SEPTEMBER 2020

SEPTEMBER 2020

September showed a lot of promise when it comes to rainfall by hosting the first rains of the season on the first day of the month! Okay, it was only 6mm of rain but it was still wet. Unfortunately there was only a further 2mm for the remainder of the month but it was overcast for a lot of the time, providing us with some spectacular skies like the photo above that was taken from the helipad facing north east. Being spring month, there was a lot of wildlife activity as everything seemed to be waiting in anticipation for the life-giving rains to arrive proper. Below is a gallery of some of those things that I managed to capture on this little camera of mine:

I was enjoying an afternoon walk with Roger Nicholson and his guests from Kliprots Creek (unit 24) when someone found this Donkey-faced Weevil hiding out inside a Saint John's Wort flower. Very appropriate it's name is, since it really does have a dufus sort of donkey face. It even has chewing mouthparts at the end of that long nose just like an ass. The snouted weevils or true weevils belong to an enormous family of beetles called the Curculionidae and although the members of this family look rather similar, their diets and behaviours are extremely diverse. Generally though, their defense, once molested, is to simply fall over sideways with legs outstretched and to play dead. The elytra, which are the hard shields on the back that cover the wings of other beetles, are fused together in snouted weevils, leaving them unable to fly but to provide them with an almost indestructible exoskeleton. In fact, even when they are trodden on by large mammals they are usually just pressed into the ground and not crushed, leaving an indentation in the ground after they move on. This suits them because most of them are very specific about their food plants and they choose the same plants as larvae (fat white grubs) and as adults. This means that they don't need to move very far in their lives and so they can be, and are, rather sloth-like. I suspect the Donkey-faced Weevils, Bronchus sp., have a similar lifestyle to their close relatives from the Chrysolopus genus and so would share a similar life cycle where the female weevil bores a hole for each egg into the stem at the base of her chosen host plant. Once the eggs hatch, the larvae burrow down into the roots of the plant and feed there until they are ready to pupate. They pupate beneath the soil beside the host plant and emerge as adults who dig themselves out of the ground and proceed to climb the host tree closest to them, slowly. This lifestyle where all stages feed on the same plant make weevils a great pest to man in many parts of the world but also make suitable candidates as bio-control agents. Depends on which side of the fence you sit...

Now, this Jewel Beetle from the Bupestridae, a different family of beetles, has a remarkably similar life cycle to the Donkey Face above: the female lays eggs in the soil close to the roots of a plant and the grub-like larvae burrow into the roots; once developed the larvae pupate beneath the soil and later emerge as adults; the adults eat foliage, stems or flowers of plants as well but Jewel Beetles are not as particular as the Donkey Face. But where the Donkey Face is slow and cumbersome, the Jewel Beetle is a jack in the box! She's quick to take flight and loves being active during the hottest time of the day. If you look closely you will see that she is also adorned with bright, iridescent colouring, hence the name Jewel Beetle. In fact, this species, Lampetis amourotica, is pretty bland compared to most of the family, who have blasts of rainbow-coloured iridescence covering their elytra, not just parts of the underside like this one. The iridescent colours that reflect off these animals change as you change the direction at which you look at them, like the rainbow colours that change on a compact disk as you move it around in your hand. Now, most insects that are brightly coloured use this aposmetic colouration (bright, bold colouration) as a warning to potential predators that they are either poisonous to eat or dangerous to molest. Or they are mimics of such but this limits population numbers of the mimic to less than a quarter of the model population, otherwise predators will not take the warning seriously any longer. Bright iridescent colouring, however, appears to have the opposite effect: it provides camouflage! Researchers at the University of Bristol filled hundreds of iridescent empty cases (exoskeletons) of Jewel Beetles with mealworms and also hundreds of cases painted with solid colours. They pinned these to trees in a nature reserve and left them for a few days. When they collected these cases they found that the huge majority of surviving mealworms were in the iridescent cases. It seems that the iridescence is difficult for a moving predator to recognise or pin-point. The diversity of the insect world is certainly extreme, that's for sure!

This little camera of mine is unsuitable for bird photography but sometimes I manage to get so close to a bird that I can snap off a poor shot. Like this Black-shouldered Kite, Elanus caeruleus, that allowed me to approach within meters on my motorcycle just beyond the driveway to Elsmere (unit 11) on the Spekboom River. The scalloping on the grey feathers, the slight tawny wash and the lack of a red eye indicate that this is a juvenile and the lack of even a yellow eye suggest that it only left the nest a month or less ago. I'm sure it is this inexperience that allowed me to get so close. Since the first clutch of eggs laid by the female is usually around March and it takes three months to get the chicks to disperse and look after themselves, it appears that this must be offspring of the third clutch of a local breeding pair. With females breeding within their first year of life, this fecundity, and the species' tendency to nomadism, the species is well adapted to respond to sporadic rodent population explosions. Black-shouldered Kites are most commonly seen perched on telephone poles or hovering over grasslands in search of their main food items, small rodents. Still-hunting from a  perch allows the bird to save a lot of energy but only provides them with a 10-20% successful strike rate while hovering, although using double the amount of energy, allows them to exploit areas far from perches and provides them with a 20-35% success rate. Although almost always seen alone, Black-shouldered kites roost in gatherings of a dozen or so individuals in large trees or reedbeds during the night.

If you go back and check my blog of September 2019, you will see a photo I posted of a Mayfly nymph under the water and gave a blurb on how they take up to two years to mature and emerge from the water as adults and how those adults, like the one from the Callibaetes genus shown above, live for a few hours to a few days only. In fact, the name of the insect order, Ephemeroptera, means "winged for but a day." They have degenerative mouthparts so they cannot eat. Even their digestive tract is filled with air to provide buoyancy, not to process food. I also mentioned that this is the insect, as larvae and adult, that flyfishermen model their flies on. What I did not mention is that the Mayfly is the only type of insect that moults as an adult, albeit only once: So when the adult emerges from the water, it is actually only a subimago, or to the angling folk, a Dun. Once these "duns" have emerged from the water they fly to a perch and rest while they escape their final moulted skin and become true imagos, or "spinners" in fisherman terms. These stages of their lives are synchronised, so when the imagos fly above the water performing their mating dance, they do so together with multitudes of others and this is known as a "hatch" to anglers. When a female is ready to mate, she flies into this cloud of performing males and is immediately grabbed by a male and held while he mates with her for a few seconds in the air before he departs and abruptly dies. She then rests while her eggs develop before she drops them into the water and dies too.

These soft, wispy flowers are common in the low-lying dry grasses on the estate at this time of the year. They are called Yellow Tulp Moraea pallida, and they resemble the Iris's of the northern hemisphere and although they are in the same family, that's as close as they get. The biggest difference is that the Moraea have corms, and as such are bulbous plants which evolved to withstand fires in the great grassland savannas of the southern hemisphere, while the Iris's in the north have rhizomatic roots. The resemblance to the Iris's comes from the double sets of three petals underneath a set of three petals above them. The lower petals usually have bright colours on the inner tip to act as a nectar guide to potential pollinators although in this species, the nectar guide is only slightly darker yellow. The Yellow Tulp, together with the Blue Tulp, Moraea polystachya, are the plants most responsible for livestock poisoning in South Africa. Their habit of growing in amongst grasses with long leaves resembling those of grasses make it easy for young and inexperienced livestock to eat them together with the grass and the cardiac glycosides present in the plant can lead to posterior paresis in cattle within a twelve to twenty four hours of consumption and death soon afterwards. It has been found that the concentrations of these glycosides in the plant is very variable and these concentrations are highest in plants occurring in the Mpumalanga grasslands in the north east of the plants' distribution, and lowest in the Western Cape at its most southern distribution. Fortunately it has also been found that the toxicity of the glycosides can be neutralised successfully, in almost all cases, with the timeous introduction of activated charcoal treatment. Of course, we don't have to worry about this because indigenous grass-eaters, those that occur here on the estate, because they evolved together with the plant, have inherently learned of the plants' toxicity and therefore do not consume them. We can simply enjoy their beauty!  

I was climbing the gorge on our boundary with Mount Anderson Ranch, high up above Kliprots Creek recently and, in the darkest shadows of the forest, I found this large, scary looking spider half in and half out of the water. The eye pattern tells me that it is in the Pisauridae family which would be Nursery Web Spiders and their allies (see blog from March this year for a Nursery Web Spider) like Fishing Spiders. This spider was standing at the edge of a well vegetated pool with most of its body resting on top of the water. I am waiting for confirmation but I think it is from the Dolomedes genus. These spiders wait at the edge of the pool and feel for vibrations in the water. Very much like a web-bound spider feels its web for vibrations when a victim is ensnared in it. When a vibration is felt, from a tadpole or Mayfly larva just beneath the surface, or an insect is caught up in the water, the spider runs across the surface, relying on surface tension of the water to keep it dry, and hooks the victim with the claws at the end of its front legs like a fisherman would a fish. The spider then drags its prey to the waters edge and immobilises it with it's powerful venom before tucking in. The short, velvety hairs that cover the spiders body keep it dry and if a predator, like a bird, snake or Pompilid wasp (see blog of March 2020) approaches, the spider dives beneath the water surface and escapes while these hairs trap a layer of air around the spider's body, enabling it to continue breathing. This buoyant layer of air forces the spider to cling to the bottom of the pond until the danger has passed or else it will pop up to the surface like a cork. When it does surface it is completely dry! 

Aaaargh! I was so excited when I found this that I did scream! Have you ever seen such delicate flowers before? This is a Mystacidium gracile, an epiphytic (air plant) orchid that I have been hunting for, in the forests, in September and October, every year for quite a few years now - and voila - here it is! It is not actually that rare but it is a tiny bundle of roots, with one or no leaves, attached loosely to branches and is very difficult to spot. The specific name, gracile, means "attractively slender or thin" which it certainly is. The extremely long spurs that hang off the back of the flowers have the nectar at the bottom end of them and this design only allows Hawk Moths with long enough proboscis's to access them and, in doing so, collect pollen on its face and hopefully move on to another plant to enable pollination. Made my month, it did.

This is a frenzy of Copper-tailed Blowflies, Chrysomya chloropyga, feeding on, and laying eggs in the carcass of a bushbuck found up on the Kliprots river. Even though they are actually rather beautiful, they are inherently regarded with revulsion by us because they are serious spreaders of disease in human communities. Because this African fly is synanthropic (meaning it associates with humans), it, together with some close relatives, has invaded the rest of the tropical and subtropical world thanks to globalisation, spreading pathogens that cause diarrhea and bacterias like E.coli, Salmonella and Shigella in developing countries. The female stores sperm donated by males which enables her to rush off to the nearest carcass or open latrine and immediately lay eggs without having to find a mate first. Together with her multitude of friends, she lays between 50 and 200 eggs (per fly!) on a carcass and before you know it, the carcass is a writhing mass of maggots! If the carcass is too small for the masses of maggots, they will turn on each other and an orgy of cannibalism will ensue! In fact, even if a maggot is injured and leaks haemolymph (insect blood), his brethren will eat him! But there are some positive sides to this ghastly story: the maggots are used in wound therapy where they are introduced into a necrotic wound where they consume all the rotting flesh and leave the healthy flesh untouched; and they are useful in forensic entomology where a pathologist can determine the post-mortem interval and determine the time of death of a murder victim.

Right at the very beginning of spring-time one gets to see beautiful pink blossoms scattered around the Spekboom valley and at places on the Kliprots. These are exotic Peach trees (Prunus persica), remnants of the times when Finsbury House (unit 23) was a farm dwelling with a peach orchard between it and K9. There's also an ancient, gnarled Pear tree (Pyrus sp) beside the Picnic spot in the Spekboom valley and it looks very similar to the blooming tree above. But we have our own, indigenous blossom tree that explodes into bloom at the beginning of spring-time and it is the Wild Pear, Dombeya rotundifolia, pictured above. Even though the Wild Pear resembles the exotic Pear, they come from different families: the Pear and the Peach both belong in the Rose family and our Wild Pear belongs in the Hibiscus family. They can be found throughout the estate on rocky slopes but are most noticeable on the slopes above the mountain hatchery (near Morrin Pools) and above SPK1 up towards Spioenkop. Now, this a magical tree for the garden because it is very fast growing; it has a beautiful, kindergarten tree shape; it attracts butterflies; it is frost resistant, drought resistant and it makes a spectacular display in the early spring with its showy flowers that bloom before the leaves come out! And that's not all... It makes an excellent bonsai specimen with corky bark forming and leaves reducing within two to three years of care. It is also beneficial in wilder zones being drought resistant, fire resistant (leading to the Afrikaans name Dikbas) and good browsing for mammals. Wow! What a tree. Why do we even have exotics in our gardens when we have indigenous beauties like this? 

Deep in one of the gorges feeding the Klipdrif stream in Hidden valley, resides this large, bulbous bracket fungi call Chicken-of-the-woods, Laetiporus sp., upon the dead trunk of a huge, but dead, forest tree. The common name is derived from the fact that it is edible and tastes a bit like chicken but with a texture very much like chicken (when they are both cooked). This individual has hardened with age so it was unsuitable but, if the fungus body exudes a watery liquid then it should be harvested and cooked in a creamy garlic sauce. In fact, it can substituted for chicken in any chicken dish and leftovers can even be frozen. It is considered a delicacy in Germany and North America and is cultivated there. I only just discovered this so I will diarise it and make sure I return to harvest it next year as the fruiting bodies apparently appear, in the same place, year after year until the tree collapses. The fungus normally attacks dead hardwood trees but may sometimes be a mild parasite when it attacks the hardwood exposed by a wound on a living tree. The Chicken-of-the-woods is the Guinness world record holder as the heaviest mushroom at 45kg in 1990. 

Found me a Wahlenberg's Velvet Gekko, Homopholis wahlenbergii, hiding in a deep crevice between two flat slabs of rock up on Goudkoppies plains recently. Pretty high up for a gecko that is quite synanthropic (my new word!). Anyway, I never put enough effort into really understanding how geckos apparently attach themselves to even smooth surfaces, until quite recently, and it is actually quite mind-blowing. Fundamentally, they use the same technique as glues and epoxies do to adhere to surfaces but, I thought to myself, how do they become sticky when they want to stick to the surface, then suddenly unsticky when they want to lift their foot off the surface? Well, it helps to understand how things stick together: when two surfaces are pressed together, even smooth surfaces, a very small area of the surfaces are actually touching each other because, no matter how smooth they appear, they are rough at a microscopic level. So what glues do is fill the air spaces between the areas that are touching each other to the point that Van Der Waal's force takes effect. You would think "well, why doesn't stuff stick if you put water between them instead of glue?". Good question. The thing is: you get dry sticky; and you get wet sticky; and nothing in between. And dry will not stick to wet, for long, and wet will not stick to dry, for long. Anyway, Van Der Waal's force is (deep breath): when the surface area of the surface to be adhered to is covered enough (all those microscopic spaces of air are filled in) by the surface wanting to do the adhering, that the molecules' electrons, in such close contact with each other, begin to interact with each other, changing orbit, and becoming electromagnetically attracted to each other instead of repelling each other as usual. With geckos then (see insert in photo), apart from having retractile claws to hang from edges, the bottoms of their bulbous toes are ridged like the soles of boots and those ridges are covers in stiff, minute hairs called setae (about 14 000 per underfoot) and the tip of each seta splits into about a thousand nano-width bristles. So when it touches the substrate, these microscopic bristles reach into all the irregularities of the surface of the substrate and Van Der Waal's force takes effect and the foot grips tight. It has now been discovered that a gecko can change direction of these setae in milli-millisecinds so that forces are pushed into different directions so as to stop the Van Der Waal's force and then be able to unstick its foot from the surface enabling it to run, jump and change direction, even upside-down! Fa-sci-nating!   

These strange, closed flowers are called Lighted Matches Mistletoe, Tapinanthus rubromarginatus, and we found them appearing to be attached to the branches of a Common Sugarbush, Protea caffra. On closer inspection, one would notice that they are actually attached to their own branches that seamlessly attach themselves to the branches of the Sugarbush, the host tree. The strange flowers of this hemi-parasite (not full or holoparasite since it does have leaves that provide some sugars to itself through photosynthesis) are attractive to sunbirds who probe the flower with their long bill until the flower pops open and slaps the sunbird on the forehead with the pistil and anthers and so deposits pollen there. The bird then pollinates the flower it visits next when the same thing happens. This mistletoe only parasitises three species of Proteacea and they all occur here on the estate: Silver Sugarbush, Common Sugarbush and Willow Beechwood. The fruits of the mistletoe are small, sweet, red berries filled with seeds in a sticky jelly and birds love them. After the bird has eaten the berry, its beak will be soiled with this sticky jelly with seeds in it and the bird will wipe its beak off on a branch of another tree to clean it. The seeds adhere to the branch and when they germinate, their roots, called haustoria, graft themselves onto the branch and penetrate the vascular system of the host tree and begin to extract nutrients or water. And so the cycle continues....

That's it for September. What a lekker month it was. Now for October when we will hopefully have decent rainfall and jolly times. The flowers are starting to bloom and remember, if you are at the estate and you want to see them, let me know on the radio and I will gladly lead you on a hike in search of all these beautiful and amazing things. See you soon.