Magical Maputaland

[Lisbeth]

I would love to see this tiny antelope live

[Klipspringer]

The Suni is a tiny antelope, only about 35 cm at shoulder hight and weighs a maximum of 5.5 kg.
It is rufous brown with faintly speckled upperparts. The mid back is darker than the flanks and legs. The underparts are white. Just above the eyes are white patches. The top of the snout has a black band and only males have horns. The translucent pinkish ears are broad and rounded at the tips and almost hairless on boths sides.

Male


Suni have preorbital glands covered with short hair on the sides of the face in front of the eyes. These secrete a sticky substance that to the human nose does not appear to have a smell, but which probably has a function in marking. Suni males mark grass stalks or twigs with this preorbital gland by inserting the tip into the everted gland. The secretion dries to a hard, grey-black, crystalline substance, which forms visible bulbous deposits as a result of re-markings.

Suni defecate and urinate in middens that are a feature of their territories and arc used by all members of the group. When using a midden the individual scratches a depression, urinates in it and then squats to defecate in the same place. Dung middens are nearly always deposited next to the well-worn pathways that sunis follow when they are moving about in their dense habitat.


Regional Red List status (2016): Endangered
Currently, the major threats affecting Suni are:
1. Bushmeat poaching: may be increasing, especially along protected area edges where human densities tend to be highest. Because they use pathways through dense underbrush, they are easily snared.
2. Sport hunting: illegal hunting with domestic dogs for sport or gambling, especially on private or communal lands.
3. Continuing loss of habitat: current habitat loss, especially from urban and rural expansion.
4. High African Elephant and Nyala densities: high or artificially inflated Elephant and Nyala abundance reduces the shrub cover needed by Suni.
5. Loss of habitat quality from resource extraction: firewood collection and charcoal production within forests are likely to decrease habitat quality for the species by removing shrub cover.

[Richprins]

Very informative, Klippies!

And you managed to see one!

[Flutterby]

How special to see a suni.

[Lisbeth]

2. Sport hunting: illegal hunting with domestic dogs for sport or gambling, especially on private or communal lands.

[Klipspringer]

Epiphytes enjoying high life

Vascular (i.e. land plants with internal water- and sugar-transporting ‘plumbing’ – from ferns and their relatives to gymnosperms and flowering plants) epiphytes are fascinating life forms. Many epiphytes quite literally live the ’high life’, perched precariously upon branches or bark of trees high above the soil surface. Closer to the sun – for life-sustaining photosynthesis (which is presumably an advantage for such otherwise rather small ground-dwelling plants in the shade of loftier neighbouring vegetation) – they appear to have solved the problem of access to their energy source. But, in so doing, have created a host of other problems for themselves. For example, in that elevated location how do they get water and nutrients (which is more usually sourced from the soil that they are no longer rooted in)? These are important concerns that Nature has long since sorted for the epiphytes.

Epiphytes are plants that germinate and root non-parasitically on other plants, i.e. epiphytes are structurally-dependent plants, and for most the structure upon which they depend is a tree.
Vascular epiphytes live non-parasitically on other plants and are a distinctive and intergral component of tropical forests and are common in Maputaland's Sand Forest.

Epiphytes are plants that grow on other plants for structural support and anchorage, and not for water or nutrient supplies (i.e. non-parasitic). Approximately 84 vascular plant families have evolved an epiphytic strategy and at least 876 genera have one epiphytic species. The number of epiphytes is estimated to be c. 29,000 species. Epiphytes are considered an important component of global plant diversity and represent c. 10% of the world’s vascular plant species. Araceae, Bromeliaceae, Orchidaceae and several fern families have a substantial number of epiphytes.

Epiphytes can be broadly classified as holoepiphytes (spending their entire life cycle in the canopy) such as the widespread Ansellia africana Orchid and hemiepiphytes such as several Ficus sp. (spending some stage of their life rooted in terrestrial soil).
The genus Ficus (Moraceae) is well documented to be epiphytic. Several South African figs are known to have a strangling habit. Representatives of the Ficus thonningii complex (F. rokko, F. psilopoga, F. persicifolia, F. petersii, F. burkei and F. natalensis) have
a strangler/hemiepiphytic habit. Ficus lutea, F. polita and F. natalensis are hemiepiphytic or epiphytic at first before becoming free-standing trees. Ficus burttdavyi is known to be an occasional hemiepiphyte or strangler.
Some epiphytes start life in the canopy and send roots to the ground (primary hemiepiphytes), whereas others start on the ground, grow to the canopy and lose terrestrial connections (secondary hemiepiphytes).
Epiphytes are ecologically important, playing a significant role in forest ecosystem processes and interactions, and contribute to species richness. They provide nutrients for other flora and fauna and play an important role in tropical ecosystem functioning by producing relatively high amounts of organic matter on host trees and fixing atmospheric nitrogen.

Epiphytes on a giant Lebombo Wattle


In the next episode I will show you the only African indigenous cactus which is - you might have guessed - an epiphytic plant.

[Flutterby]

[Lisbeth]

[Richprins]

[Klipspringer]

The Mystery of a Spaghetti Cactus' Journey - How did Rhipsalis baccifera cross the ocean?


This epiphyte usually grows on forks of tree branches, sometimes in the thin layer of soil in vertical rock cracks. The hanging cactus is especially common on the rough bark of the Lembobo Wattle and it is the only cactus that is indigenous to South Africa where it occurs along the coast of Maputaland to the eastern Cape and slightly inland.
Plants form pendolous clumps of thin spaghetti-like stems which hang down from the canopy like monstrous green dreadlocks. They carry tiny, widely dispersed clusters of harmless hair-like spines. Flowers are small, creamy white and rather insignificant. They are eventually replaced by small white translucent berries.

There’s one very special thing about R. baccifera: it’s the only species of cactus that is found naturally outside of the Americas. With the exception of this weird plant, cacti occur naturally from just south of the Arctic Circle in Canada to the tip of Patagonia in South America. Thanks to their legendary survival strategies, cacti can do well it in a broad variety of altitudes and climates, from bone-dry valleys to dripping rainforests.
Unlike all of its relatives, R. baccifera has grown wild in Africa and India at least since botanical record-keeping began. This plant has traveled thousands of miles away from all of its brethren. And despite decades of study, scientists still aren’t quite sure how it pulled this off.
R. baccifera can be found growing wild from mid-Argentina through Central America and up into the heart of Florida. But it’s also endemic in tropical Africa, Madagascar, and Sri Lanka. How did it end up all those places?

Experts have come up with a number of competing theories, some more likely than others, but all somewhat improbable.

In the first scenario, this cactus followed the path of many other plants: its seeds got a lift from hungry, migrating birds. The prevailing theory among many biogeographers is that, at some point in the past, a long-flying species of bird, snacked on berries, and then migrated to southern Africa, where they passed the seeds and begat a new plant. From there, more birds spread the cactus to more places, until it had the broad, unusual range we see today.
There are some issues with this theory. For one, frugivorous birds are not able to cross the Atlantic Ocean from South America to Southern Africa. Perhaps a tropical storm or ocean currents might have pushed the seeds from shore to shore on their own, but that’s also a rather long shot.

This brings us to the second possibility: the continental breakup theory, first advanced by botanical detectives in the early 20th century. In this scenario, neither R. baccifera nor birds had to travel thousands of miles. The Earth did it for them.
This explanation make sense if we simply assume that our heroic cactus was around during the breakup of the supercontinent of Gondwana, about 184 million years ago. In this scenario, as Gondwana separates into what we now know as Africa and South America, some R. baccifera is left on each side of the divide, slowly drifting apart until - millions of years of tectonic shifts later - they’re in completely different continents.
This theory has also some weak points: while no one is certain when cacti evolved, most estimates put the date around five to ten million years ago, far too late to have experienced Gondwana. And if they did show up early enough to hang out on the supercontinent, it’s strange that no other species of this plant family managed to make it to Africa and India.

The third and final scenario is a little more human. In the 1980s, several biologists came up with the idea that R. baccifera might have crossed the ocean with the help of sailors, potentially 16th century merchants taking on the East India Route. Before they left from Brazil, this theory goes, they gathered up one of the rainforest’s most beguiling plants, R. baccifera, which dangled gracefully from the trees and, thanks to its ability to survive without soil, could easily survive the journey. Perhaps they used it to brighten up the ship’s quarters, and then left it when they hit port again in Africa.

We may never know exactly how R. baccifera became an African cactus. But you may choose the most plausible theory for you.