Mine hated magpies. First time we took him to my mothers house I heard some miaus smd found him on a rock in the middle of a little brook next to the house being mobbed by three magpies. And I had to rescue him. A little while later I saw the setup. One magpie was limping along being tracked by the cat. The second the cat jumped in the rock the other two immediately started mobbing him and the "wounded" would join in.

After that magpies were an arch enemy. A few years later I sat on my own porch, and this magpie was hopping around for probably 20-30 minutes when suddenly my fur missile came out if a bush next to the porch. He had bided his time and actually got both his paws all around the magpie who started pecking his head. Think he was as surprised as the magpie as he actually let it go. (To my relief as I think he would have lost an eye)

I saw that the magpies had learned and was more wary when they spotted him.