Nonetheless, boas can be quite variable in themselves. While many people think of them as purely New World species, just as all pythons are native to the Old World, in fact boas have a worldwide distribution, though only in South America do they reach the size of giant snakes capable of feeding on larger mammals. The largest of the Old World boas is the one addressed in this post, the Madagascar Tree Boa Sanzinia madagascariensis. Reaching a length of 2m and a body width as much as a mans’ forearm, it is one of the top predators of Madagascar.
It is an adaptable species, living everywhere from dry forest to rainforest, and although it can climb well and hunt in trees it also spends a lot of time on the ground, unlike more specialist rainforest species such as the Garden Tree Boa from the Amazon rainforest. As with most boas and pythons, it is nocturnal, feeding on rodents, birds, smaller lemurs and anything else it can catch. As with many of its relatives, it has heat sensitive pits on its upper lip which enables it to detect warm blooded prey even in pitch darkness, which it kills by constriction.
|Sanzinia head - note labial pits|
|Green phase Sanzinia|
(images from Wkipedia and top image taken by myself at Bristol)