On February 23, the camera catches the mother blocking the entrance with her own body, as can be seen in vision tweeted by Mills. She says that in sections of the film not published the mother can be seen arching her back at the intruders. “She’s very aware that the foxes are around and she blocks the hole with her entire body. They come up and get quite close and she bristles at them,” she told the Age and the Herald this week.

Then on February 28 the camera captures footage of a cub getting deep into the hole. It later skips off, as though, says Mills, it has grabbed the puggle and is determined to keep its catch to itself. “Bear in mind that in the fox hierarchy, it’s survival of the fittest. If you’ve got something you don’t want your siblings to have, you’re not sharing it with them.”

After this, the foxes stop returning to the den. The mother returns once, at 1.55 am on March 1. Though the camera was left in place until July, it captured no more life in the burrow.

Mills says that once she recovered the cameras and began to view the footage it was hard to keep going after she discovered the arrival of the foxes.

“I was on the edge of my seat. I hoped that maybe the puggle’s spikes were big enough to save it.

“The thing that brought me to put this whole thread up on Twitter was that it is distressing, but we should be distressed.

“If this is what a fox can do to one of our more common species, one that is as an adult, but very vulnerable as a young animal, what effect do foxes have every day, day after day? They are strip mining our biodiversity.”

According to the Invasive Species Council foxes have contributed to at least 14 mammal extinctions including the Eastern Hare-wallaby, Kuluwarri, the Crescent Nailtail Wallaby, the Desert Bettong, the Desert Rat-kangaroo, the Nullarbor Barred Bandicoot, the Pig-footed Bandicoot, the Yirratji and the Desert Bandicoot.

It is contributing to the decline of a further 89 nationally listed threatened species. Research suggests that an estimated 1.7 million foxes in Australia kill around 300 million native animals each year.

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Before the fox was finally eradicated from Philip Island it had destroyed nine of 10 little penguin colonies, despite ongoing baiting and shooting programs.

Philip Island is one of 12 Australian islands from which the fox was successfully eradicated, most of them in the Dampier archipelago off the coast of Western Australia.

It was able to reinvade two, probably by swimming from the mainland.

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