 |
| The delicate spoon-winged lacewing, Halterina purcelli was first discovered on Bergvliet farm by Frederick Purcell. |
Insect Walk with Mike Picker
Meadowridge Common's nocturnal visitors
Cape Porcupines (Hystrix africaeaustralis) are nocturnal rodents, the largest rodents in southern Africa. They are occasional visitors to Meadowridge Common where they forage at night for bulbs, corms and tubers (the nutrient-packed underground storage organs of plants). During the day they shelter in burrows or caves on the slopes of Table Mountain, visiting the suburbs and farmlands at night, often finding their way through stormwater drains and along road culverts. They usually forage alone or in small family groups, communicating with high pitched calls, grunts and quill rattling. On average, they live for about 10 years in the wild, raising one litter of up to three young each year.
Porcupines are covered in coarse, long, black hair interspersed with cylindrical, needle-sharp, black-and-white quills that grow up to 30 cm long on the sides of the porcupine. There is a crest of longer, thinner, more flexible spines that runs from the head down its back. Their quills are modified hairs and will grow back if they fall out. They normally lie flat but can be rapidly erected, making the porcupine appear twice its normal size. If this display doesn’t deter its assailant, the porcupine can charge backwards and sideways and drive home its quills which are easily detachable. They cannot shoot their quills.
You may find evidence of porcupine activity on the Common. Sometimes their footprints can be seen in damp sand, or you will find a discarded black-and-white quill, or a few characteristic lumpy fibrous droppings. They leave distinctive funnel-shaped “foraging pits”, and discarded pieces of the bulbs they dig up. Their enthusiastic digging traps water and organic matter, and facilitates the germination and distribution of seeds and bulbils (small, asexual reproductive structures on many bulbous plants). They are thus important ecosystem engineers in the fynbos.
The bulbs of members of the Iridaceae family such as Watsonia, Babiana, Moraea and Romulea are their staple food source in the fynbos, as are the tubers of the arum (Zantedeschia aethiopica). Porcupines have remarkable defences against the toxins contained in some bulbs, like the Cape Tulip (Moraea collina) which is deadly poisonous to humans and domestic livestock if eaten. The bulbs contain cardiac glycosides that disrupt the cardiovascular, nervous and gastrointestinal systems of most animals. Somehow the digestive systems of the porcupines (and mole-rats too) can neutralize toxins. They can also cope with the microscopic, needle-like calcium oxalate crystals in arums that cause pain, swelling and choking in other animals.
Cape Golden Moles on Meadowridge Common
Meadowridge Common is home to a variety of plants and fungi, mammals, birds, insects and other invertebrates, as well as a whole ecosystem underground that we know very little about. This is why our patch of Cape Flats Sand Fynbos is so important as it conserves a piece of un-transformed fynbos which holds the magic ingredients for being able to withstand a changing climate. Meet some of the creatures that live on the Common.
Cape Golden Moles (Chrysochloris asiatica) are small blind, burrowing, insectivorous mammals, closely related to elephant shrews (or sengis). 
They have lots of very small pointy teeth, typical of mammals that eat insects. Despite similarities in looks, they are not related to the moles of Europe and America. Cape Golden Moles occur only in the southwestern and southern Cape, and thrive in the dry sandy soils of the fynbos.
They measure up to 8 cm in body length, with dense, sleek coats that are iridescent in the light. Males and females are the same size. Unlike most mammals, they have a cloaca, a common opening for both reproductive and urinary systems, and therefore have no external copulatory organs.
Cape Golden Moles are infamous among gardeners for their extensive subsurface runs which they excavate with their specialized forelimbs and conical nose shield (rhinarium) in search of earthworms, insects and other soil invertebrates; relying on their acute hearing to locate them. They also dig deeper permanent burrows for sleeping, defecating and breeding. They are solitary, breeding throughout the year, and giving birth to one to three young. Their main predators are owls, cats and dogs.
These moles prey on insects, many of which are harmful to plants and animals. They also enrich and aerate the soil.
Four-striped Fieldmouse on Meadowridge Common
Meadowridge Common is home to a variety of plants and fungi, mammals, birds, insects and other invertebrates, as well as a whole ecosystem underground that we know very little about. This is why our patch of Cape Flats Sand Fynbos is so important as it conserves a piece of un-transformed fynbos which holds the magic ingredients for being able to withstand a changing climate. Meet some of the creatures that live on the Common.
The Four-strped Fieldmouse (Rhabdomys pumilio), or Cape Fieldmouse, is found throughout southern Africa. The four stripes running down its back, and red-brown ears, are its distinctive characteristics. It is active in the day, unlike most mice, and is the mouse you are most likely to see here. It mostly eats seeds and grass and some flowers like vygies and proteas. These fieldmice are important seed dispersers in the fynbos, as they bury more seeds than they can eat. The uneaten seeds are thus stored safely underground, away from fire and other predators, until it is time for them to germinate. This is known as “scatter hoarding”.
Fieldmice and other rodents are also key pollinators of many fynbos plants as they feed on the flowers, and inadvertently carry pollen on their heads, to be rubbed off on other flowers, thereby effecting fertilization.
The fieldmice nest in underground burrows, lined with soft vegetable debris, with entrances at the base of clumps of grass. They also construct round nests above ground, hidden in clumps of grass with a single entrance. In the fynbos, one to three young are born in summer.
They are also prey for key fynbos animals such as diurnal raptors, snakes, mongooses, foxes and caracals.
Cape Mole-rats of Meadowridge Common
Meadowridge Common is home to a variety of plants and fungi, mammals, birds, insects and other invertebrates, as well as a whole ecosystem underground that we know very little about. This is why our patch of Cape Flats Sand Fynbos is so important as it conserves a piece of un-transformed fynbos which holds the magic ingredients for being able to withstand a changing climate. Meet some of the creatures that live on the Common.
Cape Mole-rats (Georychus capensis) are rodents. Look at the shape of the teeth: four huge incisors typical of the rodent family. Like most rodents, they are plant eaters, burrowing through the sand in search of bulbs, corms and tubers. They excavate nesting, food storage and latrine chambers, creating the mounds of sand you can see on the Common. They use their teeth to dig, unlike the golden moles who use their feet. Their lips close sideways behind their incisors to prevent them swallowing sand.
Cape Mole-rats (at 16 cm in body length) are smaller than the Cape Dune Mole-rat (Bathyergus suillus) which can measure up to 35 cm in length and also occurs near the Common. The Cape Mole-rat has characteristic white markings on its head.
Cape Mole-rats are are solitary and territorial. They give birth to three to ten young in spring. They are preyed on by snakes and, if they venture above ground, by owls, herons, dogs and cats. Although their eyesight is poor, they turn on their attackers baring their teeth aggressively.
Their digging activities enrich the soil by adding nitrogen and magnesium, provide refuges for other species, for example to escape fire, and limit surface runoff of water by loosening the soil and increasing drainage and moisture holding capacity.
Subscribe to:
Posts (Atom)