Month: March 2018

One morning after a night of heavy rain we found this mass of foam hanging over the muddy track.

About the size of a large grapefruit, it turned out to be the nest of the terrestrial African Foam Nest Tree Frog, Chiromantis xerampelina. Its construction is the culmination of a Bacchanalian orgy.

The female secrets a mucus from her cloaca, together with water from her bladder, and then she and an entourage of males whip this into a foam by churning it with their hind legs. Into this she lays her legs, and the males fertilize them, adding sperm to the mix. There can be up to 12 males, and the whole thing takes a long time, so the female takes breaks in the middle to rest and hydrate.

They build these astonishing nests above muddy puddles, and when the tadpoles hatch they drop into the puddle, where they stay until they grow into frogs. If the puddle dries out too soon, “Tough luck” as one of my guides said.

If you are still reading, you might also be interested to know how these tiny tree frogs survive the intense sun and heat of the long hot dry season. They have unusual skin that resists water loss, but their ventral skin lacks this property, so they curl up, with all the vulnerable parts tucked underneath them, and secrete a special mucus to seal any remaining gaps. There they stay, motionless, drop their breathing rate, and aestivate.

PS: According to Byrne and Whiting (2008) “Offspring of .. polyandrous encounters are more likely to survive than the eggs fertilised by a single male.” So much for monogamy. 

The young male zebras are horsing around, practicing for serious fighting when needed. They reminded me of teenage boys wrestling. They would have a go at each other with hooves and teeth, in bursts of furious energy:

and they would display apparent aggression:

Then they would suddenly stop, take a break, and indulge in affectionate nibbling at each other’s necks:

But no matter how much they honed their fighting skills, an elephant is a different sort of adversary. This zebra and his friend came round a bush, and came face to face with a very young elephant:

A brief pause, and then he sensibly realized that discretion is the better part of valor:

*Dazzle is one of several collective nouns for a group of zebras.  The others are zeal, crossing, cohort or the rather pedestrian herd.

Sacred Ibis (Threskiornis aethiopicus) are found throughout Africa, from Egypt to the Cape, and are common in South Luangwa. They roost in large groups, sometimes mixed in with other birds, like these egrets. Breeding colonies can apparently sometimes reach 20,000 birds!

Caught in flight, their wingspan is impressive, up to 1.24 meters, or over 4 feet.

You have to admire the strength and skill it takes to land a bird this size, weighing 1.35 kilograms (3 pounds).

In breeding season, the naked red skin under the wings turns bright scarlet:

As you can see, the head and neck are bare, but the feathers on the rest of the body need a thorough preening.

The scimitar-like bill is used to probe around in soft mud and sand for snails, frogs, and aquatic invertebrates. In the aerial photos you can see that the feet have widespread toes, to help spread their weight in the muck. They migrate several hundred miles to breed, within Africa, but they never cross the equator. Northerners stay north, southerners stay south: the Mason-Dixon line of the sacred ibis world.

The Ancient Egyptians venerated them as the symbol of the god Thoth, the god of science, among other things. Thoth was thought to have created hieroglyphic writing (hence the title of this post), and the hieroglyph for Thoth’s own name includes an ibis:  

I like to think that the black bill reminded them of a pen dipped in ink.

The Egyptian statue below is in the Copenhagen Museum. The sculptor got the big feet right too.

[Thanks to an unknown photographer for this photo.]

 

” But there was one Elephant–a new Elephant–an Elephant’s Child–who was full of ‘satiable curtiosity, and that means he asked ever so many questions. …One fine morning .. this ‘satiable Elephant’s Child asked a new fine question that he had never asked before. He asked, ‘What does the Crocodile have for dinner?’ Then everybody said, ‘Hush!’ in a loud and dretful tone, and they spanked him immediately and directly, without stopping, for a long time.”

Rudyard Kipling, The Elephant’s Child, The Just So Stories. . 

Elephants often cross  ‘the great grey-green, greasy Limpopo River‘ to reach lush islands, like this one:

They slide down steep banks to reach the water, leaving enormous ski tracks like these, whose scale is demonstrated by Bertram, my wonderful Robin Pope Safaris guide.:

But, O Best Beloved,  at the bottom lurks danger for a baby elephant:

And one day we found grisly evidence (avert your eyes, O Best Beloved,  if you are of a sensitive disposition):

 

The adult elephants try to protect the young by keeping them in the middle, making it hard for the crocodiles to reach them, but it doesn’t always work. ..

 

The Luangwa Valley was once called the Valley of the Elephants, and was estimated to have 250,000 elephants. The population plummeted and in 1989 was estimated at 18,000. Poaching and snaring have been aggressively controlled, and it is now stable at around 20,000, if not increasing. The Great Elephant Census* aerial survey, helped by the Nature Conservancy,  was conducted from September 4-26, 2015, over 21 million acres of Zambia. Encouragingly, there are elephants with large tusks (this photo was taken by me over the head of my guide):

and there are calves of all sizes in every group you see. At birth, they weigh about 250 lbs (100Kg). There a few guidelines to aging the babies. If it can still walk underneath its mother’s belly, it is under a year old, like this one.

This next one, with his mother’s tail to the left for scale,  is getting used to his trunk. It takes them six months or so to get the hang of it:

This one is older, and he is having a good scratch behind his ear. I chose this photo because you can just see the start of his very first proper tusk. They come in at about 2-3 years old, and are really elongated incisors. (The earlier milk tusks which are present at birth drop out at about one year old, and are only 5cm long.)

I spent some time trying to get a photo showing how they manage the mechanics of nursing. For their mouth to reach the nipple, the trunk has to be got out of the way, which isn’t easy. They drink 3 gallons of milk a day, so they have to master it pretty quickly.

 

PS We all worry about poaching. The Great Elephant Census, which was carried out all across Africa, showed areas of catastrophic decline, and also areas of encouraging stability or even increase. In Zambia, the report says that  ” … the ecologists were not only counting live elephants, but elephant carcasses and the approximate age of those carcasses. A “carcass ratio” — the ratio of dead elephants to all elephants (alive and dead) — of 2 percent to 8 percent is considered normal for a stable or increasing population. The overall carcass ratio for Zambia was estimated at 4.2%, meaning that the observed deaths were within sustainable levels.” See here for more detail.

http://www.greatelephantcensus.com/map-updates/

 

 

 

The Saddlebilled Stork  is the largest African stork at about 1.5 meters (5 feet) tall, and is unmistakable, with a red and black striped bill and a yellow shield or ‘saddle’ at the base of the upper bill.  The male and female are similar except for the eye color – this one is female because she has a yellow eye, and no wattle:

This one is male, because he has dark brown eyes and a tiny yellow wattle, and he is about 10% larger than the female. His wingspan can be up to nine feet.

It is the breeding season, and both sexes have a prominent brood patch of bare skin on their chests to allow closer bodily contact with the eggs, for better heat transfer.

They are found alone, or in pairs, like these two, and they like to hunt in the floodplains for fish, frogs, small mammals and reptiles. This male stayed for a long time in one spot, stabbing at something invisible in the grass that he seemed to be rather wary of. The guide thought it might have been a monitor lizard, getting too close to their nest.

Whatever it was, at one point it gave him a serious scare, and he leapt backwards, rather inelegantly.

Odd fact about storks: they have no syrinx, so the young can only hiss, and the adults are completely mute.

PS: As befits the largest stork, it also has perhaps the longest scientific name: Ephippiorynchus senegalensis. Ephippio comes from the Greek for ‘saddle’, or literally ‘on the horse’, and rynchus means ‘bill’.

PPS: This stork’s great height means he and I would pretty much see eye-to-eye.

( Our two year old grandson specially likes leopards. This is for him.)

The South Luangwa Valley has a very high concentration of leopards, about one for every two square kilometers,  but in the rainy season they are harder to find.

On a bush walk, we nearly trod on a leopard eating an Abdim’s Stork in the undergrowth under a large tree. The guides (who are always in front when you are on foot and in single file, for exactly this reason) caught a glimpse, but all we heard was an angry coughing grunt, and the rustle of leaves as it slipped away, leaving the carcass behind. When we came back two hours later, it had been back and taken its breakfast off somewhere else for a more tranquil dining experience.

But on a different day, from a vehicle, Charles, the National Park armed scout, saw two spotted hyenas deep in the long grass under a tree (here’s one, out in the open):

We got the vehicle as close as we could, and craning our necks saw an impala fawn carcass high in the tree, but no leopard.  So we went away, and came back at dusk. The hyenas were slinking off, having given up hopes of a handout. And there in the tree was the leopard, draped over a branch with one leg stuck through a hole:

After a while he got up:

And climbed back up to his kill:

He was a young male, not one known to Fred my guide, with a good healthy set of teeth!.

I noticed a detail in one of my photos, and I have tried and failed to find out more about it. Here is a closeup of the back feet and lower back legs of the leopard:The wear and tear suggests that not only the pads come into contact with the ground or tree, but sometimes the whole tarsus. I have found photos of leopards descending trees head first, which they often do, and it does indeed sometimes look like the whole tarsus touches the trunk. I’ve also wondered whether they make extensive contact when they push off in one of their powerful leaps (up to 20 feet forwards, or 10 feet upwards). If anyone can shed light on this, I’d be interested.

 

* The title quote is from Percy Bysshe Shelley, Prometheus Unbound.

Time for something less warm and cuddly, I think.

I see surprisingly few reptiles or amphibians in South Luangwa, but they are around. My grand total was one snake (Spotted Bush Snake, too high and too fast to catch or photograph), one terrapin, one frog’s nest, and two lizards.

Today, the lizards.  An easy one is is the tropical house gecko, (Hemidactylus mabouia), living happily in my hut, and helping keep the bug population down:

Geckos have this amazing ability to hold on to vertical surfaces, and this close-up of the feet allows you to, just, see the toe pads (and the non-retractable claws).

“.. their bulbous toes are covered in hundreds of tiny microscopic hairs called setae. Each seta splits off into hundreds of even smaller bristles called spatulae. .. the tufts of tiny hairs get so close to the contours in walls and ceilings that van der Waals force kicks in. This type of physical bond happens when electrons from the gecko hair molecules and electrons from the wall molecules interact with each other and create an electromagnetic attraction.”  https://www.livescience.com/47307-how-geckos-stick-and-unstick-feet.html

Nocturnal species of gecko also have extraordinary eyes.

They have multifocal eyes, and even in very very low light they can still see color through their large round pupils.  In higher light intensities, the pupils begin to narrow to a vertical slit with only a few pinhole openings in them. In the shot above, the gecko’s top (left) eye is between these two extremes as it adjusts to the light of my head torch. The bottom (right) eye is in shadow, and the pupil is much much larger and rounder. The graph below is from a paper on the helmet gecko, by Roth et al (2009), showing (from left to right) how pupil area decreases by a factor of 150 (compared to a factor of 16 in humans) as light intensity increases (the scales on the graph are logarithmic):

 

 

The second lizard I saw was a skink, probably a Tree Skink (Mabuya planifrons), but I am not quite confident of that!

 

Baboons tend to get a bad press, but the young ones are irresistible. This Yellow Baboon (Papio cynocephalus) mother was carrying her own tiny baby, and babysitting a friend’s slightly older one.

The tiny one wanted to play with the big guy, though his mother didn’t seem too sure:

He wriggled free:

And they played happily for a bit:

But playing in the big leagues has its risks, especially when your mother isn’t watching..

[PS: At birth, the coat is blackish or reddish, and the tiny one in these photos has not yet completely changed to the yellower coat of the older toddler: his black head coloring suggests he is under six months old.]

These photos will ask you to use your indulgence and your imagination. None of them are good enough that I would normally think of posting them, but the story they tell was one of my most engrossing experiences in the bush.

This is a juvenile martial eagle, (Polemaetus bellicosus) probably fully grown but less than seven years old because she is not yet in adult plumage. They are the largest eagle in Africa, with a wingspan of up to 260cm (8 1/2 feet), bigger than a bald eagle. They are classified as Vulnerable, due to habitat loss, collisions with power lines, and poisoning.

Maybe 1/2Km from her perch, a family of banded mongoose were foraging happily in the long grass (as you can already tell, this isn’t going to end well).

My camera was on the eagle when she took off:

She silently swooped and without pause rose again, this time with something in her talons:

This second shot is a touch clearer:

And the remaining mongeese spent 15 minutes popping their heads up and down above the grass like meerkats, trying to work out what on earth had happened:

Martial eagles (who weigh on average 4.7Kg, with the females as large as 6.5Kg) have occasionally been known to take small antelope, so a mongoose (2.25Kg, roughly half of the eagle’s weight) is nowhere close to the limit of their abilities.  They can see their prey from 5Km up, so this hunt was easy-peasy on all counts, even for a juvenile.