St Patrick's day bird thoughts
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.