Invasion Of Violet-Green Swallows

On this cool, cloudy morn along the Colorado Front Range, large flocks of violet-green swallows swirled higher upwardly the South Platte, strafing the river together with following ponds for insects.  Just equally many perched on nearby ability lines, resting inward the chilly drizzle.

Having wintered inward United Mexican US or Central America, these aerialists normally buy the farm inward in belatedly Apr or May, resting together with feeding on the Piedmont before heading into the foothills together with mountains.  There they volition nest inward tree cavities or stone crevices together with feast on a multifariousness of flight insects.  Throughout the summer, they are oft observed inward foothill canyons, feeding amongst white-throated swifts.

Damp, chilly weather forcefulness swallows to congregate along together with higher upwardly rivers or lakes, where their prey hovers over the relatively warm water.  I encountered most 850 violet-green swallows along a 1.5 mile stretch of the river this morning, joined yesteryear much smaller numbers of cliff, barn, tree together with rough-winged swallows which arrived before together with accept already dispersed along the Front Range. 

The Guessing Game Begins

From mid May through nearly of the summer, thunderstorms oft construct inwards a higher house the Front Range peaks past times belatedly morning.  Steered past times upper degree winds, they deed eastward across the urban corridor as well as thus onto the High Plains where they may grow into monster supercells; June is the tiptop calendar month for tornadic thunderstorms across the Plains of Eastern Colorado.

For those of us inwards Metro Denver as well as other Front Range cities, the path of these storms is provender for a daily guessing game.  During years when the landscape is parched, nosotros promise that i volition deed over our property, dropping heavy rain.  On the other hand, these storms oft gain damaging hail and, if the seasonal wet is upwardly to par, nosotros promise that they volition angle to our northward or south.

Today's storms began to construct past times mid morning time as well as the largest of the grouping moved across downtown Denver (no give-and-take nonetheless on whatever damage); hither inwards Littleton, nosotros received exclusively a brief shower.  While minute or fifty-fifty 3rd rounds may occur, the laid out describe of piece of job of storms is to a greater extent than oft than non nearly potent, sucking grade out energy from the atmosphere as well as cooling the air behind them.  As I write this post, the growing remnants of that initial describe of piece of job loom to the east, stretching from the Black Forest (just northward of Colorado Springs) to Fort Morgan (in northeastern Colorado).

Macgillivray's Warbler

On my stroll through South Platte Park this morning, I was fortunate to come across a MacGillivray's warbler.  Not easily observed, this migrant favors riparian thickets on its agency from United Mexican States in addition to Central America to breeding grounds inwards the Western Mountains in addition to Pacific Northwest.  Indeed, I industrial plant life this morning's visitor inwards shrubs along the South Platte River in addition to would convey missed him altogether if I hadn't noticed stimulate of the foliage.

MacGillivray's warblers too nest inwards streamside thickets or dense understory, favoring novel increment woodlands; hither inwards Colorado, they are best industrial plant life betwixt elevations of 8500 in addition to 10,000 feet during the summertime months.  Like virtually warblers, they are insectivores, gleaning prey from the vegetation or straight from the ground.

Once considered to survive a subspecies of the mourning warbler, which breeds inwards Canada in addition to migrates through the cardinal in addition to eastern U.S., the birds are straight off classified every bit distinct species.  Regardless of his classification, today's visitor is probable to survive 1 of the in conclusion boundary migrants to boot the bucket through the Front Range urban corridor this year.

Colorado & Switzerland

Since I volition survive visiting Switzerland inwards the close future, I accept begun to report its geography in addition to noticed or thence pregnant similarities to Colorado.  Of course, they are both mountainous regions (the Rockies inwards Colorado in addition to the Alps in addition to Jura Mountains inwards Switzerland) in addition to that topography gives nascency to major river systems.

Here inwards Colorado, the mount corridor stretches due north to due south through the key purpose of the State in addition to likewise curves westward inwards Southwestern Colorado.  East of the Continental Divide the terrain is drained past times the North Platte, South Platte, Arkansas in addition to Rio Grande Rivers spell the massive Colorado River Watershed drains the Western Slope.  The North in addition to South Platte Rivers merge to driblet dead the Platte River inwards Nebraska (a major tributary of the Missouri), the Arkansas eventually enters the Lower Mississippi River in addition to the Rio Grande empties into the Gulf of Mexico.  The Colorado nearly reaches the Sea of Cortez.

The Alps stretch across southern Switzerland spell the Jura Mountains ascent along its northwestern edge alongside France.  Between those ranges is the Switzerland Plateau, most of which drains ENE to the Rhine River Valley; a major European river, the Rhine flows northward to the North Sea.  Southwestern Switzerland is drained past times the Rhone, which flows WNW to Geneva (passing through Lac Leman or Lake Geneva en route) in addition to thence turns southward through Southern French Republic to accomplish the Mediterranean Sea.  Influenza A virus subtype H5N1 modest expanse of southern Switzerland drains into the Po River, which flows eastward through Northern Italy to the Adriatic Sea in addition to extreme southeastern Switzerland drains to the Danube, eventually reaching the Black Sea.  More on all of these geographic features inwards the weeks to come.

A Nervous Assassin

Late this morning, I looked out of our kitchen window together with noticed an immature Cooper's hawk inwards the side yard, seemingly lounging inwards the sunshine.  Within a few seconds, however, he began to repeatedly hop into the air, twisting close equally if performing a ceremonial dance.

Grabbing my binoculars, I focused inwards on the ritual together with observed the tail feathers of a songbird poking from the grass; from what picayune I saw, I suspect it was a family finch.  Interrupting his dance, the hawk would curl the carcass to ane side or the other together with and then resume his antics.  Finally, later 5 minutes or so, he took the victim to a grove of pinon pines where he settled on the terra firma for a fleck earlier ascending to a limb to pluck his meal.

Large adult Cooper's hawks (especially females) oftentimes pluck together with eat their victim at the site of the kill, unconcerned that crows or other scavengers mightiness plough up.  Smaller birds (males together with immatures) prefer a secluded place to bask their repast inwards peace, oftentimes taking it into a nearby tree.  I'm non certain how to translate today's display; mayhap the immature hawk was simply excited to accept made a kill but he had the expect of a nervous assassin.

Waiting On The Tanagers

Since purchasing our Littleton, Colorado, farm almost iii decades ago, western tanagers accept never failed to catch the holding inwards mid May.  Indeed the appearance of those colorful migrants is 1 of the highlights of nature's year.  So where are the buggers this spring?

Summer residents of the upper foothills as well as lower mount forests, western tanagers wintertime inwards the Tropics.  They are primarily insectivores, gleaning their prey from leafage or flycatching from the pinnacle of trees; tanagers equally good eat berries as well as oftentimes invade our mulberry trees if the fruit has ripened when they visit.

Well, nosotros accept enough of insects as well as the mulberries are or then beingness edible simply the tanagers accept non withal arrived.  We birders pride ourselves inwards knowing a proficient bargain most the demeanor as well as migration patterns of our quarry simply nature is fickle as well as the birds are non hither to entertain us.  Our farm is for certain an attractive balance goal for the migrating tanagers simply then are many other locations along the Front Range.  If I were non leaving town inwards 2 days, I'd in all probability survive to a greater extent than patient.

Front Make Rut Wave

The atmospheric ridge that has been edifice over the Desert Southwest this past times calendar week has spread northward to the Colorado Front Range.  We reached an afternoon high of 100 degrees F yesterday in addition to facial expression to top that rate today.

Beneath this high pressure level dome, air sinks in addition to heats up.  In addition, cloud evolution is suppressed in addition to Pacific mutual frigidity fronts are shunted to the northward of the dome, reducing whatever run a hazard of precipitation.  Highs inwards the Desert Southwest accept exceeded 110 degrees F at lower elevations (e.g. inwards Phoenix in addition to Las Vegas) in addition to overnight lows accept barely dipped below xc degrees F.  To the east, across the Southern Plains in addition to lower Mississippi Valley, the estrus is less intense only is exacerbated past times humidity (with dew points inwards the mid seventies), producing a estrus index close 100 degrees F.

Fortunately, the higher peak in addition to drier air along the Front Range enhances radiative cooling at nighttime in addition to our overnight lows are falling into the low-mid sixties (still nigh 10 degrees higher upwards normal).  Here inwards Colorado, the atmospheric ridge is expected to retreat past times the weekend, bringing cooler temperatures in addition to a run a hazard for precipitation.

Canadian Refreshment

While the Trump Administration believes that our northern neighbors are a safety threat, I sure enough appreciate the cool, dry out air that they sent this agency (no tariffs attached).  This morning, it felt to a greater extent than similar belatedly September than belatedly June along the Colorado Front Range.

This welcome modify was the production of high pressure level over the Pacific Northwest as well as depression pressure level over the Northern Plains.  Between these atmospheric pumps, the pleasant Canadian air was driven southward, displacing the oestrus that has plagued us for the past times calendar week or so.  Colliding alongside that heat, the cool air may spawn thunderstorms afterward today.

Unfortunately, our expose volition move brief as well as the southwestern atmospheric ridge volition reclaim the Front Range past times Monday.  In the meantime, we'll savour highs inward the upper seventies as well as depression eighties as well as overnight lows inward the upper fifties (F).  My personal thank you lot to Canada for the refreshing air, nonetheless curt it's visit.

A Golden Morning

On this cool, breezy morning, I took a walk along the South Platte River earlier summertime estrus enveloped the Front Range.  Once again, depression H2O attracted a diverseness of herons in addition to egrets to the river shallows field cormorants fished inwards the deeper pools in addition to a host of swallows strafed the H2O surface for insects.  Influenza A virus subtype H5N1 solid unit of measurement of belted kingfishers lounged along a beaver pond in addition to black-billed magpies were peculiarly noisy in addition to abundant.  But the highlight of my walk was the presence of a golden eagle, perched inwards a tree along the river.

Not close equally mutual equally bald eagles in addition to ospreys along this stretch of the South Platte, golden eagles are to a greater extent than oftentimes observed inwards foothill canyons or close buttes in addition to mesas on the High Plains where they nest on stone ledges.  Nevertheless, they may survive encountered inwards rural areas of the Colorado Piedmont, hunting for prairie dogs, soil squirrels in addition to rabbits; these powerful raptors are also known to kill grouse, wild turkeys, fox, fawns in addition to immature pronghorns on occasion.  Unlike bald eagles, they produce non typically feed on carrion though they sometimes feast on dead deer or elk during the colder months.

Residents of the Northern Continents, golden eagles are primarily flora inwards the Western U.S.A. exactly may wander to the Eastern States inwards winter.  This morning's visitor, field far from rare, was an unexpected treat, peculiarly during the birding doldrums of summer.  

An Avian Weathervane

Following a blessedly cool hateful solar daytime amongst intermittent showers, brilliant sunshine has returned to the Colorado Front Range.  Though a high most xc degrees F is officially expected, the air current has non withal shifted to the southward in addition to its northeasterly administration is producing an upslope menstruation that has a mild cooling termination along the urban corridor.

As if to emphasize that fact, a Swainson's hawk soared inwards a higher house our Littleton farm this afternoon, stopping at times to hover into the northeast breeze.  Though relatively high inwards the clear bluish sky, this raptor's groovy eyesight allows him to alternative out prey (small mammals, songbirds, large insects) most the ground, toward which he powerfulness brand a precipitous "stoop."  Today's visitor seemed to endure to a greater extent than interested inwards cavorting overhead, perchance enjoying the cool recess equally much equally the summer-weary humans far below.

Then again, Swainson's hawks create non stick around for our crisp spill weather, oftentimes circling toward Argentine Republic past times September.  There they pass the Southern summer, non to supply to Colorado until belatedly April.

Late Summertime Flocking

As the days buy the farm along to shorten as well as summertime begins to lose its intensity, attentive birders abide by flocking demeanour inward many species.  For almost birds (goldfinches are an exception), their breeding flavour has ended as well as their territorial instincts accept faded; migrants get together inward flocks to cook for their southward journeying acre many permanent residents flat flocks to evade predators as well as to ameliorate the efficiency of their foraging.

Last evening, I encountered a flock of 30+ barn swallows, strafing a nearby lake to fuel upward for their journeying to South America; then, this morning, I watched every bit a flock of eighteen snowy egrets moved southward higher upward the South Platte Valley.  Among other belatedly summertime migrants that locomote inward sizable flocks are blue-winged teal,  Swainson's as well as broad-winged hawks, shorebirds, mutual nighthawks, American white pelicans as well as Franklin's gulls.  Non-migrant flocks of cedar waxwings, doves, robins, starlings as well as diverse blackbirds are too increasingly mutual every bit summertime winds down.

While the influx of wintertime songbirds volition non laid out until mid October, these belatedly summertime flocks offering around excitement every bit birders endeavor to recover from the mid summertime doldrums.  Better yet, they are a preview of tumble migration glasses as well as hint at the cool, crisp days that prevarication ahead.

A Expert Twelvemonth For Fruit

Despite excessive rut as well as a prolonged drought through the commencement one-half of summer, the fruit crop on our Littleton farm has been splendid this year.  Mulberries were abundant inwards June as well as our diverse apple tree as well as pear trees are to a greater extent than laden alongside fruit than I guide maintain seen inwards many years.

Of course, this abundance reflects the fact that nosotros did non guide maintain a belatedly freeze this spring.  Though around upslope snowfall cruel inwards March as well as April, the temperature remained relatively mild as well as the blossoms emerged intact.  Since I am oftentimes out of town, our farm management mightiness last described equally willful neglect, characterized past times minimal irrigation as well as no role of fertilizers or pesticides; equally a result, the fruit is abundant only non terribly attractive for human consumption.  While I mightiness snack on an apple tree or two, close all of the crop is left for the wildlife.

Indeed, nocturnal squabbles guide maintain been evident this past times calendar week equally raccoons as well as skunks raid the fallen fruit.  Squirrels, flickers as well as mice likewise partake and, inwards around years, mule deer wander inwards to feast on the bounty.  What could last ameliorate for a naturalist than trees that necessitate no maintenance as well as attract a host of wild creatures? 

Prairie Sunflowers

While they may bloom from June to September, prairie sunflowers are to a greater extent than oft than non most abundant as well as conspicuous inwards August.  Native to the High Plains, clumps of these wildflowers adorn about every highway as well as province route inwards Eastern Colorado; since they favor total Sun as well as sandy soil, prairie sunflowers convey spread throughout most of the West as well as much of the Eastern U.S., wherever such weather condition exist.

These mutual annuals may await a chip scraggly where they point an abandoned plain only tin create stunning swaths of gilded inwards to a greater extent than favorable areas.  Their seeds are consumed past times small-scale mammals as well as a broad multifariousness of grassland birds as well as convey been used past times humans likewise (either inwards whole split or churned into a butter).

Prairie sunflowers are sure enough amidst the to a greater extent than widespread wildflowers on the Great Plains as well as are specially appreciated when the intense summertime Sun has baked away most of the greenery.  To me, they correspond the vanguard of tumble splendor.

A Sunset Flight

Last evening, my boy (a pilot) together with I took a flying across the Colorado Piedmont, S of Denver.  Leaving Centennial Airport an hr earlier sunset, nosotros headed westward to Chatfield Reservoir together with and therefore turned south, next the base of operations of the foothills.

Crossing over Roxborough State Park, adorned amongst scenic stone formations, nosotros could meet the prominent peaks that ascension along the South Platte River Canyon to our westward together with southwest.  Farther along, nosotros passed the craggy majority of Devil's Head together with continued upwards the Plum Creek Valley to the Palmer Divide.  Angling to the east, nosotros followed the Divide for a brusk distance, catching a sentiment of Monument together with Colorado Springs inwards the Fountain Creek Valley, off to our south.  After curving across the upper tributaries of Cherry Creek (which eventually joins the South Platte inwards downtown Denver), nosotros passed higher upwards the mesas together with buttes that characterize the scenic topography of the Castle Rock region.

As nosotros headed north, well-nigh Sedalia, the Sun educate behind the Front Range together with nosotros could meet the multiple ridges of foothills together with mountains that arrive at a stair-step landscape, leading to the Mt. Evans massif.  After taking it that spectacular view, nosotros headed dorsum to Centennial amongst a fresh appreciation for terrain that nosotros accept long known exclusively from the ground.

Visiting Coastal Colorado

After my recent locomote to beaches too coastal wetlands of the Southeastern U.S., I idea I would take in Coastal Colorado today, a term I accept previously applied to the lakes, gravel pits, sloughs too canals across the South Platte Valley of northeastern Colorado.

Unlike the Southeastern wetlands, those of the South Platte Valley are non characterized past times lush, verdant vegetation.  Rather, inward this semiarid climate, trees (mostly plains cottonwoods) are constitute exclusively along the river, its top dog tributaries or irrigation canals.  Since this summertime has been specially hot too dry, the natural grasslands accept browned, adorned exclusively past times clumps of prairie sunflowers too rabbitbrush.  Though I saw hundreds (if non thousands) of American white pelicans (especially at Barr Lake State Park), close avian species were express inward number; amid these were Swainson's hawks, American kestrels, western grebes, cattle egrets, Franklin's gulls, American avocets too shorebirds that were also distant to identify.

I accept been visiting this percentage inward slowly summertime for to a greater extent than than 30 years, enjoying the mosaic of shortgrass prairie, cropfields too ranchlands that surroundings the river, lakes too wetlands.  In recent years, however, fracking wells too fossil oil storage tanks accept begun to dominate the scene inward approximately areas too i wonders what comport on they volition accept on the lineament of the H2O too the welfare of the aquatic ecosystems.

Late Summertime Rut Wave

Following 2 weeks of relatively mild temperatures in addition to intermittent rain, the adjacent (and hopefully last) oestrus moving ridge is edifice along the Colorado Front Range.  Once again, it is the production of a high pressure level ridge, expanding northward from the Desert Southwest.  For the adjacent calendar week or so, afternoon highs are expected to accomplish the lower to mid 90s F, good higher upwards average for September.

Fortunately, the recent rains convey revived the vegetation in addition to the longer nights, combined amongst our high altitude in addition to thin, dry out air, convey allowed overnight temperatures to driblet into the fifties.  In addition, ascent hot air oftentimes ignites thunderstorms higher upwards the Front Range peaks, which in addition to thence drift eastward to render spotty relief from the heat.

Our run a jeopardy of these oestrus waves volition expire along until the jet stream becomes less stable inward mid autumn, undulating across the province in addition to dislodging warm atmospheric ridges amongst cool atmospheric troughs.  Snow unremarkably dusts the higher peaks past times like shooting fish in a barrel September in addition to upslope snowstorms by in addition to large coat the urban corridor past times mid October. 

Autumn Chill Inwards The Valley

While the afternoons are yet summer-like along the Colorado Front Range, the mornings forthwith pick out an autumn chill due to the longer nights.  Down on the South Platte River merely later on dawn, that chill was peculiarly intense and, inward response, the wild residents were noisy too active.

Canada geese, mallards, magpies too cedar waxwings were peculiarly conspicuous too migrant ducks were foremost to brand it from the north; this morning's visitors included blue-winged teal, American wigeon too gadwalls.  Influenza A virus subtype H5N1 few summertime residents yet rest too a solitary snowy egret, huddled on driftwood inward the shallows, seemed to last contemplating his escape to warmer climes.  Normally nocturnal, a beaver was active inward the post-dawn chill, inspecting his dam earlier wintertime arrives.

We humans, similar the wildlife, are likewise invigorated past times the chilly air too the riverside path was filled alongside walkers, bikers too joggers.  After all, the autumn equinox arrives this weekend (September 22) too the glorious calendar month of October, which normally brings the foremost snowfall showers to the urban corridor, is merely precisely about the bend. 

Earwigs Inwards The Apples

On this bright, warm, tumble morning, our youngest grandson visited our Littleton Farm.  Searching for an activeness that mightiness entertain him, my married adult woman suggested picking roughly of our greenish apples in addition to making cinnamon apple tree sauce.

He, of course, enjoyed the collection procedure in addition to sampled quite a few of the apples earlier they were processed.  Since nosotros produce non purpose pesticides on the farm, a skilful break showed signs of insect harm in addition to earwigs emerged from a few of the cavities.  Represented past times almost 2000 species across the globe, these elongated, flattened insects are easily identified past times the pincers at the halt of their abdomen.  Females lay their eggs inwards protected crevices past times mid tumble and, inwards roughly species, overwinter amongst them to offering protection; afterward hatching inwards slow winter, the juveniles undergo at to the lowest degree 4 molts earlier they mature to adults.  Throughout these stages, they feed on a broad diverseness of industrial plant life in addition to animate beingness matter, including flowers, vegetation, fruit, other insects in addition to carrion; since they are primarily nocturnal, earwigs are seldom encountered unless establish inside crops or inwards basements.  They, inwards turn, are preyed upon past times a various grouping of insectivores, including amphibians, reptiles, birds in addition to mammals.

Despite the earwig damage, most of the apple tree crop remained edible in addition to the applesauce was enjoyed past times all.  Though he is non soundless ii years old, I'm certain our grandson gained roughly insight into nutrient production, watching it become from tree to stove to mouth!

Looking For Migrants

On this chilly, autumn morning, amongst a total satelite balanced on the foothills to our west, I went downwards to South Platte Park, hoping to come across autumn migrants.  The early on morning time chill had brought out the songbirds, flitting together with twittering amid the shrubs together with trees, simply all was relatively tranquility on the lakes together with river.

During my i sixty minutes visit, I did expose 2 flocks of blue-winged teal, passing overhead, a handful of pied-billed grebes together with a brace of Wilson's warblers, downwards from the mountains.  That was the extent of the autumn migration, a tide that has non nevertheless gained momentum.  I did consider plenty of permanent together with some summertime residents, including an osprey, a non bad horned owl, gray catbirds, double-crested cormorants together with woods ducks, simply the migrants accept been deadening to appear.

Nevertheless, it was a pleasant walk roughly Eaglewatch Lake.  I got my exercise, enjoyed the fresh, cool air together with appreciated the companionship of the resident wildlife.  The migrants volition plough upwardly shortly enough.

Addendum:  My ongoing search for migrants was rewarded early on this afternoon, when a flock of five sandhill cranes circled southward inward a higher house our Littleton farm.

Pink Egrets At Dusk

Last evening, I went out at dusk to explore our Littleton farm.  Most of the plane sightings were of mallards, swell bluish herons too ring-billed gulls, heading toward their nightly quarters to our northwest.

Influenza A virus subtype H5N1 squadron of modest bats strafed the farm too our colony of cottontails emerged for a leisurely nighttime of nibbling.  Off toward a corner of the property, a noisy flock of magpies had gathered inward a tree, evidently heckling a hawk or owl.  Above it all, jets drifted toward DIA too the clouds took on the changing hues of sunset.  Not to endure outdone past times Earthly events, Jupiter gleamed from the southwest piece Saturn sparkled inward the southern sky.

The highlight of my eve stroll proved to endure a flock of pinkish egrets, 14 inward number, flapping toward a roost somewhere due north of the farm; of course, they were snowy egrets, painted past times the final rays of the setting sun.  Apparently unfazed past times the cooler weather, they volition pass at to the lowest degree simply about other twenty-four hours along the Front Range earlier heading south.