Sunday, March 4, 2012

A Natural History: Bitis gabonica, Gaboon Viper













Description:
Gaboon viper is in the family Viperidae, under the general name of Gaboon Vipers there are the East African Gaboon (Bitis gabonica gabonica) and the West African Gaboon (Bitis gobonica rhinoceros). The easiest way to differentiate the two species is the horns found on the West African gaboon. There has also been some suggestion that the West African has only one stripe behind its eyes while the east African has two (see images). On average the snake is between 4 to 5 feet with an extreme of 6 .75 feet. They are a very stocky snake with the characteristically triangle head found in many venomous snakes. They also have vertical pupils which are found in venomous snakes. They have keeled scales which mean they are not flat but have a line through them that is raised. An easy characteristic when identifying the viper are the rectangular marks connected by an hourglass shape (see pictures). It also has been known to have the longest fangs in the family viperidae growing to be more than 2 inches. The Gaboon viper’s size and pattern is really why my interest in them has grown over the years.







Habitat Distribution:
They are usually found in west, central and east Africa. They mostly are found in rainforests on the forest floor or in dense vegetation which they camouflage themselves into very well. The leaf shape and pattern on their back allows them to blend into the leaves when hunting.







Diet:
The Gaboon is a sit and wait predator which as their name suggests they wait until their prey walks by to attack versus actively hunting. Its diet consists of small mammals like rodents, birds and also some frogs and amphibians with large ones eating monkeys and small antelopes. Unlike most venomous snakes, when it bites an animal it does not let go, which injects massive amounts of venom into its prey. Because the viper hunts rodents it is a great way to control their populations which without predators can grow very quickly. The only predators it has a very large birds of prey that can overpower it.







Behavior:
These vipers have been known to be slow and sluggish but when provoked they will attack. An attack can be avoided by hearing the hissing, and looking for a reared up look while opening their mouths. When they bite as stated before, they do not tend to let go so they inject between 200-1000 mg of venom, which is one of the highest venom yields of venomous snakes. They have been suggested to be docile snakes. They are nocturnal predators that sit motionless for hours until a prey crosses its path. Males often times fight for mating rights to a female by pushing each others heads down and also striking without opening their mouth and injecting venom.







Lifecycle:
The females give birth ovoviviparous, which means they give birth to live young instead of using shells. The average mother produces 30 to 60 young but only gives birth every two to three years.

2 comments:

Michelle Boone said...

Thanks, Marcelo. How did you become interested in this beast? We all like a docile venomous snake.

Anonymous said...

Sorry I wasn't ignoring your comment just didn't know it was there. Anyway I got super interested in the gaboon viper because of the pattern it has on its back. Those pefect rectangles almost seemed unnatural because it was so geometrical. Then I learned about thier 2 inch fangs but of thier relatively docile behavior. The idea of having devastating weapons at your disposal but having little want to use them was very interesting in this case.