Camper Van - Day 4 (Florence Falls)
Jackamy
Paul & Derry Harper
Sun 10 Oct 2010 02:34
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Sunday 10th October
Day 4 - Florence Falls
After days and days of soaring temperatures
a dip in the refreshing waters at the waterfalls of Litchfield National
Park couldn't be resisted any longer. So after another lovely night at camp
we packed up and headed for Florence Falls via the Magnetic Termite mounds. We
weren't expecting much as we had seen hundreds of them along the roadside but we
found out that there are more than one type of termite mounds and it was all
very interesting.
 
 Magnetic Termite
Mounds
The Magnetic Termites of Northern
Australia are master architects in the insect world. They like warm, stable
temperatures. During the dry season, however, the low areas in which the
Magnetic Termites build their nests are often pools of cold air at night, only
to be baked by the sun during the day. To escape this temperature variation
other termite species migrate underground, but magnetic termites have no
underground refuges, probably because of the regular flooding. Instead, they
construct plate shaped mounds which are angles to catch the sun so as to create
a stable temperature for most of the day on their eastern faces.
On dry season morning Magnetic
Termites move to the eastern faces of these mounds which warm rapidly. By late
morning the face is comfortably warm and remains so for the rest of the day. The
termites move back to the centre of the nest as temperatures cool in the
evening.
Heating up one face of the mound
is an unusual form of temperature control that is sensitive to local shade and
wind conditions. In areas that are windier or shadier in the dry season, the
mounds need to be aligned at slightly different angles from those in clear
sheltered conditions. This, not all Magnetic Termite mounds are aligned along an
exact north-south axis, rather, they are aligned along various axes related to
local shade and wind conditions ranging from slightly west of the true north, to
10 degrees East as they are in Litchfield Park.
Biologists believe that Magnetic
Termites do not directly sense local climate conditions but always construct
their mounds along fixed, genetically inherited axes. Those mounds which are not
aligned appropriately to the prevailing wind and shade conditions perish,
whereas those mounds aligned correctly grow to maturity and produce offspring
mounds that are similarly orientated. This process is known as Natural
Selection.
It is thought that Magnetic
Termite colonies can pass on a particular mound orientation to the next
generation by having a magnetic compass sense programmed into each termite that
allows it to sense a particular magnetic bearing. The workers construct the
mound along this bearing and the sexually matured winged termites or 'alates'
which swarm from the mound and establish new colonies, will pass this bearing on
to their own worker offspring.
Clever little things aren't
they!
 Wow!
We then came across the huge
termite mound above which put all the others to shame. It's a Cathedral Termite
mound. They are amongst the largest built by termites anywhere in the world,
sometimes exceeding 6 metres in height!
 A view of Florence Falls from
the viewing platform
In the wet season, the sandstone
plateau sheds large volumes of rain water. However some water is stored in
underground cracks in the sandstone, which acts like a giant sponge. So in the
dry season water slowly seeps out feeding creeks and waterfalls meaning water
falls all year round.
It was so nice to get into the
refreshing cool water as it is so hot at the top end of Australia. Whilst
walking to the waterfall a thermometer read 40 degrees with 80% humidity. That's
seriously hot and sweaty!
 Unfortunately we weren't the only
ones who had the idea to go swimming. As Litchfield is only an hours drive from
Darwin and it was the weekend the water was quite busy. The locals have to take
the opportunity and swim where and when they can as there are only a few
locations where there aren't any crocodiles.
 
 A leisurely walk along a
creek back up to the vans
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