Sunday, April 30, 2017

A Firehose from the Gulf

Yesterday, as a potent storm system approached from the west, a massive plume of Gulf moisture was pumped northward.  Interacting with a stationary front that stretched from northeast Texas to the mid Ohio Valley, the warm, humid air unleashed heavy rain, especially from southwest Missouri to southern Illinois; here in Columbia, Missouri, we received nearly five inches of rain, an impressive amount but only half that which fell in parts of southern Missouri and southwest Illinois.

Flash flood warnings were common throughout the southeastern half of Missouri and much of the State remains under a flood watch today as intermittent rain and thunderstorms continue to move across the region.  Fortunately, the center of the storm's circulation has moved eastward (currently near Wichita, Kansas) and the firehose of Gulf moisture is now directed through the Mississippi and Ohio River Valleys.  Unfortunately, the leading edge of the system has been igniting severe thunderstorms (some of which were tornadic in eastern Texas); today, that risk has shifted to the Gulf Coast States.

Such extensive flooding is most often produced by potent but slow-moving storm systems; in this scenario, heavy rain continues to fall over the same swath of landscape, saturating the soil and then spilling into the streams and rivers.  Though a massive amount of moisture is taken up by leafing trees and growing plants during the spring season, that process cannot keep up with the sudden deluge.  Hopefully, sunshine and drier air will settle in before the next spring storm system arrives from the Great Plains.

Saturday, April 29, 2017

Morning of the Swallows

Despite the chilly air, low overcast and intermittent thunderstorms, I opted for one last visit to Eagle Bluffs Conservation Area before we head to Ohio.  As it turned out, my decision was rewarded with one of the annual avian spectacles in the Missouri River Valley.

As I drove slowly through the flooded landscape, thousands of swallows wheeled above the refuge, strafed the pools or rested atop cattails that rise from the shallows.  Barn swallows were by far the most numerous species, joined by large flocks of cliff and tree swallows and a smaller number of northern rough-winged swallows.  Just back from South America, the barn swallows will soon disperse across the Missouri River watershed, favoring open country with man-made structures in which to nest.  Other highlights on this gray, wet morning were marsh wrens, soras, green herons, great egrets, a trio of Forster's terns, a northern waterthrush and, of course, bald eagles with their growing youngsters.

As spring gives way to summer, we will hardly notice the swallows that grace our parks and farmlands, thankful for their insect consumption and admiring their agility but taking these common summer residents for granted.  But when they first appear in massive clouds, having journeyed from the Tropics to raise their young in the American Heartland, they certainly get our attention and command our respect.

Thursday, April 27, 2017

Songbird Heaven

Taking advantage of a break in our spring rain, I headed over to the Columbia Audubon Nature Sanctuary, which connects with the adjacent Bonnie View Nature Preserve, in western Columbia.  After all, late April is a great time to look for migrant and summer songbirds and there is no better habitat in central Missouri for observing those species.

Despite the cool, cloudy weather and a soggy landscape, my visit was rewarded.  While robins and cardinals were most abundant and conspicuous, I encountered an excellent diversity of songbirds in the forest, among the open woodlands and on the scenic meadows.  These included indigo buntings, gray catbirds, Nashville, yellow and Tennessee warblers, blue-gray gnatcatchers, ruby-crowned kinglets, eastern phoebes and a great crested flycatcher, joined by many common permanent residents.  Other highlights included two fuzzy, great-horned owlets, a barred owl and a sedge wren.

Veteran birders know that the spring songbird season peaks in late April as summer songbirds arrive, a few winter songbirds have yet to depart and migrant songbirds (especially warblers) are passing through, greatly augmenting the avian diversity in our parks, neighborhoods and nature preserves.  This morning's cool, cloudy weather and wet landscape may not be favored by birders but it certainly did not dampen the bird activity.

Wednesday, April 26, 2017

Before the Storms

Now that I live primarily in the semiarid climate of Colorado, I sometimes miss the balmy air of a Midwestern spring, especially the warm, humid air that flows northward ahead of a cold front.  Last evening, as storms approached from the west, I sat on our deck in Columbia, Missouri, and enjoyed a dose of that fresh spring air.

Turkey vultures drifted overhead, just clearing the treetops, while squadrons of chimney swifts strafed the cloudy sky, feasting on invisible prey.  Birdsong, primarily provided by cardinals and robins, was especially intense, perhaps an indication that they sensed a coming change.  Carried on a south breeze, the balmy air, unlike the oppressive humidity of a Midwest summer, was scented by the varied blossoms of spring; enveloped in its soothing embrace, I was reluctant to leave the deck and remained outdoors until dusk faded to night.

Checking the radar when I came inside, I saw a swath of rain with imbedded thunderstorms from Minnesota to Oklahoma, the leading edge of an atmospheric trough that dipped across the Great Plains.  The storms reached central Missouri by 2 AM and our high temperature today will be twenty degrees (F) cooler than yesterday.  That balmy air is gone for now but it will return many times before summer's stagnant heat grips the Heartland.

Tuesday, April 25, 2017

A Distant Surprise

Facing limited time in central Missouri and a forecast with several days of rain, I decided another visit to Eagle Bluffs Conservation Area was in order on this mild but cloudy morning.  I especially hoped to see some of the summer residents before I visit Ohio and then return to Colorado.

Fortunately, I did encounter a couple yellow warblers, yellow-breasted chats, orchard orioles and indigo buntings, joining the usual mix of permanent residents.  The number of blue-winged teal, American coot and lesser yellowlegs had fallen significantly but the diversity of birdlife was excellent, as usual, totaling 43 species during my two hour visit.  The resident bald eagles were especially active this morning, feeding their hungry offspring and reinforcing their massive nests.

Just before starting my return trip through the refuge, I made one final scan of the large southern lake and noticed a small flock of white birds with black wingtips wheeling above the distant shore; to my aging eyes (aided of course by binoculars), they seemed to have a pinkish or rusty tinge to their head and neck and they were clearly some species of large shorebird.  After watching them intently for a minute or so, it became clear that they were American avocets, uncommon but regular spring migrants through the Missouri River Valley.  Indeed, almost one year ago to the day, I wrote Avocets at Eagle Bluffs in response to a dozen of those graceful visitors.  A lesson for fellow birders: a final look is often rewarded!

Sunday, April 23, 2017

Lesser Yellowlegs at Eagle Bluffs

In April, blue-winged teal, American coot and lesser yellowlegs are generally the most common wetland birds at Eagle Bluffs Conservation Area, on the Missouri River floodplain.  Today was no exception.

Lesser yellowlegs (mid-sized shorebirds) were foraging along every pool and on most of the flooded fields, joined by smaller numbers of pectoral sandpipers, greater yellowlegs, solitary sandpipers and killdeer.  Very active feeders, lesser yellowlegs prefer shallow water through which they wade to snare aquatic invertebrates, larvae and small fish.  This morning's visitors are on their way to boreal woodlands across Northern Canada and Alaska where they will nest and raise their young.  By August, most will be heading for wintering grounds along our southern coasts or in Central and South America; there they may be found in both fresh and saltwater habitats.

Though they were outnumbered by blue-winged teal, at least 200 lesser yellowlegs graced the floodplain refuge on this sunny, cool morning.  I wish them well on their journey to the north and look forward to their return during the waning days of summer.

Saturday, April 22, 2017

In Support of Science

On this Earth Day, hundreds of marches across the globe demonstrated support for the scientific method, an investigative process that has led to the technologic evolution of human civilization and has greatly expanded our understanding of natural ecosystems, natural laws and the Universe itself.

Prompted by anti-science rhetoric within the Trump Administration, especially as it pertains to the science of climate change, the demonstrations were but the latest salvo in the long war between proponents of mysticism (and their industrial co-conspirators) and the scientific community.  While scientific progress relies on evidence-based facts, the enemies of science attempt to undermine this data when it threatens their religious beliefs, political agenda or corporate profits.

Science has both improved the lives of humans and unleashed industrial processes that threaten the health of our environment; we cannot accept the benefits without also acknowledging the consequences.  Unfortunately, many humans are selective in their approach to science, hailing the accomplishments of modern health care and technology while denying the legitimacy of climate science, ignoring the effects of industrial pollution or shunning the implications of astrophysics.  But the scientific method is universal and it is our only path to uncovering truth.

Friday, April 21, 2017

Late April at Roxborough

This morning, I joined my wife, daughter and grandson for a hike at Roxborough State Park, southwest of Metro Denver.  Adorned with spectacular rock formations from the Cretaceous, Permian and Pennsylvanian Periods, it is one of the most scenic preserves in Colorado.

Though rain was threatening, we completed a two mile loop through the Park.  Mule deer, often abundant at Roxborough, were represented by a single, small herd; birding, on the other hand, was rewarding as always and I spotted a fair number of scrub jays, canyon wrens,  broad-tailed hummingbirds, Say's phoebes and spotted towhees along the trail.  A lone golden eagle circled above the Park, kestrels hunted from the sandstone ridges and the season's first flocks of white-throated swifts and violet-green swallows strafed the open meadows.  Signs of coyotes and fox were evident but those nocturnal hunters remained out of sight, as did the black bears and mountain lions that may be encountered at this fabulous refuge.

As we completed our hike, light rain began to fall, soon mixing with sleet.  The fickle weather of a Colorado spring had taken another turn and we retreated to the warm, dry confines of our vehicle.  No doubt, we'll return to this natural wonderland many times in the coming year.

Tuesday, April 18, 2017

Tiny Travelers

This week, three small summer species have arrived on our Littleton farm.  I mentioned the house wrens at South Platte Park several days ago and, on the following day, one had settled down on the farm, singing from and moving among brushpiles in our composting area; he will soon be preparing nests to impress the trailing females.

On that same day, three chipping sparrows arrived.  These small, handsome sparrows winter in Mexico, the southern Desert Southwest and in Florida; those that return to the Colorado Front Range generally settle in the foothills where they favor open ponderosa parklands.  Our three visitors have yet to depart and spend most of the day searching for seed beneath the feeders.  Today, another tiny traveler arrived; the first broad-tailed hummingbird of the season is zooming about the property, his wing tips producing a loud, high-pitched trill as he engages in aerial loops.  Like the chipping sparrows, most of these hummingbirds, having wintered in Mexico or Central America, will summer in the foothills or mountains, favoring wooded meadows with plenty of wildflowers; however, a fair number stay down on the Piedmont and we host a nesting pair on the farm each year.

The tenacity and determination of long-distance migrants is always inspiring, especially when the travelers are so small.  I am honored by their presence each spring, whether they stay to nest or move on to other summer quarters.

Sunday, April 16, 2017

Painted Ladies Arrive

No, we are not hosting an Easter Parade at our Littleton, Colorado, farm.  Rather, I am referring to the arrival of painted lady butterflies over the past two days, a bit earlier than usual (again reflecting our mild winter and spring weather).

Found across more of the planet than any other butterfly, painted ladies inhabit all of the Continents except Antarctica and are reported to be the only butterflies found on Iceland.  Breeding at Temperate and Subarctic latitudes, the adults arrive in spring and feed on new blossoms, often perching atop shrubs to attract a mate.  The impregnated female deposits single eggs on the leaves of various host plants (primarily thistle, mallow and legumes); once the caterpillars hatch, they feed on those leaves and then pupate.  Adults emerge and may live for up to a month.

In autumn, most painted ladies in North America head for northern Mexico through some may stop in the Desert Southwest; if mild winter weather persists, these hardy butterflies may even overwinter in more northern locations.  Here in Colorado, they are typically present from May to early October; our current guests arrived early but are more than welcome to stay.

Saturday, April 15, 2017

Chokecherry Farm

If I were to name our Littleton, Colorado, farm, I would probably choose Chokecherry Farm.  These suckering, drought-tolerant shrubs are widespread on our property, growing along borders, fence lines and our man-made structures.

Now festooned with racemes of small white flowers (well ahead of schedule due to our warm winter and spring), the shrubs will produce clusters of black cherries that attract a wide variety of birds and mammals.  Though they are a bit sour, chokecherries have long been used by humans to produce jams, sauces, jellies and wine.  Unfortunately, the foliage of chokecherries is toxic to ruminants and can be fatal to livestock if consumed in large quantities.

Native to southern Canada and the northern half of the Lower 48 States, the chokecherry is a hardy shrub, able to tolerate both cold winters and hot, dry summers.  Here along the Colorado Front Range, where water use must be curtailed, it is a valuable component of the landscape, offering beauty and a natural food source while requiring little maintenance and no irrigation.

Friday, April 14, 2017

House Wrens return Home

House wrens breed in Temperate areas of North America and throughout most of South America.  During the colder months, they head for warmer climes and most of the house wrens that breed in North America spend the winter in the Southern States or in Mexico.

By mid spring, the males reappear on the nesting grounds and begin to construct several nests in tree cavities, nest boxes or other protected sites.  When the females arrive, the males escort them to their rudimentary nests, hoping to gain favor (and mating privileges).  House wrens prefer open woodlands with shrubs and thickets and are thus often found in suburban areas, on farms or in urban parks.  They feed on a wide variety of insects and spiders and are known to place spider eggs in their nests; it is thought that the spider hatchlings feed on mites and other parasites that threaten the welfare of the nestlings.

Despite their small size and beautiful song, house wrens are very aggressive and highly territorial, easily out-competing chickadees, bluebirds, tree swallows and prothonotary warblers for available nest cavities.  Though they have not yet returned to our Littleton farm, I did encounter several at South Platte Park this morning, just the latest confirmation that winter has made its final retreat (upslope snowstorms notwithstanding).

Thursday, April 13, 2017

Mending Fences

Having spent the morning repairing fences on our Littleton farm, the term "mending fences" kept coming to mind, especially as it pertains to human relationships.  Of course, I couldn't help but think of President Trump; having spent his campaign ridiculing leaders and citizens across the globe, he must now spend most of his time mending fences.

We humans, social creatures that we are, may offend spouses, family members, neighbors, co-workers or close friends with hasty, thoughtless remarks and must then apologize for those comments.  While most of these offenses are relatively minor, some may lead to dire consequences if not acknowledged and handled promptly (just ask the CEO of United Airlines).

Our ability to "mend fences" will depend on our sincerity and on whether we have earned the respect and trust of those we offend.  Frequent misbehavior erodes the latter and often destroys relationships.  In Trump's case, his impulsive and offensive Tweets may cement the fate of his Presidency, abolishing his effectiveness both at home and abroad.

Wednesday, April 12, 2017

Front Range Warblers

Admittedly, the spring migration of warblers along the Front Range urban corridor is far less spectacular than it is in the Eastern U.S. where their numbers and variety are much greater.  Nevertheless, regional birders look forward to the arrival of these colorful spring migrants and summer residents, an annual event that stretches from mid March to June and generally peaks in early-mid May.

Indeed, for the past month, isolated sightings of yellow-rumped warblers have been reported in the region and, over the past week or so, the first common yellowthroats have appeared.  This morning, at South Platte Park, I encountered thirteen yellow-rumped warblers (in two flocks), indicating that their migration is beginning to accelerate; last year, on May 3, I was treated to an invasion of these cold-loving warblers, when an estimated 300 filled the trees of the Park.  Yellow warblers, the most common summer warbler along the urban corridor, should begin to arrive in a week or two and will be nesting by late spring.  Wilson's warblers, which nest near timberline, are often abundant near area lakes in early May; other fairly common migrants along the urban corridor include Tennessee, Nashville, Black and White and Townsend's warblers, northern parulas, American redstarts and northern waterthrushes.  Summer residents on the Piedmont include yellow warblers, yellow-breasted chats and common yellowthroats; Virginia's warblers, ovenbirds, orange-crowned warblers and chestnut-sided warblers summer in the foothills while MacGillivray's and Wilson's warblers head for the higher mountain forests.

One need not visit State Parks or nature preserves to observe the spring parade of warblers since many turn up in suburban yards and urban parks.  Patience, a decent pair of binoculars and a good field guide are the primary requirements for those hoping to observe and identify these small, active insectivores.

Monday, April 10, 2017

A Loon on a Chilly Morning

As we continue to rebound from the recent April snowstorm along the Colorado Front Range, the afternoons are warm but the mornings remain chilly.  This morning, an hour after dawn, I made my usual circuit around Eaglewatch Lake at South Platte Park, noting that the ducks continue to decline in both number and variety.

Joining them on this crisp spring morning was a common loon, festooned in his attractive breeding plumage.  Looking at home in the dry, cold air, he was fishing on the deeper waters, stopping for periods to rest and preen.  He and his fellow common loons breed on lakes across Alaska, Canada and the northernmost States of the U.S. and primarily winter on bays along the Atlantic, Gulf and Pacific Coasts of North America.

This morning's visitor was just stopping in the South Platte Valley to rest and feed on his way to the North Country; fortunately, I was there to enjoy his presence.  As I watched him, chilled by a cold east breeze, I was taken back to my past travels through Maine, Michigan and Canada and wondered where his journey will end.

Saturday, April 8, 2017

A Wayward Mallard

I returned home on this sunny, mild morning to find a female mallard standing in the dooryard of our Littleton farm.  Undisturbed by my presence, she watched as I unloaded my pickup, neither foraging in the grass nor taking flight.  Why she had stopped by remains a mystery.

Though lakes and ponds are nearby, there are none on our property.  And while mallards often feed in fields (usually in flocks), we have two pastures and several lawn areas that, one would think, would more likely attract a duck than the small dooryard (which is hemmed in by the house, our garage, shrub lines and a grove of trees).  I was initially concerned that she might be ill or injured but there were no signs of distress and she eventually flew off, presumably headed for more typical duck habitat.

While ducks, geese and other water birds fly over our farm on a regular basis and Canada geese often crowd the pastures in winter, this morning's encounter was the first time in 27 years that I observed a lone duck on the property, let alone in our small dooryard.  If nothing else, forty years of birding has taught me that the unexpected becomes routine and that, as much as we like to think otherwise, we have only begun to understand nature and her fickle cast of characters.

Thursday, April 6, 2017

The Marsh Wren

While making my usual circuit around Eaglewatch Lake this morning (at South Platte Park), the distinctive song and chatter of a marsh wren rose from a dense cluster of reeds near the shore.  Summer residents of wetlands across Canada and the Northern U.S., these reclusive birds also breed along the Pacific coast and in marshes of the Intermountain West.  While most winter in the Southern States or Mexico, some are permanent residents of relatively mild weather locations throughout the West.  Here along the Colorado Front Range, they are uncommon summer residents but are also occasionally observed in winter.

During the breeding season, the male marsh wren constructs a number of dome-shaped nests in cat-tails, cordgrass or other low wetland vegetation and may mate with more than one female if they find his handiwork acceptable.  While the females care for the eggs and hatchlings, he defends the territory, chasing away intruders and often destroying the eggs or killing the nestlings of other marsh birds.  Throughout the year, marsh wrens feed on insects or their larvae which they glean from wetland plants or directly from the water.

Despite this aggressive behavior, marsh wrens are seldom seen, preferring to remain secluded in the dense vegetation.  On the other hand, the males are frequently heard (especially during the breeding season) and may briefly survey their territory from the tip of a reed or cat-tail.  Most of the time, however, birders must settle for fleeting glances of this wetland resident, perhaps noting its white eye-stripe, streaked back, long, narrow bill or cocked tail.

Wednesday, April 5, 2017

April Snow

Following a warm, dry March (usually Metro Denver's snowiest month), I returned from Missouri to find our crab apple trees in full bloom; it was April 3 and recent rain showers had greened-up the farm, making it look more like mid April.  Mild air augmented that illusion but change would come overnight.

Upslope precipitation developed late in the evening, starting off as rain and changing over to wet snow; by the morning of April 4, three inches coated the trees, shrubs, pastures and "lawns."  Since the overnight low hovered near 33 degrees F and since the snow offers some insulation for the blossoms, it appeared that our crab apple crop might survive the early April snowstorm. But while most of the snow melted yesterday afternoon, a second wave of snow moved southward through Metro Denver last evening, re-coating the landscape with another three inches.

Such is the nature of spring in Colorado.  In my 35 years of living along the Front Range, I have found that April often produces more "winter weather" than March does (though official statistics suggest otherwise).  Of course, these late blasts of snow and cold weather have more effect on more varieties of fruit trees than those that arrive in March.  No doubt, many homeowners and orchard managers are frustrated by this annual pattern but the many benefits of living in this region are products of the same geography and climate that deliver spring snowstorms.

Tuesday, April 4, 2017

Eastern Gray Treefrogs

On the evening prior to leaving Missouri, I stepped out on the back deck to enjoy the balmy weather; it had been rainy and cool much of the week but warm, humid air had moved in from the south.  Taking a seat, I was suddenly startled by a loud trill coming from one of our magnolia trees; it sounded like the call of a red-bellied woodpecker but no bird occupied the knotty branches.

I soon realized that I was hearing the mating call of an eastern gray treefrog.  After emerging from a winter beneath the leaf litter, these small amphibians (up to 2 inches in length) climb trees where they feast on a wide variety of insects.  Found across eastern North America, from southern Canada to the Gulf Coast, their breeding season begins in April or May, depending on the latitude; highly territorial, the vocal males stake out sites near shallow pools of water.  The larger females, attracted by their calls, lay eggs in these ephemeral pools and they are immediately fertilized by the male; the eggs hatch within a week and the tadpoles will morph to froglets within two months.

Ranging from gray to brown to green, eastern gray treefrogs may have a mottled or even color pattern on their dorsal surfaces; a white patch is present beneath their eyes.  Since they are capable of changing the color and tone of their skin to blend with tree bark, they are often difficult to see despite their loud mating trill.  Indeed, I never did find the suitor in our magnolia!

Monday, April 3, 2017

Toward Drier Terrain

After a week of rainy days in Columbia, I headed west on Interstate 70, on my way back to Colorado.  Passing through the soggy landscape of western Missouri and eastern Kansas, I encountered periods of heavy rain until I reached Topeka.  Beyond that city, I crossed the waterlogged Flint Hills, some of which poked into the low, gray overcast, and then forded the rain-swollen channels of the Smoky Hill, Solomon and Saline Rivers.

West of Salina, where the topography climbs toward the High Plains, the clouds began to lift and pockets of blue sky appeared above the western horizon.  Nevertheless, flooded fields and sloughs dominated the scene all the way to Hays; it was not until I reached WaKeeney, at the eastern edge of the High Plains that bright sunshine bathed a relatively dry landscape.

There I had traveled west of the Gulf of Mexico plume, into the rain shadow of the Rockies and onto higher terrain where the thin air transports less moisture.  The semiarid landscape of the High Plains may not support the rich woodlands and lush greenery of the Eastern Plains but the sunshine and dryness were welcome after a week of cool, wet weather.

Sunday, April 2, 2017

Wild Violets

As April dawns, clumps of wild violets begin to bloom across our modest lawn in central Missouri.  Welcomed by naturalists and many home owners, these attractive perennials are derided as obnoxious and persistent weeds by professional lawn masters.  As you can see for yourself, most internet sites devoted to wild violets focus on methods to eliminate them from your lush, green carpet of grass.

Wild violets are among 600+ species in the genus Viola, most of which favor cool, Temperate climates.  Indeed, they generally become established in moist, shaded portions of the lawn and later spread to adjacent areas that receive partial sun.  Dense, fibrous root networks spread through the soil, giving rise to heart-shaped leaves and the colorful flowers in early-mid spring; seed capsules form beneath the leaves and lawn mowing augments dispersal of the seeds.

In addition to adorning the lawn in spring and diversifying the plant life on your property, wild violets offer sustenance, providing a natural salad component that is a good source of vitamins A and C; the flowers are also used as an additive in teas, honey and deserts.  A variety of medicinal benefits have been attributed to this wildflower though I am not personally aware of scientific data supporting those claims.  For me, their seasonal beauty is therapy enough.