I have heard that Red Crossbills are rare feeder birds, but I have a flock that comes whenever there is snow. The flock has been coming since late January. Once one of them even landed on my head, and since then you can just walk up to them and sit down and they'll keep eating. They seem very fond of Black Oil Sunflower Seeds. Feel free to post anything on the topic of finches, grosbeaks, and crossbills.