There is a bird on my neighbours feeder. He looks like a super old crow or some sort of crow magpie hybrid. Black wings and tail silver grey head and a grey white speckle breaat
I was wondering about a jackdaw also, taking into count the description which suggests largish size, along with the silvery colour. We have had a crow successfully on our feeders, though not very often, they tend to feed from the ground, However, magpies and jackdaws do frequent the feeders, particularly for the fat blocks.
A photo would be ideal, even with a mobile phone could help.