Government announces imminent management actions for Cape Otway koalas

Today, the Victorian government issued a media release about upcoming management actions for koalas at Cape Otway. The program will involve checking the health of 300 to 400 koalas, euthanasing any koalas found to be in poor condition, and initiating a study to examine the potential to translocate koalas to other forest in the Otways.

This is welcome news!

Habitats at Cape Otway are continuing to decline under the browsing pressure of so many koalas. In one of our study sites, koala densities have climbed back to 9 koalas per hectare, and the trees are showing considerable stress. Although it may be too late to save much of the manna gum woodland, it may be possible to prevent the suffering of many koalas. A lot depends on koalas surviving the translocation trial. If there is high mortality of koalas in the trial, then the only option is fertility control which is too slow acting to avoid another population crash.

Manna Gum Drive - trees continuing to decline

Without translocation, this mum and joey are unlikely to survive for long

Our research which is generously funded by Earthwatch Australia and supported by Earthwatch volunteers, continues to provide important information on koala densities and habitat condition across the Cape, and has been critical in informing the government's management actions. In fact, as I write this post, a team of Earthwatchers are surveying our long-term monitoring sites. Future teams will continue to monitor those sites and participate in studies of koala behaviour and their response to their ever-changing landscape.

Planting by Earthwatchers to rebuild koala habitat

Choosing mates.... size, age, or persistence?

Remarkably little is known about the love life of koalas. Are they fussy about who they mate with, or is it simply a case of a male being in the right place at the right time?…. and by ‘right time’ I mean when the female is receptive. This breeding season we are hoping to find the answer. We are deploying proximity collars fitted with GPS loggers to every koala we can find in a woodland patch. These collars record the time and duration of interactions between collared koalas. So far, we have 19 koalas collared but still have another 17 collars to deploy.

The study is the basis of an honours project by Deakin student ‘Darcy’. Darcy has already done an amazing job of preparing the collars, and has proven to be a capable koala catcher and handler. He will now have the task of tracking and observing these koalas, mapping resources throughout the site, and in January retrieving the collars for data download and interpretation.

Darcy bonding with the joey of one of his study animals

 

Beast

RIP Beast

I was sad to learn that 'Beast' was one of the 29 koalas euthanased during the last round of health checks of koalas at the Cape. Sad, but not really surprised.

Beast was an old fellow of around 12 years of age. He was looking a bit the worse for wear at the end of the last breeding season but I had hoped he would survive to the next. He was a legendary animal; not necessarily the prettiest koala I've encountered but he had loads of character. He showed the most aggression out of all the males in our study of responses to bellows. He survived the population crash of 2013, finding ways into banded trees and constantly wandering in search of good food (and female koalas). The vets didn't think he would survive then because he was so old. He knew the drill when it came to being caught too. He grumbled but seemed to realise that resisting would only make the process longer.

Beast always sat low in trees so he would have been a prime target for the catching crews looking to sample 10 koalas from that site. I was told that his condition was poor and that the vets did not give him more than a 10% chance of survival. I think they may have underestimated him!

I was disappointed that nobody thought to tell me at the time, or save his carcass for me. I would have loved to take some samples and save his skull.

I wonder how many of the other koalas euthanased were in poor condition due to age? When DELWP reported 29% koalas euthanased, we immediately assume that it's due to poor habitat condition but is that really the case at the moment?

Finally.... a management program for koalas at Cape Otway

This week, the Department for Environment, Land, Water and Planning (DELWP) began assessing health of koalas at Cape Otway as the first part of a long-term management program for koalas and manna gum woodlands at the Cape.

This is an extremely positive action to inform management actions that are likely to include fertility control and translocation. Such management is necessary if we are to avoid a repeat of late 2013 when thousands of koalas died of starvation.

However, the media appears to be intent on stirring up the public with headlines like 'Killing to resume at Cape Otway koala colony' (The Australian), and 'Koala cull on the cards' (Sky News Australia). I spoke with a few of the reporters and advised them on the consequences for koala welfare if health is not monitored. Obviously those stories don't sell papers and reporters/editors don't mind if their poor reporting results in animal suffering.

I respect Victoria's Minister for Environment (Hon Lisa Neville) for listening to scientific advice and requesting the development of a long-term management strategy for this issue.

If you would like to hear more about koala management at Cape Otway, you can check out DELWPs facebook post or see them on twitter;

DELWP discuss this management action (Facebook)

DELWP on twitter about Cape Otway koalas

Getting the facts right

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.

These koalas seem to tolerate other koalas in close proximity

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. 

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!

Taking a breather

Today, koalas are in the media and I've been forced to take a breather from writing lectures for interviews with radio, newspaper and TV. So what is all the fuss about? After more than a year since the koala population crash and government welfare interventions of late 2013 and February 2014, the media has decided that it is a story worth reporting. It's not often that the media is that slow is it?

My day started at 6am when the bellowing of koala 'Dave' woke me. For those of you who don't know, Dave is my ringtone on my mobile. It is not pleasant to be woken by a koala bellowing in your ear! The caller was 3AW radio wanting to talk about the 'secret cull of koalas at Cape Otway'. Apparently 'The Australian' newspaper had written an article titled that and discussing the government's program to euthanase starving koalas in 2013/14. I suppose government conspiracies and cover-ups get people's attention because I have since spent my day in interviews and taking phone calls to set up interviews.

My only hope is that this media interest will result in a positive outcome for long-term management of koalas and their habitats at Cape Otway. The problem has not gone away and our November and February counts suggest that koala numbers are beginning to increase again in areas where manna gum survived the 2013 events. Without management, there will be another population crash. I definitely do not want to witness something like that again.

Here is the opening of The Australian article that triggered chaos today:

"ALMOST 700 koalas have been secretly killed by lethal injection near Victoria’s Great Ocean Road and thousands more are in danger of starvation due to an ongoing crisis caused by overpopulation in one of the nation’s key habitats. The Australian can ­reveal that wildlife officials conducted three euthanasia operations in 2013 and 2014 to kill 686 koalas, in what was a covert campaign to avoid any backlash from green groups and the community."

Despite the title and opening sentences, they at least got some of the story right:

"Deakin University koala expert Desley Whisson was part of the team that dealt with the problem a year ago and warned that the problem would continue. Dr Whisson said the density of koalas on the cape was potentially the greatest in Australia and that some of the ­animals were in such poor health that euthanasia was the only ­option.

“It was a blessing when the vets came,’’ she said. As well as invading the Bimbi Park campground, the koalas stripped stands of manna gums, virtually wiping out the trees and making it difficult for the 8000-strong group to find food. Only the fittest specimens were able to survive, leaving the oldest and, in some cases, smallest koalas to starve. Dr Whisson said the reduction in numbers had nothing to do with thinning out the population and was all about dealing humanely with sick koalas."

Koala love

I’m often asked questions about koala reproduction and considering that we are now entering the peak of the koala breeding season (at Cape Otway at least), I thought I’d put together a summary of what we know about koala ‘love’. Actually, there is not that much ‘love’ involved and for anyone who had witnessed a male koala that is full of testosterone, harassing a female koala that is not interested in him, you’d know what I’m talking about. The female will scream her disinterest and if the male gets too close, she will fight him off with tooth and claw. Eventually, he will retreat, often bellowing (in frustration?). Ten minutes or so later, he will try again. Observations suggest that he will continue to stay close to his chosen female, sitting in a lower fork of the tree and guarding her closely.

A male trying desperately to get some 'love'. He managed to grab the female but eventually
lost his grip and fell about 5m.

 

He  simply climbed back up the tree to await another opportunity

This male took an interest in me. I'd had the misfortune of being urinated on by a female that we were catching. Considering his obvious 'excitement', I think he may have thought I was a female koala.

 

I have only ever seen a few copulations in the wild. In one, the female went to the male (she actually woke him up). In another, the male went straight to the female, passing another female on the same branch. Obviously, given the number of joeys we see, there are a lot of successful copulations. Around 80% of the females in our Cape Otway population this year have joeys. This means that even the food shortage last year did not disrupt the breeding cycle.

The koala gestation period is around 33 to 35 days. The young is born at the embryonic stage (as with all marsupials) and crawls its way to the pouch. Typically there is only one young although twins can occur. In wild populations, it is likely that only one of these will survive through to independence.

Twins for a female at Cape Otway (photo courtesy of DEPI)

The young latches on to one of two teats and will remain in the pouch for about 6 months. The mother prepares her joey for its eucalyptus leaf diet by producing a faecal pap for the joey to feed on. This helps the joey transition from a milk- to a leaf-diet. At 6 to 7 months of age, the joey (300 – 500g) emerges from the pouch and clings tightly to the mother. It will begin eating leaves although continues to poke its head back into the pouch for milk.

After leaving the mother's pouch, a joey will regularly poke its head back in the pouch for a drink.

 

The mother will carry the joey on its back for around 3 months.

 

By 9 months, the joey will weigh around 1kg, and at 12 months and ~2.5kg it is fully weaned. Weaning usually occurs when the mother becomes pregnant again. The mother will become quite aggressive towards her young. This can be heartbreaking to watch – the mother screaming and lashing out at her young, and the young crying. It is not uncommon to see a few of these rejected young hanging out together. On one of my Earthwatch trips, a recently weaned joey even sought comfort from one of the Earthwatchers. It literally chased her and began climbing her leg.

This joey is nearing independence.

There are still a lot of questions about how koalas select their mates and how long males will guard females. I am hoping that we will get some answers to these questions this breeding season. We have deployed ‘proximity collars’ on males and females in the same area. When koalas wearing these collars are within a few metres of each other, each collar will record the ID of the other collar, the time, and the duration of interactions.