Saturday, 3 March 2018

Investigating a rock-slide near the vulture restaurant site (Thursday, 1 March 2018)

When we last walked on the Western Heights and stopped to look at the vultures roosting on the cliffs above the Umtamvuna River, we noticed that there had been a rock-slide into the gorge a little higher upstream, just at the confluence with the Hlolobeni River. Today was the first opportunity to get closer to the slide to see what damage - if any - had been done to the cliff edge in that area. On this occasion we were joined by Elaine's daughter, Louise.

Having navigated the ever-deteriorating track through private land to the Western Heights, we were surprised to see the area was covered in low cloud. From the gate it was evident that the colony of Kniphofia linearifolia seen on our previous visit, had gained a few more flowers.

The misty conditions that greeted us at the reserve gate

We drove around and parked at the vulture restaurant site (a site abandoned as a restaurant more than a decade ago) and set off walking down towards the bluff where we thought the rock-slide had occurred - from the vulture restaurant location there was no evidence of the rock-slide. Just below the restaurant area was a rock outcrop sporting a small garden of Bulbine sp. nov., Pentanisia angustifolia and Aeollanthus parviflorus.

Bulbine sp. nov. and Pentanisia angustifolia
Aeollanthus parviflorus

Lower down the slope, we reached another rock outcrop and here found Crassula perforata in flower accompanied by as-yet sterile Caputia medley-woodii. Nearby we found Eugenia umtamvunensis in fruit.

Crassula perforata ssp perforata
Eugenia umtamvunensis fruits

We worked our way across the grassland and started scaling the south-facing slope on the other side of the valley. There were many Kniphofia gracilis dotted around on this slope. Growing on the damp lip above some rocks we found Helichrysum adenocarpum buds starting to show.

On the Kniphofia slope
The last climb to the top of the bluff
Kniphofia gracilis
Helichrysum adenocarpum

As we got higher we started seeing clumps of Tephrosia grandiflora and once we reached the crest of the bluff we found several rock plates. There was a good collection of species growing on the shallow soil layer that collects on these plates. We saw a pink Craterostigma sp. nov. and numbers of the very attractive endemic Crassula obovata subsp. dregeana.

Tephrosia grandiflora
Craterostigma sp. nov.
Crassula obovata subsp. dregeana

Once over the brow of the bluff, we could still not see any sign of the rock-slide and realised we needed to get lower down and closer to the cliffs. Eventually we reached a spot where the devastation caused by the rock-slide could be seen. The slide had initiated some distance below the lip if the cliff face.  There was no sign of what might have caused the slip - perhaps a lightning strike from one of last month's rather vocal storms. At the cliff edge we saw the bright red bracts of Loxostylis alata and a fairly large Osteospermum imbricatum.

Osteospermum imbricatum
Loxostylis alata
The swathe of destruction carved through the forest by the slide

A side view of the cliffs near where the slide started.

It will be interesting to track the progress of recovery of the forest in this area. 

We continued around the base of the bluff, finding Silene burchellii and a patch of Monocymbium ceresiforme. There were many interesting shapes weathered into the rocks in this area and we stopped for lunch here with the confluence of the Umtamvuna and Hlolobeni Rivers below us and Cape Vultures sweeping past at regular intervals. Heading back we took the opportunity to get a closer look at some of the hollows eroded into the rocks.

Silene burchellii

Weathered shapes in Msikaba sandstone

An exclamation mark

A patch of Monocymbium ceresiiforme

Near our lunch spot - interesting rock erosion patterns as a backdrop (Photo Gail B-W)

More erosion cavities to hide in

On a steep slope to the top of the bluff we saw Abrus laevigatus in flower. In the grassy slope on the way back to the Vulture Restaurant we found Crassula alba, Aloe linearifolia, an isolated Ficus glumosa and many Pachycarpus grandiflorus scattered about.

Abrus laevigatus

Another rock shelter

Aloe linearifolia

Crassula alba

Pachycarpus grandiflorus

Ficus glumosa

Once back at the vehicles, Kate found a small patch of the rare and elusive Cineraria dryogeton at the edge of a narrow scarp forest and climbing a dead shrub was what appeared to be Dioscorea multiloba. In the forest were a few Justicia campylostemon, a last few Streptocarpus formosus in flower and over the edge we could see the top of a very floriferous Syzygium gerrardii.

Justicia campylostemon

Syzygium gerrardii
Participants: Anne S, Dorothy M, Elaine L, Gail B-W, Graham G, Kate G, Louise L, Maggie A.

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