This mix is a premium seed for feeders, with added Kibbled Sunflower Hearts to increase the calorific value making this suitable for year-round feeding, but particularly valuable during times of migration and breeding when extra demands are placed on birds. This mix is a premium seed for feeders, with added Kibbled Sunflower Hearts to increase the calorific value making this suitable for year-round feeding, but particularly valuable during times of migration and breeding when extra demands are placed on birds.