Using a little common sense you can indeed keep your garden birds happy without attracting those pesky rats.
1: Don't put out too much food at once. There's only so much food your birds can eat in a day so better to add little an often is the best option rather than excess quantities which will then be available for Roland and his chums.
2: Avoid putting out your food in the same place all the time. You will confuse the rats but your birds will soon fly to pastures new.
3: Place food off the ground. Having food from a tree or feeder or using a bird table means it will be out of the reach of rats. Attaching seed trays under your feeders to catch any food thrown out by your birds will also help.
4: Rats are not fussy - they like a mouldy leftover so regularly clean the area and never allow old food to accumulate.
5: Store your food in good sealed containers. Roland does enjoy all sorts of food that birds (and humans) like.