Juvenile Black-Crowned Night Heron (Nycticorax nycticorax)
6Mile Cypress Slough Preserve, Ft,Myers, Florida USA.

Photo is showing two distinct things that people aren't used to seeing. The first, and smaller, is the base of the tongue.
The second is the inside of the throat which requires a long neck with the head and throat kind of pushed down on it.
On looking at the heron image you can imagine the actual neck pushing out the throat from behind.
The head is sort of tucked in, so it makes sense that the heron's long neck is stuffed in the mouth to that position.
Source:- http://www.birdphotographers.net/forums/showthread.php/113527-Green-Heron-Anatomy

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