Although not their main prey, owls will take birds. (I've found bird skulls in owl pellets). And evidence that smaller birds see owls as a physical threat can be seen in 'mobbing' behaviour - where they will gang up and harrass a roosting owl in order to drive it from the vicinity. I actually see a lot of this on my own road - where we seem to have a surfeit of tawny owls.
And yes, you would assume a peregrines preference would be to hunt in daylight hours - but apparently they do also hunt at night. It's also worth pointing out that birds defensive behaviour does not necessarily kick in only when a predator is actively hunting - the mere presence of the latter can inspire evasive action.