According to a new study, giant pandas rely on old growth forest. This is the first time another environmental factor has been found to be as necessary as bamboo for these animals.
Credit: Fuwen Wei
Often the only way researchers know whether giant pandas live in an area is from traces of faeces. Above is a fresh faecal sample on the forest floor in Sichuan, China.
Credit: Lifeng Zhu
BEIJING: Think of giant pandas and their natural habitats, and bamboo likely comes to mind. But bamboo is just one factor determining whether an area is suitable for panda habitation − old growth forests are just as crucial, according to a new study.
Using data collected from 1999 to 2003, lead researchers from the Chinese Academy of Sciences and San Diego Zoo analysed more than 70% of the areas in China where the endangered bears are known to live. The study, published in the journal Biology Letters, is the largest ever on the habitat needs of giant pandas.
“We used data collected during the largest survey of giant pandas by the Chinese Government to date that took place over several years and many sites” said project leader Fuwen Wei with the Chinese Academy of Sciences.
Not understood why old growth is needed
He says the findings are significant because this is the first time another environmental factor has been found to be as necessary as bamboo for giant pandas.
“The other factors we traditionally thought were more important than old-growth forests, such as the slope of a mountain and its aspect, are not.”
But while the research challenges prevailing wisdom on the habitat needs of pandas, why the endangered species require old growth forest in particular is not completely understood.
Modelling revealed most important habitats
Old growth forests are home to a diverse range of plants and animals because of their maturity. The authors suggested that bamboo growing under this type of forest is more nutritious and may be preferred by giant pandas.
“Another intriguing possibility is that only old-growth trees grow large enough to form cavities suitable for maternity dens”, the researchers wrote.
During the five year study, researchers compared forests in which pandas are present with other forests where the bears are absent. Differences in environmental factors were then modelled to work out which habitat features are most important to giant pandas.
Rare species a tricky subject
But conservation biologist Ralph MacNally from Monash University in Melbourne says it is notoriously difficult to model rare species such as giant pandas.
