Activists try to prevent Australia's authorized kangaroo cull

Flashlight in one hand, walkie-talkie in the other, Fiona Corke is out on a dark night in a national park in the Australian capital, Canberra, looking for marksmen.

"You see them?" she whispers anxiously into her transmitter.

"I can hear them," replies a fellow member of the Australian Society for Kangaroos from inside the Crace Nature Reserve, ignoring signs that tell people to keep out.