More Anhinga photos; spread-wing posture and feather closeups...

...continued from the previous post, Anhinga closeups: those crazy Anhingas.
If you read the previous post, you know this bird came very close to where I was sitting and started drying out his feathers. Originally he was sunning himself on a branch in the water, then hopped on shore near me. After a while he returned to the branch. If I didn't know better, I'd think he wanted to make sure I could photograph all of him instead of just the closeups of his face. His look back at me seems to say, "Are you getting this?"

A beautiful Anhinga looks over his shoulder at me while I photograph him.
"Yes, Mr. Anhinga. I'm getting it..."

An Anhinga sits in the spread-wing posture as he continues to dry his feathers. 

Anhingas sit in the sun with their wings spread even when they are dry because they also use this posture for thermoregulation. 

Anhingas and cormorants both use this posture to dry their feathers, but Anhingas rely on the posture to help keep them warm too. Anhingas have low metabolic rates and high rates of heat loss from their bodies. This is why you don't find many Anhingas up north. They need the sun's warming rays to survive. According to Stanford University (click here for the article), dry Anhingas use the spread-wing posture when the ambient temperature is cool but the sun is shining brightly. They sit with their backs to the sun for optimum heat absorption. Why don't cormorants do this? Because they don't have to. Their feather structure is different. Although both have "wettable" feathers allowing them to lose buoyancy so they can dive and swim under the water to hunt for fish, only the outer part of a Cormorant's feathers becomes waterlogged. This creates an insulating layer of air next to the skin when the bird is under water.

Anhinga's feathers become wet all the way to the skin. Anihingas use the muscles in their skin to make the feathers stand on end to help them dry.

The sun shines through the wing feathers on an Anhinga (interior view) creating an amber glow.

...small feathers "standing on edge" make the upper part of this Anginga's wings look spiky.

"Water Turkey" is one of an Anhinga's nicknames. It's easy to see its origin...the striped pattern and light tips on a spread Anhinga's tail resemble a turkey's. It's other nickname, "Snakebird," is easy to figure out too. When an Anhinga's body is submerged and only its shiny, wet head and neck are visible above the water, it looks like a black snake swimming along (click here for a photo in a previous post).

...I have another post on this fellow in the works. It focuses on the beautiful pattern of white feathers on the back of an Anhinga's wings. I photographed this bird on June 14, 2012 while we were on our vacation in Hilton Head, SC. I was sitting on the bank of Lake Thomas in the Sea Pines Forest Preserve on Hilton Head Island.

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