Green Polar Bears? Yep, Green polar bears have been drawing questions from confused visitors at a zoo in Japan.

Three polar bears at Higashiyama Zoo and Botanical Gardens in central Japan changed their color in July after swimming in a pond that was filled with algae. They are normally white.

"Visitors seem to be shocked by the color, and we are asked every day why they are so green,"  zoo official Masami Kurobe said Sunday.

Higher temperatures in July and August and less-frequent water changes because of the zoo's  efforts in conservation caused an algae growth in the bear pond and safety moat, Kurobe said.

Algae that permeates hollow spaces in the bears' fur is difficult to rinse off, he said.

The bears will return to their natural color when the algae growth reduces in November.