Tagged: Andrew Carr

That great story about Rock Hyrax urine you’ve been waiting for

Those aren’t fangs – they’re tusks!

The Rock Hyrax is a remarkable animal. Native to dry, rocky environments throughout Africa, you would be forgiven for assuming that it is a large rodent, with its short legs, short neck, rounded ears and overall resemblance to a particularly large guinea pig or a coypu minus a tail.

And yet, in defiance of expectations, the creature’s nearest living relatives are elephants and manatees. This in itself should be enough to make any research involving Rock Hyraxes worth reading.

But these furry fellows have a distinctive behaviour which, by good fortune, enables climatologists to study the environmental history of rocky areas where traditional techniques – such as taking a core – are not viable. Rock Hyraxes, it seems, are very particular about where they urinate and defecate. They like specific locations underneath rocky overhangs and generation after generation of Hyraxes will use that same spot – called a midden – over and over again. For literally thousands of years.

Some of these middens can date back 30,000 years or more. That’s the Stone Age. That’s actually the Upper Palaeolithic period!

The urine crystallises and what you end up with is a block of solid, stratified material which provides the sort of historical record that is otherwise impossible to find in these dry, rocky parts of the world. Within the midden is a record of Hyrax metabolytes as well as particles which have passed undigested through their systems (and the occasional bit of organic material that just happened to get blown there). These can be accurately dated, giving an indication of how the vegetation – and hence the climate – has changed over the millenia. And that’s what some researchers in our Department of Geography are looking into…

Paleaoenvironmental knowledge of southern Africa, which encompasses countries such as Botswana and Namibia, has always been very fragmentary and largely reliant on ocean core records. The data from the Hyrax middens open up a whole new realm of research into how some of these dynamic environments have changed over 30,000 years or so. The next step is to compare this data with established models of climate change.

We’re anxiously awaiting the next regular news bulletin from the research team.

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