MAY 2020

MAY 2020

Gee, it's hard to believe that it is only a few weeks away from the shortest day of the year! May was a quiet month for most, I suppose, because everyone has been locked up in their houses, hiding from this virus. All the Finsbury labour staff returned at the beginning of the month and field work has been carrying on normally since then, except for the mask-wearing, social distancing, continuous hand washing and temperature taking. The grass has turned quickly, as it does, from green to white and frost has been a visitor most mornings in the latter part of the month, making the scenery a little more drab than during the growing months, although there is nothing drab about the floral displays of the Cliff Aloes like the one photographed above on a quartzite koppie high above Bulldozer Creek (unit 21). There is noticeably less life in the grasslands due to this but there has still been enough for me to photograph and enjoy. 

It has, though, been a great month for me regarding birds: I have enjoyed a sighting of Ground Woodpeckers on the tippy-top of Spioenkop, a confirmed identification of a pair of Plain-backed Pipits also up there; a displaying pair of Rock Kestrels above the high altitude grasslands between Morrin Pools (unit 14) and Bulldozer Creek (unit 21), and then a spectacular sighting of a pair of young (full adult plumage was not yet attained) Verreaux's Eagles involved in courtship displays. After watching the Verreaux's Eagles for a good ten minutes as they showed off for each other, the male (slightly smaller) departed and moments later, while I had her in my binocular's sights, the young female dove down towards the grasslands beside Little Joker Koppie and tried to capture a fully grown Mountain Reedbuck ewe. The explosive response from the Reedbuck was sufficient to avoid capture but was short-lived and the reedbuck just stood there, rooted to the spot, as if they didn't know where the danger was coming from! Fascinating. 

Following is a gallery of some of the interesting things that I have encountered during the month of May: 

These delicate flowers make up the inflorescence of a Plectranthus hadiensis plant that was growing in thickets on a cliff face high above Rainbow Rivers (unit 17). This unusually dry habitat for the genus ensures that this species has rather fleshy leaves to help it store water. But if you are a pollinating insect all you will see is the inviting mauve colour on the flower that is your landing strip - not the Crab Spider (Thomisidae) waiting for you to approach! The thick, powerful forelegs of the spider will envelope the prey and hold it tightly until the quick-acting venom subdues the victim. Spiders that do not use silk or a silk web to ensnare their prey require faster-acting venom than those with silk and webs. Then, look carefully at the back of the flower alongside the one with the spider and you will see minute orange dots: Those are Red Spider Mites (see blog of September 2019) feeding on the individual cells of the flower.

This little bird is a common sight around the office and surrounding lawns. It is a African Pied Wagtail, Motacilla aguimp, and one of three species of Wagtail to be found here on the estate. This is the larger of the three, and the more aggressive, and so dominates the slightly smaller Cape Wagtail with which it shares space. It will also dominate the lighter Mountain Wagtail if they are found together, although the Mountain Wagtail concerns itself more with the fast-flowing streams up in the forested gorges. Along with close relatives, the Pipits, Wagtails feed predominately from the ground by actively searching for insects and running after them with a cross-legged gait, unlike the hopping motion of most passerines. Pied Wagtails are monogamous and pairs establish a territory during the breeding and nesting time which the males aggressively defend (I have to fold the mirror on my motorcycle down when it is parked or the Wagtail fights so hard with his reflection, that he leaves blood and feathers smeared all over it if I don't!). They build a cup nest together usually in thick bush, often overhanging water or on a cliff ledge, in which the female lays up to five eggs. They share incubation and chick-rearing duties and will breed for most of the year. Chicks take two and a half weeks to fledge and then remain in their parents' territory for another two and a half weeks before being chased out so the pair can begin to raise the next brood, of which they can raise four per year successfully. They are the most common host to the Red-chested Cuckoo, or Piet-my-vrou, in this area.

If you sit amongst the rocks in the high altitude grasslands of the estate, sooner or later you will notice a solitary ant, about 12mm long, meandering slowly along the rocks. If you look closer and it is dark red to pitch black with rings of stiff, white hairs on its gaster, then it is a Granite Balbyter ant, Camponotus brevisetosus (That really is its common English name!). They reside in colonies excavated under rocks consisting of a few hundred individuals but forage alone, hunting small arthropod prey which they subdue with their jaws, or scavenging like this one inspecting a skink's droppings. They have very keen eyesight so stealth is required in order to closely approach them but if you do, and they cannot readily flee, they will immediately fold their gaster beneath their bodies so that the tip is beneath their chin, facing forward, and spray you with a fine mist of formic acid, a formidable defense. 

I remember the first time I took part in burning firebreaks on the estate, a number of years ago, Andries Maphanga, one of our long-standing field staff, introduced me to the fruits of a Tree Strawberry, Cephalanthus natalensis, which are not all that tasty but still refreshing while burning firebreaks. The handsome little tree with shiny, attractive pointy leaves, grows in rocky situations in our high altitude grasslands and boasts beautiful balls of flowers in the spring-time. The fruits are normal with internal seeds and only resemble strawberries with their aggregate accessory fruits with the seeds on the outside.

This bush of yellow daisies with its compact round shape would make a perfect rockery feature for the beginning of winter in any garden! If you drive east towards the sundowner spot in Hidden Valley right now, you will see that the distant gorge in the center of the amphitheater below the KLF road is yellow. The whole gorge. So I went to investigate and found it filled with these bright yellow bushes of Cineraria erodioides (Not the Cinerarias sold by florists which are in the Pericallis genus from the Canary Islands). They were everywhere, especially in the disturbed areas where we have removed Pine trees, growing in the full sun and in the shade. What was noticeable, though, was that the plants growing in the shade were scraggly and shapeless while those in the sun were rounded and compact like the one pictured so for gardens, full sunshine is recommended.

The beautiful four-winged fruit of a Velvet Bushwillow, Combretum molle, one of only two species of Bushwillow on the estate (the other is the River Bushwillow) considering they are a bushveld family. To find these Velvet Bushwillows, you will have to hike up to our quartzite formations where you may find one or two individuals scattered around. I photographed this individual right up on top of Spioenkop but I know of a small grove of them growing on the west-facing slopes above the picnic spot on the Spekboom river, between the picnic spot and the Miner's Cottage road. Besides being very shapely and attractive little trees, their leaves are browsed eagerly by Kudus, Eland and Bushbuck and a red dye is produced from them. The wood is hard and also termite-resistant and was therefore widely used as fence poles and implement handles. On the medical front, the bark contains anti-bacterial, anti-fungal and anti-protozoal compounds and the whole tree, together with Pomegranates and some Terminalis species, contains the anti-oxidant Pumicalagin. All of this, together with the fact that they germinate readily from fresh seeds, makes them great garden subjects.

Another larger tree that is very noticeable now is the Escarpment Beechwood, Faurea galpinii, from the Protea Family. They are particularly noticeable now because the leaves turn a dark purple at this time of the year and, as rather common, large trees in the mist-belt, this is very noticeable and gives one an indication of how common they are. Interestingly, the Pentose Sugar Xylose is unfavourable for birds and insects, suggesting the flower is pollinated by mammals like Tree Rats and Dormice. Birds do, however utilise the soft, cottony substance around the seeds as a nest lining.

A Painted Lady, Gladiolus calcaratus, in full autumn bloom.

The Jumping Spiders from the Saticidae family make up 10% of all spider species. They are easily identifiable by the large pair of anterior median eyes, like headlights, and the apparent articulated movements between cephalothorax and abdomen (this one is clearly looking down at the ground). They have the very best eyesight in the arthropod world with an entire 360 degree field of vision plus large forward facing eyes that can judge distances accurately. This is not achieved the conventional way by using the distance between the eyes to calculate but by a phenomenon called "image defocus". They have a four-layered retina and the object will focus on one and out-of-focus on the others. The spider uses the degree of "out-of-focusness" to calculate the distance to the object. Furthermore, Jumping spiders are tetrachromatic, meaning they can see all the colours that we normally see plus another, in this case the ultraviolet spectrum (colour-blind humans are only dichromats while the rest are trichromats). And when one views jumping spiders under an ultraviolet light, they show distinct dimorphism between males and females although under normal light they appear the same. This suggests that the ultraviolet component is used during courtship activities. They are also adept hunters and, after selecting a victim, will often map out an approach route that is rather complex and which entails the spider losing visual contact with its prey (this is very advanced behavior for an animal with such small brain and research is ongoing to try to explain it.) Once the plan is set, the spider will attach a silken line to the substrate, stalk its victim and launch itself with a powerful leap onto its victim, grab it tight with its enlarged front legs and subdue it with its quick acting venom. It shares the enlarged forelegs and quick-acting venom with the Crab spider mentioned at the beginning of this blog.

 

Well, well, what do we have here? A while back, maybe two years ago, my mother brought her pet cat along when she visited me. It was during that visit that I first got a glimpse of a stray/wild cat in the area, trying to defend her territory from this new invader from Johannesburg. For a long time after this, she only appeared when my mother visited with her cat in tow. On each of these occasions I offered the stray cat a plate of food and milk and she eagerly accepted.  My mother no longer brings her cat but the stray, who I have named Trash, now visits me about once a month for a few days at a time. It has got to the point where she will rub herself against my leg but will attack my hand if I try to stroke her. She's very big and powerful and she has all the characteristics of the Maine Coon breed from North America that is believed to be related to the Norwegian Forest cat. In this photo, she is posing on the chopping block in front of my house. She loves to stretch out on this block and while doing this, I can see by her nipples that she has never bore kittens before so she may have been fixed since African Wild cats have been sighted on our neighbouring properties and she would have mated by now. This would suggest that she is a stray, although she certainly behaves wild. But, what a beautiful cat. Look at that mane!

May saw the blooming of the Brittlewood trees, also known as the Common Wild Elder, Nuxia congesta. This attractive, shapely tree can be found growing on forest margins and on rocky outcrops in our grasslands. The specific name, congesta, refers to the compact inflorescence of sweetly scented flowers that adorn the tree at this time. Its sister tree, the Forest Alder, N. floribunda is also flowering now and are very noticeable for their habit of growing in Mining trenches in the open grasslands. As its specific name suggests, the flowers, although not as congested as the Brittlewood, are certainly more abundant and are noticeable from quite a distance away.

This furry little critter is an adult Stink bug, Pseudatelus raptoria, found in amongst the foliage of our trees along the rivers. The nymphs and adult both suck the juices from plants and their fruit and can become a serious pest in orchards. The barrel-shaped eggs are laid in neat rows on the underside of leaves and hatch into nymphs that have a likeness to the adults. These nymphs suck the juices from the plants parts and moult five times over just a month to become adults. In Mpumalanga, they are a particular pest, as nymphs and adults, on avocado, litchi and macadamia crops and farmers spend a lot of money and labour to get rid of them. They have few enemies because they have glands between the first and second pairs of legs that secrete a foul-smelling fluid that is made up of cyanide compounds, making them unpalatable. This odour also alerts other Stink bugs in the area of the danger and they will quickly hide, making non-chemical eradication of the pest almost impossible.

Every year at this time (except this year with the lockdown in place) many people ask me what the abundant yellow flowers in the grasslands are, and I always land up rolling this long name off my tongue: Phymaspermum acerosum because it has no common English name. Well, I finally found a common name although it is in Afrikaans: Geel Blombos. Simple and descriptive. The plant is mostly single-stemmed which branches low down and the branches grow erect after splitting, giving the plant a candelabra appearance. The compact inflorescence sits at the very tippy-top of the branches and is usually the tallest structure around since the plant prefers to grow in open grasslands. This provides a very practical perch for small birds like the Wailing and Lazy Cisticolas and one can often find their droppings covering the flower. These bright yellow inflorescences are also the meeting grounds for a gazillion different insects. Below are some examples: 

These two tiny beetles, horsing around, are among the smaller of the Blister beetles (see blog of December 2019)from the Meloidae family. They eat nectar, pollen and other parts of the flower and were caught here playing in their food! But seriously, an inspection of a flower head of a Geel Blombos will reveal much life, miniaturised.

These flat-faced beetles are called Case-bearing Leaf beetles from the Chrysomelidae family. These beetles are herbivores on any plant material both as adults and larvae. The female, when ready to lay her eggs, will place a flat plate of faecal matter on the floor (leaf, stem etc) and lay a single egg upon it. She will then place more shields around this egg like building a box around it, leaving the top open. She repeats this for all her eggs. When the larva hatches, it stands up straight, inside this box, and flips itself over so that the box opening is now at the bottom, through which the larva feeds on the plant. As the larva grows, it expands the box with its own faecal plates and once it reaches readiness to pupate, it seals the opening and pupates inside the box and later emerges as an adult. 

That's it for May month. Now we enter the chilly winter months where I miss the sub-tropical winters of the Lowveld. We are already experiencing some pretty frosty mornings and it seems we may have a real cold winter this year. See you soon...