These photos, taken Sunday at the San Diego Zoo, show proud mother Orana and her young joey scouting their enclosure. The San Diego Zoo's koalas are offered fresh branches from several kinds of eucalyptus trees each day. These picky eaters can then select their favorite varieties. Koalas eat 1 to 1.5 pounds (454 to 680 grams) of leaves each day. Eucalyptus leaves are poisonous to most animals, but koalas have special bacteria in their stomachs that break down the toxic oils.