St Patrick's day bird thoughts
WINGIN’
IT
By
Kate Crowley
Let me tell you a
little bit about how my brain works and the challenge I face every two weeks
when a column is due. The week before I
start thinking of possibilities. The
closer it gets, the more my brain and eyes search for possibilities. Sometimes
it’s really simple because a unique bird or behavior appears; more often it’s
like this;
ME: The article is
coming out right before St. Patrick’s Day – a most important holiday because of
my ancestry – what could I write about that relates to that and birds? St. Patrick is famous for driving the snakes
(paganism) out of Ireland, not the birds; so that’s out. What about green? Hmmm --- the only green birds that I know of
are parrots or parakeets – I have seen them in various places, not here of
course, I wonder why there are so few green plumed birds in the world; Lots of people keep these types of birds as
pets……. (then wandering past the windows as I’m thinking) Wow! Look at what the
sun is doing to the feathers of those turkeys – the COLORS! ……….
And so it goes. Today
I’m going to write a column that is an amalgam of those thoughts, as well as an
additional topic that I have mentioned before at this time of year.
Let’s start with the
color green and birds with those feathers. In researching this topic and
looking through my field guides, it is as I suspected – the birds that have
mostly green feathers are either parrots or parakeets. Other birds, like many hummingbird species
and the Green Jay do have some green feathers on their bodies. All of these birds live in warm, tropical
climates most of their lives, although some of the hummingbirds do venture
north in the summer months.
Like the blue we see in
other birds feathers, green is the result mainly of light scattering and
reflecting off of the feather structure.
Most birds have no green pigment in their feathers, although parrots
have
pigment in theirs called turacoverdin that does provide green coloration.
Also
by mixing blue light with underlying yellow carotenoids, you get the appearance
of green feathers. The refraction of light is called the Tyndall Effect, and it
creates the illusion of certain colors.
I did not find any
information on the reason why birds of the tropics have green colored plumage, but
one could surmise that it has to do with the ability to blend into the
overwhelmingly green forest/jungle habitat in which they evolved.
This musing on feather
colors and their origins, brings me back to those Wild Turkeys that I saw
beside our house busily pecking at the seeds Mike puts out each morning. I was looking at them from the second story
bedroom window and the sun was hitting them just right. The effect was stunning. Even without my binoculars I could see
flashes of pink, pastel blue, green, rusty red, and gold, with an overall
appearance of polished bronze. Every
time a bird moved the colors changed. It
is keratin (the same protein found in
our fingernails, rhino horns and turtle shells) that gives feathers the ability to act like a prism scattering the
longer wavelengths of light and reflecting shorter ones to create a rainbow
effect.
If you asked anyone to
describe a Wild turkey, they would most likely say they are brown birds and certainly
when seen from a distance that would be correct. But up close the truth is evident. I noticed that while both males and female
shared this shiny quality, the males were much more endowed with shifting
colors, which makes sense since most males in the bird world are more colorful
than the females; all the better to impress those they pursue. I also noticed
the fleshy pointed protuberance called the ‘snood’ on the face of the males just
below and between their eyes. This is a
secondary sex characteristic, like the wattle and ‘beard’ on their chest. To my
eyes it gives them another physical connection to their long lost ancestors,
the dinosaurs.
Now to finish up, I
want to remind everyone who has a computer and internet access to check out the
Minnesota DNR’s Eagle Cam – I have done this for three years and it never
ceases to amaze me; to be able to watch a pair of adult Bald Eagles in
their nest, incubating and then rearing their young! There is no sound, but the live streaming
images are fantastic. Most often (right
now) one or the other parent is sitting in the nest covering the eggs or
chicks. Occasionally they switch
places. I keep the link open during the
day and check in once in a while and sometimes I get lucky and see the pair
switch places, which let’s you see what is going on with the young. I know there were three eggs laid and a
couple days ago I saw two chicks. One clue
that the chicks have hatched is the appearance of dead fish, bird or mammal
parts in the nest. Let’s’ just say I’m
glad there isn’t any ‘smell’ feature to this live feed. The ‘show’ will
continue for the next month or two and since this is nature in action, the
outcome is never guaranteed to have a happy ending, but the potential to see
and understand more about these magnificent birds makes it well worth watching.
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