In 1989, six preferred foods (apples, sweet potatoes, almonds, Brazil nuts, sunflower seeds and walnuts) were supplied ad libitum each night to 12 feeding stations.
Pada tahun 1989, enam makanan yang disuka (apel, ubi jalar, badam, kacang brazil, biji bunga matahari dan walnut) telah tersedia ad libitum setiap malam hingga 12 stasiun makanan.