The western black rhinoceros is extinct … and it’s been extinct for some time now. An extensive survey carried out all the way back in 2006 failed to unearth any signs of it – no spoor, no dung, no signs of feeding. A few years later (in 2011), it was official: the IUCN, the world’s ultimate authority on the conservation status of living things, sounded the extinction knell by declaring that the western black rhino (Diceros bicornis longipes) had vanished off the face of the earth.
But unlike the rhino itself, the news story of its 2011 extinction keeps coming back to life. Just in the past week, it’s reappeared in countless social media posts and more than one news article (see here, here and here). So why all the confusion? Perhaps because extinction stories involving rhinos are just what we’ve been expecting. With a poaching onslaught of massive proportions sweeping across Africa and Asia, those of us who care about these rapidly vanishing pachyderms have been in a state of unhappy anticipation of precisely this sort of news story. And when one resurfaces somewhere, it’s carried along on a wave of social sharing that often loses sight of details (like dates) and can be difficult to dam up (extinctions might be grim and sad events, but they make for dramatic and very sharable news).
But we can also blame taxonomic trickiness and the difficulties involved in defining precisely what extinction means. Members of the black rhino (Diceros bicornis) ‘family’, past and present, are not easy to tally up. Depending on which classification system you go with, up to eight different subspecies once lived under its taxonomic umbrella – but some authorities, like the IUCN, recognise fewer than that. Within that taxonomic tangle, extinctions have come and gone. Some of the subspecies vanished more than a century ago, wiped out by relentless hunting and habitat loss at the turn of the twentieth century. Others are today critically endangered and clinging to survival on small strips of leftover habitat. Unless you're a rhino expert, keeping track of which ones are still with us and which we've lost for good can be almost impossible (and when a rhino extinction story surfaces, it can be hard to remember whether we've heard it before).
To all that confusion we can add the problem of pinpointing exactly what the extinction label means. At its simplest, it should mean that every last member of an animal group has died … but there's a bunch of complicating factors to consider. Extinctions can be merely regional – where an animal has disappeared only from a portion of its former range. They can be functional – where tiny populations still exist but numbers are so low that successful reproduction and continued survival are virtually impossible. A species can go extinct in the wild, but still endure in artificial settings like zoos.
In the case of the black rhino species as a whole, more than a few regional extinctions have taken place and some big branches of the family tree have been lost, including the one that's caused all the confusion: the western black rhino subspecies. Although it once roamed across a vast territory that stretched across a chunk of the African continent, including Sudan, Chad and Nigeria, its populations were whittled down to just a tiny cluster of survivors in northern Cameroon. By 2006, that cluster was gone.
If you prefer your information visualised, here's a graphic showing the remaining black rhino subspecies recognised by the IUCN, as well the extinct western black rhino (habitat ranges are coloured in: black = former range, red = remaining range).
So, yes, the western black rhino is very much extinct. There's just nothing new about that bit of news. But with poaching levels at an all-time high (825 rhinos have been poached in South Africa just this year), it's not all that unlikely that other subspecies will soon follow the western black rhino down the road to extinction. And that will make for some very sad news indeed.