VIENNA (AP) — Twin panda cubs Fu Feng and Fu Ban are celebrating their first birthday at a zoo in Vienna with gifts of their favorite foods — sweet potatoes and carrots.

While mother Yang Yang and Fu Ban tucked in to the treat-filled packets, Fu Feng remained in her indoor enclosure at the Tiergarten Schoenbrunn zoo.

Zookeeper Renate Haider says the pandas, who weighed in at roughly 100 grams (3.5 ounces) at birth, have gained a lot of weight in one year.

Fu Feng now weighs 22 kilos (48 pounds, 8 ounces) and Fu Ban weights 18 kilos (39 pounds, 11 ounces).