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[Phyl]

Why is the color blue so rare in nature?, continued

As for minerals, their crystal structures interact with ions (charged atoms or molecules) to determine which parts of the spectrum are absorbed and which are reflected. The mineral lapis lazuli, which is mined primarily in Afghanistan and produces the rare blue pigment ultramarine, contains trisulfide ions — three sulfur atoms bound together inside a crystal lattice — that can release or bind a single electron.

"That energy difference is what makes the blue," Kupferschmidt said.

Azurite is a copper carbonate hydroxide mineral known for its deep-blue color. (Image credit: Serge Briez/capmediations/Getty Images)

Blue animals' colors don't come from chemical pigments. Rather, they rely on physics to create a blue appearance. Blue-winged butterflies in the Morpho genus have intricate, layered nanostructures on their wing scales that manipulate layers of light so that some colors cancel each other out and only blue is reflected; a similar effect happens in structures found in the feathers of blue jays (Cyanocitta cristata), the scales of blue tangs (Paracanthurus hepatus) and the flashing rings of venomous blue-ringed octopuses (Hapalochlaena maculosa).

[Phyl]

Why is the color blue so rare in nature?, continued


Blue shades in mammals are even rarer than in birds, fish, reptiles and insects. Some whales and dolphins have bluish skin; primates such as golden snub-nosed monkeys (Rhinopithecus roxellana) have blue-skinned faces; and mandrills (Mandrillus sphinx) have blue faces and blue rear ends. But fur — a trait shared by most terrestrial mammals — is never naturally bright blue (at least, not in visible light. Researchers recently found that platypus fur glows in vivid shades of blue and green when exposed to ultraviolet (UV) rays, Live Science previously reported). 
"But it takes a lot of work to make this blue, and so the other question becomes: What are the evolutionary reasons to make blue? What's the incentive?" Kupferschmidt said. "The fascinating thing when you dive into these animal worlds is always, who's the recipient of this message and can they see the blue?"

For example, while humans have three light-sensing receptor types in our eyes, birds have a fourth receptor type for sensing UV light. Feathers that appear blue to human eyes "actually reflect even more UV light than blue light," Kupferschmidt explained. By that reasoning, the birds that we call blue tits (Cyanistes caeruleus) "would probably call themselves 'UV tits,' because that's what they would mostly see," he said.
Because of blue's scarcity in nature, the word for blue was a relative latecomer to languages around the world, appearing after the words for black, white, red and yellow, according to Kupferschmidt.

"One theory for this is that you really only need to name a color once you can dye things — once you can divorce the color from its object. Otherwise, you don't really need the name for the color," he explained. "Dyeing things blue or finding a blue pigment happened really late in most cultures, and you can see that in the linguistics."

Birds' brilliant blue plumage, such as that of Spix's macaws (Cyanopsitta spixii), gets its color not from pigments but from structures in feathers that scatter light. (Image credit: Wera Rodsawang/Getty Images)

[Phyl]

Why is the color blue so rare in nature?, continued


The earliest use of blue dye dates to about 6,000 years ago in Peru, and the ancient Egyptians combined silica, calcium oxide and copper oxide to create a long-lasting blue pigment known as irtyu for decorating statues, researchers reported Jan. 15 in the journal Frontiers in Plant Science. Ultramarine, a vivid blue pigment ground from lapis lazuli, was as precious as gold in medieval Europe, and was reserved primarily for illustrating illuminated manuscripts.

Blue's rarity meant that people viewed it as a high-status color for thousands of years. Blue has long been associated with the Hindu deity Krishna and with the Christian Virgin Mary, and artists who were famously inspired by blue in nature include Michelangelo, Gauguin, Picasso and Van Gogh, according to the Frontiers in Plant Science study.

"The relative scarcity of blue available in natural pigments likely fueled our fascination," the scientists wrote.

Blue also colors our expressions, appearing in dozens of English idioms: You can work a blue-collar job, swear a blue streak, sink into a blue funk or talk until you're blue in the face, to name just a few. And blue can sometimes mean contradictory things depending on the idiom: "'Blue sky ahead' means a bright future, but 'feeling blue' is being sad," Kupferschmidt said.

Blue’s scarcity in nature may have helped shape our perception of the color and things that appear blue. "With blue, it's like a whole canvas that you can still paint on," Kupferschmidt said. "Maybe because it is rare in nature and maybe because we associate it with things that we can't really touch, like the sky and the sea, it's something that is very open to different associations."

Editor's note: The article was updated Sept. 7 to reflect that lapis lazuli is mined in locations other than Afghanistan, though Afghanistan is the main source of the mineral.

Originally published on Live Science.

Mindy Weisberger

[Phyl]

The Bluebird Menu:

These cheery song birds usually eat grasshopper, beetles, spiders, crickets, and caterpillars.
And, a few side dishes like, flies, ants, wasps, moths, weevils. And, to the delight of homeowners---termites!

We’ve found spying with our binoculars, that during nesting season the amount of collected insects collect is much higher than some experts report.   The hatchlings need lots and lots of protein  and this is the best source for our sweet babies.

Food is usually spotted from our ribbon elms, willow and redbud trees all within a few feet or Nesting Box #1 and #2. Our BBs are often seen in our front yard  pricking the lawn . There have been several occasions in earlier seasons with fledglings educating them in how to hunt and forage.
Upon a rare occasion, I’ve seen them catch insects in mid-air  as is the true fashion of tree swallows.

[Phyl]

The Bluebird Menu (continued)

Some statistics* for feeding nestlings are:
 caterpillars-32.4%
grasshoppers-25.6%
spiders- 11.3%
Sometimes earthworms are fed to older hatch-lings. But I have read  that this can cause a bad case of  diarrhea
* Sialis.org

[Phyl]

The Bluebird Menu (continued)

The remainder of our BBs diet consists of small fruit from native shrubs  like our  Common Privet, English Ivy (Hedera helix) in our deck rail planters,  and Persian Lilac.
 We have noted that a wider selection needs to be provided and plan to plant a few more next spring.
Keeping fingers crossed that the economy improves...a lot!
They also eat, flowering dogwood, holly, mulberry, wild grape, pokeweed, Virginia creeper and Viburnum.
Either picked right from the plant or from the ground below.

[Phyl]

I am so sorry these are late  as we've had walking pneumonia. Plus, our washing machine developed issues in it's 'mother board' and wouldn't
shut-off the water during wash and rinse cycles. The result was a laundery room flooded with about 2" of rinse water that wicked  2' into our carpeted hall.
However, all that is behind us now.

These snaps were all taken in late October.


10-26-23 5:06 pm Mom #1 CR44 perched on feeder pole

[Phyl]

10-26-23 5:06pm Mom CR#44 perched on nesting box #1
The favorite of her's and Dad.  And, a wintering shelter from time to time.

[Phyl]

10-26-23 5:06 pm Dad #2 or offspring CR49 perched on feeder pole.

[Phyl]

10-26-23 5:07 pm Dad CR#47 in will tree after leaving nesting box #1.
This 'original ' Dad from the last 5 seasons.
 Sometimes called 'Dad #1"


He's that dark blue spot almost center frame

[Phyl]

10-26-23 5:08pm Mom#2 or offspring CR#51 checking out nesting box #2.
 The favorite of Mom #2 and Dad #2

[Phyl]

10-26-23 5:09 pm Dad #2 or offspring CR#49 with Purple Finch on feeder pole.

[Phyl]

10-26-23 5:10pm Dad #1 or CR#47 just entering nesting box#1 for another off-season inspection.

[Linda M]

Thanks for posting them, Phyl - they're sure pretty birds!  Glad you're feeling better, that's nothing to mess around with.

[Phyl]

Merry Christmas !

And, a most joyous and blessed day to you and your families.
 With love, Jim, Phyllis and Maggie, too.