Mining in focus
Every mine has bats on site and setting up bat
boxes for them to roost in will create opportunities
for researchers.
to Cory-Toussaint, Horseshoe bats could be
one of the most important indicator species.
“Studies in Europe, especially in Germany,
have shown that Horseshoe bats are very
sensitive to anthropogenic disturbances. The
third most populous group in this control
site was the Cape Serotine, which is a good
urban exploiter. They are prevalent in cities like
Johannesburg and Pretoria.
In another control site, also to the east and
only a few kilometres from the first one, the
population composition is dominated by Cape
Serotine’s and Zulu Serotine’s, with only 40%
of the species recorded being Free-Tailed bats.
“So, there was a clear shift from Free-Tailed
bats to Plain Faced bats (Vespe bats) and we
need to determine why. There might be a roost
close by,” Cory-Toussaint explained.
In a third control site to the west of the
mine which comprises mostly Mopani shrub
(Musina Mopani Bushveld), the species
composition differs significantly from that
of the Bushveld vegetation in the first two
control sites but was yet again dominated by
the Cape Serotine. “This again emphasises the
importance of looking at all these ecosystems
as part of a mine’s Environmental Impact
Assessment (EIA). Areas such as these may
look insignificant, but might be an important
socialising space, or could have something
to do with their reproduction. Why are
these bats found here? Why are these areas
important? There is nowhere for them to roost
and no surface water for them to drink from
or forage over. We don’t know the answer to
these questions. Furthermore, there are no
Horseshoe bats in the Mopani Bushveld area,
so there is a distinct difference even between
these control sites,” said Cory-Toussaint.
the surface water of the dam. It’s really an
oasis of sorts.
At another site on the mine, away from the
waste-water dam, up to 90% of the species
present were Free-Tailed bats. “The mine has
definitely benefitted these species of bat because
they’re roosting in the different buildings on
the site. They normally roost in small crevices
and the brick buildings have provided them
with the ideal roosts that are buffered and have
relatively stable temperatures.”
Overall, the mining footprint has a higher
species diversity than the Mopanie Bushveld,
but not the Limpopo Ridge Bushveld east
of the mine. This again emphasises the
importance of conserving certain elements of
all habitat types within a mining footprint, as
well as the surrounding areas.
Conserving biodiversity
So, what can a mine do to conserve bats as a
potential important bioindicator? According
to Cory-Toussaint a good start would be to
educate all workers about the importance,
not only of bats, but of all living organisms.
“Environmental management teams should
create an awareness about how mining affects
wildlife like bats. When you get people
interested, they will start respecting nature,
and once you have bats roosting on site, for
example, people will really start caring,” she
said. Every mine has bats on site and setting
up bat boxes for them to roost in will create
opportunities for researchers.
Environmental issues are becoming
increasingly important for mining companies,
for the shareholders who invest in them, and
for more environmentally aware citizens. By
studying the behaviour and abundance of
different species before, during and after mining
activities, will ensure that we are well prepared
for a future where conservation will become an
inextricable component of mining.
She added that the diversity of bats present
at the actual mining footprint, was much
higher than what she initially expected. In this
area there is again a very high percentage of
Free-Tailed bats (especially the Egyptian and
Ansorge’s Free-Tailed bats) and apart from the
now familiar Serotine bats, other completely
different species like Yellow Bellied House
bats, Rusty bats, Twilight bats and Banana
bats were recorded.
What is really important though, is
that the site where the bats were recorded,
is located very close to the tailings dam.
This, said Cory-Toussaint, is a significant
observation as the bats are most probably
using the water from the waste-water dam.
The Limpopo River Valley is extremely arid
and surface water is a scarce resource. The
bats are not only drinking water, but also
feeding on the insects that are attracted by
[22] MINING MIRROR AUGUST 2019
Sampling the footprint
In a control site to the east of the mine,
the population composition is dominated by
Serotine’s bats.
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