The Bili chimpanzees14 Jul 2007
A nice piece in The Guardian about the chimpanzee population near Bili, DRC. The lede is the suspicion of an apparent leopard kill -- that's chimpanzees killing a leopard -- but the other details are interesting:
[Cleve] Hicks said the animals also have what he calls a "smashing culture" - a blunt but effective way of solving problems. He has found hundreds of snails and hard-shelled fruits smashed for food, seen chimps carrying termite mounds to rocks to break them open and also found a turtle that was almost certainly smashed apart by chimps.
Like chimp populations in other parts of Africa, the Bili chimps use sticks to fish for ants, but here the tools are up to 2.5 metres long.
All these observations of chimpanzee behavioral diversity are pretty exciting, since they really provide an interesting model of early hominid diversification. Longstanding subspecies-level populations with strong behavioral differences involving food collection and diet may describe both A. afarensis (along with regional variants) and Late Pliocene Homo.
A mention is in the article about whether they should be considered a new (fifth) chimpanzee subspecies. I'd say that's probably a given at this point; doubtless the Fongoli chimpanzees will become a sixth.
Do they deserve it? Well, I suppose they're at least as distinct as the others behaviorally and anatomically, which isn't saying much. Genetically, it's an open question so far, but I wouldn't be surprised if they were as distinct as central and eastern chimpanzees, and certainly moreso than P. t. vellerosus. It's hard for me to see where ape subspecies taxonomy is going to end, since there are few scientific interests vested against further taxonomizing. Sure, there are conservatives, but none with enough firepower to roll back P. t. vellerosus, apparently. So, more subspecies lie in our future: I would guess two or three more for Bornean orangutan populations and who knows how many Western lowland gorilla populations will qualify?
(via Gene Expression)