like late September in central Missouri today. Since we just returned from South Florida, the mild conditions were gentle on the mind and body, easing us back into our life in the Temperate Zone.  Perhaps most importantly, it made the task of putting up our Christmas lights (my least favorite chore of the year), much more tolerable.

Unfortunately, as pleasant as this weather may be, our region does not need another warm, dry winter.  Coming on the heels of a prolonged drought and intense summer heat, there is hope that this season will turn the tide, bringing heavy precipitation (rain or snow...we'll take both) to revive the parched landscape and recharge our streams and reservoirs.  We're dreaming of a white Christmas, January and February!

It is thus alarming to have afternoon highs topping out near 70 degrees F as the first calendar month of winter begins; for now, the La Nina has yet to retreat. While I am not a fan of mysticism, I decided to fill our backyard feeders today; akin to stocking up on firewood, perhaps that seasonal ritual will usher in some cold, snowy weather for the Heartland.

Saturday, December 1, 2012

Traveling Blind

Those of us who love to travel look forward to seeing new landscapes, whether they are natural, rural or urban.  Some, including myself, also focus on the geology, hydrology, topography and ecology of those landscapes and often enjoy the journey as much as the destination.  We thus usually volunteer to drive and are not apt to sleep or read during road trips, unwilling to miss any interesting or unexpected sights along the way.

So I was especially disappointed this morning when our route through the southern half of Mississippi, a State in which I have spent little time, was enveloped in a pea-soup fog; for much of that segment, I saw little more than the tail lights and pavement ahead of me and, at times, the trees that lined the highway.  It was like sitting in the middle seat of an airliner when the window occupant decides to close the shade (a practice that I personally despise).  When one is blind to the journey, the act of travel looses its perspective.

Teens and young adults seem to have little interest in the experience of travel, focused as they are on their smart phones or GPS devices and generally oblivious to the environment through which they move.  Perhaps, in the distant future, when humans are transported to other locations instantaneously, the joys of travel will be lost altogether.  Unfortunately, while new technologies augment our understanding of the Universe, they tend to diminish our ties to the natural world.

Thursday, November 29, 2012

Landlubber on the Coast

After ten days on the Gulf Coast of South Florida, we will head north tomorrow.  It has been a pleasant, relaxing visit with fabulous, mild weather, beautiful scenery and a fascinating mix of plant and animal life to observe.  Nevertheless, landlubber that I am, I yearn for the interior of North America, with its more varied topography and distinct seasons.  I need hills and mountains, canyons and valleys, forest and prairie, snowscapes and deserts.

Though sea coasts harbor unique vistas and wildlife, inland lakes, rivers and marshes offer a wealth of aquatic ecosystems to explore and the wide variability of Temperate Zone habitats possess a broader range of species.  While Midwestern States do not entice tourists to the degree that Florida does, naturalists know that they are home to a rich diversity of landscape and wildlife; unfortunately, the majority of Americans are oblivious to that fact.

Tropical creatures that we are, most of us enjoy connecting with the tropics or sub-tropics on a regular, if infrequent, basis.  Some are happy to spend their entire life in sunny, warm climes and others escape to their non-threatening environment during the dark, cold months of winter.  But many of us are more attached to the seasonal gyrations and varied ecology of the Continent's interior, a nod to those adventurous souls who left Africa 80,000 years ago.

Wednesday, November 28, 2012

Crested Caracaras

The crested caracara, also known as the Mexican eagle, northern caracara or Audubon's caracara, is a widespread member of the falcon family, found primarily in Mexico, Central America and northern South America; it also inhabits southern Arizona, south Texas and the dry prairies of central Florida.  Unlike other falcons, it is not a swift, aerial hunter; rather, this omnivorous bird is primarily a scavenger and usually hunts on the ground.

Preferring dry, open country, including desert grasslands, cattle ranches and savannas, the crested caracara is generally found alone or in small groups though it is frequently in the company of vultures.  Carrion is its primary food source though it also consumes insects, small birds, small mammals, lizards and eggs.  Mating occurs in mid-late winter (depending on latitude) and a clutch of 2-4 eggs is laid in a bulky nest of sticks, usually in a lone tree surrounded by grassland.  Very slow to mature, young caracaras are unable to fend for themselves for at least three months.

The population of crested caracaras in central Florida likely became established during the Pleistocene, when oak savannas stretched across the Gulf Coast region.  As the climate warmed during the Holocene (beginning 10,000 years ago), the vegetation of the Deep South gradually changed and the savannas disappeared, leaving a remnant population on the dry prairies of the Sunshine State.

Tuesday, November 27, 2012

East to the Prairie

This morning, we left the watery landscape of the Gulf Coast and headed east to the dry prairie region of central Florida.  Following Florida 72, we crossed I-75 and entered a landscape of cattle ranches, flatwoods, dry prairie, freshwater swamps, canals, meandering rivers and citrus groves.  Sandhill cranes were very common (most often seen in pairs or small flocks) and certain birds, including cattle egrets, wood storks and anhingas, were far more common than they are near the coast.  East of Arcadia, now on Florida 70, we began to see crested carcaras, raptors that are closely associated with the dry, open grasslands; other prairie birds included American kestrels, loggerhead shrikes and numerous turkey vultures.

At Okeechobee, Florida, we stopped to view the great, freshwater lake of south-central Florida, the second largest lake that lies totally within the lower 48 states; since that vast but shallow lake is surrounded by a levee, our view was from the edge of wetlands that rim its northern shore and that image was tainted by littered sloughs and the relentless noise of airboats.  Cutting northwest on U.S. 98, we re-entered the dry prairie landscape, broken by hammocks of pine, live oak and cabbage palm.  We crossed the beautiful Kissimmee River and stopped for a picnic lunch at a wildlife management area along its western bank; the Kissimmee, which rises near Orlando, is the primary feeder stream of Lake Okeechobee and has been undergoing restoration (from past diversion and channelization) since 1997.

Heading back toward the Gulf Coast, we visited Highlands Hammock State Park, southwest of Sebring.  This 9000 acre Park protects an old growth hammock and adjacent cedar swamps and is accessed by nine hiking trails, many of which utilize boardwalks to negotiate scenic wetlands.  Resident wildlife includes white-tailed deer, bobcats, raccoons, alligators, aquatic turtles, tortoises, pileated woodpeckers and a host of wetland songbirds.  Florida panthers and black bear visit the Park on occasion and, as we observed today, feral pigs have taken up residence; since the pigs threaten the welfare of this rich yet fragile ecosystem, efforts to remove them via hunting and trapping are underway but, to date, have met with limited success.

Monday, November 26, 2012

Feisty Sanderlings

Sanderlings, one of the most widespread shorebirds on Planet Earth, breed on the Arctic tundra and winter along sandy beaches and mudflats as far south as southern Argentina.  Medium-sized and easily identified, they gather in flocks during the colder months and are known for their habit of racing along the edge of the surf, probing the wet sand for marine invertebrates.

Sanderlings are common on the beaches of Longboat Key, Florida, from late summer to mid spring and, as noted above, are generally seen in small groups or moderate sized flocks.  Today, however, these winter visitors seemed to be in a feisty mood, feeding alone and squabbling with their neighbors; in one case, a pair of these "cute" shorebirds actually engaged in brief but harmless combat.  While male sanderlings are known to be highly territorial in the Arctic (allowing some females to produce a clutch of eggs with more than one suitor), I have never observed this behavior on their wintering beaches. Since juveniles are known to remain on the wintering grounds for several years before they are capable of breeding, perhaps I was viewing their instinctual warmup for next spring.

As we often see in nature documentaries, humans have a habit of endowing other creatures with the traits of our own species.  On the other hand, we have much in common with our wild neighbors and certain behaviors that we observe in human society mimic those found throughout much of the animal kingdom.  Perhaps, like surly, hormone-driven teens, not yet ready for the responsibilities of parenthood, these sanderlings were just flexing their muscles, frustrated by the slow progress of their own maturation.

Sunday, November 25, 2012

Beach Topography

I have long been enamored with landscape and, the greater the topographic relief, the better.  So, while I thoroughly enjoy our visits to Florida, with its rich marine and terrestrial ecosystems, I find the flat terrain less than appealing.

On the other hand, the sandy beaches of the Atlantic and Gulf Coasts offer an opportunity to witness the natural processes of deposition and erosion in their most elemental form and the constant interaction of wind, water and sand provides insight into the gradual yet no less relentless development of landforms across the globe.  In areas where the sand is tightly compacted (and thus more resistant to erosion), steep-walled escarpments form, collapsing in places to mimic the rock slides along our western canyons.  In other regions, where the sand is relatively loose and easily displaced, incoming waves produce broad, flat plains, dappled by transient pools that soon fill with sand, shells and other debris, pushed in from the sea or swept across the beach.

Those of us attuned to these natural processes cannot help but notice miniature landscapes as we walk along the beach, enjoying time-lapsed cycles of formation and destruction.  Stark, resistant headlands of sand, dissected from escarpments by the pounding surf, are rounded off by subsequent waves and, eventually, erode to a flat plain, their cargo of sand deposited down the beach.  This simplistic model of landscape evolution, surely ignored by the great majority of visitors, makes a stroll on the beach even more interesting for those of us hooked on topography.  

Saturday, November 24, 2012

Leaping Rays

After a beach walk on Longboat Key, Florida, I stopped to survey the flat, blue Gulf of Mexico.  Scanning with my binoculars, I noticed a large splash about 100 yards offshore and focused on that location.  Within a minute the creature leaped again and I was able to identify it as a large ray; a third leap further confirmed the sighting and suggested that the ray had a wingspan of at least 5-6 feet.

While this was my first experience with a leaping ray, their habit of doing so is well known and well documented; indeed, a search on Google or YouTube turns up plenty of photos and videos.  The historical record also includes unfortunate injuries and at least one death related to large rays (up to 300 pounds or more) jumping into fishing boats.  On the other hand, there is no scientific consensus as to why the rays leap in the first place; explanations range from mating behavior to escaping predators (i.e. sharks).  Of course, these marine creatures may simply be stretching their muscles or engaging in playful activity.

Once again, I was fortunate to be in the right place at the right time to witness a natural behavior that, while not rare, is unlikely to be observed by the casual beachcomber.  Unfortunately, this is true of many natural spectacles; if we don't visit a variety of ecosystems and remain attentive to the possibility of unexpected sightings, we will never fully appreciate nature's spectacular diversity.  After all, it took numerous visits to rocky coasts and sandy shores over more than sixty years before I saw a ray leap from the sea.

Friday, November 23, 2012

Longboat's Shifting Beach

Longboat Key is a long, narrow barrier island off the west coast of Florida, stretching between Anna Marie Island, off Bradenton, and Lido Key, off Sarasota.  Angled NW to SE, its Gulf of Mexico side is lined with beaches while its eastern edge, along Sarasota Bay, is a mosaic of tidal marshes, mudflats, mangrove islands and residential developments; the latter are generally protected by seawalls and many are accessed by boat channels from the Bay.

The northwest tip of Longboat Key, known as Greer's Beach, is subject to regular sculpting by tropical storms and wave action.  As a result, it often harbors a mix of tidal shallows and sand spits and has defied attempts to permanently restore its condition.  While humans may prefer a wide, gently sloping beach for sun-bathing, beach games, fishing and shelling, the fickle nature of this shore appeals to marine birds, many of which nest and roost along this coast and find off-shore fishing to be productive, the result of changing and upwelling currents along and near the Longboat Inlet channel.

This morning, large, mixed flocks of gulls, terns and shorebirds gathered along the beach; these included laughing gulls, Forster's, royal, Sandwich and least terns, black skimmers and a host of shorebirds, including willets, sanderlings, black-bellied plovers, red knots, ruddy turnstones and piping plovers.  Brown pelicans, double crested cormorants, ospreys and northern gannets fed offshore and, to my delight, a large flock of black scoters moved up the coast.  Great blue herons, yellow-crowned night herons and white ibis are also common in this area.  For a naturalist, this shifting beach is among the most interesting sites on Longboat Key.

Thursday, November 22, 2012

Gulf of Mexico Gannets

The northern gannets of North America breed in six large colonies along the Gulf of St. Lawrence and the coast of Newfoundland.  Adults arrive at those rocky headlands by early April and depart by early October, wintering at sea along the coastal shelf, from Maine to Mexico.  Non-breeding juveniles spend their first three years at sea before returning to their ancestral breeding sites.

Prior to the Deep Horizon disaster, in April of 2010, it was assumed that only a small minority of North American gannets wintered in the Gulf of Mexico; this assumption was based on the results of past tagging studies.  However, a large percentage of the oiled birds found along the Gulf Coast proved to be northern gannets, primarily juveniles; the predominance of juveniles reflected the time of year of the disaster, when most adults had returned to Canadian breeding grounds.  In fact, more recent studies, using GPS, have revealed that 25% of North American gannets winter in the Gulf of Mexico at some point in their lives.

On this crisp, breezy Thanksgiving Day, we saw more gannets off the coast of Longboat Key, Florida, than on any visit in the past.  Joining brown pelicans, double-crested cormorants, laughing gulls and a host of tern species, the gannets (both adults and juveniles) dove for fish as close as 100 yards from the beach.  Diving from 100 feet or more above the surface, their spear-like entry exceeds the less graceful plummet of brown pelicans in both speed and precision.  Indeed, we were thankful to have witnessed their spectacular display.

Wednesday, November 21, 2012

Longboat Key Parakeets

Longboat Key, off Sarasota, Florida, boasts a wide variety of resident and migrant birds.  The great majority are aquatic species such as pelicans, cormorants, waders, shorebirds and ospreys.   Others include red-bellied woodpeckers, gray kingbirds, belted kingfishers and a mix of migrant warblers.  In recent decades, collared doves and black-hooded parakeets have joined the list.

Officially known as Nanday conures, black-hooded parakeets are native to eastern South America, from Brazil to Argentina.  Like other exotic species found in the U.S., they were imported for sale to zoos, collectors and private individuals and either escaped or were released into the wild.  A study conducted by the University of Florida concluded that at least 14 species of parrots and parakeets now inhabit various parts of the Sunshine State; most are found in the Miami area.  Black-hooded parakeets turned up in the Tampa Bay region over the past decade while populations of monk parakeets are now scattered across the U.S. and southern Canada, demonstrating the adaptability of that particular species.  As one might expect, the greatest variety of invasive parrots and parakeets are found in Florida and Southern California where mild weather and a diversity of vegetation have favored their survival.

The Nanday conures on Longboat Key, like most of their cousins, are gregarious birds that move about in noisy flocks and nest in colonies.  Consuming a wide variety of plant materials, including nuts, seeds, buds and flower petals, these parakeets are steadily extending their range and their impact on the welfare of native birds and on the natural ecosystems of South Florida has yet to be determined.

Tuesday, November 20, 2012

Edge of the South

Where does the American South begin?  As a child, traveling to the Gulf Coast on summer vacations, I determined that it was somewhere beyond the Smokies and defined its presence by the sighting of palm trees or of "cranes" (my parents' name for any large wading bird) along the lakes and wetlands.  Of course, I later learned that herons, egrets and sandhill cranes inhabit much of the Continent, especially during the warmer months, and that palm trees are planted as ornamentals in many regions of our country.

Politicians and historians might focus on the Mason-Dixon Line to delineate the South but this has little relationship to our natural landscape.  One might also use a specific latitude to define the northern edge of the American South but his is problematic in the Western States where climate is more closely related to elevation than to distance from the Equator.  Defining the South as coinciding with the Coastal Plain is an attractive option; however, this geophysical province extends northward to the Mid-Atlantic region and up the Mississippi Valley to southeastern Missouri and southernmost Illinois.  Finally, one might use meteorologic data such as the frost-free period to characterize the South but coastal regions of the Pacific Northwest, well displaced from southern latitudes, enjoy long periods of mild (if not sunny) weather.

As I learned this morning, however, those who travel south on I-65 will clearly encounter the edge of the South.  Just north of Montgomery, the highway drops from the hill country of northern Alabama to the flat landscape of the Coastal Plain; in concert, the air acquired a distinctive haze, squadrons of waterfowl moved across the scene and puffy cumulous clouds drifted in from the Gulf of Mexico.  Forested hills and rocky roadcuts gave way to red clay, cattle pastures, cotton fields and riparian woodlands, the latter adorned with Spanish moss, kudzu vines and an understory of saw palmetto. There was no doubt in our minds that, after traveling through the Central Lowlands and Appalachian Highlands of North America, we had entered the Deep South of the USA.

Monday, November 19, 2012

Crossing Rivers

Heading for our condo on Longboat Key, Florida, we left Columbia this morning and drove east on I-70, undulating across the southern edge of the Glaciated Plain and crossing numerous streams that drain southward into the Missouri River.  On the outskirts of St. Louis, we crossed the Missouri itself and then the Mississippi River, just south of the Arch.

Angling southeast on I-64, we left the Mississippi floodplain and travelled across the flat, rural landscape of central Illinois, fording the wooded channel of the Kaskaskia en route.  South of Mt. Vernon, we switched to I-57 and then I-24, winding through the scenic Shawnee Hills, capped with Pennsylvanian sandstone, and eventually crossed the broad Ohio at Paducah, Kentucky.  Curving eastward, we passed over the lower Tennessee and Cumberland Rivers (just north of Land Between the Lakes) and then angled to the southeast, traveling across the karst plain of Western Kentucky, a limestone region with numerous springs and caverns but few large surface streams.  Once in Tennessee, we crossed the Red River (a tributary of the Cumberland) south of Clarksville and, nearing Nashville, entered the westernmost portion of the Appalachian Plateau, locally known as the Cumberland Plateau.

Approaching downtown Nashville, we switched to I-65, crossed the Cumberland River and headed south through the heavily dissected plateau toward Alabama.  Our final and most spectacular river crossing would come southwest of Huntsville, near Decatur, where the highway arches above Wheeler Lake, on the Tennessee River, bounded by the rich wetlands of Wheeler National Wildlife Refuge.  Leaving the Appalachian Plateau and entering the Ridge and Valley Province, we snaked through Birmingham and will spend the night south of that city.  Tomorrow, on to Southwest Florida.

Sunday, November 18, 2012

Summer Kill

Most of us are very familiar with winter kill, the toll that ice storms, deep snow and severe cold take on plants, wildlife and humans as well.  This year, those of us who inhabit the Great Plains and Midwest are also dealing with summer kill, the effects of the prolonged drought and intense heat of this past year.

Today, with the "assistance" of our 5 year-old grandson, we removed a large, dead yew on the back edge of our property and I hauled its remnants to our local mulching site.  We will miss both its greenery and its role on our natural privacy fence and many of the winter songbirds that used to roost among its massive branches will certainly miss the shelter that it provided.

Compared to the hardships endured by farmers and ranchers, our loss from the heat and drought has been minimal and the death of the yew will be a minor disruption in the lives of our neighborhood wildlife.  But, when one considers the widespread effects that our scorching spring and summer had on natural ecosystems, one gets a glimpse of the long-term impact that global warming might have on Planet Earth.  The effects of the drought on native plant life will surely be passed through the food chain and a reduction in natural cover may shift the balance in favor of predators, exacerbating the advantage that those hunters enjoy during the lean, frigid months of winter.

Friday, November 16, 2012

The Nature of Retirement

Today will be my last at the University of Missouri and the last of my thirty-six year career as a private or employed physician.  Though I plan to participate in volunteer medical services, I will now devote most of my life to family, friends and other personal interests.

The news of one's retirement is generally greeted with a mix of reactions.  Most extend their congratulations and best wishes while some wonder aloud how the retiree can give up his or her life's work and a few hint that the decision amounts to a selfish neglect of social responsibility.  The latter reaction is more likely to be encountered by professionals than by others in society and includes the implication that special knowledge and abilities, partly achieved through government support, should not be denied to those who depend on such care.  On the other hand, many of us know physicians who attempted to extend their careers past their point of tolerance and effectiveness, endangering their own health and that of their patients.

In the end, the decision to retire is highly personal and generally unfolds over a number of years.  Those who have few interests outside their field of work are more reticent to move on while others sense the chance to contribute to society in different ways.  Some are happy to work until the day they die while most relish the prospect of freedom from the daily demands of their career.  Unlike the traditional image of retirement, filled with days on the golf course or fishing boat, modern retirement usually involves a transition to other commitments: creative, entrepreneurial or altruistic.  For many, including myself, the belief that we have but one life to live (and that the concept of an afterlife is a human delusion) makes the adventure of retirement even more appealing.

Thursday, November 15, 2012

Lassen Peak

Rising just north of the Sierra Nevada Range, Lassen Peak (10,461 feet) and its cohort of volcanic domes represent the southern end of the Cascade Volcanic Arc that extends from British Columbia to northern California.  All of the well known volcanoes along this arc, and those that preceded them, have formed along a subduction zone where remnants of the Farallon Plate dip below the North American Plate.

Protected within a National Park since 1916, the Lassen Peak volcanic field contains 30 peaks in addition to smaller domes and cones.  Lassen Peak, the centerpiece of the Park, formed 27,000 years ago on the northeast flank of the Mt. Tehama caldera; the latter volcano, at least 1000 feet taller than Lassen, exploded and collapsed about 350,000 years ago.  Lassen, itself, last erupted in 1915 but remains active (as revealed by numerous fumaroles, mud pots and hot springs on its slopes).

Named for Peter Lassen, a local guide and blacksmith during the early 19th Century, Lassen Peak, like the other large volcanoes of the Cascade Range, is an ultra-prominent peak.  Rising as it does at the northeast end of the Sacramento Valley, it receives upslope flow from all directions and has the highest average annual snowfall (660 inches) of any location in California.  Most streams within the National Park drain toward the Sacramento River via the Pitt River that runs north of the Park, the Feather River of the northern Sierra or Battle Creek that drops west from the Park; the eastern edge of the Park lies on the rim of the Great Basin.  Mt. Shasta looms NNE of Lassen Peak while Brokeoff Mountain (9235 feet), the second highest summit in the Park, rises to its southwest, just across the Tehama Caldera.

Wednesday, November 14, 2012

Meant to Happen

One often hears the phrase "Everything happens for a reason."  Does this reflect our natural tendency to look on the bright side or is it a human defense mechanism, quelling our fear amidst the random nature of life and death.  From a naturalist's perspective, it is more the latter.

As intelligent beings, we like to think that we have control over our lives and, to a great extent, we do.  Those of us who eat well, exercise and avoid poor lifestyle choices are more likely to enjoy a long, healthy life than those who do not; in like manner, diligence, hard work and commitment are generally rewarded.  On the other hand, genetics and happenstance play a significant role in our lives; those hobbled by bad genes and those who succumb to accidents or disease beyond their control are just unfortunate victims of life's fickle nature.

Religious persons see a grand design in both the Universe and in our individual lives and believe that tragic events are part of God's plan.  Such beliefs are reassuring and imply that suffering or early death will be remedied in the afterlife.  Still others put their faith in destiny, convinced that the twists and turns in life, however good or bad, have a mystical purpose.  Those of us who accept the fact that humans are part of nature, no more essential than other creatures, do not find a rational purpose for childhood death, tragic accidents or the less serious setbacks in life; while we recognize that our lives unfold in response to genetics and experience, continually influenced by our daily interactions, we cannot abide the role of vindictive, sadistic gods or spiritual mysticism.

Tuesday, November 13, 2012

Myanmar's Earthquake

About 90 million years ago (MYA), during the Cretaceous reign of Tyrannosaurus rex, the Indian Subcontinent split from the Antarctic Plate and began to drift to the NNE.  By the end of the Cretaceous, some 65 MYA, it started to collide with the massive Eurasian Plate, a process that has lifted the Himalayas and continues today.

On the morning of November 11, a magnitude 6.8 earthquake struck north-central Myanmar.  This quake, which was followed by a magnitude 5.8 aftershock, occurred along the Sagaing Fault, where the Indian Plate is both colliding with and slipping NNE along the edge of the Eurasian Plate.  Early reports indicate widespread structural damage and at least 12 deaths; tremors from the rupture were felt as far away as Bangkok, Thailand.

While most recent earthquakes have occurred along the subduction zones of the Pacific Rim and western Indonesia, compression quakes are common across southern Eurasia where the African, Arabian and Indian Plates continue to drift northward, colliding with their larger, relatively immobile neighbor.  Myanmar's quake was just the latest reminder that Earth's puzzle of tectonic plates remains in flux.

Monday, November 12, 2012

Snows in the Night

Soon after going to bed last evening, I was awakened by the distinctive calls of snow geese as they passed over Columbia.  Catching a ride on cold, northern winds behind yesterday's storm, they are headed for coastal marshlands on the Gulf Coast and will likely stop to rest and refuel along the Missouri, Arkansas or Mississippi Rivers en route.

The first snows of autumn are always an inspiring sight (or sound) and I begin watching for them during the first week of November.  Having bred and summered on the Arctic tundra, they use several staging areas on their way to southern marshlands, some of which are in Missouri; indeed, Squaw Creek NWR, on the northwest border of our State, is one of the best sites in North America to observe snow geese, which often peak from 300-500 thousand between late November and mid December.

Fortunately, those of us in central Missouri are treated to the spectacle of snow geese migrations in both late autumn and late winter (February to March).  The opportunity to observe and listen to these hardy travelers has been the natural highlight of my years in Missouri and they never fail to stir my soul.  Their high-pitched clamour is, for me, both the call of the wild and the voice of freedom.

Sunday, November 11, 2012

The Nature of Heroes

General David Petraeus has become the latest American hero to fall from grace, revealing that he is, in fact, human.  Unfortunately, as a society, we love to bestow the title of hero, used to praise individuals who, despite risk to their personal safety or comfort, have demonstrated a selfless commitment to the welfare of others.

Loosely applied to a wide variety of individuals, from soldiers and firemen to teachers and social workers, the label implies superhuman dedication or accomplishment and, in a twisted way, sets them up for failure.  While we cannot excuse behavior that hurts others or places the innocent at risk, we should not be surprised to find that our heroes have their own human frailties and that many have engaged in activity that we might find offensive, if not immoral.  Indeed, those who demonstrate an excessive commitment to their career are often compensating for personal deficiencies in other areas of their life.

It is best that we praise individuals for their heroic acts rather than saddling them with the title of hero.  In the end, we discover that they are mere mortals, as susceptible to temptation as the rest of human society.  Whether that truth is revealed during their lifetime or postpartum, by a diligent biographer, it serves to round out their image in the eyes of the public but should not diminish their acts of heroism.

Saturday, November 10, 2012

Escaping Brutus

Following a night of gusty winds and rattling windows, Winter Storm Brutus (so named by the Weather Channel), pushed into Metro Denver this morning, bringing much colder air and its cargo of rain, sleet and snow.  Heading east on I-70, we escaped the clouds and precipitation after crossing the Palmer Divide but the storm's powerful wind field offered additional challenges for our journey.

All across the High Plains, from Limon, Colorado, to Wakeeney, Kansas, strong southerly winds buffeted our vehicle and tossed armies of tumbleweeds across the highway; blowing dust and crop debris reduced visibility, producing a brownish haze in all directions.  The winds died down and the views broadened in central Kansas, where summer-like air, pumped northward ahead of the advancing storm, will set the stage for thunderstorms as the potent cold front invades the Heartland.

We arrived in Columbia just in time for another night of strong southerly winds.  Though we escaped the storm's assault on Colorado, the massive system will soon drag its wintery chill into the Midwest; fortunately (for travelers), we will be spared the heavy snow and ice that now coats the western mountains and Northern Plains.

Friday, November 9, 2012

Winds of Change

For the past few days, a downsloping, southwesterly breeze has scoured the Front Range urban corridor, yielding sunny skies, warm temperatures and crystal-clear air.  Early this afternoon, a noticeable haze began to develop as a cold front dropped into Colorado, producing an upslope wind from the northeast.

This wind shift is the first sign of a significant change in our Front Range weather; while sunshine and highs in the mid 60s F prevail this afternoon, a downward slide will begin overnight.  Within 24 hours, the upslope cooling and precipitation will intensify, bringing light snow tomorrow night and highs in the 20s on Sunday.  Those of us who have lived in Metro Denver for many years come to recognize the effects of shifting winds associated with fronts; in the case of a cold front, there is a sudden coolness and haziness in the upsloping air, often scented with the aroma of feedlots to our northeast.

While it has been a pleasant week for hiking and farm work here in Littleton, the promise of snow (or moisture of any kind) is welcome across this parched landscape.  Hopefully, this weekend's storm will be the first of many throughout the Front Range snow season, which generally stretches from October to May, peaking with the upslope storms of March and April.

Wednesday, November 7, 2012

A Victory for Nature

The re-election of President Obama is a victory for nature, a sign that many Americans care about our natural environment and reject the claims of the Conservative Right that industrial regulations, open space protection, mass transit initiatives and a shift toward clean, renewable energy will stifle the growth of our economy.  The President's re-election also helps to insure that our country will not ignore the negative effects of pollution, habitat destruction and global warming on natural ecosystems and will foster the conviction that the welfare of human civilization is directly tied to the health of our natural environment.

The pro-business agenda of the Conservative Right, which is focused more on profits than on the environmental effects of industry has long overlooked the threats imposed by air pollution, urban sprawl, over-fishing, groundwater contamination, agricultural runoff and fossil fuel recovery in fragile ecosystems.  Granted another four-year reprieve from their destructive political views, we will hopefully renew efforts to establish long-term, conservation policies that protect our natural environment and mitigate the negative effects of human activity.  Though Conservative Republicans have predicted dire consequences if we proceed down the road of more environmental regulations, the American public has expressed their support for these measures and, in the end, both nature and human society will benefit.

A less obvious but no less important message of Obama's re-election is the repudiation of religious-based restrictions on our funding of birth control.  The availability of these products is essential to the prevention of unwanted pregnancies and to the reduction of human pressure on our limited natural resources.  Failure to address unbridled population growth, especially in developing countries, will negate any progress that we might achieve on the conservation front.

Tuesday, November 6, 2012

Skittish Visitors

On this mild, sunny, crystal-clear morning, we took a walk along the South Platte River in Littleton, Colorado.  The usual mix of waterfowl and terrestrial birds were seen and a large, restless flock of Canada geese had settled on Cooley Lake.

Unlike our resident geese, which feast on our parks and golf courses and are rather tolerant of human activity, migrant flocks retain their skittish nature.  After all, in the wilds of Canada, their survival depends upon their wariness and they are quick to take flight or move to open water when predators appear.  And while our permanent residents often feed and move about in family groups or modest sized flocks, the migrants and winter visitors tend to retain their large congregations throughout the colder months.

According to the Colorado Division of Wildlife, approximately 150,000 Canada geese are permanent residents of the Front Range urban corridor.  From November into March, an additional 300,000 Canadas arrive from the north, attracted by our cultivated fields, open parklands and numerous reservoirs.  Today's flock gave notice that the annual influx has begun and reminded me that they, like other wild geese, can still stir the soul of man.

Monday, November 5, 2012

Crossing High Pressure

Heading to our Littleton, Colorado, farm, we left Columbia this morning, enveloped in a steady rain.  The copious precipitation, falling through chilly air, had developed along a cold front that was pushing through Missouri.  It would not end until we reached Kansas, where a dense overcast and a gusty north wind signaled that we were now behind the front.

The strong, northerly wind, produced by a large pressure gradient between the high pressure dome to our west and the storm's low pressure to our east, raked eastern Kansas, from the Missouri border to the rust-colored grasslands of the Flint Hills.  Once we passed Salina, the winds diminished and the turbines of the Smoky Hills Wind Farm spun lazily in a light northwest breeze.  As we neared the calm center of the high pressure dome, the clouds began to dissipate and intense sunshine prevailed through most of western Kansas and eastern Colorado.  Nearing Denver, we could see clouds building behind the Continental Divide, a sign of upslope from the west and a promise that downsloping, southwest winds will sweep across the urban corridor over the next few days, pushing afternoon highs near 70 degrees F.

Tomorrow, before we enjoy that mild, sunny weather, we'll head to the polls.  I'll cast my vote for environmental protection, military cutbacks, universal health care, social justice and freedom from the tyranny of right wing zealots.

Sunday, November 4, 2012

Messing with Space-Time

Getting prepared for work this morning, I noticed that my favorite college football roundup was not on ESPN and, when I arrived at the hospital, the access door was locked, forcing me to buzz the security guard.  It was not until I turned on my computer that the explanation for these unexpected events became clear: it was only 5:15 in the morning.  Busy at work this week, I had been shielded from the semi-annual deluge of warnings about the seasonal time change, leading to this cascade of disorientation.  Indeed, this blog post is a product of that ignorance.

It is now clear that we have "fallen back" to standard or daylight savings time (I frankly can't remember which) and will remain there until we spring forward sometime in March or April.  Apparently designed to reduce energy consumption, this human decree has never made much sense to me; after all, we will now be turning on the lights earlier in the evening.  Then there are those regions of the country, including the State of Arizona, that do not adhere to the time change, shifting time zones through the course of a year and confusing travellers in the process.

In reality, human time is a mathematical approximation based on the Earth's periods of rotation and revolution and must be adjusted now and then.  Of course, Einstein and others have pointed out that, as a component of space-time, it is not the simple, one-way, linear factor that we prefer to imagine.  Though we use it to govern our daily routine and to measure our progress through life, time is a dimension of the Universe that is altered by other physical forces.  Personally, I find it difficult to understand the scientific ramifications of space-time and much prefer the wise philosophy offered by Chicago: "Does anybody really know what time it is?  Does anybody really care?"

Saturday, November 3, 2012

The Bighorn Mountains

Over 200 miles in length, the Bighorn Mountains stretch from north-central Wyoming into southern Montana.  This range, which angles southeast to northwest, rises between the Bighorn Basin to its west and the Powder River Basin to the east.  The Bighorn River drains the west side of the range, cutting a scenic canyon through its northern tip on its way to join the Yellowstone River.  The famous Little Bighorn River rises on the northeast flank of the range, the Tongue River drains its central east side and the upper tributaries of the Powder River head along the southeast slopes of the range.

An outlier of the Rocky Mountain Chain, the Bighorns formed during the Laramide Orogeny, 70 million years ago, as ancient Precambrian rock crumpled upward through the overlying Paleozoic and Mesozoic sediments.  Precambrain granite is exposed along the crest of the range, which is generally 11-12,000 feet above sea level, while metamorphic Paleozoic rocks are exposed across the mid-elevation flanks and Mesozoic sedimentary rocks adorn the lower mountain slopes and foothills.  Cloud Peak, 13,167 feet, is the highest point in the Bighorns, surrounded by the 189,000 acre Cloud Peak Wilderness Area in the southern portion of the range; it is classified as an ultra-prominent peak, rising 7067 feet above the lowest topographic contour that encircles it without including a higher summit.  Prominence correlates with the extent of a summit's unobstructed vistas and Cloud Peak has the 15th greatest prominence in North America (second only to Gannett Peak in Wyoming).

Relatively undeveloped and isolated from large cities, the Bighorns appeal to naturalists and back-country enthusiasts.  Joining the usual mix of western mountain birds and small mammals are black bear, mountain lions, elk, moose and mule deer; pronghorn are also found on the lower slopes and adjacent plains.  Grizzly bears once inhabited the Bighorn Mountains but were extirpated by the mid 20th Century.

Thursday, November 1, 2012

A Close Second

Coming on the heels of glorious October, the month of November is not welcomed by many of us in the Northern Hemisphere.  Though it is officially a component of autumn, November often brings the first snow of the year and represents a final slide toward the dark, cold days of winter.

Yet, this month often brings many mild, sunny days and, from the naturalist's point of view, offers some of the highlights of nature's year.  The fall waterfowl migration peaks during November, including massive congregations of snow geese and sandhill cranes.  The cooler weather and shorter days induce a restlessness in our resident birds and mammals, making them more conspicuous throughout the woodlands, prairies and wetlands.  In mid November, the Leonid meteor shower offers one of our annual astronomical highlights and, for those of us who prefer snow to rain, winter landscapes invite exploration by late in the month.

Many humans likely prefer the vibrant month of May, with its colorful flowers and vocal birds; after all, it leads into the warm summer season.  But I'll take November, with its dry, chilly air and open vistas.  For me, it's a close second to October. 

Wednesday, October 31, 2012

Lessons from Sandy

Though Hurricane Sandy, which evolved into Nor'Easter Sandy and then Superstorm Sandy, has already been labeled "historic, unprecedented and a once-in-a-lifetime event,"  such storms have surely lashed the Northeast many times in the past.  One need only look at the landscape to see the erosive force of glaciers, floods, high winds, waves and storm surge.  While our planet has been evolving for 4.6 billion years, modern, reliable meteorologic records span less than 200 years and weather satellites have only been available for the past 60 years.

Nevertheless, Sandy was a massive, powerful storm that, once again, highlighted the risk of residential and commercial development along floodplains and shorelines; as sea levels rise in concert with global warming, that risk will only increase.  Fortunately, modern communication and advances in meteorology provided an early warning of the potential devastation and mass evacuations saved many lives.  But Sandy proved that our current infrastructure is no match for the power of nature and reminded us that, despite our advancing technology, we will always be at the mercy of natural forces.

Yet, we will rebuild along the coast and on the floodplains, convinced that this was a freak event, never to recur in the course of our lives.  We will refuse to learn from this devastating storm and will fail to respond to its message.  It may be centuries before another hurricane or massive nor'easter decimates the Northeast; then again, it might be next year. 

Sunday, October 28, 2012

Sandy's Left Turn

Most tropical cyclones that move up the eastern coast of North America either veer out to sea or continue to parallel the shoreline, raking the Capes and the Canadian Maritimes.  Sandy, however, is forecast to make a sharp left turn and come ashore somewhere between Washington, D.C., and New York City.  While some may see God's hand in this unusual and potentially catastrophic path, there is a scientific explanation for the storm's westward jog.

Tropical storms and hurricanes respond to steering winds and pressure zones.  Like a billiard ball rolling across an uneven pool table, it is deflected by high pressure ridges and attracted to low pressure troughs (bumps or dips in the table, respectively).  In addition, clockwise winds that circulate around the high pressure domes will push the storm along; in this case, high pressure over the North Atlantic is creating westward winds in the mid Atlantic region that will shove the storm toward the Coast.  Low pressure along an approaching cold front, now crossing Pennsylvania, offers an additional tug on the storm.

As Sandy moves toward the coast, it will push a storm surge ahead and north of its central circulation.  This reflects the fact that its own large wind field is rotating counterclockwise.  Since many of the bays and sounds along the Northeast Coast open to the east, the surge will be exacerbated along the edge of those shallow indentations.  The combination of high winds, heavy rains and a potent storm surge may be devastating for cities and towns along the coast while inland flooding and downed trees may leave millions in the dark for the coming week (if not longer).  Let's hope that the advancing cold front moves in fast enough to pick up Sandy and take her out to sea; unfortunately, the blocking high over the North Atlantic will likely prevent such a rescue.

Thursday, October 25, 2012

Starved Rock State Park

The Illinois River watershed extends from the headwaters of the Des Plaines River, in southeast Wisconsin, and the upper tributaries of the Kankakee River, in northern Indiana; these two rivers merge in northern Illinois to form the Illinois River which flows westward and then SSW to join the Mississippi, just north of St. Louis.

Some of the best views of the Upper Illinois River are obtained from Starved Rock State Park that stretches across forested bluffs south of the river.  Accessed from Illinois 71, this popular Park protects a spectacular landscape of cliffs, canyons and recessed caves, sculpted from Ordovician St. Peter Sandstone by torrents of water; most of the erosion occurred during the wet climate of the Pleistocene.  Indeed, the Illinois River Valley and those of its major tributaries are all products of glacial meltwater (including intermittent catastrophic floods) which peaked late in the Pleistocene (10-15 thousand years ago) as the Wisconsin Ice Sheets retreated into Canada.  The Park, which has both a Lodge and a Visitor Center, is accessed by 13 miles of trail loops which lead to overlooks atop the bluffs and into the magnificent chasms.

Named for a deadly confrontation between Native American tribes, Starved Rock State Park hosts a large number of bald eagles during the winter months and offers broad views of the Illinois River, which forms a wide lake behind the Starved Rock Locks & Dam; increasing numbers of American white pelicans congregate along the river during migrations as do a wide variety of waterfowl.  Today, raked by a gusty south wind, we enjoyed summer-like conditions at the Park; by evening, a potent cold front had pushed through the area, bringing rain and a rapid fall in the temperature.  It is, after all, late October.

Wednesday, October 24, 2012

Up the Illinois River

After zigzagging across the Mississippi floodplain, north of St. Peters, Missouri, we crossed the river on the Golden Eagle ferry as a bald eagle circled overhead.  A second ferry took us across the lower Illinois River and, after a lunch in Grafton, we paid a visit to Pere Marquette State Park, which is draped across forested bluffs east of the River.  A scenic drive takes visitors along the crest of the ridge and offers broad views across the Illinois' floodplain and adjacent terrain but the best views are obtained via trails that lead up and north from the Visitor Center; taking in the River and its associated wetlands, the spectacular vistas make one appreciate why this Midwestern stream is such a magnet for migrant waterfowl.

Heading north on Illinois Route 100, we visited parts of three National Wildlife Refuges: Two Rivers, Meredosia and Chautauqua.  All harbored large, mixed flocks of waterfowl, migrant white pelicans and a variety of shorebirds (primarily yellowlegs).  Bald eagles, great blue herons and a host of other waterbirds were also seen though I failed to spot any migrant cranes.  We're spending the night in Peoria and will continue our tour of the Illinois and its floodplain tomorrow.

The Illinois River may be the least appreciated of America's large rivers.  One often hears about the vast watershed of the Ohio-Missouri-Mississippi River System but most Americans know little about the Illinois and fail to appreciate the vital role that it plays in waterfowl migration.  Per mile, there may be more National Wildlife Refuges, State Wildlife Areas and nature preserves along the Illinois than any other American river.  Winding south-southwest through the heart of the Corn Belt (once a vast Tallgrass Prairie), this River and its spectacular floodplain appeals to human and avian travelers alike.

Tuesday, October 23, 2012

Duck Weather at Eagle Bluffs

This morning, I arrived at Eagle Bluffs Conservation Area, on the Missouri River floodplain, under a blanket of low clouds.  Curtains of rain swept across the refuge and the riverside hills were shrouded in mist.  It was a perfect day for ducks.

Yet, despite the date, approaching the peak of waterfowl migration, the major pools were relatively devoid of birds; only the occasional pied billed grebe and a few double-crested cormorants broke the surface of the calm, rain dappled channels.  Flocks of mallards, gadwall, blue-winged teal and northern pintails were found on the flooded crop fields and bands of coot nodded across the wetlands but, for late October, the waterfowl numbers were underwhelming.  Great blue herons, like water-logged sentries, hunched atop nest boxes, a lone black-crowned night heron flushed from a canal bank and a few belted kingfishers perched along the waterways, waiting out the deluge.  In the end, the only spectacle was provided by massive flocks of grackles and red-winged blackbirds that moved across the refuge.

While the birdwatching was a disappointment, the rain is more than welcome after our long drought.  We'll gladly trade in a dry, crisp, colorful autumn for an excessively wet and cloudy season.  After all, the ducks and geese will welcome those conditions and their migration has just begun.  There will be plenty more opportunities to enjoy their vocal congregations over the next two months.