Thursday, February 7, 2013

Anhinga or American Darter

Before our trip to Florida I'd never seen or even heard of an anhinga, also known as the American darter. 
The name comes from the Brazilian Tupi language and means snake or devil bird. It often swims 
anhinga going into the water
anhinga completely submerged - note that the white on its back stands out under water
anhinga with only head above water
with its long neck and head the only parts of its body above water, giving it the appearance of a snake. Its feathers are not waterproof which allows it to dive and swim underwater easily. However, its feathers can become waterlogged which makes it difficult for it to fly. To dry their feathers, they will perch for long periods of time with their wings spread. The wet anhingas look quite different from the dry anhingas as their bodies look much sleeker and less colorful. 
It has a long yellow bill, sharply pointed, about twice as long as the length of the head. It has yellow webbed feet. 
Note how the white feathers on the back barely stand out when wet.  
The male anhinga has a body that is black/green and wings, base of wings and tail that are black/blue. 
male anhinga
The back of the head and neck have elongated feathers that are gray or light purple/white 
and the upper back of the body and wings are spotted or streaked with white. The female anhinga has a pale gray/buff or light brown head, neck and upper chest, a lower chest or breast that is chestnut 
female anhinga
and a back that is a little more brown than the male. 
They can be mistaken for the double-crested cormorant, and I had that problem, as they were side-by-side and even mixed with the cormorants when we saw them in Everglades National Park (along the aptly named "Anhinga Trail"). It took me awhile to realize that I was looking at two species of birds. The tail of the anhinga 
anhinga tail
is wider and longer than the cormorant 
cormorant tail
and the bill of the anhinga is pointed 
anhinga bill
compared to the hook-tip of the cormorant. 
cormorant bill
And, in fact, the plumage coloration, head shape and other aspects are quite different, but when you are looking at them without much knowledge, those distinctions are not readily obvious. There are two subspecies of the American darter. A. a. leucogaster, the one we saw, is found in the southern U.S., Mexico, Cuba and Grenada. A. a. anhinga is found in South America east of the Andes and in Trinidad and Tobago. A group of anhingas is known as a "kettle." I fell in love with the anhingas. Their profile gives them almost an aspect of a seahorse or Trojan horse
and their beautiful black and white back looks like a modern art version of an accordion. 

1 comment:

  1. lovely photos & a very helpful description, I hope to se them in Trinidad this summer.