Yes, with this cold snap the local wildlife is certainly beginning to home in on my feeders again. The garden has been positively flowing with squirrels today, six at one point. No idea about the Yew berries - I found a link which said that the Reds can eat them but the Greys can't, which seems to be disproved by your observations. Interestingly, they're able to identify which cats are dangerous and which are not. They run rings round a pretty tortoise shell visitor known in our house as Crap Cat as it has absolutely no concept of stalking or pouncing. A pair of Greater Spotted Woodpeckers have claimed the fat feeder, while the Blue Tits and Great Tits dart in and out grabbing sunflower seeds. The parakeets are in daily now, a stunning sight against a backdrop of hard frost.