Thursday, January 17, 2013

The silver feathers on an Anhinga's wings...or...baby's got bling!

When you seen Anhingas at a distance, they appear black, and you might not even know they carry a spectacular pattern of black and white (silver) feathers on their wings. When you're sitting right next to them, however, it's easy to see the "bling" on their backs...

A male Anhinga preening, showing off the striking pattern of black and silvery-white feathers on his wings.
This is the same Anhinga I talked about in two earlier posts that sat very close to me (click here for those close-up photos). Close viewing of the Anhinga's back let me study the beautiful pattern in his wing feathers (coverts and scapulars). I always thought these feathers were white, but up close, I could see they were silver...not white, not dull gray, but shiny silver!

The "white" covert and scapular feathers on an Anhinga are a glossy silver color. From a distance they appear white because of the contrast with the black feathers.
When I got home, I looked up Anhingas to see if they really did have glossy silver wing coverts and scapulars, or had I just imagined it. It turns out they do, and they owe their silver feathers to a special structure in the barbules of the feather. I found a detailed technical article published in the Journal of Morphology that explains why those feathers are indeed silver. Click here to read "Proximate Bases of Silver Color in Anhinga (Anhinga anhinga) Feathers," by Matthew D. Shawkey, Rafael Maia, and Liliana D'Alba.

...whether silver or white, the pattern on the back of an Anhinga is striking.
Bird feathers contain a center shaft called a rachis. Barbs branch off the rachis, and barbules branch off the barbs. The barbules run almost parallel with the rachis and hook together to make the feather strong.  The barbules in silver feathers are different--they are longer than those in other feathers, and they are flattened. Additionally, they twist a little, and one side is black and the other side is translucent. The twist means part of the translucent barbule is exposed, which creates the silver sheen. I found an article on the BBC Earth News site explaining the research of Dr. Ismael Galvan by Matt Walker called "Birds unveil 'silver wings'" (click here). This article is a little easier to understand than the technical research paper and clearly explains how the silver sheen appears on the feathers.

Galvan concluded that dark-colored birds evolved the silver sheen as a way to "become more colorful and conspicuous," while still keeping the benefits of dark-colored feathers (dark feathers contain the pigment melanin, which makes them stronger and protects the feathers from abrasion and UV radiation). 

This is the third part of the Anhinga series:
Part 1: Anhinga close-ups
Part 2: More Anhinga photos; spread-wing posture
Part 3: The silver feathers on an Anhinga's wings

24 comments:

TexWisGirl said...

gorgeous patterns! very striking!

Robert Mortensen said...

Wow! Beautiful!

Pam ;) said...

You captured the feather details perfectly, Kelly.

Carol Mattingly said...

Just gorgeous.

dAwN said...

OMG! You captured it wonderfully!

holdingmoments said...

A stunning bird Kelly.
I love those blue eyes.

KaHolly said...

Awesome post!! You really did your homework. I love learning new things.

Julie G. said...

Fascinating information, Kelly! I've always thought that Anhingas have stunning feathers. Superb photographs!

Betsy Adams said...

HI Kelly, The Anhinga is a gorgeous bird... Amazing that he wasn't afraid of you... You got some fabulous shots of him... I love those colors. Beautiful.
Hugs,
Betsy

Hilke Breder said...

Gosh, Kelly, so wonderful! Your images leave me breathless!

Janice K said...

Such a magnificent bird with those big blue eyes. You must have been so excited to be so close to it. The design of the feathers is so beautiful!

Cicero Sings said...

I don't comment very often but I do still follow your blog. Your photos are amazing and I love to see all your sketches and paintings too.
This bird today ... amazing!

Montanagirl said...

Kelly, this was really interesting. That's such a beautiful bird! Love that silvery patten on their feathers, and the vivid blue around their eyes! Gorgeous photos.

Elaine said...

Truly a fascinating bird! What a special gift he gave you by plopping down so close to you, and you definitely made the best of the opportunity. Well done!!

Guy said...

Hi Kelly

These are stunning photos and the information you provided was great.

A wonderful post.

Guy

Ana Mínguez Corella said...

Wonderfull bird. Exotic and elegant.. Great pictures!!!.. Congrat..

Kerri said...

Absolutely stunning .... breathtaking!

PlantPostings said...

Your photography is beautiful! I was doing some research about Wild Ginger and happened across your blog. I'm so glad I did. Cheers!

Tammie Lee said...

so very beautiful
and stately~

Jenny said...

Ah, I've missed your wonderful photos Kelly! I've been MIA for the past year! I've written a new blog post though and am hoping to get back into it! Oh, did I say.....wonderful photos! (-: xx

Kelly said...

Thanks, everyone! What a cool bird. I'm so glad he stayed so close. I learned a lot from him!!

Steve Borichevsky said...

Wow, I've only seen these from a distance. I had no idea how wonderful they are.

Kathie Brown said...

With that gorgeous blue eyes and that silver gown this bird looks like it is ready for the red carpet at the Oscars!

E said...

Beautiful pics, Kelly, great videos.
Thanks for your nature classes, we learn all the time with you about the wonderful birds and flowers. Abrazos.