Nearly a quarter of the animals at the National Zoo are endangered species, and include giant pandas, Asian elephants, white-naped cranes, western lowland gorillas, Sumatran tigers, African lions, and cheetahs. The National Zoo was one of the first zoos to establish a scientific research program, which encompasses reproductive biology, conservation biology, biodiversity monitoring, veterinary medicine, nutrition, behavior, ecology, and bird migration.Recent exhibits include the Fujifilm Giant Panda Habitat and Asia Trail and Kids? Farm. Currently in the works is Elephant Trails, an innovative and stimulating new home for a multi-generational herd, where our Asian elephants will thrive and our visitors can experience the extraordinary reality of a living elephant. To enjoy all the Zoo has to offer? family fun, excitement, and stimulating education programs?plan to spend at least three hours. As part of the Smithsonian, the National Zoo is FREE.