Presentation on theme: "SNAKES 3-27-06 Stealths of the Shadows. Safety in the field is imperative. Never step over a log. Snakes often rest coiled up next to objects, and you."— Presentation transcript:
SNAKES 3-27-06 Stealths of the Shadows
Safety in the field is imperative. Never step over a log. Snakes often rest coiled up next to objects, and you may get bitten when your foot startles them.
Instead, always step on logs then take a stride off.
In Sri Lanka, cobra charmers are plentiful. BTW, just where is that big snake going???
Typical cobra stance photo by Thomas Eimermacher
Most snakes crawl on the ground or climb trees.
But, in the tropics, some snakes fly! Chrysopelea from SE Asia (National Geographic).
Fer-de-lance, called a Tommygoff in Belize. Bothrops asper.
Can you tell why it is called a Lance-head?
Note how the Tommygoff looks like a pile of leaves?
And look again.
We walked right by this one – the third person in line saw it. Cockscomb, 2005.
These Fer-de-lances are from Trinidad.
Tommygoff in Rabinowitzs wrecked airplane. Orlena Tampira & Ryan Englebrecht looking into the hole (bottom left is what they saw; Dr. Bob leaning inside plane to take the photo of the 6 ft fer-de-lance on the right).
Dead Tommygoff found on the highway by Sydnoid.
Eyelash Palm-Pitviper, Bothriechis schlegelii, juvenile. This species often rests flat against tree trunks in Belize forests. photo by Thomas Eimermacher
Cantil, Agkistrodon bilineatus - Belize
Cantil head shots.
What is this?
A hawk moth caterpillar, Hemeroplanes ornatus photo from Natural History Magazine
Puff Adder, Bitis arietans - Africa
Saw-scale Viper, Echis coloratus – Note that it is lying with its sides curved & in contact. This allows it to rub its sides together and make a loud hissing sound. Africa
African Horned Viper, Cerastes cerastes: Convergent with the American Sidewinder Rattlesnake due to use of desert habitat; nestles down in the sand and ambushes prey.
Velvety-Green Night Adder, Causus resinus – Africa - not all vipers look like venomous snakes.
Bibrons Burrowing Asp, Atractaspis bibronii – Africa – feed on rodents in burrows; have the ability to move the fangs out of the mouth, pointing to the rear, an adaptation for envenomating a number of mice as they scurry away and past the predator in the burrow. Dont try to pick them up behind the head – they can bite backwards! Photo by Harry W. Greene.
HOW CAN ONE TELL A CORAL SNAKE FROM ITS MIMICS? In the U.S. and Belize, remember this poem: Red and yellow kill a fellow, red and black friend of Jack. This means that if red rings touch yellow rings, it is venomous; if red rings touch black rings, it is not venomous. Warning: This does not work everywhere – check out some of the venomous coral snakes in the following slides.
Are all red, yellow (tan), and black non-venomous snakes actually mimicing venomous coral snakes? That is the theory, but there is a strong possibility that this color combination is cryptic. Remember, they mostly live underground. Also, when lying still, they tend to be obvious, but when they are 1) in the shade or 2) begin to move, they are extremely cryptic.
Black Mamba, Dendroaspis polylepis – note the venom drops – Africa. The pink skin is possibly the result of a viper bite.
In the south Pacific, there is an octopus that mimics a sea snake
Mussurana, Clelia clelia: As an adult, mussuranas eat snakes; as juveniles, they eat lizards (see a specimen extruding from a wound in this dead specimens side). As an adult it is very dark, but as a juvenile, it looks a bit like a coral snake.