Giant pandas voraciously consume bamboo and little else. But they are also fussy about where they live. Scientists have found that pandas prefer to roam in old-growth, or natural, forests—those that have never been logged or disturbed—a discovery they hope will influence conservation policies for the endangered animal and help ensure the survival of this iconic species.
To better understand the panda's habitat use, ecologist Wei Fuwen of the Chinese Academy of Sciences' Institute of Zoology in Beijing and colleagues turned to China's third national panda survey, conducted from 1999 to 2003 by the Chinese State Forestry Administration. This survey, the most comprehensive ever, tried to count every panda living in the wild, finding about 1600 of them, 40% more than were thought to exist. But Wei says no one ever mined the data to understand the panda's habitat preferences.
To address that issue, he and his colleagues analyzed the numbers of pandas in different habitats, examining the influence of forest type and age, tree diameter, bamboo availability, and numerous other variables. Not surprisingly, bamboo availability was the number one factor governing where pandas are found.
But the researchers also discovered that, given comparable bamboo availability, pandas vastly prefer undisturbed forests over immature forests that are regrowing after logging and other habitats, such as those that are dominated by shrubs. The study points to other reports that suggest that old-growth forests have more easily foraged bamboo and provide the nooks and crannies pandas use as maternal dens. But Wei says he and colleagues are planning further research "to understand why [natural forest] is so important." In their report, appearing online today in Biology Letters, the team urges the Chinese government to preferentially protect old-growth forest.
The report's conclusion "is not news to the panda conservation science world," says Wang Hao, a conservation biologist at Peking University, who was not involved in the work. Other studies have pointed in the same direction, he says. Still, the new report adds scientific weight to calls for natural forest protection that "definitely will help panda survival," says Wang.
China's conservationists already have something to celebrate. On 29 December, before the panda paper had even been published, the State Council decided to extend a decade-old ban on logging in state forests throughout the upper reaches of the Yellow and Yangtze rivers—panda country—through 2020. A Chinese news report of the decision does not mention pandas as a reason, pointing instead to flood and erosion control, providing carbon sinks, and improving ecological conditions. But it is "good news for pandas and other indigenous species," Wei says.
Wang, though happy with the logging ban, says more effort should go into protecting isolated panda groups and linking populations through protected corridors that would allow mating to avoid deleterious inbreeding. He would also like to see suitable panda habitat expanded and a strengthening of the scientific underpinnings of conservation policies. He says such suggestions are part of a draft panda-protection plan under consideration by the State Forest Administration.