The Mackenzie River

Rising at the west end of Great Slave Lake in Canada's Northwest Territories, the Mackenzie River flows northwestward for almost 1100 miles to the Beaufort Sea. Un-dammed and winding through Subarctic and Arctic wilderness, its wide, braided channel is just the final conduit of a massive watershed that covers 20% of Canada, extending from northeast British Columbia, northern Alberta, northwest Saskatchewan and the western Yukon to the massive Mackenzie River Delta, the 12th largest on our planet. If one includes its most distant tributaries, this river system exceeds 2600 miles in length (the longest in Canada) and drains a watershed of almost 700,000 square miles.

To the southwest, the Peace and Athabaska Rivers rise on the east side of the Continental Divide in the northern Canadian Rockies; these large streams merge to form a large inland delta along Lake Athabaska, which drains to Great Slave Lake via the Slave River. Leaving Great Slave Lake, the Mackenzie River picks up meltwaters from the Mackenzie Mountains (to its west) via the Liard River system and then receives flow from Great Bear Lake, to its east, the largest lake in Canada. At its braided delta, just east of the Richardson Mountains, the Mackenzie discharges copious amounts of relatively warm, fresh, nutrient-rich water into the Arctic Ocean; this annual discharge, the 14th largest on Earth, dramatically affects the regional ecosystem, allowing boreal woodlands to extend well north of their usual range and increasing the diversity of plants and animals across the ever-changing delta. Beluga whales gather here in spring to molt in the mild river current and the countless, shallow lakes provide ideal breeding habitat for shorebirds, tundra swans and snow geese. Resident mammals include black bears, barren ground grizzlies, Arctic fox, Arctic wolves, caribou, moose, musk ox and a massive number of muskrats.

However, all is not well in this seemingly pristine wilderness. Dams on tributaries of the Mackenzie have reduced flow through its primary channel and are diminishing the annual floods that are crucial to the welfare of its delta ecosystem. In addition, worrisome levels of mercury have been found in the river over the past few years, the product of mining and power plant effluent across the watershed. Of course, as with other Arctic ecosystems, global warming may dramatically affect the natural diversity of this magnificent yet fragile landscape.

From Tropical Heat to Upslope Chill

After wilting in central Missouri over the last two days, enveloped in tropical heat and humidity, I arrived along the Colorado Front Range late this afternoon under low clouds and scattered showers; the temperature was 45 degrees F. These two weather extremes were produced by the same Pacific storm system; ahead of the front, muggy air was pumped into the Midwest from the Gulf of Mexico while, behind it, a plume of moisture was swept westward through the cool air. Since this flow is counterclockwise around the storm's central low, the moisture arrived from the northeast, the classic upslope direction for Metro Denver. Cooling and condensing as it rose across the western landscape, the plume dumped its cargo of moisture across northeastern Colorado.

Over the past 24 hours, Metro Denver received a half inch of rain in most areas while higher elevations to the west and south collected .75 inch or more, a welcome respite from the recent drought. Checking the foothills as I arrived from the east, it was obvious that the upslope shroud was beginning to lift though jet traffic was still landing to the north and likely offering a bumpy descent through the showers and virga. Our Littleton farm clearly benefited from the moisture, having taken on the untidy overgrowth that promises plenty of yard work this week.

As the system continues to move eastward, the muggy air and thunderstorms will be confined to the Eastern Seaboard and high pressure will reclaim the Heartland, bestowing warmth and sunshine for the days ahead. Here along the Front Range, the wind will shift to the south-southwest, a downsloping direction for Metro Denver; we expect sunshine, mild temperatures and a chance to dry out.

Southern Soup

Hot, humid air has been flowing into Missouri for the past two days and will continue for at least another 24 hours. This muggy, southern soup is courtesy of both a broad high pressure ridge over the eastern half of the U.S. and a slowly approaching Pacific front that should ignite thunderstorms by tomorrow afternoon.

Riding this river of subtropical air, the first wave of common nighthawks appeared in our skies yesterday evening. Among the last migrants of spring, they are more cautious than swallows and swifts, waiting until plenty of insects are reliably available for their late-day feasts. They'll be with us until late summer and, perhaps, as late as early October, departing for the tropics before autumn's chill annihilates their prey.

Meanwhile, here in the Midwest, this summer-like heat in early May is not welcomed by those of us who prefer cool weather. Fortunately, a milder and drier air mass is expected to move in by early next week, bringing spring conditions back to the Heartland. By then, I'll be heading to our Colorado farm, guaranteed to escape the heat and humidity that common nighthawks relish.

Unnatural Programs

What little television I used to watch was primarily devoted to science and nature, with a bit of news and sports on the side. Unfortunately, what remains of that genre is now filled with human melodrama and a mix of reality shows focused on dysfunctional people. If you hope to get a forecast from the Weather Channel, expect to wade through a chorus of zany meteorologists, lifestyle advice experts, tornado chasers, and an ever-expanding collection of programs on characters such as turbine cowboys, bombastic ice pilots and, starting this week, macho iron workers.

The Discovery and History Channels are no better, offering a steady diet of shows on gator hunters, daredevil loggers, bleary-eyed truckers, death-defying crabbers and, just this year, full-metal jousters. Even the storied Nature program on PBS has shifted toward a more humanistic view of the natural world, seemingly in response to the public's drift from true science to emotionally satisfying entertainment. Fortunately, programs such as Frontline and NOVA continue to offer informative and fascinating presentations.

The dearth of good science programming on television is likely a concious effort of media moguls to compete with the varied enticements of the Internet. Grabbing viewers with serious, thoughtful content has, sadly, been largely abandoned. Promising an inside look at the lives of New Jersey Housewives has become their mode of operation and the future of educational television looks bleak indeed.

Wildlife of Afghanistan

Based on television images beamed to the world over the past few decades, Afghanistan appears to be a desolate region of rock and sand, a landscape of drought and human carnage. Yet, Afghanistan hosts a spectacular diversity of wildlife and many of its species have been threatened by the recurrent and protracted wars that have ravaged this country.

Among these threatened species are the reclusive snow leopard, markhors (large wild goats), Marco Polo sheep, urials (another wild sheep) and Asiatic black bears. Other native mammals include ibex, gray wolves, leopard cats, caracals, Pallas's cat, stone martens, lynx, Eurasian otters and Kashmir cave bats. At least 500 species of birds have been observed in Afghanistan, 200 of which breed in the country. Raptors include lammergeiers (large vultures), amur falcons, Eurasian eagle-owls and nine species of eagles, including Pallas's fish eagle. Other birds of note include grey herons, Dalmatian pelicans, black storks, greater and lesser flamingos, Himalayan snowcocks,, Demoiselle cranes, great bustards, pheasant-tailed jacanas and whiskered terns. Afghanistan hosts 3 species of bee-eaters, 7 species of sandgrouse, 8 species of shrike, 5 species of wagtail and 3 species of parakeet.

Indeed, when it comes to birds, Afghanistan rivals the Lower 48 of the U.S. in its diversity of species, though migrant and wintering birds account for the majority of its population. But when we consider the wide range of habitat on our Continent compared with the landlocked deserts and mountainous terrain of Afghanistan, its diversity of birds is truly impressive, reflecting the fact that Afghanistan, long a crossroads for human trade and migration, remains an important crossroads for avian travel.

Natural Afghanistan

For the past decade, Afghanistan has evoked images of war, political corruption and civil strife. It seems appropriate to shift gears and focus on the natural landscape of that isolated but starkly beautiful region of our planet.

Consulting a map, one finds that the country of Afghanistan is pear-shaped, aligned northeast to southwest; the narrower part, complete with a thin stem of territory that pokes eastward to China, is to the northeast while its broader portion is to the southwest, abutting Iran, western Pakistan and southern Turkmenistan. The high spine of the Hindu Kush, the westernmost extension of the Himalayas, bisects the northeastern half of the country, curving from its northeastern frontier to the heart of Afghanistan; some peaks in easternmost Afghanistan soar above 25,000 feet while elevations gradually decrease toward the west. On either side of this natural divide, numerous streams have carved a maze of ridges, canyons and valleys from the Hindu Kush massif, giving rise to four major river systems.

The Kabul River drains the southeast edge of the Hindu Kush, flowing through the capitol city before cutting through the Spin Ghar Range along the border with Pakistan, where it joins the Indus River. The Helmand River and its tributaries drain the southwestern and western flanks of the Hindu Kush, crossing the southwest plateau region of Afghanistan and eventually flowing westward into Iran. The Hari Rud, rising along the northwest side of the massif, also flows westward into Iran while the Amu Darya, fed by mountain glaciers of the Hindu Kush, snakes westward across the fertile plain of northern Afghanistan, forming its border with Tajikistan, Uzbekistan and Turkmenistan (east to west) before angling northwestward into the latter country. With the exception of the Kabul River, which reaches the sea via Pakistan's massive Indus River system, the rivers of Afghanistan, heavily utilized for irrigation in this dry landscape, eventually disappear into the desert sands of Iran and Turkmenistan.

Painted Buntings

I will never forget my first encounter with a painted bunting. George, my good friend and fellow birder, was visiting us in Wilmington, North Carolina, in June, 1977. As we headed down to Cape Fear for a morning of birding, George spotted a male painted bunting in roadside shrubbery and nearly rolled his aging Valiant in an effort to stop. Since then, I saw these colorful birds on a regular basis during my years in Arkansas and have more recently encountered them in the glade country of southwest Missouri; indeed, painted buntings favor woodland clearings with scattered shrubs and thickets.

Painted buntings occur in two separate breeding populations; one summers along the Coastal Plain from the Carolinas to northern Florida while the second inhabits the south-central U.S., from southeast Kansas and southwest Missouri through Oklahoma, Arkansas, Louisiana and Texas. The male, easily the most striking bird in the U.S., is identified by his blue head, red abdomen and patches of green and yellow on his back and sides; the female, while less varied, is also colorful, with a bright olive back and yellow-green chest and abdomen. Highly territorial during the breeding season, the male defends his area from a perch and may breed with two females; fights between males are unusually aggressive for songbirds and may end in death. The deep, cup-shaped nest is placed in low vegetation and 1-5 eggs are laid; unfortunately, painted bunting nests are often parasitized by cowbirds, adding to the pressure of habitat loss in the Southeast. A diet of insects and spiders is consumed during the breeding season, fortified with seeds during migrations and on their wintering grounds.

While the Southeastern painted buntings winter in South Florida and the Caribbean, those that breed in the south-central U.S. winter in southern Mexico and Central America. This latter population, like waterfowl but unlike most songbirds, uses migration staging areas (in southern Arizona and northern Mexico) where they molt before continuing on to their wintering sites. As mentioned above, painted buntings are threatened by cowbird parasitism and by habitat loss (especially in the Southeastern U.S.); their colorful plumage is also a liability and a significant number are captured on their wintering grounds for sale in the caged-bird market.