WINTER 2025

 WINTER 2025

Brrrrrrr! It sure has been cold here on the estate. Still beautiful, warm, clear, blue-sky days, but freezing in the mornings! Actually, not always warm with blue skies in the day, we had quite a few cold fronts move through that brought cloud during the winter.

In fact, we had quite a significant winter rainfall on the weekend of the 22nd of July, smack in the middle of winter, where we had a good ten millimetres of rain. Cold, but not a bad thing, because, even if plants are in a dormant stage, they will still drink when water is available, so this topped up water storage for our green friends.

As mentioned in Don's newsletter, the annual rainfall this season has been lower than normal, with an average of 830mm precipitation falling over the estate, where our average since 2010 is 920mm.

This year saw a little more preparation before the dry season to minimise the chances of a runaway fire like the two we had to fight at the end of the last dry season: Besides more thorough fire breaks, I burned a bit more last season than previously, so the fuel load is not as high as it has been, which decreases the chances of runaway fires as the dry season progresses

In the picture above, you can see the bland, smoky atmosphere that dominates our dry winters spiced up by this absolutely beautiful Cliff Aloe plant, Aloe arborescens, with its multiple blooms high above the estate almost on the tippy top of Little Joker Koppie.

Below is a gallery of a few of the things I encountered over the winter this year:

Oooh, hot lips!!! 

This is the spore-bearing apothecia of Lipstick Powderhorn, Cladonia macilienta, a type of squamulose lichen that is completely cosmopolitan, which means that it occurs everywhere. In this case in every continent, although not yet found on Antarctica but expected to occur there. 

The structure of the lichen is that of tightly packed, centimetre tall, pointed structures that develop these bright red apothecia (the structure that produces the reproductive spores) on the tips when it is time to reproduce. The lichen lives on rotting wood, often together with mosses, in the dark undergrowth in our moist forests. Check my blog of August 2020 for a photo of the lichen as a whole.

It is one of those organisms that is sensitive to atmospheric pollution, so it can be used as a bioindicator for air quality, like Old Man's Beard lichen, which is also found on the estate, especially at higher altitudes.

 Also, it has been found to produce a metabolite called biruloquinone which is a substance that effectively prevents neurodegeneration in Alzheimer's disease. Because of this breakthrough, a mass liquid culture system for the production of biruloquinone has been established in South Korea. 

The fungus is also rich in carbohydrates and its close relative, Reindeer Cup Lichen, Cladonia rangifera, grows in such abundance in the arctic circle that it is the staple pasture for Reindeer, Moose, Caribou and Musk Oxen in the wintertime where these animals access it by digging holes into the snow!

Makes me think of Marilyn Monroe....

Peeter's Smooth Ringbum Ant, Streblognathus peetersii, carrying, not dragging, a large Hawkmoth caterpillar. If I had a very sensitive scale, I would love to have weighed the caterpillar and then the ant and calculated the difference.

How on earth do they manage to lift such heavy weights? Well, they have a few physical attributes that contribute to this amazing ability.

First, is the exoskeleton. It is found in (on?) all insects, but those that require this sort of lifting strength have had their exoskeleton modified by the addition of sclerotin, which makes it much more rigid, creating a perfect anchor for the muscles to use as leverage. 

And secondly, muscle strength is determined by the size of the muscle cross-section, and their muscles are a lot bigger in cross-section in ratio to the muscles found in vertebrates, making them an awful lot stronger.

Anyway, this, together with its close relative from the Karoo (S. aethiopicus) is Africa's largest ant species, reaching a length of twenty millimetres. I have previously featured these ants in my blogs, but under the latter's name. Streblognathus was always regarded as a monotypic genus (genus with only a single species), until recently, when that species was separated from the eastern grassland species, S. peetersi, which occurs here on the estate, by a few morphological differences. 

These ants belong to the most primitive of the ant sub-families, the Ponerinae. Most ponerines live in very small colonies from a dozen individuals to a thousand or so. The notorious Matabele ant from the lowveld is an example of the latter. They live in colonies numbering more than a thousand individuals. S. aethiopicus live in colonies with an average size of thirty-five individuals, while our Peeter's Smooth Ringbum ant lives in colonies with an average of one hundred workers. 

These ant colonies are different to most others in that they do not have a queen but instead a dominant worker that is fertile. Remember, in all ants the workers are female but, in this case, the one that is stress-free will have certain physiological processes triggered that enable her to conceive. So, to remain the only one that is stress-free, she bullies her fellow workers constantly, never allowing their stress levels to drop to the point that they would become fertile too. 

A cold and crazy system, but it works. In fact, African Wild Dogs are one of the mammal species that do a similar thing. 

This poor stunned juvenile African Goshawk, Aerospiza tachiro, had no choice in allowing me to photograph it while it was trying to recover from its head-on collision with my office window. Fortunately, after a few minutes it managed to fly away.

It was most likely hatched and raised in a nest in the pine forest beside "The Croft's" (unit 19), that being one of the main reasons why that forest has not been cut down yet.

Unlike most other raptors, though, the monogamous breeding pair do not usually use the same nest over and over again but build a new one nearby. This pair, I believe, must have used the same nest again a few times because they have been nesting there for more than a decade and they would have run out of forest if they didn't use it again.

This youngster (I think a male because he was quite small, and the females are much bigger than the males) has been fully fledged for more than a month, because they do not leave the area of the nest tree for at least that long before venturing further away. After a maximum of three months they are self-sufficient and will go their own way.

When a male and female bond and enter courtship, the male will catch a prey item and deposit it on a branch for the female as a gift. If she is willing, she will alight on the given branch and begin her meal. He then comes down from above her and mates with her while she is eating.

They then choose a tree to nest in and then establish a territory around it. Bothe sexes advertise this territory by flying above it, wing-snapping and calling a soft "CHIT-CHIT-CHIT" sound while in flight. Once the territory is well established, both sexes proceed to build a nest on a lateral branch, high up in a big tree by springtime.

The female then lays two to four (usually two) eggs in the nest and incubates them for about five weeks while the male actively supports her with food that he brings for her. The nesting period lasts up to six weeks with both parents sharing nesting and feeding duties before the chicks are fledged and ready to take their first ever flight.

Their main prey item is birds, ranging in size from the tiny Bronze Mannikin to the much larger francolins and spurfowls. The hunting strategy is to sit on a perch and wait for a bird to fly (or walk) past, when the Goshawk actively pursues it until it catches it.

These lovely birds are most commonly seen by us while walking on the river paths, because they like to fly along the river paths only a few meters above the ground, often almost colliding with an unwary human. 

What a stunning little ball of flowers, of all ages, belonging to a scrambling shrubby creeping plant called a Warty Grape, Rhoicissus tridentata, from the grape family.

The Warty Grape is very common on the estate, but only smaller ones are noticed because the larger ones are only noticeable by their stems because their main body is high up in the canopy of trees.

It is a useful plant for man and beast, with the flowers attracting many insects and even sunbirds; the red to black, edible albeit very sour grape-like fruits are eaten by man, other mammals and birds; the trifoliate leaves are browsed by many different antelope and the beautiful Silver-striped Hawkmoth caterpillar (see blog of September 2019 for a feature on the adult Hawkmoth, and blog of February 2021 for a feature on the caterpillar)

A more important use, though, is medicinal. Ethnobotanically, it has been used for a few ailments, but particularly to induce labour. The University of KZN did a study to validate this, and they found that treatment with methane crude extracts from the root evoked significant increases in the rate and force of uterine muscle contractions in mice. Go sangomas!

In my previous publication, I featured a group of Firefly larvae eating a Giant Land Snail. Well, this time I can show you what a wingless adult female looks like. Excuse the blurred picture, but I had to switch my flash off so that I could capture the beautiful green light that she was emitting.

It is very easy to establish that she is a wingless adult, because she has large compound eyes, whereas the larvae, as mentioned in the previous article, have small, simple eyes.

From that article, we know that all the species with wingless females belong to the single genus Lampyris, and that these are the species where a female uses her light to attract males, who will fly down to her and commence their courtship.

We also learned that in some of the species the female has the ability to change the frequency of her flashes to attract a male firefly from a different species and that, when alighting beside her, the female will quickly grab the male and eat him!

Now, the insect produces light by the process of bioluminescence, where the insect allows a chemical called luciferin to mix with an enzyme called luciferase within a cavity at the tip of the abdomen, in the presence of oxygen, so that it oxidises and a soft green light is created. The light is extinguished easily enough by stopping oxygen from entering the chamber, and lights again when the insect allows oxygen back into the chamber.

I have featured the Silver Vlei Spider in my blogs in the past. It is a very common spider found in our dark forests. This is a close relative, the African Masked Vlei spider, Eucage festiva. Unlike the Silver Vlei spider, the African Masked Vlei spider is not as common and occurs in our open grasslands.

But look at the patterning on the dorsal part of the abdomen: It looks just like an African mask that one buys from a curio shop! Exquisite!

The web is not constructed vertical to the ground like most orb weavers but at an angle of about sixty degrees, making them easy to identify. 

It is up to the male to find the female and approach her on her web to mate with her. The black widow syndrome is very apparent with this species as the female almost always eats the male after they have mated! 

The main prey of the spider are grasshoppers, and the spider constructs the web at the height that these insects normally jump, about a meter-and-a-bit off the floor. Once the grasshopper is caught up in the web, the spider approaches the prey and injects a venom into the struggling insect to subdue it. Once subdued, the spider immediately begins to chew the body of the prey, breaking it up. It then vomits an enzyme onto the chewed pieces which begin to liquidise. 

Once liquidised, the spider sucks the fluid into its mouth by pumping the stomach muscles and tiny hairs around the mouth filter out the indigestible pieces that it discards afterwards, together with the crumpled shell of the victim. This pumping stomach action is also what spreads the nutrients around the body of the spider. 

Once enough has been consumed, and the spider feels its body growing, it will return to the middle of the web and hang there upside down again. But this time its skin will split down the middle and the spider will climb out of its smaller, older skin and leave it hanging there like an old piece of clothing. Certainly, the biggest enemy to Masked Vlei spider are Spider-hunting wasps from the Pompilidae family (see blog of March 2020), who will easily locate the spider as it rests in the middle of its web. 

One of the three places where one is almost assured of spotting a Rock Hyrax is just beyond the crossing east of S7 on the Steenkamps' road. So, when I saw this Verreaux's Eagle, Aquila verreaux, while driving my Landrover near this spot, I assumed it was eating one of these little mammals. 

I stopped the big, noisy vehicle a mere four meters from the eagle, and couldn't believe that it didn't fly away. A truly magnificent raptor it is!

We have been sighting a pair of these massive raptors over the estate for the entire winter, whereas in the past, they were only sighted once or twice over a month or more. I did see them perched on rocks on a cliff face in Emoyeni property between Bulldozer Creek (unit 22) and Whiskey Creek (close to the brewery) about six weeks ago, and the larger female definitely seemed to be inspecting a nice shelf on this cliff face. Perhaps they were planning the shelf as a nest sight.

Needless to say, I have not returned to that area for fear of disturbing them if they decided to construct a nest but will go soon on a recce mission to find out. If they did decide to settle there, they would have constructed a large, untidy platform of sticks and small branches over a period of about two months on the ledge. The larger sticks are snapped off a tree with the eagles' feet while the bird is in flight (Gee, that must be quite a sight!), with the smaller picked up from the ground.

The monogamous couple usually have four or five nests in their territory which they use over and over, with the birds adding new sticks each time it is used, until the nest can be as wide as three meters and as high as four meters! If one of the sights is threatened, usually by human action, the couple will abandon it and build another elsewhere. This is what may have happened to this pair, or they are newlyweds and are establishing their first or second nests.

An average of two eggs is laid, four days apart, in the middle of winter and the hatchlings emerge eight or so weeks after laying, with the female incubating through the nights and, at least, half of the day. The male supplies food and incubates for the remainder of the days.

One chick hatches four or so days before the second and almost always kills the younger sibling, as do most eagle chicks, even if the mother tries to intervene. The survivor is raised by both parents until it is ready to leave the nest after just over three months after hatching. After another month or so, the parents chase the youngster out of their territory, forcing it to fend entirely for itself.

I was busy perambulating the Majubane waterfall path recently, when I encountered a sedge bush crowded with Stalk-eyed Flies, Diopsis stuckenbergii, hundreds of them, resting and interacting.

I mentioned these odd flies in my publication Winter 2023, but, because they are so bizarre, I have to feature them again. The nice thing this time was that I knew what they were and what they were doing and so managed to observe their behaviour a bit.

They roost on hanging roots above the water during the night. Then, in the early morning, they gather on the bushes near the stream and the males establish a lek, a gathering of males for the purpose of competition for females. The males face each other with front legs splayed wide. They then push their faces up against each other, and the one with the longest stalks (largest space between the eyes) dominates and moves on to the next male. The females watch this and are attracted to the male with the widest eyes. Very sexy!

Once mating is complete, the female lays her eggs in and amongst rotting vegetation on the forest floor. The larvae hatch and consume the rotting vegetables and then enter their pupal stage. Once emerging from the pupa, the newly adult fly's stalk eyes are squished up against their bodies, so they gulp air in through their mouths and pump it up into their faces and inflate their stalks, like balloons, until they are fully extended!

This, like the extraordinarily long tail of a male peacock, is a great example of "sexual selection", where the female's preference for, in this case, wide-apart eyes, results in the males evolving physical traits which may even actually hinder survival. As long as the male can still breed. 

The flies on the extreme bottom-right of the photo are literally peaking around a corner :) 

These tiny little things are the fruiting bodies of the Carnival Candy Slime Mould, Arcyria denudata, and are only about one millimeter tall. You've gotta love the common name!

When it comes to classifying living things, the highest level of classification is the Kingdom. For example, animals belong to the kingdom Animalia which includes earthworms, spiders, insects, amphibians, reptiles, mammals, birds etcetera; plants to the kingdom Plantae; mushrooms to the kingdom Fungi and slime moulds belong to the kingdom Protozoa, together with Amoeba proteus, the amoeba you studied in biology class at school; Plasmodium falciparum, the protozoan that gives us cerebral malaria and many others.

 

A single spore finds itself in a suitable environment, it germinates a few flagellated (have a tail for movement) protoplasts called Swarm Cells (not to be confused with a beehive). These cells move around their environment eating bacteria and when they meet up with a mate, they form a zygote and grow into a plasmodium as they split nuclei. 

A plasmodium is defined as a living structure of cytoplasm that contains many nuclei, instead of individual cells each with a nucleus. These plasmodia (white blob) feed on bacteria and other microorganisms and grow in size as other zygotes "swarm" to join and become an interconnected network of protoplasmic strands, with each strand's cytoplasmic contents streaming back and forth within itself. 

When this mass of single-celled organisms, that now behave like a multi-cellular organism, wants to move, the strand's contents stream in the required direction while protoplasm is withdrawn from the rear, allowing it to move at a top speed of about one millimetre per hour, leaving a snail trail behind. Search for my blog of February 2021 and there you will see I featured a different species of slime mould, but the photo of the plasmodia will give you an idea what the plasmodium of this species looks like. A white, foamy blob.

Once food becomes scarce, the plasmodium breaks up and migrates to a drier, lighter area and they convert into the spore-bearing structures like in the photo above. These structures produce spores very much like mushrooms do, and release these into the environment where they are spread by insects, wind or water. 

We emerged from our nice warm houses one cold morning only to noticed masses of winged Aphids everywhere. There were millions of them on all surfaces from the ground to the exposed cars, but they were unable to move from the cold. Some of those who settled on the lower areas were frozen in the morning frost. This individual and surrounding friends began stretching limbs once the ice had melted and they were able to move.

Aphids are sap sucking bugs from the Aphididae family of true bugs (Hemiptera). They are those tiny pests you see crowded around the twigs and branchlets of your garden plants.

They are fat and soft bodied, slow moving and gentle with no defences except two chimney-like tubes, called cornicles, at the end of their abdomens that extrude a quick-hardening waxy fluid that deters a few of its enemies. Sometimes.

The only thing that makes them so very, very successful, is their fecundity, their reproductive prowess. Let me explain:

As usual, it all starts with an egg. In the weather extremes of the northern climes the egg is laid by a female in autumn, after which she dies and the egg over-winters with the nymph hatching in springtime. In warmer climes, like ours, the egg may be laid in times of struggle, like insufficient food supply and the nymph hatches when conditions have improved.

The hatched first-instar nymph (aphids are true bugs which are hemi-metabolic, so there is no pupal stage and metamorphosis) is a female and she immediately pierces the host plant with her sucking mouthparts and begins to feed. Aphids pierce the phloem most of the time to access the plant's sugars, produced by photosynthesis, but when they're thirsty, they will pierce the xylem which carries the water up into the plant from the roots.

Interestingly, when the aphids are eating, they require no effort because the sugars are produced in the plant and therefore have a positive hydrostatic pressure while, when drinking from the xylem, they are required to suck with a little pump located in their heads because the water is being brought up from the roots via transpiration.

When food is abundant, she will moult a further four times and become an adult within a week. She then begins to birth two or even three daughters each day for the rest of her forty or so days of life. After a week, those daughters, too, are birthing their own young, live, in the same way. There is no parental care. The mother continues feeding after giving birth and the nymph immediately begins feeding on her own. If there were no enemies and food remained constant, this single female aphid, that hatched from that egg, will have produced two-hundred-and-ten to the power of fifteen clone daughters over a year! That number is beyond comprehension. To me, at least. I calculated it and the answer is a scientific notation 6.812e+34. I know someone out there knows what that means :) 

Fortunately for the rest of us living things (especially plants), aphids have an entire army of enemies, from exclusive aphid-eaters like ladybug, hoverfly and lacewing larvae that eat aphid after aphid until they are fully developed, to minute parasitic Ichneumid wasps whose gravid females pierce the aphid with their ovipositor and inject an egg within. The egg hatches and the larva slowly consumes the living aphid until it is ready to pupate. The aphid perishes at this stage and the hardened body becomes the pupa where the larva can metamorphosise into an adult

Interestingly, one of the greatest advantages of a holometabolic insect, meaning it has an egg, larva, pupa and adult stage, is that the larvae do not compete for the same resources as the adult, so the population can be much bigger. The exception to this is the ladybug, they are rabid aphid-eaters as larvae and as adults!

Anyway, back to the life cycle: Once the population of aphids on the plant gets too big, or the plant is too severely damaged by the aphids themselves, then hormonal changes triggered by these factors change the morphology of the new offspring. They are slimmer, more rigid and they have wings! This enables these females to fly in search of another host plant to colonise. Once on a suitable host plant, she will feed, and her offspring will be soft-bodied, wingless clones like her mother was on the previous plant.

At the end of the growing season when resources and weather become less attractive, the aphids give birth to male and female offspring who fly off in search of mates, mate and then the females' lay eggs in safe places to hatch when conditions improve again.

This must have been what we experienced that very cold winters morning: a mass of winged male and female aphids en route to their new host plants, or finding a mate, or both.

While I was observing the Stalk-eyed Flies (above) I saw this Ichneumid wasp land on the same bush and begin searching for a prey animal to inject her eggs into. She walked up and down the bush's leaves tapping both the upper and lower surfaces with her antennae. 

I thought I was going to see some action when she encountered a Stalk-eyed fly, but they simply ignored each other when the time came. I know that caterpillars purposely spend more time on the underside of leaves particularly to avoid being found by one of these wasps, but this wasp seems to have got the memo.

The word "ichneumon", from Greek "footprint" to Latin "tracker", has been applied to this family of wasps because they have to track down a larva of a holometabolic insect to parasitise with her offspring. 

Most female wasps have a stinger which they use in self-defence or, primarily, to paralyse mostly worms and spiders which the wasp feeds to her offspring. The female wasps from the Ichneumonidae, however, have an ovipositor instead. If you look carefully at the photo, you will notice the (blurred) ovipositor sticking out above the folded wings). This long ovipositor is used to reach insect larvae or pupae and inject an egg/s within. 

Some species will follow the egg with a dose of venom that will paralyse the victim like other wasps, but most will allow the victim to continue living and feeding while the wasp larvae feed off its insides, only killing it when important organs, which are left till last, are consumed. By the time the host dies, the wasp maggots have developed fully, and they will drill a hole through the skin of the now dead host and construct a silken cocoon in which to pupate themselves, making the dead host look a little like a porcupine with quills (cocoons).  

Amazingly, in those species, like this one, only a single egg is laid within the caterpillar, but this egg "reads" the victims species, size, age and how long until it goes into its own pupa and then divides the egg the requisite number of times so that there is enough food for the number of eggs that are formed! The most recorded splits are over three thousand splits! So, one egg decided that there was enough nourishment in the parasitised animal to feed over three thousand wasp larvae without dying before they were fully developed! That is simply incredible! 

These wasps are a very important controller of pest insects, and it is estimated that between 10% and 20% of host populations are parasitised by them. This makes them excellent candidates for bio control agents and have been used to control the populations of African Sugarcane Borers and the Arctic Woolly Bear moth in the north. 

The English common name of Darwin's Wasps arose from the fact that Charles Darwin was moved by the family. He famously wrote about how he didn't believe a "beneficent and omnipotent God" would have designed such a cruel animal which eats the insides of another animal while it was still alive.

And finally, there are some caterpillar species, who had fallen victim to these wasps in the distant past too regularly, that have evolved a pattern on their bodies that looks so very much like these cocoons sticking out, that the ichneumonid wasp avoids it, apparently convinced that the caterpillar has already been parasitised (an example being the caterpillar of the Dice moth, Rhanidophora ridens, common in the Kruger Park)!

A little while back, while my team was working in the area of Little Joker Koppie, one of the team told me they saw a large, white antelope up there. I was stumped. That weekend, Ryan Steele from Rainbow Rivers (unit 17) sent this picture of an Oryx, Oryx gazella, that he took, while hiking, from the plains above his place and below the top of Little Joker Koppie.

There's always a surprise in store for us here on the estate, and this was no exception. An oryx, here on the estate? Very odd. I was told that Mount Anderson Ranch had an oryx at a stage, so this must be it, then, since they are not naturally found in this sort of habitat and this is surely the only one here. Must be very lonely.

The exciting thing about this sighting, is that it increases our antelope species count on the estate from thirteen species to fourteen species. That's a good count anywhere!

Grass Orb-web spider, Neoscona moreli, sitting in a web designed similarly to the webs spun by Garden spiders, including a stabilimentum, a zig-zag line of silk running from the centre of the web to the bottom edge.

 

There are many theories to the function of this zig-zag of silk, from reflecting UV light to attract insects, to making the web visible to larger mammals so they don't walk through it. But as its name suggests, it may just be there to stabilise the particularly flimsy web.

Although the web and the habitat, open grasslands, compare with the Garden spiders, the Grass Orb-weaver's behaviour is more similar to the bark spider (blog of November 2019), where the spider hides away during daylight hours, and then spins a web from scratch as dusk approaches, uses the web to catch food during the night, and then dismantles the web again in the morning before hiding away again for the rest of the day.

The male, half the size of the female approaches the female in her web, at night, and if lucky, mates with her and escapes with his life before spinning his own web, similar but smaller than the females', the rest of the time.

The little spiderlings hatch in mid-summer and disperse soon afterwards when they are only a few millimetres in size and immediately build their own webs. If prey items are regular enough, the little ones reach adult size within two months.

To get a photo of one, in its web, in the daytime, is apparently not a common occurrence, so bully for me.





That's it for this winter, which, thankfully, is coming to an end because I felt colder this year than usual and it has been difficult some mornings. But, as usual, the estate delivers good fishing, cycling, birding, hiking and those other lekker outdoor activities. Remember, if you want a guided excursion, be it a drive, walk or hike, just let me know. See you soon.