While those of us who live along the Colorado Front Range enjoy abundant sunshine and a mild, semiarid climate, there is plenty of aquatic habitat along the urban corridor. One of the best places to observe water-loving birds and mammals is South Platte Park, which stretches across the river's floodplain from the northern edge of Chatfield Reservoir State Park to the outskirts of downtown Littleton. A mosaic of ponds, lakes, wetlands, meadows and riparian woodlands, the Park is accessed by a paved bikeway, its parallel walking path and a number of adjoining trail loops. An Interpretive Center, west of Santa Fe Drive and north of Mineral, introduces visitors to the varied fauna and flora of the Park.
On this mild, clear morning, the refuge was teeming with birds, including many that non-Coloradans might not associate with our State. A dozen American white pelicans moved among the lakes or fished in the shallows, joined by a large number of double-crested cormorants, scattered great blue herons, a pair of snowy egrets, a flotilla of common mergansers, noisy flocks of Canada geese and a varied assortment of ducks (primarily mallards, gadwall and wood ducks). Tree and barn swallows swooped above the ponds, a Swainson's hawk circled overhead, belted kingfishers chattered along the river and a wide assortment of songbirds moved among the trees and cattails; these included yellow warblers, common yellowthroats, American and lesser goldfinches, western wood pewees, northern orioles, house wrens, northern flickers, downy woodpeckers and those ever-vocal red-winged blackbirds. A lone black-crowned night heron, spooked from his shadowy haunt, was my final sighting of the morning.
Though represented only by fox squirrels, cottontails and black-tailed prairie dogs this morning, a variety of mammals also inhabit the Park and are best seen at dawn or dusk. Among these residents are mule and white-tailed deer, red fox, coyotes, beaver, muskrats, raccoons, striped skunks, meadow voles and deer mice; mountain lions and black bear are potential visitors but are rarely encountered.
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Selasa, 10 Juli 2012
Senin, 25 Juni 2012
The Lena River Delta
On satellite imagery, the Lena River Delta on the northern coast of Siberia gives the appearance of a fan coral, its braided channels and numerous lakes forming an intricate pattern across the Arctic tundra. It is this landscape of countless pools and waterways that attracts huge congregations of loons, grebes, shorebirds and waterfowl to this 11,600 square mile wetland to nest and raise their young during the brief Arctic summer.
The Lena River, the second largest stream in Siberia, rises a few miles west of Lake Baikal, flowing northward and gradually eastward for 2700 miles to its delta on the Laptev Sea. There it delivers tons of sediment each year, gradually enlarging and enriching the delta which is also an important spawining area for Arctic fish. Nesting birds of note include red-necked grebes, four species of loon, whooper and tundra swans, bean geese, black brant, king and Steller's eiders, long-tailed ducks, Ross's and Sabine's gulls and numerous shorebird species. Of course, willow grouse, rock ptarmigan, snowy owls, peregrine falcons and a wide variety of Arctic songbirds also inhabit the delta. Resident mammals include gray wolves, Arctic fox, wolverines, least weasels, stoats, lemmings, tundra voles and reindeer; beluga whales, walruses and a variety of seals often visit the area.
Fortunately, most of this vast tundra wetland is protected within the Lena River Delta Nature Reserve, the largest nature preserve in Russia. Visited only by the most adventurous naturalists, this spectacular but remote site is relatively free of human disturbance; nevertheless, the Lena, like all rivers on our planet, is tainted by pollutants from agriculture, mining, industry and sewage and their long term effects on the delta ecosystem is yet to be determined.
The Lena River, the second largest stream in Siberia, rises a few miles west of Lake Baikal, flowing northward and gradually eastward for 2700 miles to its delta on the Laptev Sea. There it delivers tons of sediment each year, gradually enlarging and enriching the delta which is also an important spawining area for Arctic fish. Nesting birds of note include red-necked grebes, four species of loon, whooper and tundra swans, bean geese, black brant, king and Steller's eiders, long-tailed ducks, Ross's and Sabine's gulls and numerous shorebird species. Of course, willow grouse, rock ptarmigan, snowy owls, peregrine falcons and a wide variety of Arctic songbirds also inhabit the delta. Resident mammals include gray wolves, Arctic fox, wolverines, least weasels, stoats, lemmings, tundra voles and reindeer; beluga whales, walruses and a variety of seals often visit the area.
Fortunately, most of this vast tundra wetland is protected within the Lena River Delta Nature Reserve, the largest nature preserve in Russia. Visited only by the most adventurous naturalists, this spectacular but remote site is relatively free of human disturbance; nevertheless, the Lena, like all rivers on our planet, is tainted by pollutants from agriculture, mining, industry and sewage and their long term effects on the delta ecosystem is yet to be determined.
Senin, 18 Juni 2012
Missisquoi NWR
As heat and humidity grip much of the country over the next few months, those of us in the Midwest and Southeast will look for escapes to cooler, northern climes. For naturalists, one option is a visit to Missisquoi National Wildlife Refuge, in northwest Vermont.
The Missisquoi River rises in the uplands of northeast Vermont, loops westward through southern Canada and then returns to Vermont to enter Lake Champlain along its northeastern shore. There it has created a delta of marshlands, channels, mudflats and islets, providing ideal nesting and feeding grounds for migrant and resident waterfowl, shorebirds, waders, rails and wetland songbirds. Established in 1943, the Missisquoi NWR now protects the delta, the adjacent Big Marsh Slough and parcels of northern forest. At least 300 species of birds visit the refuge throughout the year and nesting species include ospreys, great blue herons, least bitterns, black terns, common goldeneyes, soras and Virginia rails, among many others.
Missisquoi NWR is located NNW of Swanton, Vermont, which is just west of I-89 (Exit 21). Like most of our National Wildlife Refuges, it is accessible from dawn to dusk every day of the year; the refuge Visitor Center is open M-F and most Saturdays from mid May through October. Adventurous visitors might want to rent a canoe in Swanton and explore the refuge marshlands from the cool waters of Lake Champlain.
The Missisquoi River rises in the uplands of northeast Vermont, loops westward through southern Canada and then returns to Vermont to enter Lake Champlain along its northeastern shore. There it has created a delta of marshlands, channels, mudflats and islets, providing ideal nesting and feeding grounds for migrant and resident waterfowl, shorebirds, waders, rails and wetland songbirds. Established in 1943, the Missisquoi NWR now protects the delta, the adjacent Big Marsh Slough and parcels of northern forest. At least 300 species of birds visit the refuge throughout the year and nesting species include ospreys, great blue herons, least bitterns, black terns, common goldeneyes, soras and Virginia rails, among many others.
Missisquoi NWR is located NNW of Swanton, Vermont, which is just west of I-89 (Exit 21). Like most of our National Wildlife Refuges, it is accessible from dawn to dusk every day of the year; the refuge Visitor Center is open M-F and most Saturdays from mid May through October. Adventurous visitors might want to rent a canoe in Swanton and explore the refuge marshlands from the cool waters of Lake Champlain.
Rabu, 13 Juni 2012
House Wren Mystery
Having spent a great deal of time in central Missouri over the past 15 years, I have become accustomed to the arrival of house wrens in late April, their loud song and buzzy chatter echoing through the neighborhood. By early summer, the parents are usually escorting their brood through the trees and shrubs, appeasing them with a smorgasbord of insects.
But this year, despite actively searching for these tiny songsters, I have not encountered a single house wren on our property and cannot recall seeing any on my walks to and from the University. I initially blamed their absence on landscaping activity in our backyard but that ended long ago and, still, no house wrens to brighten my evenings; frankly, I feel a bit betrayed. A few visits to our Colorado farm have turned up the usual number of house wrens along the Front Range, adding to the mystery here in Missouri.
Perhaps I am becoming less perceptive with advancing age or have been too busy this spring to give sufficient attention to our wild neighbors. I have even thought to blame the unusually warm spring and early leafing of our shade trees, which might have encouraged the wrens to move farther north before settling down. Then again, the populations of most other summer residents seem to be unaffected. This apparent dearth of house wrens may be just an illusion but, in some 40 years of birding, I can't recall anything quite so mystifying.
But this year, despite actively searching for these tiny songsters, I have not encountered a single house wren on our property and cannot recall seeing any on my walks to and from the University. I initially blamed their absence on landscaping activity in our backyard but that ended long ago and, still, no house wrens to brighten my evenings; frankly, I feel a bit betrayed. A few visits to our Colorado farm have turned up the usual number of house wrens along the Front Range, adding to the mystery here in Missouri.
Perhaps I am becoming less perceptive with advancing age or have been too busy this spring to give sufficient attention to our wild neighbors. I have even thought to blame the unusually warm spring and early leafing of our shade trees, which might have encouraged the wrens to move farther north before settling down. Then again, the populations of most other summer residents seem to be unaffected. This apparent dearth of house wrens may be just an illusion but, in some 40 years of birding, I can't recall anything quite so mystifying.
Rabu, 06 Juni 2012
A Morning Chat
On this bright, cool morning, we opted for a hike through the South Platte Valley, looping past several lakes that border the river channel. In one area, the trail crosses a brushy ridge with scattered groves of cottonwoods and it was there that I heard the unmistakable "song" of a yellow breasted chat, more like a loud, rambling conversation. Indeed, though classified as a warbler (our largest), the chat acts more like a thrasher or a catbird, skulking in the shrubbery and delivering its litany of seemingly unrelated calls and noises.
Solitary for most of the year, yellow breasted chats summer across the Lower 48, preferring riparian woods and brushy hillsides. Nests are placed in low shrubs and these common birds would probably go unnoticed were it not for the male's tendency to sing from an exposed perch, his bright yellow chest and abdomen glowing in the early summer sun. Here in Colorado, chats are especially common along streams of the lower foothills where they feast on insects and berries. While some winter along the East Coast of the U.S., most yellow breasted chats head to Mexico or Central America for the colder months.
This morning, our songster was accompanied by house wrens, lesser goldfinches, yellow warblers, song sparrows, black-billed magpies, broad-tailed hummingbirds, a Say's phoebe, northern flickers and those ubiquitous robins and house finches. Double-crested cormorants moved among the lakes, fishing for their breakfast, while great blue herons, a black-crowned night heron, flocks of Canada geese and squadrons of ducks passed overhead. But it was the chat that made our morning, delivering his strident lecture to all who cared to listen.
Solitary for most of the year, yellow breasted chats summer across the Lower 48, preferring riparian woods and brushy hillsides. Nests are placed in low shrubs and these common birds would probably go unnoticed were it not for the male's tendency to sing from an exposed perch, his bright yellow chest and abdomen glowing in the early summer sun. Here in Colorado, chats are especially common along streams of the lower foothills where they feast on insects and berries. While some winter along the East Coast of the U.S., most yellow breasted chats head to Mexico or Central America for the colder months.
This morning, our songster was accompanied by house wrens, lesser goldfinches, yellow warblers, song sparrows, black-billed magpies, broad-tailed hummingbirds, a Say's phoebe, northern flickers and those ubiquitous robins and house finches. Double-crested cormorants moved among the lakes, fishing for their breakfast, while great blue herons, a black-crowned night heron, flocks of Canada geese and squadrons of ducks passed overhead. But it was the chat that made our morning, delivering his strident lecture to all who cared to listen.
Sabtu, 02 Juni 2012
The Birding Doldroms
For the amateur, summer is a good season to engage in birdwatching; a wide variety of species are present and the weather is conducive to both field study and patient observation. But, for veteran birders, June and July are probably the least interesting months of the year.
By June, the spring migration has ended and a population of well-known, frequently-observed summer residents has settled in our parks and neighborhoods. Early summer is an unlikely time to find rare vagrants, the cherished quarry of avid birders; rather, such wanderers are far more common in late summer, during the spring and fall migrations or throughout the lean months of winter.
Of course, travelling to other regions of the country or planet is the best cure for the birding blues, but, for many (if not most) of us, such a remedy is not feasible. Those who cannot travel must wait for shorebirds to start dribbling south in mid summer or be satisfied with visits by our less common summer residents. During these birding doldroms, I suggest that birders broaden their horizon, taking an interest in the wide variety of plants, insects, reptiles and other creatures that share our home ecosystem; by doing so, we also develop a better appreciation of the environment in which our resident and migrant birds obtain the essential elements of their survival.
By June, the spring migration has ended and a population of well-known, frequently-observed summer residents has settled in our parks and neighborhoods. Early summer is an unlikely time to find rare vagrants, the cherished quarry of avid birders; rather, such wanderers are far more common in late summer, during the spring and fall migrations or throughout the lean months of winter.
Of course, travelling to other regions of the country or planet is the best cure for the birding blues, but, for many (if not most) of us, such a remedy is not feasible. Those who cannot travel must wait for shorebirds to start dribbling south in mid summer or be satisfied with visits by our less common summer residents. During these birding doldroms, I suggest that birders broaden their horizon, taking an interest in the wide variety of plants, insects, reptiles and other creatures that share our home ecosystem; by doing so, we also develop a better appreciation of the environment in which our resident and migrant birds obtain the essential elements of their survival.
Kamis, 24 Mei 2012
The Treetop Vocalist
Over the past month, loud vreeeps have echoed through our neighborhood on my morning walks to work. Their source is always difficult to locate but these clear, ascending calls seem to arise from the treetops, where the vocalists remain hidden amidst the dense foliage of late spring.
In fact, they are the distinctive calls of great crested flycatchers, colorful insectivores that prefer to hunt in the upper canopy of open, deciduous woodlands; suburbs of the central and eastern U.S. thus appeal to these summer residents. Nesting in tree cavities, great crested flycatchers utilize a wide variety of nesting materials, including human trash and discarded snakeskins; it is only during the collection of these items that they are likely to be seen on the ground and, even then, they fly from site to site, not hopping or walking like most songbirds. The great majority of their time is spent in the trees, snaring insects from leaves and stems or catching them in mid air.
By late summer, great crested flycatchers begin to migrate toward their wintering grounds in the Caribbean, Central America and northern South America. There they feast on insects in the canopy of rain forests and, unlike most migrant songbirds, remain vocal throughout the year.
In fact, they are the distinctive calls of great crested flycatchers, colorful insectivores that prefer to hunt in the upper canopy of open, deciduous woodlands; suburbs of the central and eastern U.S. thus appeal to these summer residents. Nesting in tree cavities, great crested flycatchers utilize a wide variety of nesting materials, including human trash and discarded snakeskins; it is only during the collection of these items that they are likely to be seen on the ground and, even then, they fly from site to site, not hopping or walking like most songbirds. The great majority of their time is spent in the trees, snaring insects from leaves and stems or catching them in mid air.
By late summer, great crested flycatchers begin to migrate toward their wintering grounds in the Caribbean, Central America and northern South America. There they feast on insects in the canopy of rain forests and, unlike most migrant songbirds, remain vocal throughout the year.
Minggu, 20 Mei 2012
Vulture Heaven at Eagle Bluffs
As a consequence of the lowest water levels that I have ever encountered at Eagle Bluffs Conservation Area, dead carp lined the central channel, providing a feast for numerous turkey vultures. Usually seen soaring above the countryside, these large scavengers had gathered on the mudflats and levees to partake in the bounty of rotting fish.
Of course, the low water was also beneficial to great blue herons, great egrets and green-backed herons, concentrating their prey in the shallow pools. Other highlights included a large number of wood ducks, the attentive females ushering their broods across the calm waters, and an unusual abundance of migrant shorebirds for late May. Cormorants and diving ducks were noticeably absent but small groups of coot, blue-winged teal and mallards plied the shallows or huddled on the shorelines. Throughout the evening, a steady background chorus was provided by bullfrogs, green frogs, cricket frogs, killdeer and indigo buntings as white-tailed deer emerged from the woods to browse the marshlands and crop fields.
Since the Missouri River is still fairly high, I suspect that the low water at Eagle Bluffs reflects an artificial drawdown, often utilized to mimic natural fluctuations that foster the welfare of native floodplain vegetation while discouraging the invasion of alien species. Whatever the cause, the drought-like conditions surely favor the hunters and scavengers; for the time being, it's vulture heaven at Eagle Bluffs.
Of course, the low water was also beneficial to great blue herons, great egrets and green-backed herons, concentrating their prey in the shallow pools. Other highlights included a large number of wood ducks, the attentive females ushering their broods across the calm waters, and an unusual abundance of migrant shorebirds for late May. Cormorants and diving ducks were noticeably absent but small groups of coot, blue-winged teal and mallards plied the shallows or huddled on the shorelines. Throughout the evening, a steady background chorus was provided by bullfrogs, green frogs, cricket frogs, killdeer and indigo buntings as white-tailed deer emerged from the woods to browse the marshlands and crop fields.
Since the Missouri River is still fairly high, I suspect that the low water at Eagle Bluffs reflects an artificial drawdown, often utilized to mimic natural fluctuations that foster the welfare of native floodplain vegetation while discouraging the invasion of alien species. Whatever the cause, the drought-like conditions surely favor the hunters and scavengers; for the time being, it's vulture heaven at Eagle Bluffs.
Sabtu, 19 Mei 2012
The Perspective of Geese
During our travels along the spectacular coast of Lake Superior this week, we encountered a pair of Canada geese, ushering their brood across the unusually calm waters of the lake. West of the roadway was a pristine wetland, stretching out from the mouth of a rushing river; we naturally assumed that the pair had nested within that scenic marsh. Such encounters often make human envious of wildlife, recognizing both their freedom and their capacity to live in beautiful natural landscapes, unencumbered by the responsibilities of the human lifestyle.
On the following day, I saw another pair of geese with their young offspring, resting along a muddy pond in the industrial port of Superior, Wisconsin. Close to a wealth of pristine habitat, far more appealing to the human eye, they had chosen to nest along this unattractive pool, bordered by a litter-strewn lawn. Perhaps, once the goslings fledge, they will move on to a more pristine location but, for now, they appeared to be perfectly comfortable at their ugly urban site.
Unlike most humans, wild creatures focus primarily on their basic needs, not on the physical beauty of their surroundings. While they are far better equipped to wander off to spectacular landscapes that we can only hope to visit, they do not share our obsession with picturesque settings. Of course, neither do they worry about the effects that pollution might have on the welfare of their family; in that respect, they unknowingly depend on the wisdom and commitment of their human neighbors.
On the following day, I saw another pair of geese with their young offspring, resting along a muddy pond in the industrial port of Superior, Wisconsin. Close to a wealth of pristine habitat, far more appealing to the human eye, they had chosen to nest along this unattractive pool, bordered by a litter-strewn lawn. Perhaps, once the goslings fledge, they will move on to a more pristine location but, for now, they appeared to be perfectly comfortable at their ugly urban site.
Unlike most humans, wild creatures focus primarily on their basic needs, not on the physical beauty of their surroundings. While they are far better equipped to wander off to spectacular landscapes that we can only hope to visit, they do not share our obsession with picturesque settings. Of course, neither do they worry about the effects that pollution might have on the welfare of their family; in that respect, they unknowingly depend on the wisdom and commitment of their human neighbors.
Selasa, 15 Mei 2012
Western Lake Superior
Facing an off-week and yearning to get back to the North Country after our memorable journey across the Upper Peninsula of Michigan, last September, my wife and I decided to head for western Lake Superior. We left Columbia yesterday afternoon, driving north across the Glaciated Plain of northern Missouri and eastern Iowa, stopping for the night in Iowa City. This morning, we resumed our journey, dropping into the Mississippi Valley at Marquette, Iowa, and then paralleling the broad river and its wooded islands along the Wisconsin (eastern) shore. Scenic bluffs rise along both sides of the Mississippi Valley in this "Driftless Area" of the Upper Midwest, which was spared the erosive force of Pleistocene Glaciers.
Protected within the Upper Mississippi National Wildlife Refuge, access to the Mississippi and its varied riparian habitats is rather limited (except for boaters). However, Goose Island County Park, just south of La Crosse, Wisconsin, provided an excellent opportunity to study the floodplain wetlands, backwater bays and eastern channel of the river; birding was excellent at the Park. North of La Crosse, we cut away from the Mississippi for a more direct route to Duluth, Minnesota, where we are spending the night on that city's restored waterfront.
In the coming days, we plan to explore the northwest coast of Lake Superior and the Apostle Islands region of northern Wisconsin. So far, wildlife encounters have been limited to bald eagles, sandhill cranes, common loons, gulls, aquatic turtles and a host of waterfowl and songbird species. But we are now in wolf and moose country and I look forward to the possibility of seeing (or hearing) those North Country residents amidst the spectacular landscape that adjoins America's grandest Lake.
Protected within the Upper Mississippi National Wildlife Refuge, access to the Mississippi and its varied riparian habitats is rather limited (except for boaters). However, Goose Island County Park, just south of La Crosse, Wisconsin, provided an excellent opportunity to study the floodplain wetlands, backwater bays and eastern channel of the river; birding was excellent at the Park. North of La Crosse, we cut away from the Mississippi for a more direct route to Duluth, Minnesota, where we are spending the night on that city's restored waterfront.
In the coming days, we plan to explore the northwest coast of Lake Superior and the Apostle Islands region of northern Wisconsin. So far, wildlife encounters have been limited to bald eagles, sandhill cranes, common loons, gulls, aquatic turtles and a host of waterfowl and songbird species. But we are now in wolf and moose country and I look forward to the possibility of seeing (or hearing) those North Country residents amidst the spectacular landscape that adjoins America's grandest Lake.
Selasa, 08 Mei 2012
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.
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.
Sabtu, 05 Mei 2012
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.
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.
Kamis, 03 Mei 2012
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.
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.
Selasa, 01 Mei 2012
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.
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.
Selasa, 24 April 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.
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.
Kamis, 19 April 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.
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.
Senin, 16 April 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.
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.
Sabtu, 14 April 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.
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.
Jumat, 13 April 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!
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!
Kamis, 12 April 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.
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.
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