The misinformation in the media over the last few days has been frustrating to read. I am writing this blog to set the record straight, clarify the need for the actions of late 2013 and early 2014, and answer a few questions about koala management.
Around 75 koalas were relocated from French Island to Cape Otway in the early 1980s. Most of these probably survived because they were hand-picked healthy individuals that were relocated from manna gum woodland to manna gum woodland. In addition to being similar habitat, the Cape Otway manna gum did not have a resident koala population. These are important points to remember!
In manna gum woodlands, koalas become manna gum
specialists and their behaviour is different to what is seen elsewhere. Their
ranges are small (less than 1/2 hectare), they tolerate other koalas in close
proximity, fecundity is almost 100%, and joeys survive to become breeders
themselves. This results in population growth and densities that are seen
nowhere else. In addition, in places where fire is suppressed (human intervention) there are no natural regulators of population growth.
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These koalas seem to tolerate other koalas in close proximity |
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This koala (joey on belly) struggles to find enough food |
In 2008, there were about 450 hectares of manna gum at Cape Otway
adjacent to the vast blue gum/grey gum/mountain ash forests of the Great Otway
National Park. By September 2013, there were around 200 hectares of manna gum left.
Koalas had defoliated and killed trees to the south and numbers had increased
in the north due to koala movement from the south and breeding. Trees began to
die but most koalas showed no sign of moving. Female koalas abandoned
their joeys and all koalas started eating bark, grass and sometimes dirt.
On a personal note, I dreaded my
weekly visits to Cape Otway because each week I would have to pick up yet
another carcass of one (sometimes several) of my study animals. The day I picked up 4 and took another emaciated one to a carer to have euthanased was my lowest. I have not seen anything like it in 25 plus years of working in wildlife management.
There was a smell of rotting koala in the air. Landholders were suffering extreme stress watching both koalas and trees die. 15 of 20 of my radiocollared animals died, most of those before the government finally stepped in
and started putting animals out of their misery.
I applaud the government for making the difficult decision, especially knowing that there could be significant negative media. Had the media of this week happened back then, 686 koalas would have still died, but their suffering would have been for much longer. I felt incredibly sorry for the team that had the difficult task.
It was not a cull. It was euthanasia of irreversibly sick animals. Healthy animals were released, females given a hormone implant.
It was not done secretly. It was done in a very public place and hundreds, if not thousands of people were there to witness it. Landholders knew. Prior to the euthanasia, I had tried contacting the media. The few times when my call/email was actually returned, it usually was to say something like "we don't want to get in the way of what needs to be done".
Perhaps if the government
had taken action sooner we may have avoided having to take such drastic but
necessary action. But in 2013 it was too late for hindsight: the problem was there and needed to be addressed.
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This animal was too weak to climb. I found some leaves for him |
So what are the options for dealing with overabundant koalas at Cape Otway? The following are the only
ones that are permitted:
1. Relocation to other forests or zoos? In 2008 there would have been between
around 4000 koalas in manna gum. In 2013 there were likely more. These koalas are manna gum specialists and there are studies that show that
between 90 and 100% of koalas relocated from manna gum to other forest types
die. There is no manna gum left in Victoria that doesn't already have a large
number of koalas so there is no manna gum to relocate koalas to. Zoos are not interested
in taking adult koalas. Adult koalas straight from the wild are difficult to
handle and feed and are stressed around people. Zoos only want joeys
or young subadults that they can hand-raise and habituate to people.
2. Fertility control? Very expensive and may only have low effectiveness. However, at this point it really is the only option to stop koalas increasing in number again. It may be more effective than first thought. Results from some of my tracking work suggests that high site fidelity means that there is little movement of koalas within some areas. The government would need to commit to a long-term plan though to address issues of koalas moving in from the neighbouring forests of the Great Otway National Park.
3.
Plant more trees? The landholders have been
doing this for years and have plans to continue.
4.
Let 'nature take its course'? Loss of the manna gum ecosystem may be the final outcome despite all our efforts. Personally, I would like to do whatever possible to avoid that. I hope you agree!