- Clawing and other visual posters
Bark-stripped trees are a form of visual communication which alters other pandas to an individual’s presence in the area
At Wolong, pandas mark only about 20 per cent of their scent kiosks on a regular basis. The rest are maintained infrequently. Territorial animals tend to concentrate their scent-posts around the perimeter of their territories like 'keep-off’ fences, but for non-territorial creatures like the giant panda scent-posts are more effective concentrated along busy routes used by residents and transients. Ridges, low passes and spurs projecting into valleys are all examples of such busy traffic areas. These motorways of the panda world are areas where the bamboo is at its least dense, allowing for easy, unencumbered travel.
There is no time of the year when giant pandas do not mark and it is the males that monopolise this activity. Wei, an adult male in the Wolong study, marked forty-seven trees over a distance of 7113 m (23 000 ft) during the winter of 1981-82. The biologists tracked a female, Zhen, for 1868 m (6000 ft) during the same period without finding so much as a claw mark. Males mark throughout the year, although efforts are stepped up in the mating season when marking is directed at females. For the rest of the year, marking is directed at other males in order to maintain mutual distance and to ascertain rank.
Bark-stripped trees Besides clawing, pandas use other visual posters to draw attention to their presence - bark stripping, tree biting, ground pawing, and rubbing and rolling - but these are not used very often and are probably minor communication aids. Claws, teeth and body fur are the pen and ink of such poster making. Bark stripping involves gnawing and scraping lumps of bark off trees, particularly conifers. In tree biting a panda usually bites a sapling in two. Most tree biting is done in April, the mating season, and is probably the work of males wanting to be noticed, but females do, on occasion, use saplings to line their maternity dens.
Claw marks higher up a tree indicate that an animal has actually climbed the tree, an activity which both males and females engage in during the mating season, the females to escape the attentions of their suitors, the males to pursue potential mates and to use the tree as a soap-box when advertising their presence by calling.
In ground pawing, a panda will brush away 30-40 cm in diameter patch of soil or snow, usually on a rise or at the base of a tree. Rubbing and rolling involves just that – rubbing and rolling the body on the ground or against rocks and other surfaces. In ground rolling, soil is rubbed over the body and the vegetation is trampled and covered in the panda's body scent.
