Wednesday, February 27, 2013

Nature's Handiwork

Unlike Winter Storm Q, which brought windswept pellet snow to our region and left behind a scenic landscape, its successor dropped heavy wet snow on Missouri, producing slushy roads and taking down tree limbs and power lines; we lost several large branches from our beloved magnolia, among other damage.

Yet, this has always been nature's way of molding the landscape; she may consist of uncountable fragile components but her means of rearranging the planet can be dramatic and heavy-handed.  We marvel at her canyons, mountains, plains, wetlands and seascapes without giving much consideration to the floods, earthquakes, hurricanes, blizzards, glaciers, wildfires and tectonic forces that were instrumental in their creation.  Though these natural forces have been molding Earth's landscapes for 4.6 billion years, it has only been during the last few thousand years, when they have impacted human ecosystems, that they have come to be known as natural disasters.

We humans have learned to monitor and predict some aspects of nature's fury but we are powerless to prevent them from impacting our lives.  What we can do is to avoid putting ourselves in harms way by heeding the forecasts of meteorologists and climatologists, stop building homes in high risk areas, adopt technologies that are shown to be protective and, most importantly, learn to respect nature's power and acknowledge its essential role in the ongoing evolution of our magnificent planet.

Tuesday, February 26, 2013

Feeder Magnetism

During periods of heavy snow, as has occurred in Columbia this week, backyard feeders are especially effective at attracting a wide variety of birds.  A few days ago, I reported that a fox sparrow had joined our common winter songbirds and, since that time, a small flock of American tree sparrows has also stopped by to feast on the handouts (the first I have encountered on our suburban property).

In addition, the commotion near the feeder brings in other birds that have no interest in the sunflower seed but sense that food availability is attracting their neighbors.  In the last couple of days, eastern bluebirds, yellow-rumped warblers and a pileated woodpecker have graced our modest-sized parcel of land.  Of course, the large concentration of songbirds may also catch the attention of their predators, especially Cooper's and sharp-shinned hawks.

Beginning birdwatchers soon realize that a backyard feeder is the quickest way to expand their life list, introducing them to many common species that they had overlooked in the past.  Veteran birders, on the other hand, know that artificial feeders are a magnet for common residents and uncommon visitors alike and are generally the sites at which rare "accidental" species are first observed and photographed.  The potential for these rare finds is what keeps experienced birders focused on their feeders, especially when heavy snowstorms send in their quarry.

Monday, February 25, 2013

Twin of Q

Before Winter Storm Q has completely departed the Northeast, its twin, nicknamed Rocky by the Weather Channel, is spinning over the Texas Panhandle, producing blizzard conditions from western Kansas to northeastern New Mexico.  As the day progresses, this smaller but more tightly wound storm will move to the northeast, drawing in moisture from the Gulf of Mexico and spreading a rain-snow mix in advance of its cold front.

The heaviest snow (12-18 inches) is expected to fall from Wichita to Kansas City and, here in central Missouri, we are promised another 4-8 inches atop the remnants of Q that still coat our lawns and choke our side streets.  Yet, it's hard to complain about the much needed precipitation and we won't know until tomorrow morning what this twin storm has wrought; rain showers are expected to begin this afternoon, changing to steady snow overnight and throughout most of Tuesday.

Indeed, it appears that the drought pattern of the past 18 months has finally broken.  The high pressure dome that diverted Pacific storms to the north of the Great Plains has faded away and the typical track of late winter and early spring storms appears to have returned.  In other words, while the drought has not yet resolved, the stagnant weather pattern that produced it has broken down; if Q and its twin are reliable omens of change, soil moisture, river flows and reservoir levels will gradually return to normal across the American Heartland.

Sunday, February 24, 2013

Australian Volcanism

Most of the active volcanoes on Earth occur along subduction zones of the Pacific Rim and western Indonesia.  Others rise above hotspots (both oceanic and terrestrial), atop mid-oceanic ridges (Iceland) and at continental rift zones (e.g. the East African Rift and Rio Grande Rift).  Examples of these geophysical processes can be found in parts of the Americas, Europe, Asia, Africa and across the major oceans of planet Earth; however, one does not generally associate volcanism with Australia, which lies far from active plate boundaries.

Nevertheless, volcanic terrain is found throughout eastern Australia, from northern Queensland to Tasmania and South Australia.  The many volcanic centers, now extinct or dormant, were produced by a cluster of hotspots over which the Continent has moved during the past 40 million years.  Since the Australian Plate is moving slowly to the NNE, the oldest volcanic sites are in the north while the youngest are near the southern coast; indeed, the most recent volcanic eruption on the Continent occurred more than 4000 years ago, in South Australia.  Some of the southernmost volcanoes are dormant (not completely extinct) and may erupt again.

While active volcanism is not currently found on the Australian Continent, it will eventually return when a dormant volcano reactivates or in the form of a new hotspot or rift zone, either of which would be triggered by a new mantle plume.  In the meantime, Australian Territory does possess active volcanism at the Heard and McDonald Islands, a volcanic island group in the Southern Ocean, some 2500 miles southwest of Perth and 1000 miles north of Antarctica.

Saturday, February 23, 2013

A Conspicuous Visitor

The heavy snow cover across central Missouri has dramatically increased visitors to our backyard feeder.  After all, when natural food sources (i.e. plant seeds) are less available, birds are more inclined to take advantage of our handouts.

The usual mix of songbirds have made their appearance, dominated by house finches, chickadees, titmice, white-throated and house sparrows, cardinals, mourning doves, juncos, Carolina wrens and white-breasted nuthatches.  Blue jays, downy, hairy and red-bellied woodpeckers, purple finches and American goldfinches have also stopped by for the sunflower seed.  Joining these common winter residents, a large, handsome fox sparrow has been especially conspicuous.

Fox sparrows breed in the coniferous woodlands of northern Canada, Alaska and the mountain corridors of the American West, wintering across the southern half of the U.S. and along the Pacific Coast.  While they feed primarily on insects and other small invertebrates during the warmer months, scratching beneath shrubs and thickets for their prey, fox sparrows switch to a diet of seeds and berries in winter and may turn up at backyard feeders, where they search for fallen morsels on the ground.  On their wintering grounds, these large sparrows, which have a wide range of plumage colors and patterns, are generally solitary and, in my experience, most often visit feeders in late February or March.  Of course, this hardy and handsome visitor is welcome anytime.

Friday, February 22, 2013

Human Colonization of Australia

Current DNA evidence suggests that humans evolved in East Africa about 130,000 years ago and did not migrate from our home continent until 80,000 years ago; at that time, expansion of the Sahara would have discouraged migration to the north and it is thought that they followed the coast of the Red Sea (or crossed a shallow portion of that channel) and then the southern coast of Asia, reaching Indonesia about 70,000 years ago.

By that time, the Wisconsin Glaciation was underway and sea levels were much lower than they are today.  In fact, the islands of Indonesia were joined to form a broad peninsula and New Guinea was continuous with the Australian Continent.  While the oldest human fossils found in Australia date from 40,000 years ago, artifact evidence suggests that humans first reached that Continent between 60,000 and 55,000 years ago.  Since there is no evidence of human seafaring before the Phoenician and Polynesian cultures developed, some 4000-3500 years ago, it is presumed that the first human Australians, having crossed at least 50 miles of open sea, arrived accidentally, perhaps swept southward by a tropical storm.  Of course, others may have set out on rafts to find them and met the same fate.

Until additional evidence is discovered, the timing and circumstance of man's initial colonization of Australia will remain uncertain.  It is known (via DNA evidence) that native populations of New Guinea and Australia share a common ancestry (though the islands separated 8000 years ago as sea levels rose) and that humans occupied all regions of Australia, including Tasmania, by 30,000 years ago.  Of course, we also know that the earliest European settlement was established in 1788, at least 53,000 years after the first humans set foot on the Continent.

Thursday, February 21, 2013

Thundersnow in Missouri

Winter Storm Q lived up to its forecast, dumping a foot of snow in Columbia.  The powdery flakes began to fall about 7:30 AM and, by late morning, snow was accumulating at a rate of 3 inches per hour, accompanied by frequent lightening and thunder.

Thundersnow, an uncommon phenomenon, is most likely to occur in late winter or early spring, when a potent storm system mixes relatively warm, moist air at the surface with cold, drier air aloft; the lightening and thunder usually develop during periods of intense snow, as occurred today.

A dry wedge has entered our region over the past hour and should last until "backside" flurries pass through later this evening; since the storm's central low is moving rapidly off to the northeast, we may miss any additional precipitation.  Nevertheless, the heavy blanket of snow, which stretches from west-central Kansas to western Illinois, should put a significant dent in our prolonged drought.  Unfortunately, to our south, a swath of ice, from eastern Oklahoma to the Ohio Valley was not as beneficial and severe thunderstorms, some tornadic, continue to rumble along the Gulf Coastal Plain.

Wednesday, February 20, 2013

A Gathering Storm

Winter storm Q, so named by the Weather Channel, was spinning over Southern California this morning, bringing snow to the Sierra Nevada, the Transverse Ranges and the mountains east of Los Angeles and San Diego.  As it moves eastward, crossing the Desert Southwest, the storm will blanket the Mogollon Rim and the Southern Rockies before moving onto the Plains.

There it's counterclockwise winds will sweep Gulf Moisture toward the Front Range, producing heavy snow across the High Plains and, to a lesser extent, along the Front Range urban corridor.  While Pacific storms generally produce a warm, southerly flow in advance of their cold front, a dome of high pressure, centered over the northern Great Lakes, has locked the Midwest and Great Plains in its icy grip, negating the usual pre-storm warmup.  As a result, the storm is forecast to move eastward across the Southern Plains, lifting Gulf moisture above the entrenched, sub-freezing air; where the surface layer of cold air is thin, from Oklahoma to Kentucky and Tennessee, an ice storm may develop while, to the north, where the Arctic layer is thick, heavy snow is expected.

Here in Missouri, the southern part of the State will likely receive an icy mix of sleet and freezing rain while central and northern latitudes can expect anywhere from 4 to 12 inches of snow.  Though travel may become hazardous, the heavy snow will be welcomed, especially across the drought plagued regions of the Great Plains.  Within a few days significant melting should occur, returning moisture to the parched soil and depleted reservoirs.  Hopefully, more southern storms will arrive in the coming months.

Tuesday, February 19, 2013

Trouble on the Mekong

The Mekong River of Southeast Asia rises on the southeastern edge of the Tibetan Plateau and flows SSE for more than 2700 miles to its delta on the South China Sea.  From its source, more than 17,000 feet above sea level, the Upper Mekong drops through steep, narrow canyons in China's Yunnan Province; by the time it leaves China and becomes a slower, wider river, meandering through a broad floodplain, the Mekong has dropped more than 14,000 feet.

The Lower Mekong flows along and/or through five countries: Myanmar, Laos, Thailand, Cambodia and Vietnam.  Crossing its subtropical and tropical corridor, this portion of the Mekong has produced and sustained one of the most biologically diverse ecosystems on our planet.  Renowned for its large fish species, the primary channel and its tributaries support rich wetlands, vital to a spectacular variety of aquatic plant and animal life; seasonal flooding along the Mekong has played an essential role in the evolution and ongoing welfare of this riverine ecosystem.

While four dams stretch across the Upper Mekong, in China, the Lower Mekong has, to date, not been channelized or dammed.  Nevertheless, hydroelectric dams have been constructed on many of its tributaries and, despite the establishment of the Mekong River Commission (in 1995) and the efforts of regional and international conservation organizations, plans are moving along for at least a dozen dams on the Lower Mekong.  Spurred on by the financial benefits of hydroelectric power (to be consumed primarily in Thailand and India), the countries of Southeast Asia are tempted to overlook the impact of these dams on the ecology and culture of their region.  International Rivers, listed with other conservation organizations in the right column of this blog, has been highly involved in the struggle to protect the Lower Mekong and your support is encouraged.

Monday, February 18, 2013

Origin of the Pacific Ocean

When the continental land masses merged into Pangea at the end of the Paleozoic Era, some 250 million years ago (MYA), that supercontinent was surrounded by the Panthalassic Ocean, a global ocean that was already 500 million years old; indeed, it had torn apart the supercontinent of Rodinia near the end of the Precambrian Period, about 750 MYA.

Before Pangea began to rift apart, the Panthalassic Ocean was composed of three major oceanic plates, separated by a network of oceanic ridges.  The northern, relatively small plate was the Kula Plate; the Farallon Plate stretched eastward from the central, north-south ridge while the present-day Pacific is the remnant of the plate west of that ridge.  Beginning in the Triassic Period (200 MYA) and continuing today, the opening of other oceans, including the Tethys, Atlantic and Indian Oceans, forced segments of the Panthalassic Ocean to subduct beneath the North American, South American, Eurasian and Australian Plates.  The Kula Plate has all but disappeared beneath the northwestern segment of the North American Plate while most of the Farallon Plate has subducted beneath the western edge of the North American, Caribbean and South American Plates; the Juan de Fuca Plate of the Pacific Northwest, the Cocos Plate off the west coast of Central America and the Nazca Plate off the western coast of South America are remnants of the once massive Farallon Plate.

In effect, the opening of the Atlantic Ocean (which began about 160 MYA) has pushed the American Plates westward and they now overlie the eastern half of the ancient Panthallasic Ocean, leaving (for now) the Pacific Plate and small remnants of the Kula and Farallon Plates.  The residual portion of the central oceanic ridge, known today as the East Pacific Rise, remains an active spreading zone, forcing the Pacific Plate to the northwest and the Farallon remnants to the east.  Like all past dominant oceans, the Pacific will eventually disappear, subducting entirely as younger oceans become the primary engines of continental drift.  Perhaps 200 million years from now the East African Rift will have produced the largest ocean on Earth.

Sunday, February 17, 2013

Pelican Parade at Eagle Bluffs

Yesterday morning, it was sunny and cold at the Eagle Bluffs Conservation Area on the Missouri River floodplain; the temperature was 25 degrees F.  Though one does not generally associate pelicans with such conditions, a flock of twenty American white pelicans huddled on a mudflat.

Then, about 10:30 AM, a series of large flocks began to arrive from the south, totaling 1500 individuals or more.  Unlike the noisy flocks of Canada, snow and white-fronted geese, the stately pelicans drifted by in silence, flapping and gliding above the primary channel of the refuge.  About 200 of the migrants dropped to join the resting flock but most continued up the Missouri River Valley, headed toward breeding grounds across the Northern Plains of the U.S. and Canada; they will surely stop to rest and feed at other refuges along the way.

When we first moved to Missouri, 15 years ago, I would encounter occasional small flocks of American white pelicans in late March or April and again in late summer as they migrated between their breeding grounds and wintering areas along the Gulf Coast.  In recent years, however, they have begun arriving earlier in the "spring" and huge flocks have been stopping at Eagle Bluffs.  Yesterday's spectacular pelican parade appears to be the new norm.

Saturday, February 16, 2013

Cosmic Missiles

Yesterday's spectacular meteor explosion over Russia and the near miss of a sizable asteroid (which passed closer to Earth than our communication satellites) were reminders that we live in an active and potentially dangerous Universe.  Like the tragic tsunamis, earthquakes, volcanic eruptions and superstorms of the past few decades, they confirm the fact that the evolution of our planet did not end when humans appeared.

While the meteor and asteroid were unrelated, their arrival on the same day had a significant impact on the complacency of human society, forcing us to face threats over which we have little control and, in the case of small meteors, no warning.  Indeed, the Earth impacts tons of meteor-producing debris every day (left behind by comets and asteroids) though most meteors burn up in the the atmosphere before reaching the surface of our planet.  Fortunately, impacts from large asteroids, like the eruption of supervolcanoes, are rare events (even from the perspective of geologic history) but, when they do occur, they threaten all life on Earth, including human civilization.

Fortunately, the meteor explosion over Russia did not result in any fatalities (based on initial reports).  Nevertheless, it traumatized local residents and, via the power of international communication, sent shock waves across the globe.  On the positive side, this cosmic missile provided a jolt of reality, a clear message that we are not a chosen species; in other words, we are not immune from sudden annihilation.

Friday, February 15, 2013

The Panama Connection

While some controversy remains, most geologists believe that Panama initially formed as a peninsula of Central America, projecting southward along the southwestern edge of the Caribbean Plate.  It is thought to have formed primarily from two periods of subduction volcanism and oceanic crust accretion involving the oceanic Farallon Plate, now represented by the Cocos and Nazca Plates off Central and South America, respectively.  The first period is thought to have occurred from the late Cretaceous into the early Tertiary, some 70-50 million years ago (MYA), while the the latter began in the Miocene (about 20 MYA) and continued intermittently until about 4 MYA.

At that point, the southern tip of the peninsula began to collide with the northwest edge of the South American Plate, crumpling both regions and bending Panama into its current shape, a curving east-west strip of land separating the Caribbean Sea from the Pacific Ocean.  The formation of this Isthmus had a dramatic effect on ocean currents and, most climatologists believe, on our planet's climate.  In particular, the Gulf Stream began to bathe western Europe with its mild flow, significantly warming the climate of that region; at the same time, this ocean current brought copious moisture to the Arctic region, dramatically increasing snowfall and, in concert with other factors, precipitating the Pleistocene Ice Age.  Indeed, current geologic evidence indicates that the Isthmus of Panama blocked the Atlantic-Pacific seaway between 3.5 and 3.0 MYA and that the Pleistocene Ice Age began 2.2 MYA.

Finally, when Panama joined North and South America, flora and fauna from those Continents began to mix.  Armadillos, opossums and tapirs spread northward into Central America while rhinos, llamas and other northern species moved into South America.  Among these migrants were human beings, which crossed from Siberia into North America about 20,000 years ago (via the Bering Land Bridge) and had colonized South America before the last Pleistocene Ice Sheets retreated into Canada, some 12,000 years ago.

Thursday, February 14, 2013

The Nature of Adventure

Adventure is the opportunity to explore the unknown, an exciting experience that may entail risk.  It follows that adventurous individuals are those who relish such exploration, whether it involves new places, new relationships, new careers or new ideas.

When it comes to travel, one need not visit distant, exotic locations to experience the thrill of adventure.  There are plenty of areas close to home that invite exploration: untraveled roads, un-hiked trails and unvisited parks or nature preserves are common sources of adventure, even for experienced naturalists.  Of course, since the unknown is inherent in any excursion, whether to a new or familiar destination, a sense of adventure accompanies all journeys, from wilderness backpacking trips to a walk through the neighborhood park.

Those who recognize the adventure in any excursion are more likely to focus on the details of their surroundings, including the landscape, topography, vegetation and wildlife.  By doing so, they come to appreciate the magnificent diversity of our planet and, in turn, their own life is enriched.  After all, life itself is an adventure, filled with unexpected twists and turns; if we are open to those challenges, willing to explore untraveled avenues, we are rewarded with a better understanding of ourselves, our fellow man and our natural environment.

Wednesday, February 13, 2013

Vanguard of White-Fronts

Flocks of snow geese have been passing over central Missouri for a week now and I observed several more at Eagle Bluffs Conservation Area yesterday afternoon.  As on my visit the previous week, an excellent variety of ducks and raptors were also encountered and, following a trend in recent years, a squadron of American white pelicans was already visiting the refuge.

Then, about 2 PM, a large flock of greater white-fronted geese arrived from the south, the first that I have seen this season.  After circling the floodplain refuge for twenty minutes or so, they settled down in a shallow lake surrounded by marsh and tall grasses; there they joined a flock of northern pintails, a handful of snow geese and a mix of other puddle ducks.  They were soon followed by two more flocks of white-fronts which, having spotted their cohorts, were less skittish about dropping into the sheltered marsh.

Greater white-fronted geese breed on the Arctic tundra across Alaska and Canada and winter on crop fields and coastal marshes from southern California to Louisiana, including northern Mexico; migrations are generally west of the Mississippi Valley though a Greenland population of white-fronted geese may winter along the Atlantic Coast.  Their spring migration through Missouri usually peaks from late February into early March and yesterday's flocks were the vanguard of what has become an annual spectacle in our State; indeed, the number of greater white-fronts is increasing in North America and massive flocks may be encountered along the Missouri River Valley.

Tuesday, February 12, 2013

Depth of the Great Lakes

Scooped from Precambrian and early Paleozoic bedrock by the Pleistocene glaciers, the Great Lake basins of North America have varied subsurface topography.  Like the ocean floor, their depth varies dramatically from one region to another.

Lake Superior, largest of the Great Lakes in both volume and surface area, has an average depth of 483 feet and a maximum depth of 1332 feet; the latter is in the east-central part of the lake, just ENE of the tip of the Keweenaw Peninsula.  Lake Michigan has an average depth of 279 feet and a maximum depth of 923 feet between the central Door County Peninsula of Wisconsin and Frankfort, Michigan.  Lake Huron's average depth is 195 feet and its deepest section (750 feet) is along its eastern edge, just west of Ontario's Bruce Peninsula.  Lake Erie is the shallowest of the Great Lakes, having an average depth of only 62 feet; its deepest pool (210 feet) is near its eastern end.  Finally, Lake Ontario, while the smallest of the Great Lakes in area, ranks second in average depth (283 feet) and has a maximum depth of 802 feet in its eastern section.

While the basins of the Great Lakes will gradually fill with sediment and may be rearranged when glaciers return to the Upper Midwest, the surface shape and hydrology of the lakes may be altered by another factor.  As southern Canada continues to rebound from the weight of the Wisconsin Ice Sheets, the basins are tipping toward the southwest and, eventually, may drain into the Mississippi via the Illinois River corridor.

Monday, February 11, 2013

Polynesian Migration

When humans first reached Southeast Asia, some 70,000 years ago, most of Indonesia was a broad peninsula; in like manner, due to the lower sea levels of the late Pleistocene, Taiwan and Japan were connected to the mainland via land bridges.  Then, as the glaciers melted and sea levels rose, Indonesia became a vast archipelago and both Taiwan and Japan were cut off from the Asian mainland.

About 3500 years ago, a seafaring culture arose in Southeast Asia, initially exploring island chains throughout the western Pacific; current archeological and genetic evidence suggests that they were closely related to the ancestral residents of Taiwan.  By 3000 years ago, these adventurous sailors, using catamaran-like craft, reached Fiji and Samoa; a thousand years later they had colonized the Society Islands (which include Tahiti) and, by 1800 years ago, had settled in the Marquesas Islands, further east.  Polynesians reached the Hawaiian Islands about 1500 years ago, Easter Island 1200 years ago and New Zealand 800 years ago.

It is humbling to know what these early human explorers achieved without the advantages of modern technology; indeed, many present-day Americans seem unable to navigate their home towns without the aid of GPS.  European explorers would not reach the far-flung settlements of Polynesia until the 1500s and modern citizens of the globe, pampered by centuries of human progress, need only endure a long plane flight to visit these Pacific archipelagos.

Sunday, February 10, 2013

Rooting for Champions

While I am a fan of many college sports, I am not especially devoted to any particular team.  And when it comes to the professional leagues, I lost interest after my baseball card days in Cincinnati; I'm frankly amazed that anyone is emotionally tied to teams on which many of the players change squads every year.

Though it is politically correct to root for the underdog, unless one's alma mater or home team is favored, I generally prefer to see the best team win.  Of course, it's more enjoyable to watch a close match than a blowout, but, in the end, I want the better team or individual to prevail.  After all, underdog victories are generally due to a poor performance by the favored contestant.

My inclination to root for the champion is surely tied to my naturalist philosophy.  In nature, the best equipped species or pack member is the victor (unless luck intervenes) and those of us who are students of nature admire traits that favor victory and survival.  Nature is not sentimental; she has no interest in how the game is played and only rewards the winner.  In the end, the purpose of life is to protect and pass along our genes; second place is often fatal and extinction is not an option.

Saturday, February 9, 2013

Mark Twain Mergansers

The Salt River and its numerous tributaries drain a large part of northeastern Missouri, flowing eastward to join the Mississippi just north of Louisiana, Missouri.  In 1962, Congress authorized construction of the Clarence Cannon Dam on the Salt River, producing Mark Twain Lake just south of that famous author's birthplace (in Florida, Missouri).

Yesterday, my wife and I headed northeastward from Columbia to visit the Lake and its scenic basin.  Our journey was beneath a low, gray overcast through which multiple flocks of snow geese wandered in various directions, seemingly disoriented by the opaque sky.  Across the Glaciated Plain, red-tailed hawks lounged in barren trees, American kestrels hunted from powerlines and massive flocks of starlings swirled above the rolling farmlands.  A cold, north breeze swept across Mark Twain Lake where a mix of waterfowl fed in the shallows and a dozen or more bald eagles perched along the shoreline or fished on the open waters.  But the highlight of our visit was the large number of common mergansers, which were especially abundant on some of the north shore coves.

These large diving ducks, equipped with long, thin, serrated bills, are native to woodland lakes and rivers across southern Alaska, Canada, the northern tier of the U.S. and the Cascade, Sierra Nevada and Rocky Mountain corridors.  In winter, they migrate to large lakes, reservoirs and rivers throughout most of the United States where they gather in sizable flocks to feast on freshwater fish and crustaceans.  Unlike their red-breasted cousins, common mergansers are seldom found on brackish bays or estuaries.

Friday, February 8, 2013

Northeast Blizzard

Yesterday, a chilly rain fell across Missouri on the south side of a winter storm that was centered over eastern Iowa; north of that central low, snow was falling across the Great Lakes region.  Meanwhile, a second, stronger storm was spinning over southwest Georgia, dragging in copious moisture from the Gulf of Mexico and igniting thunderstorms across the Southeast.

By noon today, these storms are forecast to merge along the Mid-Atlantic Coast, producing a potent winter storm system that will move to the northeast, producing heavy snow throughout New England and blizzard conditions along the Northeast Coast, from New York to Maine.  Storm surge is expected to be severe in Massachusetts and snowfall totals may exceed two feet throughout the eastern half of New England as well as in the mountains of Vermont, New Hampshire and Maine.  Good news for the ski resorts but a nightmare for the larger cities and their transportation hubs.

Potent Nor'Easters tend to occur in late autumn and early spring when an unstable jet stream favors the clash of cold, dry and warm, humid air masses.  Counterclockwise winds, whipping around the central low, pull in Atlantic moisture and force it above cold air at the surface, unleashing heavy snowfall.  These same winds, strongest near the center of the storm, combine with the intense snow to produce blizzard conditions and shove ocean water toward the coast, spawning a destructive storm surge.  The peak of the storm should occur from late this evening into the morning hours on Saturday before the system moves out to sea.

Thursday, February 7, 2013

Nature's Audio Recovery

As the cold, quiet season begins to lose its grip and inches toward the north, nature's varied noisemakers are greeting the first signs of spring.  Morning birdsong, led by robins, cardinals and Carolina wrens, has a fervor not heard since mid September; even blue jays are tuning up their musical voice, in sharp contrast to their raucous shrieks of winter.  Not to be ignored, northern flickers are practicing their first, tentative calls of the season which, by March, will explode into loud, hysterical monologues.

Out in the wetlands, male red-winged blackbirds will soon begin their incessant song of spring and, by the end of the month,  upland chorus frogs and spring peepers will dominate the airwaves.  In the open countryside, red-tailed hawks have paired off, delivering their sharp mating cries as they cavort above the fields and meadows.  And, as if on cue, the first wavering flocks of snow geese are passing over the Heartland, their high-pitched calls echoing from the cold, February sky.

This varied audio of spring will intensify through June as avian migrants and summer residents stream into the American Midwest and a host of amphibians add their voices to the chorus.  Then, as heat and humidity build in July, the noise will gradually fade; by mid summer, only the insects will have the energy to sing.

Wednesday, February 6, 2013

Black Bears in Missouri

It's February and the next generation of Missouri black bears is arriving in dens throughout the wooded hills of the Ozarks.  How many are out there remains uncertain but their numbers are surely increasing; indeed, more than 3000 black bears inhabit Arkansas (see below) and it is reasonable to believe that at least 300 have spread into Missouri.

Native to Missouri, black bears were thought to have been extirpated from the State by the 1940s, primarily due to overhunting and habitat loss.  Then, Arkansas initiated a black bear reintroduction program (importing 256 bears from Canada and Minnesota during the period from1958-1968); since that time, the bears have gradually expanded their range into southern Missouri.  Ongoing studies, conducted by the Missouri Department of Conservation, the U.S. Fish & Wildlife Service and the University of Missouri, indicate that Missouri's black bear population is concentrated in the Ozarks (especially south of I-44) though individual sightings have been documented throughout much of the State.  In recent years, Missouri black bear research has included DNA analysis and, contrary to past assumptions, this data suggests that a small native population managed to survive, having since bred with the Arkansas immigrants.

Mother bears will emerge with their cubs (usually 2 or 3) in April; females without cubs mate by late spring but implantation of the fertilized eggs is delayed until autumn and, as noted above, the cubs are born in February.  Black bears (25% of which are actually brown in the Ozark population) are naturally wary of humans and will avoid contact whenever possible; however, they are attracted to hives, food-containing compost and edible garbage; homeowners and campers are advised to bear-proof such sites and to never feed bears or encourage their visits.  Mothers with cubs are especially dangerous though, to date, black bear attacks on humans have not been reported in Missouri.

Monday, February 4, 2013

Before the Snows

On this bright, cool morning at Eagle Bluffs Conservation Area, southwest of Columbia, snow geese had not yet graced the Missouri River floodplain.  On the other hand, ducks and raptors were abundant.

While some ponds remain frozen, open channels attracted a wide variety of ducks, dominated by mallards, gadwalls and northern shovelers; a fair number of green-winged teal and northern pintails were also present.  Large flocks of Canada geese fed on the open grasslands, great blue herons waded in the shallows, belted kingfishers chattered above the waterways and white-tailed deer raced through the corn stubble.  Surveying all of this activity were four adult bald eagles, a few American kestrels, a handful of red-shouldered hawks and the usual abundance of northern harriers and red-tailed hawks.

The snows should begin to arrive over the next week, followed by white-fronted geese later in the month.  March and April will bring American white pelicans, sandhill cranes, the peak of duck and grebe migration and the arrival of early shorebirds.  Spring and autumn waterfowl migrations are, for me, the highlights of nature's year and its a joy to know that the semiannual spectacle will soon unfold.  For now, a bit of patience is in order.

Sunday, February 3, 2013

Cedar Creek Bluffs

Cedar Creek snakes southward through central Missouri, forming the border between Boone and Callaway Counties, before entering the Missouri River just upstream from Jefferson City.  Southeast of Columbia, on its way through the Mark Twain National Forest, this creek has exposed cliffs of Mississippian Limestone, deposited in shallow seas some 320 million years ago (an era of fern forests, vast swamps, giant amphibians and the first winged insects).

One of many trails within the State Forest begins at the east end of Route H (2.4 miles east of Englewood, Missouri).  After crossing the old Rutherford Bridge, it climbs the east wall of the Cedar Creek Valley via a jeep road and then cuts away to the right, paralleling the stream toward the south.  Within a short distance, this trail provides access to a number of scenic overlooks atop the limestone bluffs, perfect sites for birdwatching, nature photography or a picnic lunch.

Popular during the warmer months and throughout the colorful days of autumn, this area is all but abandoned during the winter.  As at many nature preserves across the country, humans underestimate the advantages of winter hiking, which include open vistas, solitude, good footing and the absence of annoying insects.  Yesterday, we enjoyed a three-mile, round-trip hike through the oak-cedar forest, serenaded by winter songbirds and undisturbed by other humans.  Sitting atop the limestone bluffs in the cool sunshine of early February, we looked out across the Cedar Creek Valley, so close yet so far from the noise and congestion of city life.

Saturday, February 2, 2013

Nadir of the Year

For human residents of the Northern Hemisphere, early February is often viewed as the low point of the year,  We are, after all, tropical creatures and, while many of us enjoy winter weather, a craving for mild, sunny days seeps from our DNA.

Indeed, early February often brings the coldest weather of the year and blizzards seem to be especially common during this maligned month.  Of course, the fact that it is followed by the first calendar month of spring seems to slow its progress, despite its reduced allotment of days.  Ground Hog Day, Superbowl Sunday and Valentines Day offer little compensation for this final gauntlet of frigid weather and our yearning for the mild fragrance of spring only augments our discomfort during the raw days of late winter.

Yet, for the naturalist, February has much to offer.  Skunk cabbage pushes through the cold soil of our icy wetlands while crocuses, hyacinths and snowdrops bring the first wave of color to our suburban lawns and flower beds.  Vocal flocks of snow geese, moving northward through the frigid air, instill hope in our winter-weary souls and the lengthening daylight confirms our steady, if uneven, march toward spring.  In the woodlands, great horned owls attend to their downy youngsters while, later in the month, the din of tree frogs gradually intensifies throughout our marshlands.  Why rush toward the mud of March, the violent storms of May and the stifling heat of summer when February has so many gifts to enjoy?

Friday, February 1, 2013

Preying on the Weak

Throughout the animal kingdom, predators tend to prey on the weak: the young, the old, the frail, the injured or the sick.  Biologists and ecologists point out the benefits of this behavior; the predator expends less energy to obtain nourishment and its culling of the weak improves the overall health of the prey population.

We humans, natural predators that we are, also prey on the weak.  In some developing countries, hobbled by ineffective or corrupt governments, sweat shops and child labor fuel economic benefits for the elite.  In other societies, caste systems determine one's opportunities, ensuring that lower class citizens do not climb the social ladder, regardless of their talent and work ethic.  Even in the United States, the champion of personal freedom and capitalist philosophy, undocumented workers are exploited for their hard work and low wages; in most cases, social benefits are withheld and their illegal status insures that abuse will not be reported.

Then there is the practice of targeting those weakened by ignorance, desperation or addiction, a lucrative tool of the tobacco, alcohol and gambling industries (their advertisement disclaimers notwithstanding). Taking a cue from corporate leaders, State governments have joined the fray, encouraging citizens (especially the desperate, naive and impoverished) to risk limited resources on the lottery, a means to fund projects without the hassle and uncertainty of election-dependent taxation.  Unlike the predator-prey relationship observed in natural ecosystems, there is no evidence that human predation on the weak benefits society; indeed, there is plenty of evidence to the contrary.