Monday, April 30, 2012

Divisions of Hunting

To my knowledge, all States have a Division of Wildlife or a Department of Natural Resources, charged with protecting that State's native fauna and flora as well as cooperating with federal programs to manage wetlands for migrant waterfowl. Beyond their role in protecting open space, these State agencies also participate in the restoration of natural habitat and the reintroduction of once native species. In the course of doing so, they provide vital habitat for a wide range of plants and animals and extend the opportunity for many citizens to study and observe their wild neighbors.

Nevertheless, these Divisions and Departments are, to a large extent, funded by revenue from hunting licenses and their publications, while paying homage to a diversity of wildlife, tend to focus on hunting and fishing opportunities on the lands that they manage. Of course, one can be both a conservationist and a hunter and, unfortunately, hunting has become essential to the control of species such as white-tailed deer. We have, after all, eliminated the wild predators that once kept these populations in check.

Ideally, the reintroduction of native species would include an effort to balance predator and prey populations. However, U.S. Divisions of Wildlife have a long history of supporting the reintroduction of prey species while restricting or completely prohibiting the recovery of their natural predators; this policy appears to be a response to pressure from ranchers, who fear loss of their cattle or sheep, and a nod to hunters who relish the opportunity to control the herbivores themselves. Thus, State wildlife officials continue to reintroduce species such as moose and elk without bringing the wolves and cougars along; by doing so, they have become Divisions of Hunting, answerable primarily to those who fund their work.

Sunday, April 29, 2012

Caught on the Track

For the past 24 hours, a stationary front has stretched from the Southern Plains to the Great Lakes, separating cool, drier air to its northwest from warm, humid air to its southeast. Bisecting Missouri from southwest to northeast, it passes across the Columbia area, bringing intermittent heavy rain and thunderstorms as pulses of atmospheric instability have moved along the front.

Since the front is not connected to a potent storm system, tornadoes are unlikely but intense lightening, hail and periods of torrential rain have occurred and are expected to persist through the day. Of course, when these thunderstorms train along a stationary front, flooding often develops beneath their path and our creeks will soon be bank-full if the storm track does not bow northward or shift to the south and east.

On the positive side, the copious precipitation will nourish the verdant tide of spring, triggering an explosion of insects for the warbler wave and our returning summer residents. With hot, humid weather expected for the coming week, this steady dose of rain will also fuel the seasonal intensity of plant growth, insuring a healthy start for our woodlands and plenty of yardwork for suburbanites.

Saturday, April 28, 2012

The Illinois Basin

Like the Michigan and Permian Basins, the Illinois Basin is a structural bowl of Precambrian basement rock within which younger layers of sedimentary rock have accumulated. This bowl, which covers the southern 75% of Illinois, the southwestern 40% of Indiana, western Kentucky and a small portion of northwest Tennessee, is surrounded by structural "arches," uplifts of the deep, ancient Precambrian rock; these include the Kankakee Arch to the northeast, the Cincinnati Arch to the southeast, the Wisconsin Arch to the north, the Mississippi River Arch to the northwest, the Ozark Uplift to the west and the Pascola Arch to the southwest.

Three miles deep at its center, this broad basin of Precambrian rock, 1.3 billion years old, accumulated layers of sediment throughout much of the Paleozoic Era (from 600 to 270 million years ago); the great majority of these deposits occured within shallow seas, which invaded and retreated from the basin at least 50 times during that period, while others were carried in by streams or deposited within vast wetlands. As the basin filled in from the Cambrian to the Pennsylvanian Periods, these layers of sediment dipped from the surrounding arches toward the center of the structural depression; at the surface, older sediments are thus found at the periphery of the basin while the youngest (Pennsylvanian) cover its center. Following this prolonged period of deposition, which was intermittently disrupted by uplift and erosion, the Illinois Basin has undergone surface molding by the Pleistocene Glaciers and numerous streams; the glaciers flattened northern portions of the basin and coated them with a thick layer of glacial till while streams have carved southern portions into a maze of hills and valleys.

Travelling across the Illinois Basin today, one sees no evidence of the Precambrian bowl that underlies the region; indeed, its edge only outcrops in limited areas of southern Wisconsin and southeastern Missouri. Glacial erosion and till have produced the flat, productive Corn Belt across much of Illinois and western Indiana while Carboniferous sediments of the basin have been mined for their coal and drilled for their oil. As in most regions of our globe, the surface topography of the Illinois Basin only hints at the miles of sediment and complex geologic formations that lie below.

Tuesday, April 24, 2012

Sage Grouse Saga

Greater sage grouse, the largest grouse in North America, inhabit sage grasslands of the Intermountain West, from Colorado to the Columbia Plateau and from southern Alberta to southern Utah. Closely tied to their habitat, these grouse feed solely on the sage plant in the winter while supplementing that diet with a variety of forbs, insects and grasses during the warmer months. Unlike many game birds, they do not possess a muscular crop and cannot digest hard seeds.

Come spring, sage grouse gather in clearings (known as leks) at dawn and dusk, where the dominant males attract mates with ritualized strutting, tail fanning and a variety of noises from their air sacs; most of the females mate with only one or two of the performers. Nests are placed on the ground and females are solely responsible for both incubation and protection of the young; six to twelve eggs are generally produced. Able to forage soon after birth, the young are vulnerable to a wide range of predators, including snakes, prairie falcons, crows, magpies, badgers, coyotes, bobcats and owls.

Once abundant across the American West, greater sage grouse have long been threatened by habitat loss; their population, estimated to have been about 16 million in the early 1900s, has fallen to less than 500,000 today, a drop of 97% over the past century. The loss of sage grasslands to mining, ranching and oil production has been primarily responsible for this decline and efforts to list the greater sage grouse as an Endangered Species have been successfully blocked by Western Governors and their Federal colleagues. Perhaps a 99% population decline will be more convincing.

Monday, April 23, 2012

The Nature of Dissent

Dissent is the fortitude to challenge established doctrine, whether formulated by governments, religious organizations, industry or other social groups. While the leaders of those organizations often view dissent as a threat to their power, it is essential to the development and maintenance of fair and effective policies.

Reasoned and rationale dissent insures that laws are established and imposed without discriminating among social groups, whether based on gender, income, race, culture, religion or other human traits. Though often dismissed as rebellious or unpatriotic, dissent is vital to any democratic system and governments or organizations that attempt to suppress or limit its expression will eventually suffer the consequences.

The steady advance of human knowledge has always been guided by dissent, a willingness to question assumptions that, in the end, proved to be inaccurate. Nevertheless, at each stage of human civilization, social pressure offered resistance to such change and those courageous enough to dissent were persecuted for their ideas. Today, modern society retains that resistance and, while some nations are more democratic than others, the struggle for human enlightenment continues. Reasoned, nonviolent dissent is the key to removing our shackles.

Thursday, April 19, 2012

Back from Argentina

Swainson's hawks are back from their winter in Argentina. Working on our Littleton, Colorado, farm today, I observed several of these large buteos cavorting overhead, soaring, hovering and stooping, as if to display their pleasure in having completed a long migration. Indeed, making a roundtrip journey of more than 4000 miles each year, Swainson's hawks travel further between breeding and wintering grounds than any other American raptor (with the possible exception of Arctic breeding peregrine falcons).

Monogamous, these hawks are highly territorial during the breeding season and their high-pitched calls are commonly heard from the time of their arrival in spring until their chicks are fledged. Nests are generally constructed in large, solitary trees in open country and may be used repeatedly over the years. The female incubates the eggs and the male brings food during that time; once the chicks hatch, both parents hunt for food, which generally consists of small mammals, reptiles and birds throughout the breeding cycle. During the rest of the year, Swainson's hawks, despite their size, are known to prefer insects, feasting primarily on grasshoppers and dragonflies.

The summer breeding range of Swainson's hawks extends from western Minnesota, Iowa and Missouri to the Pacific Coast and from western Canada to northern Arizona, New Mexico and Texas. Though a bit smaller than red-tailed hawks, their long wings give them an eagle-like appearancer in flight and their plumage pattern (especially in the common white-phase subspecies) aids identification. By August, their territorial instincts have abated and Swainson's hawks begin to congregate in large flocks, drifting southward on their two month journey to the pampas of Argentina; there they have long been threatened by the use of DDT and other pesticides, highlighting the importance of international cooperation in efforts to conserve migratory birds. Fortunately, this practice has diminished and populations of this majestic buteo seem to have stabilized across most of its breeding range.

Wednesday, April 18, 2012

Warfare, Stress & Atrocities

Yet another story of U.S. military misbehavior in Afghanistan has surfaced today, at least the fourth revelation in the past year. Deplored by the Department of Defense, the Military Leadership and other Administration officials, the behavior was decried as an embarrassment to the United States and dismissed as not representative of the vast majority of American soldiers.

Of course, these reactions are expected and serve to assure the American public that such events are rare and that they undermine the goals of our vital mission. While many are shocked to learn of inhumane behavior by our troops, it is likely that these reports merely scratch the surface when it comes to the atrocities witnessed and/or performed by participants in human warfare. Enduring extreme stress, including the possibility of imminent death, it is understandable that soldiers lose touch with the personal boundaries that may have governed their civilian lives. To deny that humans are capable of such acts in the course of warfare is to close our eyes to the conditions under which they serve. It is only the brotherhood of soldiers that keeps us from learning about the majority of these incidents and it is generally through the effects of post-traumatic stress disorder that we catch a small glimpse of the mental anguish that war inflicts on the individual.

Rather than making an attempt to minimize the frequency or severity of the atrocities that occur in warfare, it is best that we publicly recognize both the immediate and long-term effects of combat on mental health and human behavior. The only effective means of eliminating these tragic events is to put an end to needless military intervention. The futility of our ongoing operations in Afghanistan has become clear to most Americans and, hopefully, will discourage similar engagements in the future. The deaths of so many young soldiers and innocent civilians, coupled with the life-long effects on those who survive, cannot justify what few benefits, if any, result from our nation-building crusade. Those who are the most vocal advocates of military intervention are generally those who never faced the extreme stress of warfare.

Monday, April 16, 2012

Long-Billed Curlews

While crossing the stormy Plains yesterday afternoon, I encountered a small flock of long-billed curlews, attempting to fly into the teeth of an icy north wind. After wintering along the western Gulf Coast, in South Texas, in Southern California or in Mexico, this largest American shorebird returns to grasslands of the High Plains, Great Basin and Columbia Plateau for the warmer months.

Once on their breeding grounds, couples engage in courtship rituals, including dances, looping flights and preliminary nest site scooping by the male. The female eventually selects one of his open ground sites, engages in additional scooping and collects a variety of plant materials to place in the floor of the depression. Four eggs are deposited and incubated by both parents; like many game birds, the young are able to move about and feed soon after hatching and are attended by both parents for a week or so. Thereafter, the female parent departs to join other wayward mothers and juveniles in large feeding flocks while the father stays to watch over the youngsters until they are fledged. The long, down-curved bill of this curlew is used to probe mudflats, wet meadows and sandy shallows for a variety of invertebrates (worms, insect larvae, shrimp, sand crabs) and small amphibians; they may also snare grasshoppers, crickets and other insects from the grass and occasionally consume the eggs of other prairie birds.

Once common in parts of the Eastern U.S., long-billed curlews have retreated westward due to over-hunting and habitat loss to agriculture; fortunately, the western populations seem to have stabilized but remain sensitive to the health of shortgrass ecosystems. Small numbers of long-billed curlews may turn up on Atlantic beaches during the fall and winter months where they can be distinguished from whimbrels by the curlew's larger size, longer bill and unstriped crown and from the occasional Eurasian curlew by the latter's darker plumage, white rump and heavily streaked breast; the cinnamon wing linings of long-billed curlews also aid identification when this large shorebird is in flight.

Sunday, April 15, 2012

Crossing the Storm

After stewing in the warm sector of our latest Pacific storm for 36 hours, enduring periods of heavy rain, intense thunderstorms and interludes of steamy sunshine, we left Columbia this morning, bound for our Littleton, Colorado farm. Having checked the Weather Channel before our departure, we noted that the storm system's upper level low was still centered over western Kansas and that its dry line, responsible for the wealth of tornadoes over the previous 24 hours, was about to reach Kansas City.

Fortunately, the severe weather was down in northeast Oklahoma and we left the balmy air of Missouri as we crossed through a modest band of rain showers and entered cooler, drier air in eastern Kansas. Sunny conditions persisted into central Kansas but once we reached the Smoky Hills Wind Farm, its massive turbines spinning in a strong south wind, a band of clouds appeared across the western horizon. We soon realized that the clouds represented the eastern wall of the storm's low pressure swirl; produced by uplift and rotating counterclockwise around the center of low pressure, the direction of cloud movement changed as we continued west along I-70. Moving northward in central Kansas, the clouds were coming from the west in western Kansas and were drifting southward in eastern Colorado. Finally, as we neared the Front Range, upslope showers developed as a northeast wind from the atmospheric swirl pushed humid air toward the Palmer Divide and Front Range foothills. Rising, cooling and condensing, this upslope flow produced snow showers above 7000 feet and sleety rain on the High Plains.

An eleven hour (800 mile) drive had taken us from balmy, 70 degree F air on the west edge of the storm system to chilly showers of rain and sleet on its western rim. En route, we crossed all of the storm's component air masses and directly witnessed the atmospheric swirl of its central low. What better way to appreciate the structure and power of these massive storm systems?

Saturday, April 14, 2012

Nostalgic Birding

When I pull out my old Birds of North America, by Robbins et al., words such as Lonoke, Keo and Scott appear in the margins, indicating first sightings of various birds. These are towns east of Little Rock where my birding jaunts increased significantly in the early 1980s. On my visit to eastern Arkansas this past week I was thus anxious to revisit these areas, recognizing their importance in my life and hoping to relive some of those birding memories.

As one might expect after 30 years, the landscape had changed, though not nearly as much as one might find in large urban areas of the country. Development had taken its toll on some of the fields and wetlands that I had once explored while access to others had been withdrawn. Just west of Lonoke, a large group of man-made catfish ponds had once been the local hotspot for waterfowl viewing and it was there that I first saw many species; while the ponds and ducks remain, "private property" and "no trespassing" signs now rise at every entry point and all viewing must occur from the bordering roadways. Wetlands south of Scott, my favored site for herons, egrets and other waders, are now unrecognizable, surrounded or replaced by housing developments to the point that I could not locate my old birding haunt. Of course, the farmlands that introduced me to many raptors and shorebirds remain intact and, on my visit, a huge flock of lesser golden plovers had stopped to forage on a muddy field.

Such efforts to feed our nostalgic urges often lead to mixed and disappointing results. We humans tend to erase the landscape of our past and, in the case of natural habitats, wildlife that depended on them must relocate or adapt to human development; of course, some fail to do so and their population suffers accordingly. Until we become more committed to the protection of open space, the welfare of our wild neighbors will be threatened and those of us who enjoy their company will be unable to revisit our past.

Friday, April 13, 2012

A Stormy Morning at Eagle Bluffs

Veteran birders know that high winds and heavy rain are the least favorable weather conditions for productive birding since most birds will take cover until conditions improve. Then again, if you plan to observe aquatic species from the comfort of your car, rainy weather can have its advantages. Waterfowl and waders could care less about the presence of rain and some birds, such as rails, are best seen on dark, cloudy, rainy days.

With such positive thoughts in mind, I headed down to Eagle Bluffs Conservation Area this morning, a superb wetland refuge on the floodplain of the Missouri River. To my surprise, I was greeted on the entry road by a scissor-tailed flycatcher, the first I had ever encountered in central Missouri. As expected in mid April, the waterfowl were abundant, dominated by northern shovelers, blue-winged teal and American coot; some wintering species were also present, including lesser scaup, ring-necked ducks and a few canvasbacks. Other aquatic birds included a large number of double-crested cormorants, a fair number of pied-billed grebes and a lone white pelican. Shorebirds were scattered about the mudflats and flooded fields, dominated by lesser yellowlegs, and, as if to support my rationale for visiting, a pair of soras foraged along the edge of the cattails, dipping in and out of cover.

Otherwise, muskrats went about the morning chores, great blue herons and great egrets stalked the shallows and northern harriers hunted low across the fields. Summer birds may have returned to the bottomland woods but, due of the intermittent lightening, I was reluctant to leave my pickup and they were likely waiting out the storm. Not a bad morning on the floodplain, despite the weather!

Thursday, April 12, 2012

Bald Knob NWR

Many nature buffs are familiar with National Wildlife Refuges such as Horicon, Squaw Creek and Aransas. But there are many others that evade the attention of the general public, some of which are close to home and readily accessible. One such refuge is Bald Knob NWR, just east of Searcy, Arkansas (and south of Bald Knob), at the western edge of the Coastal Plain. Established less than 20 years ago to protect wetlands along the Little Red River, this refuge blends with the the Henry Gray/Hurricane Lake WMA, to its east; spring flooding along the White and Little Red Rivers often precludes entry to southern and eastern sections of the combined preserves.

Characterized by agricultural fields, man-made ponds, sloughs and bottomland timber, the Bald Knob NWR is accessed by a network of graveled roads and earthen trails, most of which run atop levees. On my visit this morning I encountered mixed flocks of ducks and coot, migrant shorebirds, numerous killdeer and a flock of at least 100 American white pelicans; as is typical, the pelicans waited for mid-morning thermals before taking to the air and soaring above the refuge. The highlight of my visit was provided by a lone peregrine falcon that repeatedly strafed and spooked the waterfowl.

Access to Bald Knob NWR is best achieved from the city of Bald Knob, a few miles northeast of Searcy on US Highway 67. From the downtown area, turn south on Hickory St., which becomes Coal Chute Road, the northern entry road for the refuge; during periods of spring flooding, this may be the only route of access.

Wednesday, April 11, 2012

White River NWR

The bad news? White River NWR is currently flooded and almost totally inaccessible to humans without boats. The good news? White River NWR is currently flooded and is almost totally inaccessible to humans. How refreshing to discover that we have at least one portion of a major river that has not been channelized, dammed or corralled by levees for the benefit of human recreation. And, of course, letting rivers flood is essential to protecting what little remains of bottomland forests along the Mississippi Valley and elsewhere on our planet.

Established in 1935 to protect wintering habitat for waterfowl as well as this remaining tract of swamp forest, White River NWR hosts up to 350,000 ducks and geese each winter and is home to a wide range of wildlife, including American alligators, black bears, bald eagles and, possibly, ivory-billed woodpeckers. Though my observations were limited to fringe areas today, graveled roads and five trails provide access to the heart of the refuge when conditions permit. For those who have not visited in the past, I suggest a stop at the refuge Visitor Center, in St. Charles, Arkansas, to obtain maps and to find out what areas might be open to the public; some sections are closed from November through February to protect wintering waterfowl from human disturbance.

Nearly 90 miles long and up to 10 miles wide, White River NWR harbors a vibrant ecosystem; in addition to the vast bottomland, hardwood forest are numerous lakes, ponds, sloughs, bayous and marshlands. Wading birds, especially common and varied during the warmer months, are present throughout the year, as are barred owls, pileated woodpeckers, belted kingfishers and red-headed woodpeckers. In spring, prothonotary warblers, scarlet tanagers, yellow-breasted chats, yellow-billed cuckoos and a host of other summer songbirds add color to the deep, dark woods.

Tuesday, April 10, 2012

From Ozarks to Coastal Plain

Leaving Columbia this morning, I headed south on U.S. 63 and crossed the Missouri River at Jefferson City. After jogging east to cross the Osage River, this highway turns south once again, climbing into the Ozarks between the valleys of the Osage and Gasconade Rivers; dipping to cross the latter north of Rolla, it finally reaches the hydrologic divide of the Missouri Ozarks at Cabool, passing from the watershed of the Big Piney River (a secondary tributary of the Missouri) to the watershed of the White River of northern and eastern Arkansas.

At Batesville, Arkansas, I stopped to photograph the White River as it emerges from the Ozarks; though not as well known as our major Midwestern Rivers, the White is a large and powerful stream, taking in copious flow from both northern Arkansas and much of southern Missouri. Indeed, all through eastern Arkansas, signs near the White River warn drivers not to cross flooded roads and, this year, the river has spilled across its floodplain just east of Des Arc.

The Coastal Plain of eastern Arkansas is a mosaic of crop fields, wooded bayous, cypress swamps and stands of pine. Today, plumes of dust rose from this flat landscape as massive plows tilled the dry agricultural fields. Though I did not stop at any particular birding sites today, I observed a large number of scissor-tailed flycatchers on the powerlines and saw huge, mixed flocks of shorebirds in the flooded rice paddies. Tomorrow I'll visit the White River National Wildlife Refuge and then re-visit some of my old birding haunts east of Little Rock.

Monday, April 9, 2012

White River of Arkansas

Just over 720 miles long, the White River heads on the north slope of the Boston Mountains in northwest Arkansas. Flowing north and gathering tributaries, it passes through Beaver Lake and then loops across extreme southwest Missouri, primarily within Table Rock Lake and Bull Shoals Reservoir.

Dipping back into Arkansas, the White River receives the flow of the Buffalo River, which drains the eastern portion of the Boston Mountains, and then joins the North Fork of the White, which carries runoff from much of south-central Missouri before passing through Norfolk Lake. At Batesville, Arkansas, the White River leaves the Ozark Uplift and enters the broad, flat Coastal Plain of North America, coursing east to merge with waters of the Black River and then winding SSE all the way to its junction with the Mississippi (just north of the latter's junction with the Arkansas River). En route, it takes in flow from the Little Red River, coming from central Arkansas, and numerous meandering streams and bayous across the Coastal Plain.

The southernmost section of the White River snakes through the White River National Wildlife Refuge, a landscape of dense swamp forests on the Mississippi floodplain. The refuge will be my destination this week as I embark on my annual spring road trip. After following the White River from southern Missouri to its mouth at the Mississippi, I plan to return through my old birding grounds along the Arkansas Valley, east of Little Rock, where I honed my skills back in the early 1980s. Details to follow in the coming days!

Sunday, April 8, 2012

Easter Awakening

By the spring of my 28th year, I was bored with the rituals of the Catholic Mass and had come to renounce the vindictive God of Western religions. So, on that Easter morning, I elected to forego a church service and paid a visit to our local arboretum. There, undistracted by public piety, I found solitude, natural beauty and quiet inspiration.

On that mild, sunny morning, I walked slowly through the forest, stopping on occasion to listen to the birds or to view the spring wildflowers. Approaching a secluded pond, I caught sight of a mother wood duck and her brood, gliding silently across the calm water. It was that encounter, thirty four years ago yet still clear in my memory, that set the stage for the naturalist philosopy that I have since adopted. Ever since that Easter morning at the arboretum, nature has been my church.

Beyond relishing the peace and inspiration offered by the natural world, I have come to despise the divisive force of organized religion, which, by its very nature, promotes discrimination and intolerance. On this annual celebration of rebirth, I am grateful for the Easter awakening that changed my life so many years ago.

Saturday, April 7, 2012

Bombay Hook NWR

One of the most renowned birding locations along the Eastern Seabord, Bombay Hook NWR stretches along the northwest shore of Delaware Bay, about 10 miles northeast of Dover. Established in 1937 to protect wetlands for migrant and wintering waterfowl, this 16,200 acre refuge offers spectacular wildlife viewing throughout the year.

From mid April through early June, large, mixed flocks of shorebirds descend on Bombay Hook as they make their way toward Arctic breeding grounds. Attracted by the vast tidal marshes and mudflats of the refuge, they are also drawn by the nutritious eggs of horseshoe crabs which fill the shallows in May. Joining the shorebirds are a wide variety of waders, gulls, terns, raptors and migrant songbirds. Among the many species that nest at Bombay Hook are bald eagles, ospreys, clapper and Virginia rails, least and American bitterns, black-necked stilts, barn owls, sedge and marsh wrens, blue grosbeaks, fish crows, seaside sparrows and salt marsh sharp-tailed sparrows. By autumn, huge flocks of geese and ducks descend on the refuge.

Access to the tidal marshes, freshwater pools, cordgrass meadows and wooded swamps is provided by a 12-mile auto tour road, which begins near the Visitor Center; five trails, boardwalks and three observations towers are also provided for visitors. Bombay Hook NWR is open from dawn until dusk every day of the year; an entrance fee is charged.

Friday, April 6, 2012

Mountain Bluebirds

By April, mountain bluebirds are returning to Colorado, having wintered on the Southern High Plains or in the Desert Southwest. The sky blue males are the first to arrive, searching for nest cavities which they use to attract a mate; those settling in the foothills, canyons and mountain valleys must compete with western bluebirds and violet-green swallows for those treasured sites.

Once the grayish females arrive, mountain bluebirds pair off and begin their nesting activities; while the males provide token assistance, the female takes charge of the nest construction, most often tucked within a tree cavity but sometimes in a rock crevice or a gap in an old cabin. Favoring open woodlands, mountain bluebirds may be found from the ponderosa parklands of the Colorado foothills to the krummholz at the alpine timberline; those that nest at lower elevations sometimes raise a second brood later in the summer.

Mountain bluebirds breed and summer in the mountain ranges of western North America, from Alaska to New Mexico. Like other bluebirds, they usually hunt from a perch, dropping to the ground to snare insects; they also snatch their prey in mid-air and mountain bluebirds often hover above their quarry before striking. During the colder months, all bluebird species supplement their diet with berries. Mountain bluebirds are especially nomadic in late summer and early autumn, regularly appearing on the Great Plains and, occaionally, in the eastern U.S.

Thursday, April 5, 2012

April Encore

April, last seen in central Missouri back in early March, has returned to the Heartland. Cool and showery weather, more typical for this time of year, has displaced the summer-like warmth that dominated the last few weeks. As I walked into a chilly east wind and misty air this morning, it was 47 degrees F; today's high should stay in the fifties and tonight's low is expected to dip into the thirties.

The culprit for this dose of reality is a potent upper level low, the same system that produced the Texas tornadoes and Front Range snow earlier this week. Now parked over the central Mississippi Valley, it is pulling down cool air from the Great Lakes region while also drawing moisture from the Gulf of Mexico and Atlantic Ocean. As a result, thunderstorms will rumple across the Deep South while the rest of the eastern U.S. will experience the seasonal invasion of chilly April showers.

After the exceptional heat of March, many in the Midwest and East likely anticipated an unbroken run through summer and may have packed away the sweaters and parkas. But the extended forecast suggests that April weather will hang on for at least another week, just in time for the Opening Day of baseball and the Masters Golf Tournament, cultural symbols of the American spring.

Wednesday, April 4, 2012

Urban Tornadoes

Most Americans over age 50 associate tornadoes with open country, posing a risk to cropfields, barns and small, rural communities. We long assumed that these spectacular storms could only develop over flat terrain and that the varied topography of cities would tear them apart.

However, in recent decades, as occurred yesterday in Dallas, we have witnessed an increasing impact of tornadoes on large, urban centers. Some surely see God's hand in this apparent turn of events, punishment for the decadence and sinful behavior of the urban elite; perhaps the storms are directed toward Planned Parenthood Centers or non-Christian communities.

In reality, this increased incidence of urban tornadoes reflects the same process that threatens the Florida panther and corrals prairie dogs into tiny plots across Metro Denver. Suburban sprawl and commercial development are eliminating vast tracts of open space, urban areas are merging with one another and natural habitat is rapidly disappearing. The tornadoes that once tore across prairie, forest and farmland are now cutting swaths of destruction through our ever-expanding cities. As a result, the cost imposed by these storms, both in terms of damage to structures and the loss of human life, will continue to rise.

Tuesday, April 3, 2012

The Western Ibis

Cousin to the glossy ibis of the Southeastern U.S., the white-faced ibis winters along the Gulf Coast (from Louisiana to Texas), in valley wetlands of central and southern California and in Mexico. While some are permanent residents in these areas, most migrate through the central and western U.S. to breed on freshwater wetlands of the Northern Plains and Intermountain West.

Since wetland conditions tend to vary across the dry country of the Western U.S., these nomadic migrants are opportunistic, choosing their colonial nest sites based on the conditions that they find; for this reason, their numbers in any given area varies widely from year to year. Preferring broad, shallow wetlands with islands of vegetation, white-faced ibis nest in marsh grasses or in low trees along the shore. Both parents incubate the 3-4 eggs and participate in feeding regurgitated insects, worms, amphibians and small fish to the nestlings; the young are fledged within a month and are self sufficient by August.

Known to wander widely in late summer, small flocks of white-faced ibis turn up in the eastern U.S. on occasion but generally return to their traditional wintering grounds by mid autumn. Peak spring migrations across the Great Plains generally occur from mid April to early May and it is then that most of us encounter these attractive birds, stopping to rest and feed on shallow lakes, braided rivers or flooded fields.

Monday, April 2, 2012

Lake Missoula & the Channeled Scablands

Near the end of the Pleistocene Ice Age, about 13,000 years ago, a lobe of the Cordilleran Glacier that covered the Rocky Mountains blocked the flow of the Clark Fork River, in northwestern Montana. Behind this dam of ice, a massive lake developed; 200 miles long and 2000 feet deep, Glacial Lake Missoula contained 500 cubic miles of glacial meltwater.

Eventually, the ice dam failed and a torrent of water rushed across the Idaho Panhandle, eastern Washington and the Columbia River Valley. In fact, as the glacier advanced and retreated over 2500 years, the lake repeatedly formed and drained, eroding the Channeled Scablands of the Columbia Plateau. Characterized by broad, braided canyons, dry falls, rippled rock formations, massive gravel bars and countless erratic boulders, this unique topography attests to the power of the recurrent floods; indeed, the Columbia River Gorge was primarily carved by these torrents.

While similar glacial lake floods occured elsewhere across the Northern Hemisphere (including the Bonneville Flood of southern Idaho), none were as powerful as those arising from Lake Missoula. Geologists and hydrologists estimate that the flow of these deluge events (which numbered three dozen or more) exceeded the current total flow of all rivers on Earth and emptied the Lake within a few days.

Sunday, April 1, 2012

Fooled by March

This may be April Fools Day but March did the fooling this year. April first is so thirty days ago!

Thanks to our exceptionally warm weather in late winter and early spring, April begins as many of its annual flowers have already come and gone. Here in central Missouri, it looks like May and feels like June. Were it not for the lack of summer birds, still waiting for their solar cue to come north, we'd have no April events to anticipate.

Whether or not winter will attempt a token return to the Heartland remains uncertain but our average last freeze is rapidly approaching. It appears that old man winter concentrated on the Eastern Hemisphere this year and that we might experience one of the longest frost-free periods on record, beginning back in February and, perhaps, lasting until October. Then again, the jet stream could shift and we might endure the coolest summer in recorded history; such possibilities fuel our interest in nature's fickle behavior and discourage complacency.