Friday, June 27, 2014

The Nature of Art

 
Reverberating with my Halibut Point green heron endeavor a reader sent along this photo of a mythic moment between Nature and the human psyche. Her photograph is a work of art.

Green Heron
Lois Brynes photo

What can we say of beauty? Perhaps that it is an awareness uniquely planted in people to temper our species' capacity to alter our environment. A conservative, cautionary, bonding element. It exists independently of art, and is only one of the qualities that art may choose to portray. Nature is bigger than art.

A few decades ago Slow Turtle of the Wampanoag Tribe gave a talk on Cape Ann with a dark outlook on modern life. I asked him what 'beauty' meant to him. He said "I see beauty wherever things are as God intended them." It was a satisfying answer, removed from logic, and comforting.
 
Art may also appear ironic, didactic, or angry. It may suggest non-aesthetic associations to the intellect, such as an Oriental cast to Lois's heron photograph.


Having rendered our green heron experiences in our particular ways  we have exchanged gifts like emissaries taking up diplomatic posts at an exotic station.

Thursday, June 19, 2014

The Eye of the Hunter


Positioned between brain and beak, a bird's eyes guide it's every movement and meal.  These eyes differ in size, placement, and anatomy according to the lifestyle adaptations of each species.
Magnolia warbler
Migrating warblers pass through Halibut Point just as spring-green caterpillars are hatching among the spring-green leaves. Where we employ three sets of sensors to make up our color world, most birds have four or even five.(1) The high concentration of red- and green-sensitive cones in their retinas enables warblers to find tidbits in the verdure more easily than we can.
 
Birds also have colored oils in their light receptors that filter out certain wavelengths to sharpen others. The proportions vary from species to species to give particular advantages.  Just as the yellow tint of aviator sunglasses sharpens clouds against a blue sky, a warbler benefits from red filters to enhance differentiation among greens.

Brown thrasher
A thrasher's eyes are positioned on the side of its head as a compromise between vigilance and foraging. This location, and the somewhat flattened shape of its eyeballs, give it a panoramic but monocular view in all directions for maximum safety. Its eyes can focus together only where these paired fields of vision overlap directly to the front. In this overlap zone the bird has its best judgment for flight maneuvers, and for the use of its  beak, the critical meal-catching spot requiring good depth perception made possible by the binocular vision that we humans  emphasize  in our reliance on hand-eye coordination.

Snowy egret
As befits a hunter of fast-moving prey, an egret's eyes are oriented frontally for increased concentration on minnows. The penalty it pays of diminished sight to the rear has been an acceptable tradeoff in egret  habitat where predators would have to cross wide-open spaces undetected.  

Light bending at the water surface confuses our eyes on the precise location of objects underneath. Egrets are able to correct for refraction. Their strikes are most successful when made at an acute angle, where they seem to be less detectable to fish.  

Phoebe
Seeing and snatching bugs in midair is the sustaining life of flycatchers like the phoebe. Notice the protruding eye lenses for superior scanning and binocular overlap. The lateral placement of its eyes, and specialized receptor areas, enable it to track images to either side independently. 

Birds that hunt on the wing tend to have retinas highly enriched with cone sensors, several times that of humans. They can process images more quickly than we do into a series of discreet sights that to us may appear as an undifferentiated picture, like seeing individual film frames in slow motion.

Pigeon skull (2)
Birds' eyes take up a larger portion of their heads than any other creature. Surrounding tissues reveal only a small part of the bird's eye to the outside world. 

To save space for optical developments birds have given up the muscles that allow us to move our eyes from side to side or up and down. Neck muscles move their whole head instead. As food gulpers rather than chewers they streamline their skulls without teeth and large jaw muscles.

Grackle
Grackles search the meadow with one eye to the ground and the other cocked to the sky. Their brains synthesize bilateral information in their own version of multi-tasking, then converge the overlap binocularly to peck or fly. 

This hunter's posture is all purpose and focus, leaning into the prospect of taking a life to carry on its own. The full force of its intent lies poised behind the eye in a chilling acknowledgement of survival equations. The eye reveals the bird's nature as acutely as it guides its actions.

 ***
(1) Physiology resources: Wikipedia article "Bird Vision"; and the website "How Birds See their World" by Dr. Esteban Fernandez-Juricic, Purdue University  

(2) Image from Skullsunlimited.com




Thursday, June 12, 2014

Homesteading Birds

Chickadee
A hard-working chickadee pair sensed the potential of this dead birch tree for rearing its brood.


They hollowed out a knot hole to family specifications.


After many trips out to dispose of their excavations they were ready to line the nest in time for the eggs.

Kingbirds
High overhead a kingbird pair had chosen a tree fork for their domicile.


They foraged for construction material.

 
The nest would have to be strong and cozy for the coming nursery,


as well as for the long days of brooding.

Phoebe
Beside the quarry a phoebe searched  for a sheltered crevice in the cliff.


A promising nook with an overhanging roof drew a closer look.


The phoebes got right to work adhering their nest to the wall with mud. It's just visible at the top of the recess.


Once the family is born the parents have a busy job keeping the chicks fed with their fly-catching forays around the quarry. 

Do we devitalize our wonder with the explanation: instinct?

Friday, June 6, 2014

Common, But Seldom Seen

It's one thing to know a bird is there and another to get a good look at it. For visual appreciation you need clear sight lines, which some birds are explicitly reluctant to grant. Trying to obtain a clear view, such as across a pond,  gives the bird an open look at your stealthy moves and the chance to disappear. If you have to approach through the brush you might as well be crunching bubble wrap en route.
Green Heron

On a lucky day in the spring I got this photo of a green heron beside one of a network of small quarries. It whetted my hope for further sightings, maybe even a rookery, but no luck until last week when we surprised each other at his fishing post on a pond near the tip of Halibut Point. He dashed into the woods and flew off a bit later with a companion (the missus?), in the direction of the first quarry, silhouetted like a pair of short-tailed crows against the sky. 

The next morning I tiptoed back to the pond at dawn thinking to be ahead of the herons. It seemed a more reasonable plan than spending the night. Unfortunately my portable hunting blind malfunctioned. Any possibility of staying invisible was lost, but I lingered quietly for a while in Little Eden.
Almost subliminally I became aware of a soft hooting sound which gained volume as a mysterious creature drew closer in the brush behind the pond. I never got a look at it. Later, in a rather comical email exchange with a birding expert at Mass Audubon, I tried to describe the sound. Once I got him the right combination he zeroed in on the black-billed cuckoo. I went to the Cornell Ornithology website to hear a recording of that very sound from the bush, along with this assessment: "Common but secretive, the Black-billed Cuckoo is heard far more often than seen." 

Now I had a double incentive to infiltrate that charmed terrain for photographic trophies. Early the next morning I threaded down a 'game trail' to the rear side of the quarry and set up station beneath an oak tree. The solitude nurtured reflections on strategy, and on obsession. 

Obsession? How else do you stretch experience? I was mobilized, yes. I wanted those photographs, but not necessarily at all costs. Hmmm. I could admit to being fairly far to the right on the interest - passion - obsession spectrum. Those words slide into one another. 
 
It's not a zero-sum game. I don't see any losers. Time outdoors with a quest makes for winners. Of course you will be tested. I, for instance, am learning to accept that the trees have to have their leaves even though they interfere with bird watching. But couldn't science give us a mini-laser to snip out an annoying branch or two?

Something moved off to the left of my lair. This little fellow peered back at me from within the canopy, then flitted to a spot that revealed a bit more of its identity to my Mass Audubon consultant: female common yellowthroat.  I have a new acquaintance.

The last couple of outings to Halibut Point I've heard the cuckoo again, sotto voce and alluring beyond the catbrier tangles. Oh, what a coup that photo would be!  Let's see...cut a trail...build a tree blind...play a recording to bring him closer...

Black-billed Cuckoo
Christopher L. Wood photo
Courtesy of Cornell Ornithology Lab
Years ago on a field trip a novelty came into view. My companion remarked, "Well, I guess that's a life bird for you." I replied, "No, it's just the first time I've seen it." Remembering that perspective helps keep my obsessions in check.