bonobos – how did they do it, and how should we?
Science is always at its most thrilling when unsettled: it is the process of tackling mysteries, not the habit of accumulating facts.
Matt Ridley
bonobo matriarchy – still a mystery
So let’s switch from the ridiculous to the sublime and get back to bonobos. A recent bonobo video I’ve watched, together with my current reading of Carl Safina’s Beyond Words, which, so far, deals mostly with elephants, has made me wonder about the survival of these fascinatingly intelligent creatures in the wild. The human story of the DRC, where all wild bonobos live, has, since the arrival of white men, been one of horrific slaughter and suffering. The whites have mostly left, with their treasure, having created the boundaries of this new nation, where over 200 indigenous languages are spoken. Its official language, though, is French. It’s the second largest country in Africa, and has ten other mostly white-invented countries on its borders, along with a wee bit of the southern Atlantic. The land is very heavily forested, with bonobos being unevenly spread over an area of half a million square kilometres, bounded by the Congo, Kasai and Lualaba rivers.
The estimated minimum number of bonobos in the wild is between 15 and 2o thousand. Obviously it is hard to ascertain very precise numbers due to the dense terrain. The human population of the DRC is over 110 million. Habitat loss has been a problem, as has the bushmeat trade, hunting for medico-magical cures, and selling as novelty pets. Human depredations, enfin. Safina estimates the effects of such depredations on elephants:
Since Roman times, humans have reduced Africa’s elephant population by perhaps 99 percent. African elephants are gone from 90 percent of the lands they roamed as recently as 1800, when, despite earlier losses, an estimated 26 million elephants still trod the continent. Now they number perhaps 400 thousand (the diminishment of Asian elephants over historic times is far worse).
Bonobos were separated from chimps by the creation of the Congo River, said to be the deepest river in the world. The river is estimated to have formed between 1.5 and 2 million years ago, and this is supposed to have created the separate species. It sounds plausible, but I wouldn’t know.
Bonobos have been described as the hippy apes – probably by hippies. They’ve also been lauded for their vegetarianism, but they’re not vegetarian. Their lush environment has promoted a largely frugivorous and nutatarian diet, but the odd small monkey or large rodent-like creature, savagely ripped apart, doesn’t go amiss. What’s most interesting about them, for me, is their matriarchy, developed over those couple of million years, despite a slight, and apparently diminishing, size difference in favour of males. Bonobos are generally more gracile than chimps, and weigh less, on average (they used to be called pygmy chimpanzees). Their lips are more pink and kissable – well, maybe not, their faces are darker at birth, but lighten up with age, though their ears remain much darker than those of chimps. They have longer legs, and are more bipedal, and finally they generally have more high-pitched vocalisations than the guys north of the Congo. But does any of this offer a clue to their matriarchy? And are they really matriarchal? I’ve read articles that have claimed that there have never been any human matriarchies, though this seems to depend on the definition. After all, we can say that we, e.g. in Australia, live in a patriarchy, though it is less patriarchal than it was, a mere two hundred years ago. The change in that time has been social rather than physiological or genetic. Bonobos and chimps have, however, undergone physiological changes, as aforementioned – with respect to each other, and we have no way of knowing which of them has changed most. Interestingly there are four subspecies of chimps, with the possibility of a fifth. What’s the basis of these differences? Presumably they can interbreed, since bonobos and chimps can do so (they’ve done it in captivity and ‘genetic studies show that they have exchanged genes at least twice in the past 550,000 years [in the wild]’ – thanks, AI). And here’s what AI, which I presume is in this case a combination of primatologists, geneticists and such, has to say about the establishment of these subspecies:
Primatologists distinguish chimpanzee subspecies (or populations) based on a combination of genetic differences and geographic distribution. Genetic studies, including genome-wide analysis, reveal distinct populations with unique genetic markers. These genetic differences are often correlated with geographic separation, suggesting that physical barriers like rivers or mountain ranges have historically limited gene flow and led to the evolution of distinct subspecies.
References
Carl Safina, Beyond words: what animals think and feel, 2015
https://en.wikipedia.org/wiki/Democratic_Republic_of_the_Congo
https://www.bonobos.org/blog/whats-the-difference-between-a-bonobo-and-a-chimp/
Christopher Tyerman, God’s war: a new history of the crusades, 2006
Leave a Reply