October 2019

OCTOBER 2019

October, the month when rains traditionally arrive, has been hot and dry. All the plants are rearing to grow but the clouds remain light and rain still seems far away with the water levels dropping to all time lows. The above picture shows the thirsty grasslands surrounding Mount Anderson as seen from the south west, from Emoyeni above Bulldozer Creek. It may have been dry, but I got to see a whole bunch of interesting goodies while working this month:

Poised to spring away or defend itself with the sharp spines attached to extremely powerful hind legs, a Garden Locust, Acanthracis ruficornis, watches me as I approach it. Although it is called a locust, that word that rightfully conjures up images of massive swarms, only about a dozen of the 10 000 odd species of locusts or grasshoppers in the family Acriddidae actually swarm like that. There are two species, one a sub-species of the swarms of biblical times, and another, the Brown Locust that looks very much like the one above, that swarm in South Africa but only do so after a few seasons of continuous high rainfall. There's even a Red Locust response team with a dedicated helicopter based in Pretoria. We should rather be putting all these resources into harvesting the locusts when they swarm because the locusts themselves are a better source of protein than the crops they destroy! anyway, I digress, this is a solitary species and, after mating, the female drills a hole into the ground with the tip of her abdomen, lays a batch of 30 - 50 eggs and then covers them with a foamy liquid that hardens and protects them. She covers the egg sack up and, if it is late in summer, the eggs will over-winter and only hatch when it warms up and the rains arrive the following season. Otherwise they will hatch in about a fortnight and tiny little hoppers will emerge and begin to devour the grasses around them. These will continue to grow and molt until the sixth and final instar when it's wings are fully grown and functional.

Is it a bee? Nope. It is  a fly that mimics a bee, which offers a certain amount of protection. The quickest way to tell them apart is the very obvious single pair of wings in the flies as apposed to a double pair of wings in all other flying insects. These Hover Flies from the Syrphidae family are not attracted to the flowers for the nectar, instead they are there to mop up the pollen grains and, although they eat the pollen, some grains still adhere to them and they still pollinate other individual flowers as they get to them. Like Ladybird beetles, these flies also lay their eggs on plants that are infested by aphids, and the slow-moving, slug-like larvae hatch and eat these plant pests by the hundreds, so, over-all, the Syrphid fly is a gardener's friend. This individual has chosen the little yellow flower of a Three-leaved Clover, Oxalis corniculata, as its meal.

This Common River Frog, Amietia quecketti, was resting on a half submerged rock in a small plunge pool in the high altitude grasslands near Goudkoppies and s/he let me get really close. I type "s/he" because it is not possible to tell the sex by simply looking at a frog. Once a frog has been caught and is in-hand, the best way to tell the sexes apart is to look at the underside of their chin and, if there is a gular sack visible, then it is a male. A gular sack is the loose skin that expands into a massive bubble/bubbles when the frog is croaking. So then, the males are the ones that croak, and the females are the ones that are attracted by the croaking. The croaks are usually rhythmic and repetitive except for with a very limited amount of species. The only two species that I have noticed that don't have a rhythmic, repetitive croak are the Foam Nest Frog from the Lowveld and this one, the Common River frog. Their calls are soft and contain many elements like croaks, chirrs and squeaks all jumbled together. Although male frogs are the ones that do the croaking, both sexes are able to emit distress calls and a release call. The distress call is a scream that is emitted when the frog is being attacked by a predator. The release call is a soft squeak that is emitted by an individual when a male frog attaches himself to the wrong sex or species in moments of amorous mayhem in crowded areas. Both the above calls are emitted by all frog species but they have to open their mouths do do it, unlike when males croak. After a bit of digging, I found that the Common River Frog has 7 distinct call note types that range from advertisement calls aimed at females, to calls resembling a roll call aimed at established neighbouring males (used to weed out imposters), to calls aimed at both sexes giving particulars about ones size and fitness, and then a few recognition calls. So when you listen to the sweet cadence of the River Frog, know that they are having quite an in-depth conversation.
  

The leaves and drying flowers of a Forest Silver Oak, Brachylaena transvaalensis, a large forest tree that has somehow gone unnoticed by me for many years until the copious flowers caught my attention this month. What a grand tree! With a beautiful, thick and shapely trunk and hard, slightly wavy leaves, glossy green above and white and felty below. The flowers are produced in large axillary and terminal panicles and are made up of ray florets typical of the Daisy family. The strong, fine-grained wood was extensively used for implement handles and fence poles and aqueous extracts have been found to have anti-bacterial properties. Large forest trees are difficult to learn because everything but the trunk is out of reach. I was lucky to find this one beside a steep slope so I could reach the leaves and flowers to identify it. 

A very busy butterfly that is extremely difficult to approach, a Pirate, Caterocroptera cloanthe, is on the wing during October and can often be seen fluttering to and fro over the paths near the weirs, sometimes aggressively approaching people too. They fly fast and low and males spend most their time defending their small territories, otherwise you can find them sucking the sap from a wounded tree, or the juices from a rotten carcass or, better yet, courting a female. The bright flash you saw could well be this.

Isn't that just stunning, the flower tubes of the Ifafa Lily, Cyrtanthus stenanthus, on the vast, dry high altitude plains of Goudkoppies. This small, but common Amaryllis is easily overlooked in the grasslands because of it's size. The scientific name means "curved flower, narrow flower".

This drab, elongated moth is also easily overlooked, even if you're looking for it. This is because of its habit of holding its camouflaged, elongated body parallel with the  grass stalks and folding its antennae backwards. They are looked for, you know. In some European countries, like Germany, the are used, together with certain butterfly species, to test the potential toxicity of newly developed GMO crops. Here, being in the grasslands, they are one of the most abundant of our moth species and occur in a bunch of colour variations (all earthy) but all have the same body and wing shape. They lay their eggs on the base of a grass plant and the larvae, after hatching, burrow into the ground and feed on roots.

Although I have seen the notorious Rinkhals, Hemachatus haemachatus, twice in the time I have been here, both sightings were so brief that I could not even get a photograph before they disappeared. The Mackenzies from Pebble Creek have shown me a great video of an encounter they had and photos of a more recent encounter too, but alas, I still do not have a photo for my files. But the other day, up on the Goudkoppies plains, I came across this perfectly preserved sloughed snake skin that I immediately identified as belonging to a large male Rhinkals. Immediately as their skins are certainly the easiest to identify because the scales on the underside and of the head are smooth (like any shiny snake) and the dorsal scales are keeled (like adders that are not shiny), check the insert. Other snakes are mostly either one or the other. I could tell it belonged to a large male because the skin measured 120 plus centimeters long, which is maximum size for a rhinkals, and the tail was over 20 centimeters long, so I would not be able to fit 6 tail lengths into the snakes full length. Females have shorter tails so I would have been able to fit more that 6 of them to the full body length (general rule for sexing snakes). Although the rhinkals resembles the cobra, it is even further from a cobra than a Black Mamba is. The most notable difference between a rhinkals and a cobra are the keeled scales, as mentioned above; the fact that rhinkals' have no solid teeth whereas cobras do; and the fact that a cobra is viviparous, meaning it lays eggs, while a rhinkals is ovoviviparous, meaning that the eggs hatch just prior to birthing, within the mother's body, so that live young are born. Well, that was almost as good, for me, as seeing a living specimen but still, one day... 

I was attracted to this Hypoxis rigidula by the light lemon yellow colour of its petals, as apposed to the dark, richer yellow normally present in these beautiful flowers. While checking it out a common fly, Musca sp., settled on the petals and started mopping up the pollen grains from on and around the filaments, just like I noticed with the Hover Fly above. Makes an interesting photo, though.  

A handsome big male Grey Rhebuck, Pelea capreolus, triggered the camera trap on Loop road just before I went to collect the card and replace the batteries on the last day of the month. These common buck are endemic to South Africa and only occur in regions with large mountains.They live in a harem system where a dominant male establishes a territory, that he maintains by means of scent markings and vocalisations, in which he allows only his ewes and their offspring. He alone mates with his ewes from February to April and they give birth to a single lamb after a gestation of 8,5 months around the end of the year. They co-exist with the similar sized Mountain Reedbuck on the Estate but do not compete because they are browsers (eat woody plants) while the reedbuck are grazers (eat grass). Bizarrely, though, they have been known to kill reedbuck with those sharp horns of theirs, on occasion. 

This is a picture taken at the same place at the end of August of a handsome big male Mountain Reedbuck, Redunca fulvorufula, easily confused with the previous species, mainly because they are similar size, shape and colour and the fact that they congregate in similar herd compositions. The males are easy to distinguish because the reedbuck (above) have curved horns while the rhebuck (previous species) have sharp, straight horns. The females are more difficult to distinguish apart because they do not have horns. The easiest way to tell them apart is when they run away, which is inevitable once they know they have been spotted: The Grey Rhebuck (previous species) always holds out a bright, white pom-pom tail when it is running, whereas the Mountain Reedbuck (above) only unfurls its broad, flat white tail momentarily, as it begins to run away, then quickly folding it back again as it runs off. The Mountain Reedbuck does not have a particular breeding season like the rhebuck, and the reedbuck is a grazer of grass, with a specialised digestive system so that it can handle even the lowest grade grasses in the dry season. Both species are common on the Estate but one normally has to hike up into the grasslands to find them.

The housekeeper at Coch-Y-bunddhu (unit 1), Maggie Mashabane called me on the radio in distress because there was a large green snake in the laundry room. I responded and this is what I found behind the washing machine. It is a Western Natal Green Snake, Philothamnus natalensis occidentalis, and it was angry, with its throat puffed out in the photograph because I had just hauled it out of the laundry room. It did actually bite the index finger tip that was holding the camera and nearly made me drop the thing! Fortunately they are not venomous. The advantage about catching it is that I got photographs of all parts of its body that I thought I would need to identify it because there are 3 species of green snake on the estate that are difficult to tell apart. Well, as you can see from the long scientific name, I got this one right down to subspecies level because of the following:
This individual had keeled (remember from the rhinkals?) belly scales up to but not onto the tail like the natalensis subspecies, while the Green Water Snake has smooth belly scales. The keeled belly scales (inverted compared to rhinkals and adders) help it to find purchase while climbing, which they do more than the water snake; this individual had only a single temporal scale where the ear would be while the Eastern Natal Green Snake (natalensis subspecies), which also occurs here, has two. All species are associated with water and the main prey item is frogs and toads although anything of suitable size will be captured.

Some workers were clearing the thickets between the office and my house when they exposed a rabbit's nest. The nest contained two little rabbit kittens with their eyes still closed. There has always been some confusion as to which species occurs here, with some saying we had the Jameson's Red Rock Rabbit and others saying we had the Natal red rock Rabbit. Well, it seems like the taxon has been revised and what we get here is the Hewitt's Red Rock Hare, Pronolagus saundersiae. So the common name is named after Hewitt, the guy that described this as a subspecies of another species in 1961, and the specific name is named after the person, Saunders, who collected the skulls that Hewitt used, all very confusing! Anyway, when these little bunnies grow up they will become one of the solitary, night active grass grazers that we encounter on the roads in our headlamps. The story has a happy ending, I think, because the kittens had disappeared by the following day which means that Mom probably moved them to a new nest. 

These tiny yellow worker ants scramble to move the pupae of workers and soldiers to safety after I lifted the rock they were living under. I have been clearing rocks off the new hiking trail that I am cutting up on Goudkoppies and this disruption exposes many little creepy-crawlies, unfortunately for them. The ants in the picture only measure 2 mm in length and they are the workers of the Yellow Fire Ant, Solenopsis punctaticeps, in the Myrmecinae sub-family. They have powerful stingers and these, together with their multitudes in numbers helps them to subdue prey items much larger than themselves. In fact, the venom contained in their stingers is called  solenopsin and it is composed of alkaloids derived from  Piperidine which can cause an allergic reaction in some people, resulting in anaphalaxis, resulting, if untreated, in death! Beware the FIRE ANT! 

Another victim of my rock lifting activities was this recently sloughed Highveld Lesser Thick-tail Scorpion, Uroplectes triangulifer. This tiny little scorpion is the second species of Uroplectes I have found on the Estate. This individual's skin is still shiny and tender after it has climbed out of its previous skin that had become a bit too tight fitting for comfort. The pair of comb-like appendages (visible on the upside-down skin) are called pectines, and they are sensory organs that pick up minute vibrations in the substrate. When two scorpions come together they communicate via vibrations which are picked up by the others pectines etc. When a mating pair meet and they are satisfied with each other after communicating as above, then the male will clasp the female and begin to shuffle her around while he searches for a suitable place to deposit his spermataphore. Once this is completed, he drags her over it and she absorbs it. They release and go their separate ways and after a minimum of 3 months the female gives birth to 8 to 10 tiny scorplings that attach themselves to her back until they have molted for the first time.   

The daintiest marsh-dwelling plant around. A Utricularia arenaria that I found in the small marshes up close to Troutkloof waterfall. In February this year I posted about a strange little marsh dweller that I struggled so to get into my files. Well, this is another member of that fascinating family, Lentibulariaceae, whose members use modified, underground leaves to sift through marshy waters and extract bacterians and protozoans  as food, essentially making them carnivorous plants. The little flower, with the spur, only measures 5mm long.

As I write this there is a gathering of clouds and I hope it is a omen of what is to come. Rain, rain, please come and visit... You also need to come and visit. Enjoy the mountains and the fresh air.