Walnuts (In Shell) Walnuts can be used as a treat for many birds. Walnuts are a good source of protein, vitamin E, folate, antioxidants and even some healthy omega-3 fats. Your bird will also enjoy the de-shelling process as it will keep them occupied and entertained for longer. Recommended For Large Birds - Amazons (Lilac Crown, Blue Front, Yellow-naped), Timneh African Grey, Alexandrine, Yellow Collar Macaw, Small Cockatoos (Goffins, Major Mitchell, Galah, Lesser Sulphur), Chattering Lori, all Pionus Parrots, Eclectus, Medium Macaws (Severe, Red Fronted), Large Amazons (Double Yellow, Yellow Nape), Umbrella Cockatoos, Congo African Grey and similar sized birds. X-Large Birds - Blue & Gold Macaws, Scarlet Macaws, Moluccan Cockatoos, Sulpher Crested Cockatoos, Hyacinth Macaw, Black Palm Cockatoos, Green Winged Macaws and similar sized birds.