Svatojánský okruh
AVIFAUNA AT THE CAVE ARNIKA
Light greenwoods for varied selection of food inhabits big line of mostly
insectivorous species of birds. Many from these nest in the cavities in
trees.
In this area are three types of warblers – leaf warbler, chiffchaff, willow
warbler. Their recognisation isn’t much easy and their objective determinative
sign is characteristic singing and structure of the formulas of the wings.
The European Honey Buzzard nests high at the tops of the trees and its nest is
compound from the fresh twigs. It hunts wasps and its larvas, other species of
insect and small vertebrates too. Arnika Cave
Very heavy rain from the 1st to 2nd June 1995 changed dry karstic gorge
Propadlé vody to soaked area traversed by surface flows. At the places of
today’s entering shaft to the cave were observed noticeable losses of the
small creek under the surface of shallow slough.
14th June 1995 was addluent water marked by kitchen salt. It started to show in
the monastery in Svatý Jan pod Skalou after 20 hours in the springs ‘Ivan‘
and ‘Ivanka‘. The connection of the newly observed ‘Arnika‘ and springs
was approved. During roll-over works on 9th and 17th June 1995 it managed to
penetrate to the cracks 9 metres deep. Discovered corridor steeply falled on
the layers of limestones to JJZ. In September 1995 was achieved the crack of
dimensions 300×15 m, the process slowed down very fast. At the winter
1997–98it managed to penetrate to a little cathedral ‘U svíčky‘. Here
are found fractions of primeval ceramics. 7th March 1998 is discovered steep
space with chaotic set of crawls which looked like spirals. In the deeper part
is ‘Rohovcova chodba‘ posed almost exactly under entering strait. In the
depth of 25 metres it is blocked by gravel sediments.
Continue other hard works and inevitable building of the cableway to the deepest
places, by it is quarried material transported to the ground. It’s also
necessary to fresh the air in here. In winter of 2002 is discovered corridor
‘Za Žumpou‘ and depth of the cave is 28 metres.
In the deepest, rarely flooded place works still continue. Total length of the
Arnika’s corridors is in 2004 cca 80 metres. Straight distance to the
springs is 1 km in elevation of 127 metres. Speleologic group Geospeleos,
which does the discovering work, expects that bigger discoveries will be here
really soon.
