Plettenberg Bay Oumatjie Cave

Length: 150m | Grade: 5D | Surveyed: 1998-07-01

Region: Caves West of the Tsitsikama National Park

Oumatijie Cave

Description

The entrance to Oumatjie Cave is a high, sloping slot, that narrows
considerably during the first 20m of passage. The entrance passage then
opens into a large chamber, with guano covered boulders on the floor.
Off to the left is another chamber partially filled by a scree cone of
very sharp boulders. These seem to have poured from a hole in the far
southwestern corner of the cave. Although the passage at the top of the
boulder pile is not easily negotiable, the draft that we detected
indicates that there may be an upper entrance.

Biota

Oumatjie Cave is home to a large colony of bats. At least 3 species of
insectivorous bats roost in their hundreds in both the main chamber, and
in the scree-slope chamber. During our visit, we collected, measured and
released Rhinolophus clivosus, Miniopterus schreibersii and
Miniopterus fraterculus. The Miniopterus species were identified by
both measurements of live bats, and from carcasses collected from the
floor of the cave.

A lady by the name of Elizabeth, who works at the local community
centre, said that when she was young, they used to remove bat guano from
the cave. She also said that they used to burn shells in the entrance of
the cave, but could not remember why this was done.

The remaining guano in the cave provides a suitable habitat for a number
of invertebrates. With the exception of a spider, and an amphipod, all
of the beetles, spiders and other invertebrates that we observed did not
appear to be cave adapted. The spider's body was less the 1mm in
diameter, and white in colour, with long spindly legs. Norma Sharrat
examined the spider and identified it as Smeringopine pallidus, one of
the Daddy-long-legs spiders, of the family Pholcidae. A number of
species of this family has been found in caves and animal burrows. (2)

A small stream issues from the back of the cave, and in one of the pools
in the stream we found a large number of small shrimps. Dr Charles
Griffiths identified these amphipods as Aquadulcaris dentata. These
animals have been collected only from the Cape Peninsula before.

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