

Susan Milius
A giant panda that upends itself into a handstand may be sending a message that it's one big bamboo-thrasher and not to be messed with.
Adult pandas roam mostly by themselves, so the scents they leave behind play a major role in communication, explains Ron Swaisgood of the San Diego Zoo. He, zoo colleague Angela M. White, and Hemin Zhang of Woolong Nature Reserve in China are trying to decode those scents.
Part of the chemicals' messages may depend on their height from the ground, the team suggests in a paper to be published in Behavioral Ecology and Sociobiology. Pandas leave marks—squirts of urine, or smears from glands on their rears—at different heights on, say, rock faces and trees. The height depends on whether the animal was squatting, just backing into a surface, lifting a leg, or doing a handstand. Despite their pudgy profiles, pandas upend themselves quite well, backing up to a vertical surface and walking their rear legs upwards (SN: 1/27/01, p. 61: http://www.sciencenews.org/articles/20010127/bob10.asp).
The researchers mimicked marks applied from the various positions and watched reactions of 28 captive male and female pandas. The marks that drew the longest investigations were dashes of male panda urine at handstand height on the enclosure walls, say the researchers. After the initial sniffing, nearly grown males tended to avoid a high-marked spot. The researchers propose that putting a mark way up on a surface could warn rivals that the marker is a really big guy.
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White, A.M., Swaisgood, R.R. and Zhang, H. In Press. The highs and lows of chemical communication in giant pandas (Ailuropoda melanoleuca): effect of scent deposition height on signal discrimination. Behavioral Ecology and Sociobiology. Abstract available at http://dx.doi.org/10.1007/s00265-002-0473-3.
Milius, S. 2001. The lives of pandas. Science News 159(Jan. 27):61. Available at http://www.sciencenews.org/articles/20010127/bob10.asp.
Ron R. Swaisgood
Office of Giant Panda Conservation
Center for Reproduction of Endangered Species
Zoological Society of San Diego
P.O. Box 120551
San Diego, CA 92112
Angela M. White
Office of Giant Panda Conservation
Center for Reproduction of Endangered Species
Zoological Society of San Diego
P.O. Box 120551
San Diego, CA 92112
Hemin Zhang
China Research and Conservation Center for the Giant Panda
Wolong Nature Research
Wenchaun County
Sichuan, China 623006
People's Republic of China
From Science News, Volume 161, No. 14, April 6, 2002, p. 221.