Are crows and jackdaws the same size?

Are crows and jackdaws the same size? Picking out the jackdaws, magpies, and rooks is easy. I only had one big black bird visiting, so I assumed it was a crow. Then all these smaller black birds starting showing up (not blackbirds). About the same size as the jackdaws, they're completely black. Now there's a second big bird showing up, leucistic, I think. It's wings are almost all white, but black everywhere else. So are the smaller birds crows and the larger ones ravens? I didn't think ravens were prolific. I'm in the central belt of Scotland. This is one of the smaller black birds I'm talking about.



And the little ones at the back, jackdaws and the black ones, against the two big ones at the front. Sorry, I know the pictures aren't great.