Sunflower hearts wild bird food.Provide birds with the ultimate in high energy nutrition. Hearts are produced by removing the husks from black sunflower seeds which are rich in oil, so less mess in your garden and an easier meal for your birds.Surprisingly, the more calories the better!Garden birds use lots of energy in their daily activities. Foods rich in fats and oils will contain high calorie levels and it is these calories that provide them with the energy they need to breed, survive and thrive throughout the year.So when it comes to bird food, the higher the calories, the better for your birds!Available from retail outlets nationwide, National Trust products include a large selection of bird feeders, premium quality foods, nest boxes, feeding accessories and much more.For more garden birds, Ideal for feeders, table and ground feeding, 600 calories per 100g Request your free Handbook of Garden Wildlife, packed with practical advice and stunning photography to aid bird identification.