Jackdaws are probably my favorite birds. I'm fortunate enough to have a roost a few hundred yards from my house, and I really love to hear them and watch their evening flights - I find their call really evocative and joyful. Jackdaws pair for life, and if you watch you'll see that they virtually always fly together as pairs - if people were as loving the world would be a happier place.
I find them to be quite shy birds. They would rarely land on the allotment if anyone was about, and they will visit the garden sometimes but again they're very shy, and they don't seem to be very agile on the feeders, though they will sometimes have a bit of a go. They'll also try for a few cherries from my cherry tree but they're not particularly good at that either.
Enjoy them.