Do you have any seed-type recommendations or strategies for discouraging crows and jays from monopolizing my feeders? These birds scratch all the seeds out onto the ground and chase away the songbirds I'm trying to serve.
Crows and jays both belong to a family of birds known for their intelligence and group communication skills. Thus, they can be tough to manage.
Excluding large birds
Your best strategy will be to exclude or block them from reaching the food. Retailers sell various designs, with the keywords being caged feeders.
Another alternative is to try using 2"x4" welded wire to retrofit a cage around your existing feeders, assuming they're hanging. The main idea is to make sure the desirable smaller-bodied songbirds can get in to feed while the larger-bodied birds cannot.
Many species of birds will benefit from shelled sunflower seed and if your feeder has a shelf/tray to catch kicked-out food, the ground spillage (and potential free meal for crows and jays and squirrels and rats) will be minimal.
You might alternatively decide to only feed specific groups, such as finches (Nyjer seed) and hummingbirds (nectar mixture) whose food isn't attractive to crows or jays.