Eyes on the Wild

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.

 

The African Open-billed Stork (Anastomus lamelligerus) is a large handsome bird (up to 94cm tall) with glossy purplish-black plumage and a wicked-looking bill.

Its name comes from the fact that even when the tip of the bill is closed, the sides still gape open:

I spent about 30 minutes photographing this one hunting in the weed-covered lagoon while I was lounging by the camp’s (weedless) plunge pool (it’s a tough life). The stork evidently wasn’t going after fast-moving prey like fish or frogs, because it rooted around vigorously in the same underwater spot for some time. When it finally had what it wanted, it raised its head and swallowed in one swift motion, never showing what it had caught. Finally, I got two lucky shots just before the food went down, because of technical malfunctions where the victims got stuck on the stork’s bill!  Turns out what it liked best were tiny fresh-water snails, just visible in the photo above. The next shot is a close-up of the second successful foray:

The unusual bill is highly specialized for gripping the snail while extracting the meat. This description explains the rooting around that I saw.

“..it holds the snail against the ground, using its razor sharp bottom mandible to sever the muscle that connects the snail to its shell, vigorously shaking its head until the snail body is extracted and promptly swallowing; the whole process can take under 15 seconds.”

(http://www.biodiversityexplorer.org/birds/ciconiidae/anastomus_lamelligerus.htm)

After their abortive hunt, the dogs ended up widely dispersed. They slowly reassembled at their original starting point, and as each small group met other dogs, they greeted each other. In this photo the two in the foreground are being greeted by four others.

These social rituals are central to the pack’s cohesion.

After a while, they decided to set off in a new direction. No-one really knows how these group decisions are reached, but the pack only all follow once one of the alpha pair sets off. It is now thought that sneezes are among the subtle signals they use to coordinate their movements, using a quorum system where movements start once the number of sneezes reaches a certain threshold.

After five minutes, they saw impala in the distance:

In fact there was not one but two impala (look carefully at the next photo), and they proved to be the dogs’ Achilles heels, because the pack split, and both attempts failed.

These two hunts took place within half an hour of each other. They obviously went on trying, because next morning we found them some distance away, fast asleep with full stomachs.

Two days later, we followed a single wild dog who was trotting in the opposite direction to some fleeing impala, and he was heading towards a group of vultures. Underneath we found a freshly killed and already devoured impala. There was still blood on the grass, and stomach contents on the sand.  The pack eat on the spot as soon as they kill, usually polishing off an impala in about 20 minutes. We were too late to see them eating.

A final yawn, and next time, I promise to move on to another topic!

[PS: There is a terrific conservation organization in Zambia collecting data on the collaborative large carnivores (lions and wild dogs). If you are interested, here is their website http://www.zambiacarnivores.org. ]

As it gets cooler at the end of the day, the dogs start to stir.

They wander around, greet each other, stretch, and start to pay attention to the surrounding wildlife. They hunt at least once a day, running down their prey at speeds of up to 35 m.p.h. in chases as long as 3 miles. Their main prey is impala, but they will tackle larger animals such as kudu and wildebeest.

Once they see a prospect, they all point towards it:

And then they are off:

At this point they were moving so fast away from me I put down my camera and just watched. They are very successful hunters, 80% of their hunts result in a kill, but the kills are rarely seen because they run so fast and so far they can’t easily be followed. This time around, however, they failed.

Next time: regrouping for a second attempt.

African Wild Dogs are for me almost mythical creatures. Secretly, this whole trip was really focussed on a burning desire to  see them in the wild. To my great delight, I spent a day and two mornings in their company, and I am going to spread them out over more than one posting.

The more poetic name for them is Painted Dogs, reflected in their scientific name, Lycaon pictus, which derives from the Greek for ‘wolf’ and the Latin for ‘painted’. Each one has its own distinctive body pattern:

 

 

They live and hunt in large packs: the pack in my photos has 20 dogs. They have a close-knit social structure, led by an alpha male and alpha female pair, who are the only ones to breed. They do however have large litters, up to 20 pups, with 10 being the average. The entire adult pack regurgitates food to feed the young (and also any elderly and injured dogs).

When I first saw them they were resting in a damp riverbed to escape the heat of the day. There were heaps of comatose dogs strewn around everywhere, and their coloration is such that it takes some time to work out how many different dogs there are in a single cosy pile:

 

Their intimacy is intensely appealing:

Next time, the hunt…

This is breeding season for many birds in the Luangwa valley. In some species, the males have the most astonishing change in plumage at this time of year.  The Southern Red Bishop (Euplectes orix) is a nondescript brown most of the year, and the poor female remains drab all year long. But look at him now:

These small birds (14cm long) hop around in the longest new grasses, often near water:

and weave delicate basket-like nests:

It amuses me that brilliant scarlet birds often seem to be named after similarly robed clerics or soldiers: Red Bishop, Northern Cardinal, Military Macaw.