A few weeks ago I got an
email from Mark Venosta, a Senior Consultant Biologist from Biosis Research
Pty. Ltd., to chat about the Thermal Target Tracker (T3) software I’m using to
count the bats at Bat Cave. I met Mark back in December at the Gluepot bat
course, and we talked a lot about our research and the possibility of using T3
for his work. He and his group are monitoring Byaduk
Caves near Hamilton, Victoria
(a known over-wintering site for Southern Bent-wing Bats) for a wind farm
company to help determine if the Southern Bent-wing Bats might be affected by
the development of a new wind farm nearby. He wanted to try out T3 at their
next bat census at the caves and he asked if I could come out for a few days to
help set everything up and run through the program with them. Of course I said
yes! Another chance to see some more caves in the area and travel a bit (with
my motel room, food, and fuel paid for!). So last week I headed to the caves,
which are about 2 ½ hours from Naracoorte.
Once I met up with Mark and
Gavin (another Biosis worker) we headed to the caves to assess how to best set
up the cameras for the emergence counts. Walking to the caves was quite
difficult, as the ground was extremely rocky and grass-covered. I was paranoid
the whole time about twisting an ankle or tripping and hurting myself again (I
did have a few close calls). Luckily nothing bad happened. We took two nights
of emergence counts at one of the caves so Mark could play around with T3 on
his thermal camera. These caves are really neat as they are part of a
solidified lava flow from the Mount
Napier volcano eruption
8,000 years ago (during which a lava fountain several hundred meters high
spurted from the crater) and were formed by molten lava continuing to flow
beneath. They are much different from Bat Cave.
While Bat Cave is just a “small” sinkhole with a
horizontal entrance dropping straight down into the cave, the Byaduk caves are
massive sinkholes with large vertical cave entrances (think typical cave
entrance). They were beautiful! And much, much different from Bat Cave
in terms of cave microclimate. Bat
Cave is a maternity site
for the Southern Bent-wing Bats, which means it needs to be warm and humid in
order to provide a suitable climate for rearing pups. The giant mounds of guano
decompose and add to the warmth, and the domed roof allows heat to build up. Bat Cave
is therefore quite warm and humid, and the guano is relatively dry. The Byaduk
caves, on the other hand, are overwintering sites for the bats, which means
they need to be cool so the bats can easily enter torpor and conserve energy
over the winter. The one cave we entered to estimate bat numbers with an
infrared camera was very, very cold (you could see your breath) and very wet.
The guano was like mud. We literally sank into it and could hear the
“squelching” sounds as we picked up our feet with each step. I was finally able
to appreciate the vast differences between a maternity cave and an overwintering
cave. I also gained a better appreciation of just how important Bat Cave
is to the life history and conservation of these bats. Bat
Cave (and the other maternity cave, Starlight Cave in Warrnambool) has such a unique
structure that allows heat and humidity to build up to create ideal conditions
in which to raise young. Other caves just don’t have the ability to provide
those conditions for the bats. That’s why Bat
Cave and Starlight Cave
are so vital to the conservation of this species. Without them, the bats would
have nowhere suitable to raise their young, and the population would collapse.
It felt very weird to be
considered one of only a few “experts” on something, especially something to do
with computers! It was strange to be asked advice on how to set things up and
run the software and to be turned to as an expert. It’s a great feeling, but of
course it comes with a bit of responsibility! Mark has asked if I can come back
out the next time they do a census there (at the end of April) so hopefully
I’ll be able to get back out there again. Who knew I’d be doing consultancy
work while on my Fulbright in Australia?
Mt. Napier volcano
The lava (foreground) flowed from Mt. Napier
(background) through Harman Valley 8,000 years ago.
The nearby wind farm development (the company wants to
expand the site, which is why we were taking the bat census at Byaduk Caves).
No comments:
Post a Comment