From: itannman@boris.ucdavis.edu (Ann Mansker)
Subject: Critter of the Week: Bitis gabonica rhinoceros
Date: 06 Oct 1998 00:00:00 GMT
Newsgroups: ucd.life

The West African Gaboon Viper ( http://www.aqua.org/images/gaboon.jpeg )
is the largest of the Old World vipers.  Though their length tops out at
about 7 feet, they are thick-bodied and may weigh up to 25 lbs.  On the
largest examples, the head can be nearly six inches across its widest
point.  When observed against a neutral background, Gaboon vipers are
gaudily marked with diamonds and stripes against a light buff-to-pink
background.  This striking pattern is excellent camouflage in the snake's
native forest  habitat, however, blending into the leaf litter.  The head
mimics a fallen leaf.  These two images show closeups of the pattern,
and of the head, displaying the scaly "horn" that gives this snake its
subspecies name:

http://www.photovault.com/Link/Animals/Reptiles_Snakes/
ARSVolume01-02/ARSV01P05_01.2467.jpg  (pattern)
http://www.photovault.com/Link/Animals/Reptiles_Snakes/
ARSVolume01-02/ARSV01P04_02.2467.jpg  (head)

Gaboon vipers are passive hunters, waiting concealed to strike at whatever
small creatures pass within range.  They have the longest fangs of any
snake, reaching 2 inches in a large specimen.  Most snakes strike and
release, but the gaboon viper holds its prey until the victim dies.  Due
to the snake's placid nature, bites to humans are rare; most occur when the
snake is stepped on before it has an opportunity to get away.  If
harassed, it will raise the upper part of its body and hiss in threat
before actually striking.  In addition to its unwillingness to bite, the
viper can control whether and how much venom is injected, so the result of
a strike can range from no effect to rapid death.  A hungry snake will
strike at almost any lateral movement, so some bites might well be a
result of mistaken identity.

There is an article on the various aspects of caring for the victim of a
Gaboon viper bite, including a rather lengthy list of potential effects,
at http://www-surgery.ucsd.edu/ent/davidson/Snake/Gabonica.htm  .