Volunteers arrive, two-by-two, every night for one week to
monitor closely Mei Xiang and Tian Tian and record what they're
up to -- or in some cases, not up to. The night watch is
historic because it is identical to the study conducted at the
panda exhibit here 29 years ago when Ling-Ling and Hsing-Hsing
were the residents of the panda exhibit. The data collected will
be used to make comparisons amongst the four pandas to see if
our panda couple in 2001 act any differently at night than Ling-
Ling or Hsing-Hsing did in 1972. When the night watch concludes,
behaviorists will begin tabulating the data they need to begin
to draw conclusions. Both pandas are watched simultaneously by
two people who record the behaviors of each animal. Start and
stop times are written down for rest/sleep, eating/drinking,
grooming, bathing, scent marking, urination/defecation, or a
catch-all of "other" in which volunteers record rolling or
anything else that doesn't fit into the other categories. Also
recorded is the exact location