What has probably been the most noticeable change during the Autumn time, though, are two species of plant that are flowering en masse. The first is the bright yellow Geelblombos, Phymaspermum acerosum, that grows in the valleys (note: I have told everybody that I couldn't find an English name for this plant. I now have. It's called "Grassveld Sheepsdaisy"). The second is the Wilms' Paperflower, Helichrysum wilmsii, which grows up in the grasslands. In the picture above you can see Mark and Theresa Cotterell and their pooch, Charlie the poodle, from Rainbow Rivers (unit 17) hiking into a field of these paperflowers on the Amphitheater hike above Hidden Valley.
Although these paperflowers are very beautiful with the outer side of the petals (actually bracts) a deep maroon and the inner sides white, with these petals surrounding a bright yellow center, and all the flowers facing the same way as they follow the sun (like sunflowers), having fields of them dominating the grasslands is a sign of environmental stress. These are the woody plants that I was going on about in my last blog that, if they dominate, indicate that that area has not burned frequently enough which is, in turn, allowing woody plants like these to overtake the grasses in a grassland. This will ultimately kill the grasses and the absorptive quality of the grasslands will be compromised (see last blog), affecting the healthy flow of our rivers.
The burning projects that we have undertaken in the last few years have reformed lots of our grasslands but there are still some areas that are affected, as seen above. No worries though, I'm on it: I'm hoping, if we have nice spring rains next season like we had this season, to burn this area in spring with a hot fire so that it is nice and green by Christmas time, sans the everlastings. Well, the everlastings will still be there but, with a proper fire regime, will never dominate and choke the grasses out.
These fields of Wilms' Paperflowers are vast magnets for generalist pollinators like bees, beetles and butterflies who are attracted to the nectar and pollen produced. Here we see a Painted Lady butterfly, Vanessa cardui, sucking up nectar from one of these flowers.
The Painted Lady butterfly is the most widespread butterfly in the world and occurs everywhere except Antarctica and South America. They also take part in massive migrations in Asia and North America. In the largest of these migrations, it takes six generations of the butterfly to migrate, in generational steps, using the sun for direction, from Tropical Africa right up to the Arctic, a fourteen thousand five hundred kilometer round trip. That's, like, almost two thousand five hundred kilometers per butterfly per generation!
Most butterfly species have a very limited amount of plant species that they use as host plants for their caterpillars to feed on and the gravid female butterfly finds these plants by recognising the unique volatile chemicals released by those particular plants and then lays her eggs on them. This ensures that the caterpillars are on the correct food plants when they hatch. This system ensures that there is less competition between species for food and therefore increases the survival rate of the offspring. The migratory habits of the Painted Lady make this strategy impossible to follow because very few plants are widespread enough to be available to the butterflies over the massive areas that they roam. There are more than three hundred species of plant that the caterpillars of the Painted Lady have been observed feeding on. The gravid female Painted Lady butterfly does not select particular plant species to lay her eggs on, she chooses the plants that have open flowers and nectar for the adults to feed on as the host plants, no matter which species they are.
This strategy negatively affects the survival rate of the caterpillars but these butterflies do not have a mating season and so breed throughout the year, laying batches of eggs over and over, ensuring that, at least, there is enough offspring to counter the massive mortality experienced by their caterpillars.
While walking the Spekboom river footpaths recently, I noticed that the base of many tree trunks in the thick riparian bush on the north side, had two or three of these hollow exuviae, sloughed skins left by Cicada bugs once they emerged from their final nymph stage into their winged, adult stage.
Cicadas are best known to us by the loud, high-pitched, incessant buzzing sound that the males produce to attract the attention of a potential mate. The females hear this with with their tympanal organs which pick-up and analyse sounds, particularly the mating buzz of the males. The males also have these hearing organs but must disconnect them when calling because the sound he produces can reach, in some species, one hundred and twenty decibels (a gunshot is around 130db) and that would damage his own hearing.
If you manage to catch one of these bugs and turn it on its back, it is easy to distinguish between male and females: The female will have a sharp, scythe-like appendage (ovipositor) at the tip of her abdomen while the male will not. Instead, he will have two semi circular plates at the rear underside of his abdomen which cover his sound-producing organs. Both sexes' "ears" are situated here in the abdomen too. The sound-producing organ of the male are, in effect, two separate membranes supported by powerful muscles that vibrate and "pop" the membranes up and down, very much the same as you pressing the bottom of a tin in and out. Most of the remainder of the male's abdomen is hollow which helps amplify the sound. The hollow cavity in the males' abdomen also has folded membranes on each side that can be unfolded and re-folded to adjust the volume of the sound produced and when the bug calls it constantly adjusts the volume and this helps to create a ventriloquist type of scenario where it is difficult for predators (and curious human beings) to pin-point the insect.
Once the female responds to the mating call and mating is complete, she will cut a slit into the bark of a branch or twig and lay an egg within, repeating this process until she has laid all her eggs. After about six weeks, the nymphs hatch from the egg and drop onto the floor and immediately burrow into the ground with their powerful, folding forelimbs. They dig down until they encounter the roots of a plant and then create a little chamber in which they will reside while they puncture the root and the xylem within with their rigid proboscis and suck the juices out. The xylem is the vascular pathway that transports water and minerals from the roots to the rest of the plant.
These Cicada nymphs will reside underground, burrowing from root to root, until they are fully developed. Most species are referred to as "annual cicadas" and their nymphs will spend from two to nine years feeding like this underground before they are fully developed and ready to transform into an adult. But at least two species in North America (and more than likely in Africa too) are referred to as "periodic cicadas" and they synchronise their breeding and egg-laying activities so that the nymphs emerge thirteen and seventeen years later respectively en masse! This strategy is employed to increase the survival rate of the insect by flooding the "market" with youngsters so that, even with a high predation rate, the survival rate will be adequate for the species' survival. Also, it reduces the chances of a specialised predator from evolving because the long time frame between the emergence of the generations is longer than most insect will live, forcing them to find other prey species.
Periodic cicadas or not, when the nymph emerges from underground, it climbs up the base of a tree trunk and secures itself there with it's powerful forelegs and rests. After a while, the skin on the back of the nymph splits open and the adult slowly emerges, wings and all. Adults retain productive mouthparts and, instead of feeding underground from the roots of a plant, they puncture the stem of the plant above ground, and suck the juices from there. The big rounded "nose", easily visible on the nymph and the adult, houses the pumping muscles that suck the fluids from the host plant. If one manages to find a bunch of these insects together on a branch of a tree, one can safely deduce that it comprises a mixed sex grouping at a feeding site.
How cool is this relatively small Golden Baboon spider, Harpactira tigrina? It certainly is a large spider but they grow a lot bigger than this, big enough to fill my hand almost completely. And, as you can see, although they appear menacing, they are actually rather placid and tame quite easily, making them popular pets the world over. Unfortunately, this results in people collecting them from the wild which put natural populations under stress. Even making them locally extinct!
Although Baboon spiders prefer subtropical and tropical climates, they are still quite common in our grasslands but are seldom encountered because they are active almost strictly at night-time only. The days are spent resting within the safe confines of a neatly constructed burrow that extends about thirty centimeters vertically underground with a sharp corner at the bottom that opens up into a small chamber. The whole affair is thickly lined with silk and, often, once the spider is in attendance, the circular burrow entrance is closed over with a silken barrier (See my blog dated November and December 2020 where you can see a huge female spider, with spiderlings, right at the entrance to her burrow).
I encountered this chap in the open grasslands, in the daytime, far from any burrow. This leads me to deduce that it must be a sexually mature, wandering male, in search of the scent trail a mature, unmated female left behind her while out hunting in the nights before (see same blog for an explanation of his actions after he finds a scent trail). The lifespan of the male is very much shorter than that of the female (who lives to 25+ years!) because he spends so much time outside the safety of his burrow and is thus exposed to more predators.
The burrow is dug and modified over a period of many years as the spider grows and sheds skin. Once an adult and fully grown, the spider loses the ability to dig efficiently and so no longer modifies the burrow, mainly because she has reached full size. And so, if the burrow is exposed and damaged, the spider will be forced to abandon its home which puts it under significant risk because it is unable to construct a new home. In this case, it will usually build a roof of silk in a concealed spot and spend its resting time beneath this hammock-like web where it is exposed to more predation and fires and weather dangers than it otherwise would be.
I just had to add this photo to this publication! I arrived at K24 while it was still very early and the sun had not yet risen. Unbeknownst to me, I parked on the stem of a Wild Stockrose, Hibiscus canabinus, and off I went to complete my chores. When I returned to my bike a few hours later I noticed how the strangled flower still stubbornly opened up to fulfill it's function of attracting pollinators. I gingerly removed the front tyre from the neck of the plant and it immediately stood up proudly! See, even plants can be stubborn :)
This nasty looking critter is, well, just that: Nasty! This terrifying beetle is a Ground beetle from the Carabidae family of beetles. The main feature that separates beetles from other insects is the fact that the first pair of wings have hardened and serve as armour over the abdomen. The second pair of wings are folded up beneath these hardened wings and, when the beetle wants to fly, the hardened wings open up on hinges on the top of the abdomen, nearest the thorax, and the wings unfold and the beetle flies away with the rigid front pair of wings awkwardly folded open like this. Many species of beetles' first pair of wings, like this Ground beetle, have fused together and they have lost the second pair, rendering them flightless but extremely well armoured.
Ground beetles have a pair of glands at the tip of the abdomen that store and then, when its life is in danger, mix and expel noxious gasses like formic acid which, in some species, has an audible "pop" as it explodes. Other species, like one I know from the Lowveld, squirt the formic acid, with precision, towards the attacker's face and eyes. The common Afrikaans name for this species is "Oogpister" for that reason. In fact, the newly hatched babies of the Bushveld Lizard look nothing like the cryptic coloured adult lizard. Instead they are black with two yellow spots on the side of their bodies and when they are molested, the lizard arches its back and walks slowly just like the Ground beetle it is mimicking and, hopefully, scares the attacker off. This is one of the very few examples of vertebrates mimicking an arthropod!
Either this individual belongs to the few species that do not have this ability or this beetle was not upset or afraid enough to use this defense (the formic acid is expensive for the beetle to produce so it will only use it in extreme circumstances) because it remained quite relaxed in my clutches. The jaws, though, are something that needs to be avoided because they are quite capable of administering a painful bite. These jaws are used to grab and subdue their prey items as they run across the ground in search of anything they can overcome. A seriously well-armoured insect with massive jaws and a chemical defense system is not to be trifled with!
These are the leaves and fruit of a Narrow-leaved Sand-olive, Dodonaea viscosa ssp. angustifolia, very widespread with a tolerance of a wide variety of habitats from semi-arid deserts to forest fringes in high rainfall areas. They occur in tropical, sub-tropical and even temperate climes from South America, through Southern Asia and into Australia, New Zealand and the Pacific islands. Possibly the tree with the most common names because each country has its own name for it. Probably best known as a Hopbush, one of the Australian names that has been adopted by nurseries around the world. Hopbush comes from the fact that it was used instead of hops in the brewing of beer in Australia. The tree is resistant to salinity which has made it the preferred tree to plant to stabilise dunes. It is elasticky (not really a word) which affords it resistance to high winds and it is thus used for windbreaks. It also has a tough, durable wood and has been the wood of choice for weapons, walking sticks and implements in all the countries it occupies.
Although the tree is more like a large, shapeless bush, the shiny leaves, pretty little clusters of flowers and attractive fruit (the fruit in the picture is newly formed and will turn a shade of pink as it develops) make it a good garden subject. An easy place to find them on the estate is on the steep bank that leads down to the carport of Kingfisher Lodge (unit 6).
In my blog of November 2019 I featured a little blurb on Bark spiders, Caerostris sp. There I mentioned how they spin a massive orb web in the evening and then dismantle it by eating it around dawn the next morning and then lay up against the bark of a tree during the day, almost invisible thanks to their camouflage. I also mentioned how my daughter and I witnessed a Bark spider eat its web in less than two minutes (it's a huge web!). In fact, it was dazzling because, I'm sure if I scrunched the web up in my hand and rolled the silk into a ball, the ball would be bigger than the spider, not just its stomach! If the spider did not do this, the web would simply be too expensive to build because it would have to build a new one everyday. This is because it would most certainly get damaged during the day because the web is usually spanned across a large open area and would be in many an animal's way during the day.
Anyway, what is exceptional about this spider is that, although it is the same species as the spider I previously featured, this individual has a snow-white patch on the forepart of it's abdomen which would negate the effectiveness of it's camouflage in the habitat that the other one occurred but here, where I found this one, there was a ton of white lichens attached to the stems and trunks of the trees, making this spider's camouflage even more effective! Just goes to show how local conditions can affect the morphology of a species.
In my blog of December 2019 I featured a photograph of a male Drakensberg Crag lizard with his mix of cryptic colouration and bright orange. They are endemic to these parts of the Drakensberg where there is an abundance of Firedot lichens (see blog of May 2019) attached to the rocks and boulders. The Firedot lichens are bright orange making the bright orange on the lizard an efficient camouflage! This spider goes one further: a single population of spiders of a specific species is marked differently to the rest of the species because of it's immediate surroundings. Now that's adaption!
This is a picture of a completely defoliated Common Sugarbush, Protea caffra, taken on the crest of a hill high above Pebble Creek (unit 25) and Kliprots Creek (unit 24). Since the beginning of the rainy season I have noticed that at least half of the Common Sugarbushes on the estate have been under severe stress. The leaves have been discoloured and the flowers were dying while they were still mere buds. I checked the entire property and noticed that the problem was occurring throughout the estate and was affecting from a third to a half of the population. But only the Common Sugarbush was affected, not the Silver Sugarbush which is just as widespread and lives together with the Common Sugarbush in our grasslands. I took photos of the infected leaves and flower buds and sent them off to some of my botanist friends at the Mpumalanga Plant Specialist Group and, fortunately, they responded that it looked merely like a fungal infection, possibly caused by the long, wet rainy season we have endured, and that I shouldn't worry but need to keep observing the situation.
Now recently, all of those dead leaves have dropped off and brand new, bright red leaves are emerging (in Autumn!) on all the affected trees. This is good news because it means that the trees are still fine and it was just a single generation of leaves and flowers that may have been affected. We'll see next growing season if the sickness has gone or not.
As you can see by the date stamp, this photo was taken, by one of our camera traps, during the month of May six years ago. The reason I am publishing it is because just the other day I was a spectator to a severe battle between two male Natal Spurfowl, Pternistis natalensis, in my garden that persisted for some time and I did not manage to get a decent photograph because they were so very mobile! Afterwards I walked around the garden and found tufts of feathers all over the place!
I went through my francolin photos and found this one which I think it is appropriate because the photo was taken extremely close to where my house is now. In fact, I think the house may be on top of the place that this photo was taken. If you look carefully at the photo, you will notice a large spur at the back of the bird's leg, just before it is covered by feathers. That feature distinguishes the bird as a male because the female does not have this spur as it is used exclusively as a weapon and the males are the ones that get into fights. This will mean that there is a good chance that the francolin, sorry, spurfowl, in the picture is the great great (many times removed) grandfather of one of the two spurfowls that were fighting so enthusiastically around my house. How cool is that?
Natal Spurfowl are monogamous and sedentary, meaning that the two males were more than likely fighting because of a territorial dispute. They groupings of Spurfowls and Francolins are called "coveys" and a covey of Natal Spurfowl consists of the mating pair and their offspring who remain strictly within this territory, with the youngsters dispersing when they are sufficiently confident to do so.. The female lays up to eight eggs in a shallow scrape on the floor, in thick bush, lined with only a few feathers and the eggs hatch within three weeks. The chicks are born altricial, which means their eyes are opened immediately and they can run around with their mothers as they hatch from the egg. They are so well developed at hatching that they can fly within ten days!
For the younger folks: We used to call all of these partridge-like birds Francolins but, even though they appear similar, they are now classified into different clades after genetic research. Generally, the Spurfowls tend to be bigger, live in denser environments and have harsh, crowing calls which they often emit from an exposed position (like a rooster from a perch). While the Francolins tend to be smaller, live in open environments and have whistling, melodic calls that are made from the ground. So in Finsbury then, we have Natal and Red-necked Spurfowls in the thickets mainly in the river valleys, and Red-winged and Grey-winged Francolins in the open grasslands
Meat product manufacturers use meat preservatives to prolong the onset of oxidation, enzyme reactions and microbial spoilage, and thus extend the shelf-life of their products. I'm sure we all remember the Listeriosis breakout a few years ago that killed many people who ate the infected meat products.
Synthetic preservatives have been, and still are, used in meat production but there have recently been concerns over the potential carcinogenic threats these preservatives pose to the consumer. Also, it has been found that the microbe Listeria monocytogenes, amongst others, are resistant to these synthetic preservatives (hence the Listeriosis outbreak a few years ago). Even more worrying, adding these synthetic preservatives to meat products has resulted in the emergence of resistant strains of microbe that are difficult for the industry to manage, creating a need for natural, organic preservatives.
This tiny, delicate little flower is that of a Fever Woodsage bush, Teucrium trifidum, found here on the estate and widespread over Southern Africa. It is used widely in traditional medicine for its anti-microbial activities and, because there has been a recent demand for natural preservatives, scientists at the Govan Mbeki Research and development centre at the university of Fort Hare have tested it, in 2020, to determine its potential as a source for natural meat preservatives.
This was their conclusion: " The aqueous acetone, ethanol and methanol T. trifidum extracts contained condensed tannins, flavonids and phenolic compounds which showed significant free radical mopping capabilities. In addition, the extracts demonstrated anti-bacterial activity against gram-negative and gram-positive bacteria. The T. trifidum extracts can potentially be used as a natural source of antioxidant with antimicrobial components and can therefore be used as preservatives..."
Funny how we moved from natural to synthetic and now we are moving from synthetic back to natural. When will we learn?
Well, that's it folks! Autumn has now come and gone as we now enter w-w-winter, the big chill. See you next time!
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