BLACK MAMBA SNAKES DENDROASPIS POLYLEPIS

The Black Mamba (Dendroaspis polylepis) is well known to show defensive behavior, such as raising the front part of the body and spreading a narrow hood (Ionides 1969. Mambas and Man-Eaters: A Hunter’s Story. Postscript by Dennis Holman, Mayflower, London, pp. 1–236). On 27 February 2002, while conducting field studies in Botswana, we observed an unusual defensive behavior by a female D. polylepis that, to our knowledge, has not been recorded in this species. On 26 February at ca. 2100 h as we spotlighted, we sighted the snake climbing an acacia tree (5 m) at a private game ranch situated in the southeastern part of the country.

Nocturnal activity by mambas is poorly understood and rarely recorded; this is the first individual we encountered active at night. After a minor chase the snake was captured, measured (ca. 2.5 m TL), and sexed, whereupon it was placed into a cloth bag to be photographed the next day. On 27 February, at about
0800 h, the snake was removed from the bag and allowed to climb another small tree where it was to be photographed. The snake moved in the tree and after about 15 minutes it descended to the ground. Because we also wanted photographs of it on the ground we approached it to within a distance of ca. 2 m whereupon it displayed its typical defensive behavior (i.e., raising of the front part of the body off the ground and spreading of a narrow hood).

BLACK MAMBA

We remained still and the Black Mamba snake lost interest in us and moved into an open area. One of us investigated how the snake would react if it were constantly cornered (it was not allowed to approach any of the nearby thickets, which were ca. 10 m away). The Black Mamba snake again reacted by raising the front part of the body and spreading a hood. However, walking around the snake at a distance of about 2 m for 5–10 min made it impossible for it to reach the thickets. At the end of this exercise, the snake displayed a very peculiar defensive behavior. It coiled up and hid its head under the coils and raised the tail tip about 20–30 cm above the ground. The tail was constantly moving in the middle of the coiled snake, a behavior very similar to what has been described as defensive behavior in the garter snake Thamnophis radix (Arnold and Bennett 1984. Anim. Behav. 32:1108–1118). We are certain that this behavior was not caused by heat stress. Such tail displays have been suggested to divert attacks to a more ‘disposable’ part of the body compared to attacks directed to the head, which is common among several avian and mammalian predators (Jackson 1979. Copeia 1979:169–172).

It is interesting to note that in a very thorough study of temporal and spatial ecology of D. polylepis in South Africa, individual identity of the specimens studied was based upon on scarring and bits of tail missing (Phelps 2002. Herpetol. Bull 80:7–19). Thus, perhaps the latter injuries might have been due to predator attacks
on individuals displaying behavior similar to tail-raising observed by us.