This looks a lot like last week's cormorant, seen at http://www.backyardnature.net/n/b/cormrant.htm.

However, notice that the Anhinga's beak is sharp while the cormorant's was rounded and hooked at the tip. Anhingas spear fish with their sharp beaks, flip them into the air and swallow them head-first. I've read that sometimes the Anhinga's beak skewers the fish so that the bird must return to shore with the fish Shishkabobed on the bill and somehow pry it off.

The Anhinga's neck is so long and slender that Anhingas often are called Snakebirds. They swim with their bodies submerged under the water, with their necks stretched forward. From a distance they can look like snakes with their front ends raised.

Often you see both cormorants and Anhingas sunning themselves with their wings spread against the sun. All the larger birds at Anna's Bottom seemed too nervous for that. I'm guessing that people go there to take potshots at them.

Anhingas are permanent residents in much of the Deep South. They breed in open freshwater wetlands from here through Mexico and Central America into South America.

from the May 23,  2004 Newsletter, from near Natchez, Mississippi
ANHINGAS SPREADING THEIR WINGS
As if the alligator and softshell turtle weren't enough, Chimney Swifts kept Pipes Lake's water splashing as they flew along its surface, scooping up water on the wing. Easier to watch were the Anhingas, ANHINGA ANHINGA, who between long dives underwater swam with nothing but their snaky necks and heads above the water's surfaces. Anhingas look a lot like cormorants, except that their beaks are sharp, not hooked at the end like a cormorant's, plus there's a lot of white in the anhinga's mostly black wings, while cormorants have uniformly dark wings.

The most striking thing the anhingas did was to climb onto a snag emerging from the water, spread their wings and tails, and hold them against the incoming sunlight, frequently fanning and shaking them.

While watching the wing-spreading, a question came to mind: Since Anhingas have no more exposure to water than ducks, why do Anhingas spend so much time drying their wings while ducks don't? Gradually I began coming up with an answer as it occurred to me that often I see ducks preening -- smearing waterproofing oil from their preen glands over their feathers -- but I don't remember ever seeing Anhingas doing this. Maybe Anhingas don't have preen glands, I decided. Moreover, since Anhingas are such primitive-looking birds, maybe they don't have preen glands because they came into existence before the bird-world evolved preen glands.

This made such a great story that I almost didn't check it out. However, I did, and found an article entitled "Why do Anhingas spread their wings?" here.

There it's stated that Anhingas have unusually low metabolic rates and unusually high rates of heat loss from their bodies. Moreover, they don't have to be wet to exhibit spread-wing postures. Since they typically orient themselves with their backs to the sun, it's deduced that Anhingas spread their wings mainly to absorb solar energy to supplement their low metabolic heat production and to offset partly their unusual high rate of heat loss. Wing-spreading is mainly a thermoregulation behavior, not a drying one. Moreover, the newest insights from genetic sequencing don't appear to support the idea that Anhingas are especially primitive, despite their look.

Still, it's clear that when Anhingas emerge from the water they do want to dry off, for they very plainly agitate their wings and you can see water being shaken off them.

By the way, that nice word "Anhinga" proves to have passed into English from Portuguese, which took it from the Tupi name for the bird, "ayingá." Tupi is a member of the Tupí-Guaraní language stock of coastal and central Brazil and Paraguay. We can deal with that since Anhingas are found from here all the way to southern Brazil.