Frank, I give up on chickens a couple of years back. The Pythons are troublesome but it is the feral cats, foxes, dingoes and goss hawks that were the major culprits here. The european fox (grey & red ones)is nasty as it only rips out the chest to get the liver/kidneys. Large Wedgetail eagles seemed too wary of our dogs & us humans but my daughter's little terrier is kept inside almost all the time: she weighs about 2.5 kg or 6 pound=perfect for goss hawks & pythons. A neighbour's dog was taken by wild dogs but its coat broke & it escaped to live another day. The bush is a wonderful place to live so long as we are boy scouts=prepared. I just came in from shed where i heard the tell tale scales on metal sound: slow, so probably a big python. Off I go back to a job there now I have had some sustanence.
Cheers