Friday, November 26, 2010

New addition



There's a new arrival on the block.
Or perhaps I should say on the tree.

The vervet troop that sleeps in the big nyala tree outside my backdoor has a brand new member.

He's black, meagrely furred and very unsteady on his pins.
And he spends most of his time upside down.

At the moment (actually during most of his moments), he's clinging to his mum's tummy, his tiny fingers and toes entwined in her silvery fur, and his tail encircling her leg. Every now and then, while everyone else is busy nibbling buds and flowers, he clambers down to poke about, carefully examining twigs and leaves with an air of enraptured wonderment.

I haven't even tried to take his photograph because his mum's so protective. Each time she sees me watching him tottering about, she hauls him back by the tail, bundles him up against her stomach and retreats to a more sheltered spot. But I tracked down some photos so you can share in the pleasure of seeing him. I mean, one baby vervet looks much the same as the next, doesn't it? (I may be committing vervet sacrilege here).


New vervet monkey (Cercopithecus aethiops).
Photo by Louise and Arno Meintjes.

Well, yes I know that troop members discriminate between babies. You see infants possess a strong allure in vervet society, and mothers are happy for other group members to babysit their kids. In my local troop, the young females spend lots of time sifting through the little one's sparse fur, tickling him and rolling him about in play, and retrieving him from real and imagined perils. Meanwhile, last year's youngster (whom I think is much more appealing in his coat of soft grey) is now spending his time sitting alone looking forlorn. I considered hurling an apple at him, but I suppose I mustn't encourage him in bad habits (ah, the perils of comfort eating...).



Vervets lose their black baby-fur at around three months of age.
Photo by Louise and Arno Meintjes.

Research has shown that vervets prefer to fuss over the kids of family members, and babies with high-ranking mums are more popular than those whose mums are lower on the social scale. But the monkeys aren't just babysitting to curry favour, because - just as in humans - first-born infants top the popularity stakes, regardless of their mum's social standing (written with the gritted teeth of a fifth-born child).

Vervet mothers might be relaxed about letting their companions dandle their babes, but if a dispute arises, they rush to their little darling's aid, regardless of who instigated the trouble. As a result of this blind dedication, baby vervets enjoy the same social standing as their mums; so if she's top dog, the little monster can pretty much rule the roost.


Angelic innocence? Take a closer look.
 This little guy has two nipples clamped in its jaws (you can just see its darker pink tongue in between). The nipples of female vervets are positioned close together and it's routine for infants to guzzle from both nipples at once.
Photo by Louise and Arno Meintjes.

Saturday, November 20, 2010

Hopping into housework


Today I'm doing housework.
Not momentous, you think?
Well you're quite wrong.

If cleanliness is next to godliness, I'm playing out-field for the atheists.
Being blessed with an astonishing tolerance for grime and clutter, and living alone, I'm happy to wallow in slovenliness. In truth, I simply don't notice the carpeting of dust, the haunted-house cobwebs billowing around the lights or the snowy drifts of dog fur under the sofa. It takes something unusual to make me stop and think, 'oh, I suppose I should clean up'.

Of course the most dreadful manifestation of this is the Unexpected Visitor (oh my God, oh my God...). But such ordeals are rare (thank Heaven) and my wake-up calls are usually more subtle. You know the sort of thing (well you probably don't, and if you do, it's best not to admit it): the computer refuses to type S and P because cat fur is sprouting from the keyboard, a procession of dung beetles trundles past on route to the kitchen bin, the dog starts licking random places on the floor, or a strange green fluid is seeping from the fridge.

Well today's wake-up call was a bit different.

It was uttered by a frog.
'A series of discordant croaks or squeaks', to quote my frog guide.
Not your usual call to dish mop, I admit.

But this is the call of the foam nest frog. To be precise, the foam nest frog that perches by day on the cupboard above my sink. Still don't see the problem? Then let me fill you in on the idiosyncrasies of foam nest frogs.


The Southern foam nest frog (Chiromantis xerampelina) is one of 15 species of foam nest frog which gallivant about in tropical Africa and South East Asia. This photo was snapped on a cool, rainy evening and features the same individual (my croaking sink-dweller) as the last two photos below (taken on a hot, sunny day).

These attractive little amphibians, with their big round eyes and sucker-like toes, suffer paranoia. Rightly or wrongly, they're convinced that every body of water is brimful with ghastly predators whose sole purpose in life is the annihilation of frogs' eggs. To avoid this rampant egg-consumption, foam nest frogs deposit their spawn in trees. Courting males find themselves a romantic spot with a waterside view - preferably a branch overhanging water – and then tell the world about it. If a lady frog gives their potential nursery the thumbs up, she'll secrete a gelatinous goo which the pair treadle into foam. It's into this confection of froth that the female lays her eggs. Additional gentlemen will help in the arduous whisking operation, surreptitiously fertilising some of the lady's eggs while they kick up a storm.



Southern foam nest frogs building the nursery.
Photo by Arno & Louise Meintjes.

The meringue-like nest hardens on the outside, forming a crust that protects the little embryos from harsh temperatures and drying out. After 4 to 6 days the young tadpoles wriggle down to the base of the nest, where the crust softens, dropping them - with a plop - into the water below.

So the frog sitting croaking above my kitchen sink, believes he's found the ideal nursery.

OK, I admit that my sink probably does qualify as 'permanent water'. Filled with a clutter of encrusted pots, half-empty coffee mugs and milk-rimmed cat bowls, it does provide an alluring mosaic of puddles and pools. And while I realise that it isn't every day one gets the opportunity to witness the miracle of amphibian procreation in one's own kitchen, the prospect of 1200 tadpoles (no exaggeration, according to my frog book) plopping down among my dirty dishes is more than I can face.

So today I'm doing housework.

Starting with the washing-up.


When they aren't loitering in my house, foam nest frogs sit in trees, exposed to the elements. To avoid heatstroke, they turn chalky white (to reflect heat) and secrete tiny droplets of sweat. Unlike other frogs, they don't pee, excreting nitrogen waste as uric acid (rather than ammonia or urea) in an almost water-free, white paste.



Foiled foam nest frog.

Tuesday, November 16, 2010

The pitter patter of little paws


The time has come!

Far and wide, baby mongooses are tottering out of their termite mounds to view the world for the very first time.

Of course, it can be a shock.



At this tender age (2.5 weeks), the pups haven't yet learnt the meaning of alarm calls.


Goshawk?  What's a goshawk??


So they can't be left on their own.




When the group heads off on their daily hunting trip, one family member has to stay behind to babysit.


A hungry and tedious job.
  



But then everyone loves a pup.




The two little guys featured here are the newest members of Bugbears: Urchin and Squirt (named after marine invertebrates).

They're only two inches (5cm) long, excluding tail.
At almost three weeks old, they're just discovering the delights of solid food (if you consider beetle larva delightful), but won't be up to travelling with the group for another week or so.


Plenty of time to snooze.



 
And discover the world.


Thorns!

 

Saturday, November 13, 2010

Look before you leap


When I was fourteen I met the love of my life.

Alright, I admit it, he wasn't human.

He was a small Arab gelding. Dark chestnut and flaunting a blonde mane and tail, he danced along with all the grace and elegance of his breed.
And for me - during my fraught teenage years - he epitomised everything joyous and good.

Of course being highly strung (the horse not me), he also had his foibles. For example, he refused to set hoof in puddles (not an issue in the Arabian desert but endlessly problematic during Melbournian winters). But his most distressing eccentricity related to jumping.

Without fail, we'd come galloping boldly up to a hurdle, only to have him slither to an abrupt stop with his chest almost against the bar. He'd then carefully inspect the far side of the obstacle and, once he'd ascertained a lack of large, fanged beasts lying in wait, he'd rear up on his hind legs and leap the obstacle from a standstill. As you can imagine, this was miserably uncomfortable for me, and utterly heart-stopping to watch. Nevertheless it seemed to work, and the dire predictions of everyone who'd seen us in the jumping ring (that sooner or later he'd kill us both) never materialised; he remained my dearest companion for almost 25 years.

Why am I telling you this? Because since coming here, I've realised that my horse's idiosyncratic approach to show jumping wasn't that idiosyncratic at all.

Take yesterday for example. While out on our evening stroll, the dogs and I met a kudu. Now kudus are my all-time favourite antelope. They're regal and stately, and they stand 1.4 m (4 ft 8") at the shoulder. They remind me of those computer-enhanced images of lingerie models, where the elegant legs just go on and on. Clothed in soft fawn or dove grey, kudus are drizzled with trickles of white, to break up their outline and help them blend in. And their faces are simply gorgeous: huge ears, an irresistible bambi nose and big dark eyes.

The horns of the greater kudu (Tragelaphus scriptus) are the longest of any antelope, reaching 1.8 m (6 ft) in length. When making a getaway through the dense thickets in which they live, kudu bulls raise their chins like haughty aristocrats, so their horns lie harmlessly along their backs. Photo by Arno & Louise Meintjes.

Yesterday, as we ambled along a track that follows a game fence, the dogs heard something in a thicket on the fence line. Trembling with eagerness, the pair dragged me forward. I couldn't see what was hiding there (kudus put their camouflaged coats to good use, freezing in the face of danger) until we were about 12 m (40 ft) away. Then a huge kudu bull leapt out. Much to my surprise he didn't gallop away from the fence, he just gave one massive leap (from a standing start) up and over the 2.3 m (7 ft 6") fence. There was a ricocheting boing as his forelegs rapped the top wire and the fence swayed precariously, but the knock didn't slow his flight and within seconds he was gone.
With my usual photographic ineptitude, I failed to capture the event but I did snap a dreary photo of the kudu-less fence, once all the excitement was over.

The fence the kudu leapt. Grubby husky included for scale.



Careening kudu. Renowned for their jumping ability, greater kudus can easily clear 2.5 m (8 ft). Photo by Arno & Louise Meintjes.
 
Thanks to this impressive disregard for fences, kudus are free to indulge in seasonal pilgrimages. I don't see hide nor hair of them in the wet season (because they're off roaming far and wide) but once food gets short, they all come trooping back, to hang out near the koppies and the river. Kudus dine almost exclusively on foliage and, because of their size, they need plenty of it; especially the males (who are 50% heftier). Late in the dry season, I often come across emaciated bulls tottering about, and many starve if the rains are late to arrive. A study in Kruger found that a six-year-old kudu bull (who's just attained adult size) has only a 50% chance of reaching his seventh birthday. In contrast, svelte lady kudus often live to fifteen.


Crown of thorns. Cryptic and stealthy, greater kudus are able to survive outside protected areas and are gradually infiltrating much of their former range (after rinderpest epidemics almost annihilated them early last century). Photo by Arno & Louise Meintjes.

 
Fortunately, all the kudus I've met this year are looking OK (thanks to the heavy rain last April) so I don't have to feel guilty about chasing them over fences. But the prodigious leap I witnessed was by no means unique. I've also seen impala, bushbuck, duiker and eland leap over large obstacles from a stationary start. And, thinking about it, both my dogs and cats jump from a standstill. Maybe my darling horse was just behaving naturally??


When love is in the air (around May), kudu bulls slap on the neck muscles. Why? Because rival males lock horns and neck-wrestle to win the hoof of lady kudus.
 Photo by Arno & Louise Meintjes (who clearly share my love of kudus).

Saturday, November 6, 2010

Rain


Last night we received our first good dowsing of rain.

Although the runoff seeped in to flood my kitchen, and the pets took fright at the golf-ball sized ice-chunks crashing on the roof, we're now all celebrating (a doubling of chocolate consumption).
  
Well, perhaps all isn't strictly accurate, since the composition of my household has undergone a change.
 
Last night all my resident red toads (eight, it turned out) lined up at the door to be let outside. As they hopped off into the rain to do their froggy thing, I felt I should be waving a handkerchief or something. But as they say, 'Nature abhors a vacuum', and I now have several foam nest frogs calling the place home.
 

A foam nest frog (Chiromantis xerampelina) enjoying the view from my curtain rail.


After one light shower of rain last week, the bush is already edging its way toward green. Its absolute faith in the coming of rain terrifies me. I guess I spent too long in the Kalahari where all the plants lie doggo until there's been enough rainfall for them to sprout, bloom and set seed all in one hit.

With everything breaking out in leaf and the air scented with flowers, the first summer migrants are starting to wing in. I heard a red-chested cuckoo calling for the first time this morning (cause for nervousness, no doubt, in all hairy caterpillars, thrushes and robin-chats).

Red-chested cuckoo (Cuculus solitaries). Photo by Johann du Preez.

I'm now going to inflict on you photos of some of the flowers that are currently burgeoning (sorry, I can't resist them).


The mopane pomegranate (Rhigozum zambesiacum) pins its sweet-scented flowers on a stark thicket of bare twigs.




The weeping boer-bean (Schotia brachypetala) literally drips nectar, attracting a deafening buzz of insects. Around here, these trees grow almost exclusively on termite mounds, sucking up the moisture generated by these little control freaks (a mound is not a home unless it's humidity-controlled!). Every man and his dog (well maybe not his dog) eats this tree: starlings, monkeys and baboons scoff the flowers, antelope nibble the leaves, and both monkeys and people chomp the carb-rich beans (apparently you roast the pods). Oh, and black rhinos (who've presumably been partying) like to gnaw the bark, which is said to cure heartburn and hangovers.



The red bushwillow (Combretum apiculatum) is a handy plant for practical jokers. The seeds, although consumed by birds, are poisonous to humans, causing prolonged hiccupping.



Natal plane (Ochna natalitia). These lovely perfumed flowers last only a day or so. Then they fall to create drifts of golden petals.




The blood flower or fireball lily (Scadoxus multiflorus) is utterly bizarre. Once a year it sprouts a single flower head (26cm/10" across) comprised of about 200 individual flowers. Laden with alkaloids, the plant snuffs out livestock, and is used to coat poison arrows in Cameroon and Gabon, and as a fishing poison in Guinea and Nigeria.


Another species of plane (Ochna spp.) that I've yet to identify.


The migratory yellow-billed kites (Milvus aegyptius) began to rock up last week. Each morning at dawn, as I drive to the study site, I follow one skimming along the road – kilometre after kilometre - searching for beasties that were flattened in the night.
Photo by Matt MacGillivray.

Friday, November 5, 2010

Monkey see, monkey do (well, sometimes)


Do you ever feel unappreciated?
As if others just aren't noticing the effort you put in?

The feeling's not uncommon. And not only in people.
Male vervet monkeys also have cause to feel this way.

Even as I write, a small troop of vervets are sitting nibbling bushwillow flowers in the trees outside my window. Mostly I only glimpse some soft, smoky fur beneath the foliage, but now and again there's a quiet churring call or a small sooty face pops out from the leaves to peer down at me. Some of the group are now heading off; they shinny down the tree's lower branches, dangling from the sagging twigs and dropping into the soft river-sand below. One little youngster, dancing after its Mum, executes the manoeuvre as a cartwheeling back-flip, landing with all the aplomb of an Olympic gymnast's finale. I feel a bit ashamed that I've made no effort to get to know the individuals in this troop, and I can't tell you which ones are male.

Vervets monkeys (Chlorocebus aethiops) are highly sophisticated critters. They converse by means of 36 distinct calls and more than 60 gestures. And they can recognise every monkey in their troop, as well as members of their neighbouring troops, simply by voice.
Photo by John Tolva.


Like most monkeys, vervets are intelligent, inquisitive and opportunistic (as you're likely to discover, to your cost, at picnic and camp grounds throughout their range). Their remarkable talent for exploiting new opportunities is at least partly due to a willingness to learn new things from one another. However, recent research - by Erica van de Waal from the University of Neuchatal, Switzerland – shows that not all monkeys are equal when it comes to passing on new skills.


Up to new tricks. Photo by Martin Heigan.

Erica presented natty little fruit boxes to six wild vervet troops at Loskop Dam Nature Reserve. Each box housed a slice of apple that was accessible via two different doors. She taught one monkey (either the dominant male or the dominant female) in each troop how to open just one of these doors, and then she presented the snack boxes to the whole troop. The vervets quickly learnt how to pilfer the apple, but the troops differed in the technique they used. In troops with a trained matriarch, almost all the monkeys used the same door as she did (suggesting they'd learnt the skill from her), but in groups where the dominant male had been trained, the monkeys were just as likely to use either door, suggesting they'd learnt by trial and error.

But why the difference? It seems that although the troop's leading man monkey fathers most of the troop's infants, he doesn't actually rate much notice with his group mates. Erica found that the vervets simply didn't bother looking at the dominant male, so they didn't see how he opened fruit boxes. In contrast, the group's first lady was the centre of the group's attention for much of the time.


Restoring self-esteem. Male vervet monkeys perform the, so called, 'red, white and blue display' to intimidate male group mates. (Warning: do not try this at home, even if you are feeling overlooked.) Photo by Louise and Arno Meintjes.


You see, in vervet society, females believe in hearth and home. They spend their entire lives in the troop in which they were born, and so they develop very strong bonds with their sisters, aunts and nieces. Which, of course, translates into paying lots of attention to 'the girls'. In contrast, young males must pack their bags (metaphorically speaking) at around five years old. Most choose to sign on with a troop that includes someone they know (e.g. an elder brother) but they usually change groups several times during their lifetime. Thus their ties - and importance - to the group are not so deep.
Interestingly, this set up means that new innovations are slow to spread through the vervet world (since incoming males are unlikely to pass on their bag of tricks) and – over time - cultural differences will burgeon between different vervet troops.

So if you're feeling unnoticed and unappreciated, at least you can be pretty sure that no one's going to steal your innovative ideas (or, for that matter, your fruit box).


Keeping it in the family. Vervet territories are passed down from mother to daughter; generation after generation. It horrifies me that people shoot encroaching vervets (so the troop will 'go away') when their house is built on land that's belonged to a vervet family for many hundreds of years. Where is the troop supposed to go?
Photo by William Warby.

E. van de Waal, N. Renevey, C. Monique Favre, R. Bshary. 2010. Selective attention to philopatric models causes directed social learning in wild vervet monkeys. Proc. R. Soc B.


Monday, November 1, 2010

Beasts for the bedridden


"The universe contains any amount of horrible ways to be woken up...

A dog's wet nose is not strictly speaking the worst of the bunch, but it has its own peculiar dreadfulness which connoisseurs of the ghastly and dog owners everywhere have come to know and dread. It's like having a small piece of defrosting liver pressed lovingly against you."

Terry Pratchett (Moving Pictures)


This quote holds particular significance for me this week because I spent the better part of it in bed, fighting off the horrible ravages of malaria (you're allowed to use phrases like 'horrible ravages' when you've got a bona fide tropical illness).

It's only been 'the better part' because of the regular intervention of the aforesaid noses. Oh, and don't let's forget cats' whiskers; equally unnerving when pressed into the face of a sleeper.

Of course their eyes are reproachful:  you know it's time to let us out...  feed us breakfast...  refill our water bowl...  turn on the air conditioner...  clean out the litter tray...  take us walking...  prepare our dinners...  shut the leopards out...

They've watched with deep concern as I trembled and shook, coughed and spluttered and fed-the-fishes (a phrase that's not as euphemistic as I'd like, given the state of the house's plumbing). Being cynical (a consequence of the illness, I'm sure), I couldn't decide whether they were genuinely worried about me or simply monitoring symptoms indicative of their continued neglect. But on Friday I decided it WAS true love. When I ate my first meal for four days, I had an utterly transfixed and joyous audience; and no one tried to beg a thing!

Being bedridden restricts one's wildlife encounters, so I thought I'd write a nice gentle post about the vervet monkeys who hang out in the trees beside my bedroom window. I love these little guys, silvery-furred and lithe, they're like wood sprites or dryads as they dance through the foliage. But my contemplative mammal post was not to be. The local wildlife came inside.

On Thursday night I was just drifting off to sleep - in a semi-drugged daze - when I felt something brush against my thigh. Magic's tail, I wondered? Tentatively I reached down and felt about a bit: no tail. Magic was lying too far away. Since our recent serpent-visitations, we've all been a little paranoid (Wobbly Cat still hasn't placed a paw outside and Magic won't sleep there), so I decided miserably I'd better wake up and check it out. I groped sleepily for my torch and shone the wavering beam toward my feet.

Within seconds I was out of bed.

There was a large black scorpion crouched among the sheets.
It was about 12 cm (5") long with a huge armoured tail upraised threateningly over its back.

Oh, S#%*T!

It wasn't just any scorpion, it was a Parabuthus transvaalicus, one of the most lethal scorpions in southern Africa.

ISN'T MALARIA ENOUGH? I thought in anguish.

Parabuthus transvaalicus grows to 15 cm (6") long. But size isn't what counts. As a rule of thumb (although it's best to keep them out of the way), your scorpion-related panic can be accurately tuned by examining the beasty's body bits. Scorpions with whopping pincers live hand to mouth, so to speak, crushing their prey to death, and so they have wimpy tails and weak venom. But scorpions (like this one) with petite little pincers kill with their sting (both prey and those that piss them off) so they have hefty tails that produce lots of lethal venom.


Trying to ignore my throbbing headache, I began bundling the pets out of the room.
Fleetingly I considered taking a photo, but thought 'To hell with the blog'. (Forgive me, dear reader, but I'm sure it was the wicked malady speaking, and I also remembered I'd taken a few shots of a dead specimen in the garden last August.)

Wielding a plastic drinking cup, I rumpled the sheets behind the scorpion and it obligingly trundled into the cup. Then, while stuffing a blanket over the beaker, I fumbled it and the scorpion scuttled out again. Not good. I should probably point out, at this stage, that this species doesn't just sting like normal scorpions, it can also spray it's venom for distances of about one metre/yard. Thankfully, it didn't. My second attempt was more successful, and despite a few nervous moments, trying to keep the lid on the cup with my chin while unlocking the back door, the release went smoothly.

While I'm not keen on scorpions, I have to admit their interesting little guys; especially when it comes to romance.
After following the trail of his true love's pheromones, the smitten male performs a little tap dance, juddering his body, tapping his pincers or wagging his tail (depending on his species). His lady detects these 'love vibes' through highly sensitive hairs on her feet and body, and sensibly curbs her predatory inclinations. Next the couple embrace, lovingly locking pincers or - more intimately - mouth parts. The male then whisks his sweetheart into a waltz (lasting 5 to 30 minutes), fanning out his pectines (fluffy sensory combs on his stomach that feel the ground) in search of the ideal place to consummate their love. The dance only halts when he finds a smooth hard surface. Here he deposits his spermataphore: a little package of sperm that's sticky on the bottom and hooked at the top. Once it's stuck firm, he helps his paramour move above it; they have to get the position just so, because the hook on the spermataphore must catch and pull open the covering of her genital opening. Ain't Nature grand!

While this is the end of the story for the male, the female's destined to a 2 to 18 month pregnancy (depending on her species). She then gives birth to live young, a feat virtually unheard of among arachnids. Withdrawing to the safety of a burrow or shelter, she arches her tail over her back and places her front two pairs of legs beneath her genital opening to create a birth basket for the emerging babies. She then helps the newborns (tiny, but pale and soft, versions of the adult) clamber up on to her back. Here they remain, safe and snug, (while she forgoes foraging) for their first 9-14 days.


Parabuthus transvaalicus' monstrous tail churns out large quantities of neurotoxin (drop for drop as potent as any snake's). It causes severe pain, muscular cramps, uncontrolled limb movements, numbness, difficulty breathing and swallowing and death by respiratory failure (depending on the victim's body size and health- yikes!). To be fair, the species also uses its tail to excavate burrows, and to sing. Metaphorically. It emits a 'chick-chick' sound by rubbing its sting against the roughened surface of its second tail segment. Oh, and those spiffy hairs detect the air vibrations generated by hapless prey.


Sharing a bed with a scorpion is not my idea of fun, especially when I'm already feeling under the weather. But my sense of persecution evaporated instantly when I read the latest blog post by the hyena researchers  in the Masai Mara Reserve in Kenya. Oh my! I urge you to check out  what intruded on their sleep this week. Your life will suddenly seem so much better!
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