Bamboo makes up almost 99% of a Giant Pandas food source. So availability of bamboo has always been a basis of concern for the pandas.
There are 42 species of bamboo which Giant Pandas eat. Each species has a life cycle and will flower and die off every 20 to 40 years depending on the species. Giant Pandas need to have other species available to eat or be able to migrate to a different area when the bamboo dies off. After the bamboo flowers, it can take 4-10 years before the bamboo begins to grown again.
During this die off, in an ideal situation, the pandas just move to a new area of their habitat to find food. However human damage to their habitat may prevent this migration necessary to find fresh bamboo. Roads, Villages, Electrical lines and human activity can block the pandas from finding the necessary bamboo.
“Corridors” to allow the pandas to move from one bamboo forest to another have been discussed for many years, but progress has been slow.