Common Icterid, with Uncommon Beauty

Common Icterid, with Uncommon Beauty

Dr. James J. S. Johnson

Deck thyself now with majesty and excellency; and array thyself with glory and beauty.    (Job 40:10).

CommonGrackle-bronze-morph.RhodeIslandBirdHunter.jpg

One of the most spectacular icterids, known for its iridescent shine, is the Common Grackle. As I observed years ago, it is a sobering thought to realize that God could have – if He had chosen to – made me (or you) a grackle!  [See “Of Grackles and Gratitude”]

One birdwatcher in Maryland describes the Common Grackle as follows:

The common grackle (Quiscalus quiscula) is a widespread, common bird in the eastern United States.  Bigger than most other blackbirds [and robins], it stretches to about 12 inches from its long, tapered tail to its bill.  The black beak is prominent, more long than heavy.  Grackles stand on tall, stout black legs.  They prefer to forage on the ground but they will perch precariously if necessary to reach food.  The diet of the common grackle centers on grain, especially corn [i.e., maize].  Common grackles will descend upon a corn field from the moment it’s planted until it’s harvested.  Walking boldly behind planting equipment [!], they peck at newly sown seeds or unearthed grubs.  As the corn begins to tassel, they tear at maturing ears to eat growing cobs.  After the harvest, they descend [in a mob] like a dark cloud, eating any remaining kernels.  Common grackles do millions of dollars of damage [“robbing” cornfields] annually.  …  Though they prefer grains, grackles readily eat thistle, suet or sunflower seeds.  If those foods are not available, grackles will eat just about anything else on hand, including insects, frogs, mice, worms, other birds and even fish.  (Grackles wade into shallow water to nab schooling minnows.)  Discarded garbage [including fast-food litter] is another food source for these omnivores.

[Quoting Mike Burke, “Grackles’ Aggressive Behavior Not Helping its Survival – A Lesson?”, in CHESAPEAKE BAY JOURNAL, 27(3):39 (May 2017).

Ranging from the Midwest to the Eastern coastlands of America (plus some summer breeding ranges northward into central Canada), with most of their wintering range limited to the lands from the East Coast to the sates that straddle the Mississippi River Valley, the Common Grackle is known throughout most of America’s Lower 48 states.

But the Common Grackle’s iridescent plumage is its most conspicuous glory:

Common grackles display an odd geographic variation in color. Those south and east of the Appalachian Mountains [i.e., the so-called “Purple Grackle” variety] have an iridescent purple-blue head, purple belly, and blue-green tail.  Those north and west of the Eastern continental divide [i.e., the so-called “Bronze Grackle” variety of New England and west of the Appalachians] have blue-green heads and brassy bronze bodies.  From afar, all of the birds look black, but at closer distances the iridescent head is easily distinguishable from the glossy body.  Of course, there are exceptions, but generally the grackles in the Chesapeake [Bay] watershed have purple-blue heads.

[Quoting again from Mike Burke, “Grackles’ Aggressive Behavior Not Helping its Survival – A Lesson?”, in CHESAPEAKE BAY JOURNAL, 27(3):39 (May 2017).  Of course, these grackles are similar to the Boat-tailed Grackles that I’ve observed in Florida, and the Great-tailed Grackles that dominate Texas, but the tails of Common Grackles are not as conspicuously lengthy as those of its cousins in Florida and Texas.

CommonGrackle.BillHubick-photo

Like most grackles, the Common Grackle is noisy, gregarious (often congregating on power lines, or in trees near shopping centers), and confident (strutting about in parking lots, hunting for edibles discarded by humans).  Grackles are routinely bold, sometimes to the point of being aggressive.

But is this temperament-like habit a guarantee of the Common Grackle’s success?  Apparently not, according to the Breeding Bird Survey.

The North American Breeding Bird Survey is a joint venture of the U.S. Geological Survey and the Canadian Wildlife Service, for monitoring avian populations, provided time-indexed data that is relied upon for bird conservation policy and programs.  Because these voracious blackbirds are an expensive nuisance to crop farmers, their recent population decline is unlikely to evoke lamentations by crop farmers.

Common grackles are in serious decline. Although they seem to be expanding farther westward and they are still [very much] abundant, the population has fallen nearly 60 percent since 1966, according to the [often-relied-upon] Breeding Bird Survey.  Ornithologists are thus far stumped about why the bird’s abundance has fallen so significantly.

[Quoting again from Mike Burke, “Grackles’ Aggressive Behavior Not Helping its Survival – A Lesson?”, in CHESAPEAKE BAY JOURNAL, 27(3):39 (May 2017).

Could it be habitat loss?  Of course, the Eastern half of the United States continues to convert its croplands to urban and suburban development —  the farmlands of America continue to disappear all too quickly (and the Common Grackle’s “robberies” are not the main cause!).  The cornfields that I knew as a boy (and sometimes worked in), growing up in different parts of Maryland, have substituted housing complexes and shopping centers for what were cornfields (and other crop fields).   If the habitat shrinks, and the readily available food supply shrink, is it any wonder that the population shrinks too?

Another possibility should be considered, too, the empirical science may be less than accurate –  i.e., it may be that the grackle population measurements are not as reliable as the “authoritative” data that they are advertised to be.  To illustrate this possibility, consider how the Atlantic Sturgeon was lamented for years – by Chesapeake Bay bioscientists who opined that it was nearly extirpated, only to be embarrassed to learn that they were looking for the anadromous fish at the wrong season of the year, phenologically speaking, and the fish was actually thriving in some of the Chesapeake Bay’s tributary waters!  [For details on that empirical science foible, see “Anadromous Fish ‘that Swam with Dinosaurs’ Neither Extinct Nor Extirpated,” Creation Research Society Quarterly, 51 (3): 207-208 (winter 2015).]

But to close on a simpler note: the Common Grackle may be common in many parts of America, yet its beautiful shimmering and glossy iridescent colors are anything but common.   Only God’s artistry could design and build a blackbird that reflects sunlight with such majestic magnificence.


FAIR USE PHOTO CREDITS:

Bill Hubick, Maryland: Common Grackle (bold pose & hungry pose)

Jason Major, Rhode Island:  Common Grackle perching (bronze variety)

 

 

One thought on “Common Icterid, with Uncommon Beauty

  1. It is a beautiful bird in the sunshine. Great info. Their decline is interesting. I hadn’t realized that but between loss of habitat and so much pesticides it’s no wonder. I can’t help but compare the grackles to the boat-tailed grackles in Mexico who have a lovely song but are very similar. I wonder why the difference in voice?

    Liked by 1 person

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