Tree snakes:
This yellow rat snake
(Pantherophis obsoletus quadrivittatus=
Elaphe quadrivittata) was
navigating the branches above the boardwalk. I fondly recall seeing one
boardwalk visitor (human) leaving the preserve as I took this photograph.
Obviously she had reached her limit of tolerance, and had been creeped
out by all the animals. She was walking at a brisk pace down the exact
center of the
boardwalk, head scrunched down onto her shoulders and arms wrapped tight
against her body. Poor little thing.
(Thanks to Mike Howlett for the snake identification!)