The past, the poop and palynology

Do you ever imagine how your neighbourhood looked before humans rocked up?
How about back when giant ground sloths pottered in your garden, or a Tyrannosaurus bedded down where your house now stands?

It’s only a blink ago, in geological time.

Of course we tend to forget that hopping and squeaking, right outside our doors, are the direct descendents of those monstrous beasts.

Photo posted on Flickr by kibuyu.



 OK, I know sparrows are a bit of a comedown, but if you're ever up close and personal with an ostrich’s foot, you’ll never again doubt the dinosaurishness of birds.



Living outside my own backdoor (well actually it’s about 0.5 km away) is a seriously anachronistic beast. Small and inconspicuous with a curmudgeonly air, it cunningly hides its connections to an illustrious past.

  

You see if you pop back 40 million years here, you won’t meet many of Africa’s iconic beasts. There’ll be no antelopes or zebras, buffalos or giraffes; even the hogs hadn’t tromped in yet. (Of course, there were mongooses; but who could imagine a world without them?).

Back in those days, Africa’s principal veggie-eaters came from an entirely different family; creatures whose great grand-pappy also sired the mastodons and mammoths. These herbivores stomped and frolicked in a carnival of diversity, ranging from diminutive mouse-like critters to rhino-sized brutes; some slick and fleet of foot, others dumpy and lumbering.

So who were these creatures?

Hyraxes.

Yep, that’s right, good ol’ dassies.

Ellies' rellies? Rock hyraxes (Procavia capensis) might look marmot-like but they've more in common with their elephant kin. Both are scrotum-free (their testes are internal), lack a gall bladder, sport impressive tusks, have hoof-like toenails and endure pregnancies that last forever (7-8 months in hyraxes).
Photo posted on Flickr by Koets.

Small human shown for scale.
Photo (taken on the Cape Peninsula) by Danie van der Merwe.

Sadly, the arrival of ruminants put paid to the Golden Age of Hyraxes. Out-competed by these consummate vegans (who would have thought that chewing your food twice could prove so beneficial), hyraxes withdrew to the nooks and crannies of the continent. Today only four species remain.

Possibly because of this fall from grace, rock hyraxes are obstreperous little beasts. Although they live in colonies of up to 35 animals (one macho male with a harem of sisters, daughters and aunts), social relations are strained. Look closely at a mob of hyraxes basking atop a rocky outcrop and you’ll notice that they never sit facing one another; they fan out like iron-filings around a magnet.
When they bounce down off the rocks to graze as a herd (harvesting a different section of their range each day) they also arrange themselves like this. And when a hyrax wants to join a huddle or enter a crevice, it reverses in backwards.

Weapons of dassie destruction.
Fights (mostly between males) can be fatal
due to the hyrax's tusks.
Photo by Brian Burger.

Why?

Well in hyrax-speak, eye-to-eye contact is equivalent to a rude hand gesture and, let me tell you, a pissed-off hyrax is scary. It growls, it gnashes its molars, it erects the black fur around its dorsal gland (a smelly, goo-secreting patch in the middle of its back), it curls its lip and slashes with its gruesome tusks.

Oh yes, despite their heart-warming shape, hyraxes are not heart-warming beasts. Unlike my charming mongooses, they will not suckle one another's pups; heck, they won't even groom each other!

And in the breeding season everything gets much worse due to a massive influx of testosterone: the dominant male's testes increase 20-fold in size! 

   

For the biblical ‘coney’, soaking up the sun isn’t just a leisure activity. Being of ancient origin, the hyrax’s thermostat is faulty so it basks and huddles to stay warm (even ‘stacking’ on chilly nights) and hides in shady crevices when it's hot.
Photo by Steve Krane.



Quite a mouthful. With their top incisors transformed into tusks and their lower ones converted into a grooming comb, rock hyraxes must nip off their veggies with their molars. Their huge gape lets them take bites as large as a sheep’s (as my deformed thumb will testify).

Photo by Damien du Toit.

 



Baby hyraxes are born in summer (all the girls in a colony give birth syncronously). They immediately clamber up on to Mum's dorsal gland: their favourite hang-out spot for the next five months.
 Photo by Paul Genge





A teat of one's one. Infant hyraxes divy up Mum's nipples, remaining faithful to their chosen teat/s for the entire 3-5 month suckling period.



Thanks to the tenacity of this weird little animal (it's only got three hind toes: i.e. proof of weirdness) we can begin to imagine the bygone fauna of Africa. But it’s actually one of the rock hyraxes more mundane habits that’s proven most helpful to our understanding of the past.


Like all sensible creatures, rock hyraxes deposit their poop in latrines. Their toilet facilities are conveniently located close to the colony’s sleeping quarters (usually beneath a rock overhang) and are used, unswervingly, for centuries. The hyraxes not only poop here, they merrily splash pee over the rocks, and when the calcium carbonate in the urine crystallises, it not only creates tell-tale white stains, it cements the droppings in place. Protected from the weather, these piles of poop provide an amazing, stratified compilation of the past.


A pile of poop or an
invaluable historical record?



Now I didn’t realise this until I researched this post, but hyrax middens are the bee’s knees for palynologists (pollen enthusiasts). You see air-borne pollen grains stick enthusiastically to fresh hyrax poop, so by sifting through the layers of stratified shit and identifying the attendant pollen, these diligent souls can ascertain past climates. Thanks to radio-carbon dating we know that a hyrax midden from the Karoo provided 1130 years of compiled hyrax history, and a Namibian midden yielded 2000 years worth of ongoing shit data! But it doesn’t stop there. In dry climates, hyrax dung readily fossilises, and fossil middens have shed light on 20,000 years of southern Africa’s past.

Go hyraxes!

 

 

Reparation. "This picnic is mine!"
Photo by Tim Parkinson.