Friday, 30 January 2015

Today's koala sighting

Before I talk about today's koala - quite a lot of people have asked me what a koala call sounds like.  Here's where you can find a typical koala call.  There's nothing that sounds like it, unless you happen to know a pig that rides a motorbike.

Just this morning (31 January 2015) the koala below was seen at Adare, less than 900m from the motocross track.  It was snoozing high in a Moreton Bay Ash, and was woken by the voices of the photographer and her friends, even though they were about 70 metres away.

Imagine the blast of sound it would have got from 40 motocross bikes charging around the track.  According to the Noise Impact Assessment contained in the application for the motocross facility, if this koala had been feeding at night on the ground at the base of the tree, it would have been subjected to 65dB of noise (louder than a suburban expressway at 90 metres).  Of course if it was feeding high in the tree where we found it, the noise would have been much greater because it would be in direct line of sight to the track, with nothing to attenuate the sound.

Today is the day of the State election in Queensland, when we are able to have a say in the kind of future we want. What say does this koala have about its future?  None.  Its future, and that of may other koalas in this part of the Lockyer, depends on whether you join us in speaking up on its behalf.

What about the koalas actually on the bush on the property where the motocross is proposed to operate? They will be exposed to much higher levels of noise.  How do we know they are there?  Well, the habitat is the same.  Have a look at the map below.

Today's koala was seen on private land, in the edge of Essential Habitat, beside a large area of Bushland Koala Habitat, (both mapped by the Queensland Government) and, as you can see from the above map, these habitats extend into and occupy most of the motocross property.

In fact, pretty much all of our koala sightings from across the Vinegar Hill / Adare area are in these two habitat zones.  Given that our sightings are only "incidental" sightings by people who were doing other things and not focussed on finding koalas, the density of koalas in these habitats can be expected to be many times greater than our observations suggest.

Koala populations in and around Brisbane are subjected to a range of pressures and threats from highly urbanised environments that make it unlikely that they will survive long term.  We have a koala population here that has a National Park as a "refuge" and, outside the National Park, shares bushland areas with relatively low densities of human population and very few busy roads.

If the motocross operation goes ahead, this koala population, on and outside the motocross property, is going to be subjected to stressfully high levels of noise which are likely to reduce their "fitness" for survival.  The nearest part of the Essential Habitat to the motocross track will be exposed to levels of noise between being exposed to an "in sink" garbage disposal one metre away and being in a very noisy restaurant.

Koalas have evolved on a specific diet of Eucalyptus leaves which have an extremely low energy content and are difficult to process and digest.  As a result, they have adapted their physiology and behaviour to minimise energy expenditure, e.g. sleeping up to 20 hours per day.

Since energy is required for basic living and koalas have limited resources of it, any unnecessary use of energy is likely to be of importance to their welfare.  The stress response is a very costly biological response in terms of energy metabolism.  It is possible that the triggering of stress responses may have a greater impact on koalas than other native species due to their reliance on a low energy diet.

In addition, there is circumstantial evidence that the level of chlamydiosis infections in koalas might increase as a result of noise stress impacts on their immune systems.

Please, let the Lockyer Valley Councillor and the general public know that this is an unacceptable impact on a koala population that does not have any way to speak for itself.

Not only is the presence of a large number of koalas an ongoing source of interest and pleasure to local people, it is a quality of the Lockyer Valley environment that we should be proud of and make widely known - not something to be destroyed for the sake of a motocross track.

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