FEBRUARY 2022
The shortest month of the year was very wet with thirteen days of rains and a whopping 165mm falling over the office. In the twelve years that the rainfall has been measured with data available on the Finsbury News website, it only rained more in February (288mm) in the 2016-17 season. Even last year February's Cyclone Eloise dropped less, albeit only 11mm, rain onto the estate. And after all of this, the rivers have generally remained nice and crystal clear. The rainfall was also very localised and erratic with that 165mm falling over the office and a mere 50mm rain falling over Rainbow Rivers (unit 17) in the south, 126mm falling over Pebble Creek in the north, 93mm falling over Rock Solid in the east and 68mm falling over Gate 2 in the west. This makes the average rainfall over the estate 100mm but the recorded measurements of the past 12 years have been what has fallen over the office. The above photograph of a lone Eland cow (in the centre in the distance) in the vast, open grasslands with Little Joker koppie in the background gives you an idea of how lush the grasslands are. Lots of rain means lots of life so below I have posted a bunch of interesting life that I encountered during the month.
This is a pair of Assasin bugs from the Reduviidae family of true bugs, Hemiptera, preparing to mate. They have chosen the venue well - the soft, pleasantly scented petals of a Gladiolus flower! The female underneath is showing us her rostrum, the thick proboscis that she folds under her chin, which she uses to pierce her prey which she has ambushed. She then injects enzyme-filled saliva into her victim which liquifies its internal organs. She then sucks this up through that rostrum. I have touched on these insects before with a species that exclusively preys on millipedes (The jolly season 2018) and an individual I snapped while it sucked a termite dry (December 2019). Once the female has been mated with, she will deposit a clutch of eggs on the underside of a leaf or on the flat face of a tree trunk. The eggs will hatch to reveal a whole gang of Assasin bug nymphs that will hunt as a pack initially before becoming solitary. The nymphs resemble the adults although they are usually coloured differently and they do not have a pair of wings. The nymphs of many species excrete a sticky substance all over their bodies and then throw sand over themselves as a camouflage. This enables them to avoid detection by their victims as they lie in wait to ambush them. They acquire their wings and adulthood after their fourth molt and once this has occurred, they no longer excrete the sticky substance and so no longer camouflage themselves. Finally, The tip of that powerful rostrum fits neatly into a groove on the underside of the insect's body when not in use. If the insect is threatened, it can apparently produce a relatively loud sound that may frighten the enemy away. It produces the sound by rubbing the rostrum up and down along ridges within this groove. This is called stridulation and is the same method employed by grasshoppers etcetera to make their sounds, although they rub their legs up and down on ridges on the sides of their bodies.
I can't help myself. I love these pugnacious little snakes, and so not too long goes by before I feature one of them on my blogs. In my blog of August 2020, I explained the function of the forked tongue, in May 2019 I did a feature on the unique venom of the snake and in my blog of November and December of 2020, I displayed photographs of four different colour forms of the snake that I have encountered on the estate. This chocolate one was so relaxed that she allowed me to approach within a few centimeters with my camera and she didn't even budge. I say she because this individual had a short tail, and that is the only way, without handling the snake, that one can identify the sex. When the female is ready to mate, usually in the early spring time, she will deposit a trail of pheromones on the floor behind her as she moves around. The pheromone scent persists for up to a week if the conditions are right, and if a male runs across this scent, he will immediately begin to follow the trail like a sniffer dog! If he encounters another male with the same intentions en route to the female, they will fight for dominance. Well, more like wrestle, and the victor will usually press the front of their bodies down on the head of the loser, subjugating it. The victor will then continue to track the female down. When he locates her, they will mate after a brief courtship and then immediately part ways. The female will store the sperm of the male beside her ovaries for up to seven years! Using a portion of it when required to ferilise the eggs in the ovary. The Berg adder is viviparous, which means that the young are developed within the womb of their mother instead of within an egg. And so the Berg adder female will give birth to eight to fifteen live young, quite large in fact, like about thirteen centimeters long per youngster, compared to the mother's length of between thirty and forty centimeters, towards the end of summer, and these youngsters immediately disperse and look after themselves. These little snakes feed on insects, like grasshoppers etcetera until they are large enough to pursue their usual prey of skinks and lizards from the rocky grasslands. The end of summer is on the way!
A Silver Vlei spider, Leucauge sp., Metidae family, stretched out in her "disappearing pose" on the inflorescence of an Amaranthus plant. These attractive spiders are certainly the most commonly encountered spiders in the dark, moist forests on the estate but are usually found hanging upside-down above the center of their orb-webs at thigh-height between ferns and trees. One cannot help destroying these webs as one navigates the forests because they are everywhere! When disturbed, then the spider retreats to nearby vegetation and adapts the stretch pose. 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. Again, 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 small dipterans, particularly mosquitos, which are abundant in the moist, dark forests. Once the mozzie is caught up in the web, the spider approaches the prey and 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 undigestable 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 the Silver 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.
Still in the moist, dark forests of the estate, you may stumble upon a bracket fungi like these pictured above that look a lot like Oyster mushrooms (P. ostreatus). They are Pleurotus pulmonarius from the same genus as Oysters and are just as tasty too. In fact, in warmer areas these are the mushrooms that are cultivated and sold as Oyster mushrooms in the shops. Like the genuine article, the mycelium are grown in a petri dish and then transferred to a grain of sorts. Once established, they are then deposited onto a bale of straw or something similar where the mushrooms will develop en masse, ready to be harvested. Besides the fact that these mushrooms are very tasty, they are also filled with healing properties which was recently established with experiments on mice: They are found to have major analgesic properties which is used for pain management; they also have anti-inflammatory properties and also delay carcinogenesis, meaning that they could be used to fight cancer; they also have an antihyperglycemic effect, halting the progression of diabetes; and finally, powdered mushroom in water inhibits the release of histamine which means it could be used to treat hay fever! Wow! That's a lot of medicinal uses even if only effective on mice for now. When I looked from underneath to see the gill pattern, I noticed it was crowded with tiny Rove beetles which, although they all look very similar, belong to the largest extant family of any organisms, the Staphylinidae with around sixty three thousand species! Rove beetles are mostly predatory but I have since learned that there are a few species that specialise in collecting and eating spores, the minute "seeds" of fungi. They're easy to distinguish from other beetles by their long, pointed abdomen and very short elytra (the hardened pair of wings that cover and protect the flying wings when at rest against the body). The second pair, or flying wings are quite large and must fold up rather elaborately to fit beneath the tiny elytra, apparently like watching a sports car fold its roof into a small area in the boot...
Now, when I looked closer, I also saw a tiny wasp clearly laying her egg/s (see by the bent posture) within some unfortunate victim who is not visible in the photo. I have discovered that the wasp is more than likely a, wait for it, koinobiont endoparasitic Alysiine braconid wasp. Jissis, that's a long name! It actually simply means that the wasp belongs to the Alysiinae subfamily in the Braconidae family and it is parasitic by injecting its egg into the body of its host and the egg hatches and the wasp larva eats the victim from inside, finally killing it! These wasps normally parasitise fly larvae (maggots) but I'm not sure what a fly larvae would be doing in the gills of a mushroom. I suspect the wasp is injecting its egg into the larvae of one of the rove beetles. Normally, the larvae of the wasp will eat the insides of its victim, careful not to harm it too much to avoid killing it too soon. Once the victim pupates, then the wasp larvae eats out the lethal organs and the victim dies, allowing the wasp larvae to pupate within the pupa of the victim and then, once developed, emerging as an adult! Quite a lot of action taking place in the gills of this mushroom.
This is a Stinkbug, Cletus ochraceus, sitting on the beautiful silver-haired seeds as they develop on the inflorescence of Natal Red-top grass, Melenis repens. A glimpse of the rostrum (rigid proboscis) reveals that it is also a true bug, like the Assasin bugs above but these are the vegetarian version. The rostrum is used to pierce the stems of plants instead of the bodies of insects, and the juices of the plant are sucked out. The common name is derived from the fact that they possess glands that emit a revolting smell as a defense when harassed or handled.
Streptocarpus hilburtianus growing from between the rocks on a cliff face. Streptos are special. They are commonly referred to as Nodding violets or Cape Primrose and we have seven species here on the estate, so far discovered. Although some grow in very exposed places, they grow on or associate closely with rocks and shade. If you've seen the photograph on the cover of the lovely book, Finsbury Estate, Through The Lens, for sale in the office, you'll see how they can add splendid colour to the dark, shady gorges. Check my blogs from 7 February 2015; February 2019 and January 2021 for interesting facts about these plants. This one, though, is special because it only occurs here, at Long Tom and on the Steenkampsberg, the only point higher than Mount Anderson in Mpumalanga, and it only occurs at high altitudes (above 2000masl). It is listed as vulnerable (VU) on the South African plant Red List.
I went the whole of last year without seeing a Transvaal Dwarf Chameleon, Bradypodion transvaalense, and so I was delighted to find this one in the gorge that runs from the most northern point of Loop road up to Black Hawk Down crash site in Mount Anderson Ranch. Chameleons are quite unique lizards and are well known because of these unique traits, like being able to move their eyes independently and look at two different places at once. This enables them to search more thoroughly for potential prey and enemies. When it locates a prey item, like an insect, the chameleon will focus both eyes onto it and thus enjoy stereoscopic vision which allows it to accurately judge distances so that, when it has crept close enough, it can shoot out its long, sticky tongue which can reach twice its own body length, and latch onto the prey item and pull it back into its mouth. Another unique trait we all know so well is their ability to change their body colour. This they do for three reasons: one, to effectively camouflage themselves so that their prey and enemies find it harder to see them; two, and probably the most important reason, is they use colour changes to communicate their intentions to other chameleons. Bright colours dominate other chameleons who respond with dull colours etcetera; and thirdly, to help regulate body temperature. They will turn lighter shades if they want to cool down and darker shades if they want to absorb more heat and warm up. This one was very well camouflaged because I nearly squashed it with my hand when I was about to grasp a tree trunk for support and, fortunately, I saw it at the last moment.
This is a close-up shot of a Wandering Donkey Acraea butterfly, Acraea neobule neobule, at rest on a Bracken fern frond. These butterflies are extremely laid back, and if you don't make very sudden moves, you can get right up to them. They also have a noticeably slow, floating flight as if they fear nothing in the world. They can feel like this because their bodies are covered in an extremely rubbery integument and also glands that release poisonous fluids. So if a young, inexperienced bird comes along and snaps the butterfly up in its beak, the butterfly secretes this poison and the bird immediately spits it out, and because of the rubbery integument, the butterfly continues on its merry way, unharmed. The bird, on the other hand, learns quickly that butterflies that look like that are not worth pursuing in the future!
I was walking the Zebra trail when I saw a spider run from the path in front of me, into a hole at the base of a grass clump and just disappear... I was, like, where did it go? Mmmnn, I bent down and investigated. I found that, after some unconservative digging, the arachnid had run into an apparent hole and swiftly closed a door over it. A trap door! I remember finding Trapdoor Wolf spiders in my time in the Lowveld and, once you knew what to look for, they were relatively easy to find. But this? There was no crease. Nothing. I have learned that this spider is actually an Ant spider from the Zodariidae family of spiders. They are daytime free-range hunting spiders that usually associate with ants, releasing pheromones so that the ants do not bother them. This one is from the Cydrela genus and is apparently one of the very few species that does not associate with ants and one of the only species to employ a trapdoor in their digs This is a free range spider that emerges from its burrow and actively hunts its prey, consumes it, and then retreats back into its burrow. Like a day-active Baboon spider but a lot smaller. And it is obviously a spider that is very rarely seen because it usually disappears into its invisible den in a flash when disturbed.
I was trying to climb from Olinia gorge onto the steep grasslands and, as I was pushing my way through the thick forest fringes, I startled a little Cape White Eye, Zosterops virens, from a nearby but well hidden nest. I looked down to see this little picture. A newly hatched chick just out of the egg squirming beside its still unhatched sibling. The little thing was not any bigger than my little pinky finger! According to the literature, which I have mentioned before in my blog of January 2021, their diminutive size results in only about fifty percent of hatchlings fledging because they fall prey to even smaller nest robbers like Common Fiscals, Fork-tailed Drongos, Southern Boubous and Olive Thrushes. And in that blog you will see that I could have captured that little fledgling as well, and if I was a hunter-gatherer, eaten it just like those common birds do. But many people, including me, have a soft spot for these lovely little birds because they can get very close to you while they are foraging through the bushes in the riparian areas of the estate.
Finally, a photo of a Fishmoth, a very primitive, wingless insect that have the ability to consume and break down pure cellulose, which is the usually indigestible material that makes up the cell walls of plants. We all know them because they can eat the pages in our books if we don't look after them and, amazingly, do not require drinking water despite the dry diet they live on. They absorb all their water requirements directly from the water vapour present in the air.. They are so primitive that they do not have wings. Many insects do not have wings anymore but they evolved from winged ancestors and have lost their wings while Fishmoths, together with Springtails and a few others were around before wings evolved on insects, almost four hundred million years ago. In fact, they are so primitive that they do not have a definite larval / nymphal stage in their lives. They just hatch from the egg, resembling an adult and just grow up molting into an adult. Their common name is derived from the fact that they have long, fish-like bodies which are covered in minute silver scales, arranged much like those of a fish. The scales are rounded with delicate little patterns on them. In fact, in the old days, the scales were used to test the quality of microscope lenses. If you could make out the ornamental patterns with the microscope then it was regarded as a good quality one.
That's it for February. I see that Easter is quite late this year, around the middle of April but March still has a public holiday so it will hopefully be busy here then. We look forward to seeing you all as we reach the end of the first quarter of the year.
