Owls in a Steam Bath

Immersed in another heat wave, it was 82 degrees F at six this morning and the afternoon high is expected to reach 100 degrees. Combined with the high humidity, this heat has enveloped central Missouri in an atmospheric steam bath.

Yet, as I left for work in the predawn haze, two barred owls called from the nearby woods. Unlike their great horned cousins, these owls are often heard throughout the year and, in early spring, frequently call during the daylight hours. Even so, their questioning voices seemed out of place in the soupy air of a Midwest summer.

The owls will retreat to shaded roosts before the morning sun fuels the damp inferno, re-emerging tonight to hunt for mice and cottontails. We admire their hardiness during the frigid months of winter and, trapped in this steam bath, I appreciated their visit this morning; their distinctive calls reassured me that the cool, refreshing days of autumn are on the distant horizon.

The Joy of Flight

Most birds use their natural flight capability to move about, migrate, escape predators and attack prey; but some, at least for part of their day, appear to indulge in the pure joy of flight.

Eagles, vultures and buteos are perhaps the most notable participants, soaring above the landscape for hours at a time with no apparent purpose other than surfing the wind. Others include various gulls, petrels, white pelicans and kites; one might also give a nod to frigatebirds and albatrosses but their physical limitations on land keep them aloft.

Of course, hardcore evolutionary biologists will attribute this nonfuntional activity to the natural instinct to exercise flight muscles but most of us know whimsical behavior when we see it. After all, humans have envied this avian capability throughout our history and have attempted to mimic their aerial freedom with parachutes, gliders and a wide variety of aircraft. Alas, we will never fully experience the joy of flight that our feathered neighbors have inherited.

The Ground Cuckoo

Natives of Mexico and the Desert Southwest, greater roadrunners have spread eastward and northward over the past Century and now reside in California's Central Valley, across the Southern Plains, in western portions of Louisiana and Arkansas and in the glade country of southwest Missouri. Unlike their North American cousins, the yellow-billed and black-billed cuckoos, which feed primarily on caterpillars and migrate south for the colder months, roadrunners are omniverous and occupy their range throughout the year.

Easily identified by their classic silhouette, shaggy crest, streaked plumage and long tail, these birds have relatively small wings and rarely take flight; rather, equipped with long, powerful legs, they outrun their prey and predators. Food sources include berries, seeds, insects, scorpions, lizards, snakes and small mammals; renowned for their willingness to attack rattlesnakes, roadrunners often cooperate to make a kill. Nests, consisting of sticks and dry grass, are placed in low shrubs or cacti and 3-5 eggs are usually produced.

Well known to generations of children as the nemesis of Wile E. Coyote, this ground cuckoo may fall victim to hawks, golden eagles, owls and, yes, coyotes; human vehicles also take a significant toll. Nevertheless, the North American population of greater roadrunners is on rise and this resourceful bird will likely spread further north in the coming decades.

An Evening Kite Display

Stepping onto our back deck last evening, I caught site of three hawks circling in the distance. Initially assuming they were red-tails, I soon realized that they were smaller, more agile birds. Though they did not manifest the jerky flight of nighthawks, I was leaning toward that identification when one of them suddenly went into a steep dive before careening upward to rejoin the others. Wondering if they might be falcons, I rushed in to grab my binoculars and was able to study their distant forms in more detail; their long, tapered wings were relatively narrow and dark colored, their bodies were light gray and their buteo-like tail was black. Our mystery visitors were, in fact, Mississippi kites.

Recently confined to southern regions of the U.S., these raptors have spread to the north and west, now inhabiting open woodlands and tree-studded wetlands from Iowa to southeast Colorado and from the Desert Southwest to the Gulf Coast. Highly sociable, they often nest in colonies, building platforms of sticks and grass in trees near open fields or marshlands. Like nighthawks, they feed on large, flying insects and are frequently observed in groups, soaring and diving above their feeding grounds.

By late summer, Mississippi kites congregate in large flocks and soon depart for wintering areas in South America. My chance encounter yesterday has reminded me of their presence in central Missouri and I'll be sure to watch for these aerial acrobats on my local field trips.

The Nature of Haboobs

Haboobs are dense, atmospheric walls of dust or sand that are encountered in arid regions across the globe. Ironically, they usually develop during the monsoon season when downdrafts from nearby thunderstorms produce outflow gust fronts that sweep particulates into the air. Moving out from the central storm, the imposing wall may be a mile or more high and closes in at 30-50 miles per hour, producing a visual doomsday effect.

Though short-lived, haboobs dramatically reduce visibility and, while they may bring destructive winds and induce breathing difficulty, their primary danger results from the rapid loss of visibility, leading to vehicular accidents. Fortunately, they can usually be spotted from a safe distance and modern radar systems provide ample warning of their development, reducing the occurrence of injuries and fatalities.

Yesterday's haboob in Phoenix, Arizona, was spawned by a cluster of thunderstorms northwest of Tucson. According to the Weather Service, this arc of dust and sand was 60 miles across, one of the more spectacular haboobs to strike the Desert Southwest in recent years.

The Masked Warbler

One of the most common and widespread warblers in North American, common yellowthroats breed from southeast Alaska to Newfoundland and from the Subarctic treeline to the Gulf Coast. Though they have a preference for marshes, wet meadows and riparian thickets, these small birds also inhabit dry washes of the Desert Southwest and can be found in the lower canyons of western foothills.

The male common yellowthroat is easily identified, sporting a wide black mask across his eyes, which separates a white stripe on his forehead from his bright yellow throat and chest; females are more drab in color, with an olive back and yellow throat, but may have a faint mask as well. Common yellowthroats stay close to the ground, hunting insects among the thickets, cattails, tall grass or shrubs; their loose nest of grass and plant debris is often placed directly on the ground, where both parents incubate the eggs (usually 3 to 5). Since these warblers often remain secluded in dense vegetation, it is their distinctive "witchity-witchity-whitchity" song or sharp chips that first reveal their presence.

Come September, common yellowthroats that breed at northern latitudes depart for the Coastal Plain, Southern California, Mexico or Central America, where their insect prey remains active throughout the year. Until then, we'll enjoy the presence of these energetic, noisy and colorful songbirds in our wetlands and along our streams.

Moose in Colorado

When 12 moose were transplanted to North Park from Utah, in March, 1978, there was a general consensus among State Wildlife officials that these large herbivores had never been common in Colorado. In early 1979, another 18 moose were brought to the upper watershed of the North Platte River from Wyoming and, unchallenged by natural predators (wolves and grizzlies), the herd blossomed to 600 individuals by the mid 1990s; in fact, by that time, the moose had spread across the Rabbit Ears and Park Ranges, colonizing the Upper Colorado, Fraser and Upper Yampa river valleys.

Gratified by the success of this reintroduction program, the Division of Wildlife initiated a moose hunting program and transported some of the herd to the Upper Rio Grande Valley, near Creede. Continued expansion of the Colorado moose population has prompted additional transplantations within the State, including the establishment of a herd atop Grand Mesa, east of Grand Junction. Today, estimates of the Colorado moose population range from 1600 to 2000 individuals, likely far more than ever inhabited this portion of the Southern Rockies.

As one who has been interested in wildlife conservation for most of my life, I have gradually come to the conclusion that Federal and State Wildlife Departments are more closely aligned with hunting, fishing and tourism interests than they are with those who truly understand our natural ecosystems. Wildlife conservation programs must pay close attention to the balance of predator and prey populations; the rapid expansion of Colorado's moose herd over the past 30 years will surely produce negative consequences.

Tropical Storm Dynamics

The development of a tropical storm is dependent upon three factors: warm ocean waters, hot, humid air at the surface and light upper-level winds. For these reasons, early season Atlantic hurricanes usually develop in the relatively shallow waters of the Gulf of Mexico, across the Caribbean and along the Southeast Coast of the U.S. While tropical waves begin to move westward, out of Africa, in early summer, they encounter cool waters in the central Atlantic and tropical storms do not usually develop; by August, the ocean temperature has increased and the peak of the Atlantic hurricane season begins, continuing through September and into mid October.

Once a tropical storm develops, favorable conditions, discussed above, may cause it to strengthen into a hurricane. Conversely, if the storm moves into cooler waters, makes landfall or encounters strong upper level winds, the storm dynamics break down and the system weakens or dissipates. In some cases, favorable conditions may be re-encountered and the storm may redevelop; this occasionally occurs in Central America, when Gulf of Mexico storms weaken over land and then re-blossom in the eastern Pacific.

Global warming may extend the hurricane season by producing warm ocean waters earlier in the summer and later in the fall. Then again, climate change might alter upper level wind patterns, shifting the zone of tropical storm development and impact. Time will tell.

Humans & Heat

Native to the Tropics, we humans are better equipped to deal with heat than with the cold; indeed, given shade and adequate water, we can survive in temperatures near 130 degrees F for limited periods of time. Nevertheless, heat waves kill more Americans each year than any other form of weather, including tornadoes, hurricanes and floods.

The elderly are most prone to heat-related illness and death; their aging bodies are less capable of dissipating heat and efforts to do so place significant stress on their cardiovascular system. The other population at risk is the young athlete; blinded by the immortality of youth or prodded on by an ignorant coach, they exercise during the heat of the day and, despite fluid intake, court heat exhaustion or heat stroke.

Human tribes that inhabit hot desert regions or tropical areas know to escape from the sun during the afternoon hours. Wearing light-colored, loose-fitting clothes, they adopt the habit of mid-day siestas, retreating to shaded areas and consuming plenty of water. Advanced human societies, though equipped with air-conditioned buildings, have less appreciation for the danger of heat and, too often, suffer the consequences.

A Summer Clipper

During the winter months, most Americans in the central and eastern U.S. dread Alberta Clippers, those pockets of frigid, Arctic air that plummet southeastward to reinforce the seasonal chill. Over the past 36 hours, we have enjoyed the summer equivalent of those clippers; a trough of cool, Canadian air has dipped across the Midwest, pushing the hot, humid air of late June to the south and east.

Unlike the winter invasion, this Summer Clipper is a welcome reprieve, bringing drier air with highs in the upper 70s to low 80s. Unfortunately, like its winter cousin, its effects will be short-lived as the atmospheric trough moves rapidly off to the east and conditions moderate. Indeed, our next heat wave will develop over the coming days, sweeping the thick air of summer back into the Heartland.

While weather patterns are more stable in winter and summer than they are in the spring and fall, the jet stream is a fickle beast and sudden shifts in its course trigger these Canadian invasions. Depending on the season and on our personal perspective, they may be viewed as gifts or as unwelcome intrusions.

No Equipment Required

Anyone who watches cable TV is subjected to numerous ads for exercise equipment; these infomercials offer a vast array of devices that promise a lean, muscular physique, often with little effort on the part of those who use them. In fact, the human body is already equipped with the features needed to produce and maintain physical fitness.

Our musculoskeletal system, under the control of our nervous system, allows us to walk, run, swim, jump, climb and engage in a wide range of physical activities, all of which combat obesity, tone muscles and improve aerobic conditioning. Stair climbing is an excellent example of efficient, no-cost exercise that burns calories, strengthens muscles and benefits the cardiovascular system. For most adults, walking and swimming are the best forms of exercise, offering many benefits with little risk of injury; younger or more fit individuals might add jogging, situps, pushups and a variety of aerobic exercises but, in the end, no external equipment is necessary.

Of course, humans purchase and use a wide variety of things that are not required for their personal welfare and many succumb to the promise of six-pack abs and tight, muscular butts. It is, after all, better to exercise with that magical equipment than to spend the day on the couch.

The Nature of Child Abuse

Mention child abuse and most people think of pedophiles, sweat shops and child prostitution. But there are more insidious and widespread forms that are often overlooked, if not condoned, by human societies.

Parental belief systems and lifestyle choices have a significant impact on the present and future welfare of innocent children. In some cases, these victims are denied access to proper healthcare or education while, in others, poor habits such as overeating, tobacco use and inactivity are instilled. Many children are indoctrinated with various forms of discrimination, whether based on race, gender or sexual orientation and ingrained religious dogma is a common source of fear, guilt and low self esteem.

While many adults overlook these widespread forms of child abuse, they are, in the end, the catalysts for most of our social and political problems. Unless we rescue children from the climate of ignorance and intolerance that envelops their formative years, all future intervention will likely be in vain.

Cicada Aftermath

Returning to central Missouri after a brief visit to Florida, we found twigs and clumps of leaves scattered across the lawn; also noticing numerous broken stems in the canopy of some trees (especially the maples and mimosas), we initially assumed that a powerful wind storm had passed through Columbia. On closer inspection, however, we saw grooves on the underside of these terminal branches, indicating that cicadas had produced the damage.

Though their adult life is limited to a week or two, female cicadas can cause significant damage to young trees and shrubs by carving a linear trough along terminal stems in which to lay their eggs. Since tender shoots are favored, young trees are more severely affected and, in some cases, the numerous wounds are fatal. The massive number of periodical cicadas is especially devastating to regional vegetation while the annual cicadas, just now emerging, produce limited damage.

We often ponder how each plant and animal species plays a unique role in nature's delicate balance but uncovering the importance of periodical cicadas, which spend 13 or 17 years beneath the soil followed by 2 weeks of frenzied mating and tree damage, is a challenge indeed. Their mass emergence may play a role in soil aeration, their huge numbers provide a welcome bounty for many birds and mammals and their glut of rotting bodies may be a valuable source of nutrients for growing plants; however, the associated damage to trees makes one wonder if these benefits outweigh their cost to the ecosystem. Then again, cicadas, like all other species, are focused on the survival of their genes, not on the welfare of their natural environment. They may not realize it and we may not like it but, so far, they have been very successful at evading extinction.

Into Thick Air

Invited to a family wedding in South Florida, we returned to Longboat Key this week, leaving the hot weather of the Midwest for the equally hot but more humid air of the Subtropics. With lows in the mid 70s (F) and highs in the low 90s, summer is not the ideal time to visit this area.

While winter is the quiet season in more northern latitudes, it is summer that subdues the wildlife of South Florida, causing some species to disperse to the Northern Gulf and Mid Atlantic regions. On the beaches, shorebirds are limited to small groups of turnstones and willets, joined by the solitary great blue herons and yellow-crowned night herons that stalk the shore. Small flocks of royal terns and laughing gulls, extremely vocal for much of the year, now hunt in relative silence or lounge in docile groups on the baking sand. Brown pelicans, always rather mute, patrol the coast in silent squadrons, diving now and then to grab a meal.

Away from the beach, white ibis monitor broods of growing youngsters, favoring shaded lawns, mangroves and the shallows of streams, ponds or backwater coves to escape the heat. Magnificent frigatebirds soar high overhead, avoiding the hot, thick air at the surface, ospreys retreat to the relative comfort of islands in the bay and, except for red-bellied woodpeckers and wandering flocks of parakeets, the songbirds are reclusive and quiescent. Thunderstorms, which form over the Gulf and build as they move onshore, offer temporary relief but the intense sunshine of South Florida soon converts their refreshing showers to a blanket of suffocating steam.

Human Paternalism

Father's Day seems like a good time to reflect on our paternalistic approach to other species. Self-designated caretakers of the planet, we often interfere with the lives of "lower" animals, rescuing them from natural predators, storms and other threats that play an important role in the balance of ecosystems.

Of course, we must try to minimize unnatural human impact on animal populations; poaching, pollution and habitat destruction via agriculture or development are continuous threats to their welfare. On the other hand, our tendency to micromanage the natural environment by culling predators, introducing alien species or directly interfering with the life cycle of other species is frought with danger. Even our humane attempts to feed orphaned creatures or rescue beached whales is ill-advised; nature is not sentimental and the adversity suffered by one animal may be a crucial bounty for another.

If we truly care about the health of natural ecosystems, it is best that we leave them alone as much as possible. Our role should be limited to the protection and restoration of habitat and the control of human activities that threaten wild populations. When our structures, chemicals or behavior are responsible for the injury or entrapment of animals, rescue is appropriate; otherwise, it is best to let nature take control, however uncomfortable that may be to witness.

Colorado's Alpine Wildlife

In Colorado, the alpine timberline lies at about 11,500 feet, somewhat higher on south-facing slopes and a bit lower on shaded, northern flanks of the mountains. This biologic barrier, characterized by krummholz (stunted, wind-shaped conifers) and pockets of bristlecone pine, marks the upper edge of the Subalpine Zone; above timberline is the alpine tundra, a sun-drenched ecosystem of lichen-splattered rocks, glacial lakes, tussock grass, cushion plants and an amazing diversity of wildflowers.

Ravens are the most conspicuous birds of the alpine tundra, joined by American pipits, horned larks, mountain bluebirds and those ubiquitous American robins during the warmer months. White-tailed ptarmigan, though difficult to spot, are also fairly common and brown-capped rosy finches congregate near the rock-rimmed lakes. Avian hunters include golden eagles, prairie falcons and northern goshawks and the open woodlands of timberline attract white-crowned sparrows, Wilson's warblers, Clark's nutcrackers, pine grosbeaks, Cassin's finches and olive-sided flycatchers. Mammals of the alpine tundra include elk (primarily bachelor herds), mule deer, bighorn sheep, yellow-bellied marmots, pikas, short-tailed weasels, golden-mantled ground squirrels, chipmunks, coyotes and the occasional mountain lion; mountain goats have been introduced in some areas and are expanding their range.

When the snows of autumn arrive in the Alpine Zone, most birds depart for southern climes or migrate to lower elevations and most mammals den up, hibernate or descend to the milder life zones of the Rocky Mountain corridor. By winter, only the ptarmigan, ravens and mountain goats are evident amidst the frigid snowscape of the alpine tundra.

Landscape & Soul

As a child, in Cincinnati, I was always attracted to images of the West, whether they appeared on calendars, in Life Magazine or on our black and white TV. Since my family only vacationed on Lake Erie or along the Gulf Coast, I did not have a chance to visit the Western U.S. until I was twenty-five, the year that my wife and I took a road trip to interview at medical residency programs.

In that fall of 1975, we headed west on I-40 and finally escaped the humid air and greenery of the East in western Oklahoma. My first glimpse of western mountains came as we approached Albuquerque and, over the next week, we circled through the desert landscapes of New Mexico and Arizona. Turning northward, we climbed across the Mogollon Rim, passed the snow-capped summits of the San Francisco Peaks and visited the spectacular scenery of Grand Canyon, Zion and Bryce Canyon National Parks. For me, the emotional zenith came as we rounded the north edge of the Mt. Nebo massif, in Utah, and the Wasatch Front unfolded, towering above the Salt Lake basin; John Denver was singing Calypso on the radio and I was suddenly sure that I belonged in the Mountain West.

Like most naturalists, I enjoy visiting the varied ecosystems of our home planet and I know that many humans prefer lush forests, rolling prairies, pristine beaches or vibrant wetlands. But I'll take the dry air, stark beauty, and magnificent landscape of the American West, far from the site of my birth but very near to my soul.

The Non-Prairie Warbler

Prairie warblers are among the more common summer warblers in the Midwest, Mid-Atlantic and Southeastern U.S; despite their name, they do not inhabit prairies. Rather, these colorful and active birds favor overgrown pastures, cedar groves, pine barrens and other pockets of second-growth forest.

Nesting and feeding close to the ground, prairie warblers are easily identified by their olive back, yellow face and underparts and black streaks on their cheeks and sides; their tail wagging habit also aids identification. Primarily insectivores, gleaning prey from the leaves and limbs of small trees and shrubs, they will consume berries on occasion. Their cup-shaped nests are placed within ten feet of the ground and 2-5 eggs are produced; of interest, female prairie warblers consume the egg shells after hatching.

Prairie warblers that breed across the central and eastern U.S. winter in Mexico, Central America or the Caribbean. A subspecies permanently resides in South Florida, favoring mangroves but also inhabiting shrubby flatwoods.

Warm Front Storms

Severe thunderstorms and torrential rain generally develop within the warm sector, just ahead of an advancing cold front. Energized by a potent zone of low pressure and a dip in the jet stream, the cold air knifes beneath the warm, humid air, producing lift, heavy precipitation and potential tornadoes.

But storms can also develop as warm fronts move into cooler air along the back edge of atmospheric troughs. Over the past few days, a stationary front has curved through the Heartland, separating intense heat in the Southern Plains from relatively cool air across the Upper Midwest and central Mississippi Valley. Tied to a low over eastern Kansas, this front has begun to nudge to the northeast; in concert, counterclockwise winds around the low have been sweeping Gulf moisture across the front, producing waves of thunderstorms through Iowa, Missouri and southern Illinois.

While these warm front storms are not as intense as those along cold front squall lines, they may yield significant amounts of precipitation; in addition, since backside fronts often progress at a snail's pace, the storms redevelop over the same area and flooding ensues. Such has been the case this week as southeastern Iowa and south-central Illinois have been deluged with rain.