Käyttäjän peterswart päiväkirja

Trip Date: 2024-05-08

Oresti took me to Hangklip Cave on Hangklip. We spent 3 hours looking for the cave, and found a new, 4m deep, vertical shaft while searching. The sides of the entrance are very sandy, and it looks like a potentially dangerous descent.

The Hangklip Cave was probably a large chamber that has collapsed, and there a number of entrances into the cave. A stream runs through one side of the cave.

The largest residents of the cave were a small colony of Rhinolophus and Miniopterus bats. I saw about 20 bats. Oresti said the colony was far larger on his previous visit, so the cave is probably a seasonal roost.

There were Paramelita in the stream and many Wishbone spider tunnel openings in the floor. These entrances ranged from a few millimeters in diameter to approximately 10mm.

Oresti saw small cave crickets, but I did not see them, so that will be something to search for on the next visit.

Trip Date: 2024-05-18

Cave Zones

I currently use the field "Cave Zone" to indicate where in cave the observation was made. I have used the following definitions:

• Entrance: Where there is enough light for some vascular plants to grow.
• Twilight: Where there is not enough light for vascular plants, but some mosses may grow/
• Dark Zone: No light at all

It appears that another zone between Twilight and Dark is needed. This 'Transition Zone' would describe the zone between Twilight and Dark, and would be characterized by being mostly dark, for most of the day, but where some dim reflected light may be seen at certain times of the day. The reason for this extension is that this area seems to be a popular habitat.

Trip Date: 2024-05-29

Vivarium is a small cave with two entrances. The 'back' entrance is via a boulder choke, and the 'front' entrance is a largish opening into the main chamber of the cave. The opening is large enough to allow a lot of light (and wind) into the chamber. A stream flows from the dark part of the cave into the main chamber. This configuration means you often find animals from 'the dark zone' in a relatively well lit zone.

This trip was confined to the boulder choke entrance and the dark, 'up-stream' part of the cave.

The top of the boulder choke is outside the cave, and bottom is well into the darkest part of the twilight/transition zone. The boulder choke was full of the usual suspects:

• Cave crickets
• Bristletails
• Cave daddy-long legs spiders

Just inside the entrance of the cave was a crane-fly like creature.

At the deepest part of boulder choke, where the dark part of the twilight zone becomes complete darkness, there were two bristletails, a few cave crickets, and a centipede. The centipede hid in a rock crevice before I could photograph it.

Bristletails

Bristletails seem to prefer being in the darkest part of the twilight zone of the cave. They are usually found inside the crevices between boulders in the twilight zone. Out side of the boulder pile, indirect light may be visible to the human eye, but 1m into the boulder pile, only dimly reflected, indirect, indirect would be present, and it appears to be completely dark to the human eye.

Spiders

A Metellina spider had its web across a gap in the boulders, but the wind coming out of the cave was buffeting the web quite violently, and the spider decided to hide in a crevice next to its web.

There were lots of Spermophora of all sizes in the twilight zone and in the gaps between the boulders.

Aquatic

I saw some quite large (18mm?) Paramelita and a lot of Spelaeogriphus lepidops in the upstream section of the cave.

A visit to the main chamber is still needed.