The Aerialist

I snapped the photo above in April of 2011 while turkey hunting; which for reasons of being concealed in a blind is good for all manner of wildlife observations.

Meet Tachycineta bicolor - the tree swallow. 

This blue-green feathered bird is an early spring arrival and they are a delight to observe as they are spectacular aviators who hunt flying insects.

As a cavity-nesting species this bird had historically been found only in wooded habitat where they nested in tree cavities.  However, the distribution of nest boxes by songbird enthusiasts has allowed for the expansion of its range to include open habitats,  They compete with bluebirds and house wrens for rights to nest in our boxes.  

I the photo the two birds were engaging in their courtship ritual and selection of a nest box.  I observed the very same ritual while turkey hunting this April; only it was bluebirds.  

And if you follow this blog the courtship, along with other nesting sites, has yielded another batch of bluebird hatchlings calling for cigars all-around.

But I digress. 

With regard to the tree swallows; both birds gather materials as the female constructs a cup-shaped nest of grass lined with feathers.  Four to seven small eggs follow about a week after mating. 

I took this photo the same day I took the bluebird hatchling photo immediately above. As soon as eggs are laid mama lines her nest with feathers gathered from all species.  They are incubated by mom for a couple of weeks and after hatching both birds feed the young who fledge at about three weeks of age.

Aside from being splendid aerialists the tree swallow is fearless. Evidenced above, mama swallow is not to be shifted from sitting on her clutch of eggs if some galoot pokes his nose in to take a photo .

Nest predation typically occurs by snakes, raccoons, weasels and cats. Birds on the wing can be picked-off by most any of the resident raptors.  It is during this critical nesting period I have to wear a ball cap when walking the dog as we get dive-bombed when approaching an active nest.

By the time August rolls-around these bird are gone.  Vamoosed!

They leave their breeding grounds to congregate in large flocks in marshy areas with plenty of flying insects to feed-upon.  From there they migrate to Florida, Cuba, Central and South America.  Other than the dive-bombing it is a hoot to watch this talented aerialist.

Return of the Timberdoodle

While out walking the dog recently she flushed several doodle birds.  I have mixed feelings about this; on one hand I do not care to discourage a flusher retriever’s natural instincts. On the other hand it is nesting season for all birds and I’m loath to allow a dog to trample or otherwise molest an active nest.  So I try to keep her close at all times. 

About those doodle birds, they’re common around here because of the remnant alder and willow thickets in the lowlands and younger reforested uplands.  Nevertheless, outside of the local situation this curious bird is becoming less common every year.

The American woodcock - Scolopax minor - also known as the timberdoodle - is a ground-dwelling shoreland bird species found in young forest and shrublands. Woodcock breed across eastern North America with Wisconsin part of its western range.  This migratory bird winters in lowlands from the Mid-Atlantic south to the Gulf Coast states. 

Like other shorebirds, American woodcocks, also known as timberdoodles, are well adapted to life on the ground. The location of their eyes allow them to be able to look skyward for predators while probing the earth with their beaks.

 

Earth worms are their meal of choice. Their long, flexible ~3 inch beak is great for digging through soft, moist soil. Their beaks function like forceps allowing them to eat their body weight in worms daily.

 Like other ground birds, woodcocks are precocial when they hatch. Meaning they hatch in a more advanced stage of development compared to other nesting birds and are able to leave the nest a few hours after hatching.

Historically, woodcock were found in much larger numbers.  This was a consequence of a landscape that included larger amounts of early successional habitat - the technical nomenclature for younger forest.  Not surprisingly those younger forest have evolved and grown to mature forest where woodcock do not live. Fire is suppressed and logging is in decline so the extent of younger woodland habitat continues to shrink.  Urban development also destroys former habitat and because of all of these factors the woodcock population has fallen by about 1 percent each year since the 1960s. 

Aldo Leopold’s - A Sand County Almanac - describes the courtship display of the male Woodcock.  This is one of the true harbingers of spring around here and a delight to observe before sun-up.  From the chapter titled Sky Dance in this excerpt.

I'm tickled to listen to the courtship ritual.  It is another sure sign of the arrival of spring.

One Tough Bird

We've had a pair of resident sandhill cranes nesting here for as long as we've had our big pond; making it thirty years.  I don't believe it has been the same pair for the duration ; nevertheless, we've been witness to cranes arriving here in the month of March is some remarkably harsh weather conditions.  Including Winter Storm Elsa which ended late Monday.  Our cranes have been here for a couple of weeks already and when I arose yesterday they were easy to spot given all the snow on the ground.

There they were - several hundred yards north of the house - at the edge of the frozen pond, in a couple feet of snow, on a sunny 18F morning.  The sandhill is an incredibly hardy critter always arriving at their northern breeding grounds while there is still snow covering icy wetlands. 

This bird comes factory-equipped with some sophisticated physiological adaptations that allow it to thrive under the harshest of conditions.  One of these is a sophisticated network of blood vessels in their legs called rete tibiotarsale.  Also found in penguins and turkey vultures this allows warmer arterial blood from their heart to transfer heat to the cold venous blood returning from their feet.  This keeps their core temperature warm while allowing their feet to remain at a lower temperature while standing in snow or icy water.  

When airborne cranes typically fly with their long legs trailing behind.  If it is too cold at 10,000 feet of altitude the bird will tuck their legs into their belly feathers to conserve heat.  Speaking of which, the crane's plumage is a dense layer of soft downy feathers beneath an outer layer of contour feathers.  Air trapped by the inner layer provides thermal insulation beneath the outer feathers that repel wind and freezing rain.   

Crane behavior strategies include the use of tail winds to speed their migration from Mexico and southern states, roosting in warmer waters adjacent to power plants and preening their gray feathers with mud to make a rusty-brown camouflage to hide from predators.  Until the arrival of spring green-up, this is a bird capable of digging beneath snow to locate waste grain in agricultural fields and tubers and dormant invertebrates and amphibians in frozen mud. 

Anyway, we're looking forward to observing the ritual mating dance of Wisconsin's tallest bird.  The birds will face each other, bow and jump while flapping their wings and making loud cackling calls.  Yes, this tough bird can dance too.

Stay-tuned for any lucky trail camera photos I might capture this season. 

Sky Dance

In his classic: A Sand County Almanac, Aldo Leopold characterized the courtship display of the male American woodcock as the “sky dance.”  

Knowing the place and the hour, you seat yourself under a bush to the east of the dance floor and wait, watching against the sunset for the woodcock’s arrival. He flies in low from some neighboring thicket, alights on the bare moss, and at once begins the overture: a series of queer throaty peents spaced about two seconds apart, and sounding much like the summer call of the nighthawk.             

Suddenly the peenting ceases and the bird flutters skyward in a series of wide spirals, emitting a musical twitter. Up and up he goes, the spirals steeper and smaller, the twittering louder and louder, until the performer is only a speck in the sky. Then, without warning, he tumbles like a crippled plane, giving voice in a soft liquid warble that a March bluebird might envy. At a few feet from the ground he levels off and returns to his peenting ground, usually to the exact spot where the performance began, and there resumes his peenting.    

– Aldo Leopold              

Meet Scolopax minor – The American Woodcock – colloquially known as the timber doodle.   Superbly camouflaged this chunky bird - unlike its shore-dwelling relatives - spends much of its life on the forest floor probing with its long bill for insects and earthworms.    

A woodcock’s eyes are positioned high and near the back of their skull. A unique adaptation that allows them to keep watch for danger in the sky while they have their heads down poking around in the soil for food.  This diminutive bird's coloration also makes it difficult to find except during flight at dawn or dusk or when the dog flushes one.  On occasion when you are innocuously walking to or from a turkey blind or a deer stand in the dark - with no advance warning - the sudden explosion in the darkness that originates from the immediate vicinity of your feet will most certainly have come from a doodle bird.  After the adrenaline rush has ebbed you resume your walk. Tiptoeing gingerly.  

 

Witnessing the woodcock courtship display is truthfully more a patient exercise in listening rather than seeing.  As the sky begins to darken or the dawn begins to glow if you are attentive this time of year you will hear the nasal BZEEP.      

The male will perform his plaintive beeping call on the ground followed by launching into a spiraling flight of 200 to 300 feet.  Like a barnstorming acrobat he then tips into a twisting descent.   The air rushing thru specialized wing feathers whistles to the accompaniment of bubbling vocalizations.   

photo - Thomas Gaertner

 

Upon landing the male fans his tail much like a gobbler or ruffed grouse with the hopes that his dance has attracted a lady charmed by his advances.  In case you care to know - the boys are promiscuous and will mate with any and all females attracted to their affections. 

 

  

Woodcock displays can last for several hours between dusk and dawn from early-March through early May.  The following video was taken in the rain.  Turn-up the volume and listen carefully for the peents followed by twittering flight.  Can you identify the other birds calling in the background?  

 

Spring has officially sprung....