The zoo said bamboo supplies on its grounds did not regrow this year and the main consumers of the green stalks, giant pandas Tai Shan, Mei Xiang and Tian Tian, collectively eat about 1,400 pounds of bamboo per week, The Washington Post reported Wednesday.
Smaller amounts of bamboo are also consumed by raccoon-sized red pandas, elephants and gorillas at the zoo. Officials said the current bamboo supplies might not last the winter.
The zoo said it is seeking supplies of bamboo that cover at least one acre, are located within 25-30 miles of the zoo, stand at least 100 feet away from the nearest roadway and have not received herbicide or pesticide treatments.
"We need clean stuff," said Don Moore, assistant director for animal care at the National Zoo.