From: itannman@dogbert.ucdavis.edu (Ann Mansker)
Subject: Critter of the Week: Anhinga anhinga
Date: 1999/04/06
Newsgroups: ucd.life


The somewhat repetively-named Anhinga is an aquatic bird with several
nicknames, the most common being darter, snakebird and water turkey.  In
the US, it breeds mostly in south Florida and Louisana swamps and winters
throughout Florida and along the gulf coast in Louisiana and Texas. It is
thinly distributed in the gulf coast states between the main population
centers.  Anhingas are also found in Carribean.

The snakebird designation comes from the bird's distinctive, elongate
silhouette, especially the long, sinuous neck held in an odd curve.  Bill
and tail are both long and straight. The sexes are easily distinguished.
Adult males are from with white edging on the wing coverts 
( http://www.interlog.com/~barrow/anhinga.html ).  Female anhingas are tan
on the head and neck.  The males have a bright blue eye-ring and greyish 
head plumes ( http://www.photospot.com/photos/everglades/img0007.htm) 
during the breeding season.

Anhingas have poorly developed oil glands.  Though their feathers do not
repel water or trap air well, they acquire their food by underwater
pursuit.  Swimming at surface, most of the bird's body is submerged, as if
barely able to keep afloat, yet they are strong and agile underwater 
swimmers.  Out of water they are frequently observed posed with wings
extended ( http://theory.lcs.mit.edu/~rajiyer/pictures/anhinga.html ).
Most people assume that this is to assist drying, but there is some
evidence that the birds do this to regain body heat, since unoiled
feathers are poor insulation.