Safflower is a hard-shelled seed that attracts Northern Cardinals, Mourning Doves, Black-capped Chickadees, Carolina Chickadees, and Rose-breasted Grosbeaks. Some birdwatchers switch to safflower during periods when grackles and starlings are present. The seed is difficult for them to open and so discourages feeder visits. And it is one bird seed that it not liked by squirrels (although hungry enough and they seem to eat anything)!
Start feeding the birds anytime and keep feeding year round. Natural food supplies are at their lowest in the spring. Spring brings exciting migrants. Summer feeding provides nutrition during breeding and nesting season. Enjoy seeing parents bring their young to your feeders. Fall and winter feeding is especially helpful during periods of cold and snow.