Crows |
Grackle |
I looked up iridescence
on Wikipedia. It said that peacock feathers are actually brown, made vivid by
various internal surfaces microscopically structured to interfere with visible
light, sometimes in combination with pigments. Out of that comes decorative
hues with glossy, metallic sheens.
Cowbird |
Red-wing |
Blackbirds
with flashier accessories come foraging to Halibut Point from the cattail swamp
across Granite Street. Red-wings were probably the next step we took with
crayons, adding a vivid splash at the shoulders.
It turns out
that ornithologists classify grackles, cowbirds and red-wings together within
the icterid family, next to crows. Icteridae
refers to yellow feathers in Greek. The family includes orioles.
Orioles
don't look particularly black. Gloucester's Chris Leahy offers a calming
overview of these relationships in his essay on "Systematics" in The Birdwatcher's Companion. Members of
the blackbird family diverged relatively recently from common ancestors.
'Adaptive radiation' continues all around - and within - us.
Then we have
a black bird that is not a blackbird. Taxonomically, the starling resides in
the sturnidae family alongside but
not within the icteridae. Its compact
sturdy body suggests a different lineage. In the right light its colorful iridescence
helps to compensate for its swarming vulgarity.
Back on
apparently firm black ground the crow anchors the corvid family, the third
branch of blackbirds. Like the others corvidae
are considered songbirds even if their caws and other chatter don't appeal to
us musically. Crows are smart and social. The fellow pictured above interrupted
his preening routine about every twenty seconds to send a message to compatriots
in the neighborhood.
Crows have
meaningful complexities in their coloration that help distinguish the sexes and
individuals. The patterns that are invisible to us include their ability to see
ultraviolet and iridescent subtleties that organize crow life. They know who's
who in crowdom.
The corvid
family has transcended black by engendering magpies and jays, who fully retain
the family's rascally nature and its near-human brain-to-body weight ratio. Like most colorful creatures blue
jays enjoy their own splendor and provide a loquacious account of their doings.
I walked about Halibut Point pondering the
mélange of coloration and classification that assigns black and blue to the
same family. When a flock of jays screeched overhead in tenor variations of a
crow's honest 'caw-caw-caw,' I understood the pairing straight from the
corvid's mouth.
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