I was there yesterday, see my birding day forum, it surprises me they do this as there were plenty of Corvids and Raptors about, I thought they had accepted predators! Would have thought the rats would be just as big a danger to the Partridge Chicks as the stoats and as you say the stoats would kill the rats. Have to say, as someone who is against killing things for fun, the habitat they have created is pretty special and would say if the majority of farms did the same ,Farmland birds and other wildlife would have a much better Outlook, would be nice if government subsidies were targeted at this.I didn't mention that on Thursday I was down at the Burgh in West Sussex looking for farmland birds now difficult or impossible locally. I added Grey Partridge and Yellowhammer to the year list and had some excellent views of Brown Rats feeding under a pheasant feeder, having dug their holes right next to it for the purpose. I'm in favour of farming for farmland birds even when it includes game shooting as part of the business model, but the estate in question kills predators which are legal quarry - I've seen the tunnels where they trap Stoats and Weasels, and they have also been proved to use Larsen traps - but what you get if you kill small predators and provide loads of grain is rats in profusion. It's stupid as well as wrong.