some things I have taken from the debate, not aimed at anyone, just my thinking.
watched a video on Feral.org.au the other night. They had filmed a cat toy with a bandicoot for some time before it dismembered it, ate it's legs and head and left the torso behind. The cat is at the top of it's game, it may not have emotions, but it likes to have fun and torment it's chosen kill. We don't know it if it has a conscious, but it certainly has feeling just like the bandicoot.
I struggle to think domestic type feral cats have been here for eons. Nothing has a defence against them. I do acknowledge Quolls are a type of cat, but they are in decline also. If not from loss of habitat, then surely from feral domestic type cats as well.
I struggle a bit with the argument of being humane when killing a cat. We as humans, have been asked to leave our human side behind and see our enemies as a terrible people. And collectively do our best to kill them for our won survival. Any war will do and we still are dong it.
Though I have a choice and would like to dispose of the animal as quickly as possible. Trouble is people before me have been in-humane and used guns to shoot other people in non war times. So I no longer have a choice of a gun. Or it is very difficult to obtain, particularly to travel with through each state legally. Barrel through the cage, cat bites barrel, pull the trigger. Safe, quick, and probably the best and humane by far.
Drugs, well if the vet would give me some, and the knowledge to somehow inject the cat without loosing an arm this would be a good option. But drug addicts, and agin possibly being inhumane to each other have removed that option for me.
Thank you for the comment of driving over the cat. It had passed my mine and perhaps placing a board under the bottom surface is viable. Particularly in sand environments.
However I think in the end the cave man option of a bludgeon is an answer. It's up to me to get it right so its as quick as possible. Getting the cat from the cage into a bag may prove tricky, and perhaps to hard for a city slicker in the end, so the cat may cash in on another of its 9 lives.
The bleeding hearts and greenies can support being humane, but their approach basically leads to no action, or just talk for most. No guns, no drugs, no biological approached, no suffering. Well where does that leave me. Standing buy pretending I didn't see that cat near camp. Or expected to drive the trapped cat to a "proper disposal" facility in the desert or anywhere outside a city isn't realistic.
I want to have an input to the problem. Be it one cat a night or none. It the dam thing meows for 1 blow or 5 at least I have done something.

