Foxes have been caught on camera climbing trees and sniffing out koalas in Australia

Red foxes – capable. Picture: 20th Century Fox

Red foxes in country NSW have been caught on camera climbing eucalyptus trees inhabited by koalas.

Last year, Valentina Mella at the University of Sydney was studying the koalas on a property in the Liverpool Plains. She set up cameras to watch how koalas used drinking fountains installed in the trees several kilometres apart.

The last visitor she expected to see was a European red fox:

“I was quite shocked because I’m from Europe and I’ve never seen a fox in a tree before,” she told New Scientist.

Obviously it’s a huge concern given the decline in koala numbers in the past two decades. In August last year, a report on the “Koala Coast”, in and around Brisbane, found 80 per cent of the population had disappeared.

It’s listed as “vulnerable”, but there are movements to ramp that status up to “threatened” as dog attacks, urban expansion, climate change and disease increasingly take their toll.

Now, it seems even their home high above the ground – the koala’s main defence – is not safe.

The owner of the property Mella was studying koalas at said he’d seen foxes in trees “regularly”, up to four metres off the ground.

Mella’s footage didn’t catch any predatory behaviour from the foxes, but she said the foxes were clearly looking for prey.

“There was always a lot of sniffing and investigative behaviour by foxes where koalas and other native fauna had been, so I would say that the reason for climbing the tree was definitely to look for a prey,” she said.

“Simple curiosity could be another explanation but this is a trait that makes foxes such clever and opportunistic predators, so curiosity does not exclude predation motives.”

Red foxes have been seen climbing trees in Europe, but footage is scarce:

Mella believes Australian eucalypts are much easier to climb than predominant pine forests in Europe. And while koalas are known to be aggressive, Mella fears that baby koalas and other species such as sugargliders could eventually find their way onto the red foxes’ menu as easy options.

“There is no mammal predator in Australia that would climb trees to hunt an adult koala, so the question is not whether koalas are defenseless but how can they cope with a predator that they do not expect to encounter in a tree?” she said.

“We did not notice any change in the behaviour of the koalas and this is the real worry. Foxes represent an unrecognized threat for Australian fauna and as such, a very dangerous one.”

The report, “Foxes in trees: a threat for Australian arboreal fauna?”, can be found here.

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