If we lived in an ideal world, right about now I would have been putting on my headlamp to begin stalking katydids in the luxuriantly green savannas of Gorongosa National Park. But, alas, we don’t. For reasons beyond my control I had to postpone a trip to Mozambique, although I hope to be able to get there within the next couple of months or so, and witness the park in its full, rainy season splendor.
When I was in Gorongosa in May, conducting a biodiversity survey of the Cheringoma Plateau, I was introduced by our intrepid herpetologists, MO Roedel and Harith Farooq, to an interesting little snake. The Cape centipede-eater (Aparallactus capensis), feeds, as the name suggests, exclusively on centipedes. These arthropods are not the friendliest of creatures, in fact I have a very healthy dose of respect for these powerful, blindingly fast predators. All centipedes are venomous and those large enough to be able to puncture human skin can deliver nasty, nasty bites. Their body shape, however, seems to make them ideal prey for snakes – they are long and thin, and a single centipede would nicely fill a snake of comparable size.
Aparallactus hunts by grabbing the victim in the middle of the body and slowly working its way towards the head, eventually swallowing the centipede head-first. The scales on this snake’s body are particularly hard, making it difficult for the centipede to sink its fangs (forcipules) into the reptile. At the same time the snake’s venom quickly subdues and kills the prey. Aparallactus belongs to a lineage of snakes known as side-stabbing snakes (Atractaspididae), which includes several deadly venomous species. But despite being powerfully venomous, centipede-eaters are not dangerous to humans as their short fangs are located in the back of the jaw and cannot reach the surface of our skin; one of the members of the genus, Aparallactus modestus, is even entirely fangless and feeds mostly on earthworms.
I have read that Aparallactus are immune to venom of their centipede prey, but the same cannot be said of other snakes found in Gorongosa. One rainy night on Mt. Gorongosa I ran across a scene that reinforced my high opinion of these multi-legged invertebrates: a large centipede was efficiently chomping to bits a House snake (Lamprophis capensis). If this is not the best example of poetic justice then I don’t know what is.