Magpies certainly have a different temperament from crows. I tried to feed a local crow a few years ago, and while it was busy acting confused (you're giving this to me? Seriously?) a magpie swooped in for the treat. These days I'm on good terms with both. The magpies are easily bullied away by the crows, and I've learned the distinctly unfriendly noise they make when a crow comes close (three rapid, sharp chatters). I think they have a sound for me as well, a rising chi-chik very quietly. Probably to avoid announcing the arrival of the food guy to the crows.