I have a hunter and he could catch a bird blindfolded with his paws tied behind his back
I have tried the bell and collar thing- he can get them off himself, have cat-proffed my garden with the propper Secure-a-cat fencing and he can still get over that, even tho it's 8ft high
I have just really found out if they are determined enough, there is actually no way to stop them
I did consider keeping him as a house cat but felt this would be taking away his kitty rights
One good thing about the cat proofing is he cant bring birds back into the garden- so I dont see the killing, which has made it somewhat better for me as you just feel helpless
I only get to see him chomping on the occasional mouse when I open the front window for him, which by that time it's too late for me to do anything, but at least Im not having to deal with the mauled birds in my back garden