Week of 03.10.25
Spring is right around the corner in the Midwest! The sun is shining, weeping willows are turning green, the clocks have changed, and American robins are popping up everywhere.
American robins are small to medium size birds with a brown head and orange colored underside. They have yellow beaks and white markings around their eyes. They are not easily confused with many other species of bird, partly due to this characteristic coloration. Robins have a sing-song call that sounds like “cheerily cheer up”.
Robins display “cartoonish bird behavior”, pulling worms from the grass and sitting on tree branches to sing. Robins flick their tail feathers and puff their chest out as they call. While robins migrate away from states that experience colder winters, they will over-winter in more temperate climates. Some robins will even stay though Chicago in the winter, as long as they have steady sources of food and shelter. When it is cold, robins can been seen in large groups, roosting together in trees or foraging for food.
A notable and unique characteristic of American robins are their blue eggs. Other types of robins that live overseas do not produce blue eggs. Instead, their eggs are cream and speckled.
Blue is a notoriously difficult color to create in nature. Blue plants are outnumbered 10 to 1, surpassed frequently by red, yellow, and green. Most animals with “blue” in the name (great blue heron) are actually greyish with a cool tinge. In nature, to find a bright blue, like a peacock, is rare. To find a true pale blue is even more difficult. You can read more about what makes different animals blue here.
Photo by Mohan Nannapaneni/ Thomas Love American Robin vs European Robin eggs
The presence of blue in birds eggs is due to a naturally occurring pigment called biliverdin. Biliverdin means “green bile” in Latin.
Think of the last time you got a bruise. Did you call it “black and blue”? The “blue” (sometimes greenish) color your skin turns is a response to the presence of biliverdin. Eventually, this pigment is filtered out of your body by the liver. This same type of pigment is transferred to a robin’s egg when it is created.
Amazingly, the bright blue color of these eggs does not seem to increase risk of predation. Studies on other species of thrush (the family which the robin is part of) prove that blue eggs stand no greater risk of danger due to their coloration. It can be reasonably assumed that this logic carries over to robins as well.
In 2001, Tiffany Jewelers approached Pantone about the standardization of their brand color. The now iconic “Tiffany Blue” was chosen as a derivation from a pre-existing Pantone color - you guessed it - robin’s egg blue. Tiffany Blue is heavily protected by copyright law and I’m not going to put it in this newsletter so I don’t get demolished by a Tiffany lawyer, but click here if you want to see it.
Robins are usually seen as signs of hope and spring after a long winter. Sometimes, robins are believed to be the presence of a departed loved one coming back to visit. Whatever you believe, they are always a welcome sight and sound to kick off spring.
Have a great week!
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Sources:
https://www.nhm.ac.uk/discover/rainbow-nature-life-in-blue.html#:~:text=Even%20among%20plants%2C%20blue%20is,plant%20species%20produce%20blue%20blooms.
Art by Anne Longman