Are Kangaroo Island’s koalas under threat?

(C) Hanson Bay Wildlife

SOUTH Australia’s Kangaroo Island may have gotten its name because of the abundance of native kangaroos running wild through its dense bushland.

But there is another furry, Australian icon also living on the 4,405kilometer island that’s become a top draw card for tourists: the koala.

Introduced in the 1920s in an effort to safeguard the species from the threat of extinction on the mainland, koalas have since flourished on the island

However, the once-robust species may now be the ones under threat. An AIDS-like retrovirus has been detected on the island that could eventually wipe out the population, some experts warn.

“This virus may be as devastating to koalas as the Tasmanian devil facial tumor disease in devils,” Dr Jon Hanger, the koala veterinary specialist credited with discovering the koala retrovirus, told CNNGo.

Kangaroo Island was believed to be the only koala population not infected by the virus, which has struck with a vengeance on mainland Australia.

But a recent Senate inquiry investigating the health of Australia’s koala population heard evidence from Koala Research Network that the virus is now sweeping through the island’s koala population.

An initial population analysis discovered no infections on the island in 2004 — but the rate of infection quickly jumped to 15 percent in 2006 and then again to more than 36 percent in 2009.

The virus is linked a range of diseases in koalas, including lymphoma, leukemia, malignant tumors and immune deficiency disorders.

“We don’t exactly know how the virus is spreading, or how quickly,” said Dr Hanger. “But if our suspicions about disease association are correct, then the potential impacts on Kangaroo Island koalas are serious. They are less genetically diverse than mainland koalas, so hypothetically may be even more susceptible.”

To date, no disease linked to the retrovirus has been detected in the island’s koalas.

But Dr Hanger is still wary. “It is possible that it takes years for disease impacts to occur.”

Island’s koalas still abundant

The South Australian Government, however, doesn’t believe the retrovirus is a threat.

“There is no evidence to suggest that the koala population on Kangaroo Island will become extinct from the retrovirus,” a Department of Environment and Natural Resources spokesperson told CNNGo.

“Although the koala retrovirus is present in some koalas on Kangaroo Island, no physical symptoms from the disease have been detected.”

In fact, the Department says it remains necessary to actively manage the island’s “over-abundant” population for the sake of the native habitat and the koalas themselves.

More than a decade ago, the state government introduced a sterilization program to get their numbers under control. Slightly more than 10,000 were sterilized and 3800 relocated to the state’s south-east.

As a result, the overall population size has dropped from an estimated 27,000 koalas in 2001 to 13,000 in 2010.

And this is a good thing, maintains the Environment Department.

“The symptoms and signs of the retrovirus tend to appear when populations are put under stress, and the stresses on the koala population on Kangaroo Island are reducing with the declining population,” the spokesperson said.

“It is unlikely that the retrovirus would pose a risk to the viability of the population.”

Meanwhile, the health of island’s native vegetation has also improved.

The island’s eco-tourism

The island’s recently discovered retrovirus, however, has caused some concern among tourism bodies.

Even so, koala numbers remain high and the island continues to be a top tourist destination, the South Australian Tourism Commission (SATC) told CNNGo.

It is estimated that about 190,000 visitors make their way to the island each year, funneling more than $100,000 million into the local economy.

Apart from koalas, the island is home to a host of native flora and animals, including kangaroos, Tammar wallabies, possums, sea lions, fur seals and echidnas.

But it’s the elusive koala that tends to be the big draw for wildlife spotters. Often difficult to sight on the mainland, koalas are easy to find on the island, in part, because of strict quarantine regulations that prevent predators, such as foxes and rabbits, from accessing the island.

“The island [is] a wildlife sanctuary,” said a SATC spokesperson. “One third of the island is conservation or national park and there are more than 2,200-square kilometers of native vegetation, making it the perfect habitat for koalas.”

But there’s another contributing factor: local groups’ commitment to eco-tourism and preserving the island’s pristine landscape.

More than a decade ago, as a result of a surge in tourist numbers, management groups — such as SATC — teamed up with local tourism businesses and the wider community to develop a plan to measure the effects of tourism on the long-term health of the island.

“Environmental sustainability is a key focus and operators are proactive in minimizing their impact on the environment,” the SATC spokesperson said.

The program, titled Tourism Optimization Management Model (TOMM), has received a positive response so far. It was presented at the International Conference of Sustainable Tourism Management at Heritage Sites organized by the United Nations and the World Tourism Organization, and is currently being considered for adoption by tourism destinations worldwide.

Places to see koalas

Among the island’s top places to spot a koala dozing high in a eucalyptus tree is the Hanson Bay Wildlife Sanctuary situated on the island’s south-west coast.

Once farmland used for cropping and grazing, the 9,500-acre site was transformed into a refuge for native animals and birds more than a decade ago — while the original farmhouse was converted into an upmarket hostel, alongside six self-contained cabins.

One of the sanctuary’s main attractions is its Koala Walk, which is nicknamed “Koala Avenue” and runs along the old sheep farm driveway lined by hundreds of Blue Gum eucalyptus.

“You are guaranteed to see a koala,” said the Sanctuary’s manager James Tomlinson. “Some guests find up to 25.”

Still, he admits he’s worried about the future.

“We are always concerned about the virus effecting koalas on Kangaroo Island and more studies need to be done followed by action. Koalas do more for international tourism than anyone is giving credit too. International visitors reactions here are testament to that.”

To find the published version of this story on CNNGo, go here.

Leave a comment