This month I had the pleasure of walking in the forest with VS, AE, ME and HN, who came from Germany, Kenya and India to visit the project.
One morning we travelled out by boat to reach the northern parts of the forest in search of the elusive Rubondo chimps. We walked for several hours and climbed right to the top of a hill, but we didn’t hear any calls or catch a glimpse of them.
During our forest walk we learnt from VS that army ants (or Siafu in Kiswahili) live in colonies, but unlike most ants, they do not have a permanent home. Instead they move to a new place when they have eaten all the prey in an area. They form a highway as they travel from their old lair to a new nest.
Siafu hunt by sensing the carbon dioxide that animals breath out. You can tease the Siafu by blowing on them, then watch as they burst into activity, pincers held high, in search of prey.
Siafu, though aggressive and painful, are not at all a bad. If you live in Africa and Siafu swarm into your house, they eat all of the other ants, cockroaches, spiders, and everything else that slithers crawls or creeps.
VS also showed us the two different ways chimpanzees eat army ants.
1. In the ‘‘direct-mouthing’’ technique (‘‘ant-dip-single’’), a chimpanzee dips for ants with one hand and then sweeps the wand directly between the lips (‘‘swiping’’) or nibbles the ants directly off the stick.
2. In the ‘‘pull-through’’ method (‘‘ant-dip-wipe’’), a chimpanzee holds the wand in one hand, dips it into the army-ant nest, waits for the attacking ants to crawl up the tool, then withdraws it while sweeping off the ants with the other hand, and rapidly transfers the mass of ants into the mouth.