They will find an unoccupied place in the area and sit down, content to munch on bamboo or other food items totally oblivious of each other. But at crucial stages in their lives giant pandas, like all solitary mammals, are forced to spend time with each other. In the spring males and females must seek each other out in order to mate. Giant pandas rely heavily on their sense of smell. They use their sense of smell to forage for food as well as knowing when they are crossing into another's territory.
Scent marking is a vital role in the communication of the giant pandas to each other.
It is like the community bulletin board to all passer bys. It is also believed that the scent can distinguish the sex, age, breeding condition and other vital communications of the giant panda leaving the scent by other giant pandas. It can be detected for up to 4 months and is used as a calling card by females and for territory marking as well as enticing females closer for mating by the males. Peak estrus in the female lasts from one to three days, and the gestation period varies from about 97 to 165 days. This is believed to be an intimidation factor to other males.