When is the best time for keepers to separate giant panda cubs from their mothers? New research by Zoo Atlanta psychologist Rebecca Snyder, PhD, and colleagues indicates that cubs should stay with their mothers longer than scientists initially believed.

The researchers are following two groups of pandas: cubs separated from their mother at four months and cubs raised by their mothers until they were a year old.

In a recent Journal of Comparative Psychology (Vol. 117, No. 3) paper, the group reported on data gathered on eight cubs when they were 5 to 12 months old.

Snyder and her colleagues collected 12 to 13 hours worth of data each month on the cubs and mothers, recording such behaviors as play-fighting, bamboo manipulation, inactivity, feeding and self-grooming. They also measured social behaviors, such as charging and lunging during play-fighting, and solitary behaviors, such as falling.

The small sample yielded some of the first data on giant panda developmental behavior:

  • The importance of play. Although the kinds of behaviors the cubs used to play, such as chasing, lunging and self-play, changed over the seven months, the amount of time they spent playing did not decrease as they matured. Snyder says that shows social play is a substantial behavioral development component throughout the first year.

  • Sex differences. Compared with mothered females, mothered males spent significantly more time play-fighting with their mothers. The finding could indicate that play-fighting is an especially important component of behavioral development for male cubs, say the researchers, since male cubs may use what they learn to compete for access to females as adults.

  • Mother- vs. peer-raised differences. The mothered cubs appeared to engage more often in social learning activities. For example, they spent a greater percentage of time manipulating bamboo, while the peer-raised cubs spent more time being inactive.

Moreover, when researchers examined mother-raised twins, they found that the twins spent more time play-fighting with their mother than each other, and that they approached, initiated contact and followed their mothers more than each other.

Taken together, the findings indicate that mothers enhance cubs' behavioral development by initiating play and other social learning, says Snyder, and that peer-raising may not give cubs adequate social stimulation and interaction.

"It would be a meaningful finding if these kinds of behavioral differences have long-lasting effects into adulthood," says Snyder. "For example, if cubs who spend more time with their mother have more successful mating encounters or produce more cubs."

Since the cubs are just now beginning to reach sexual maturity--the oldest are about five and a half years old--the researchers will soon see if their hypothesis proves true.

--D. SMITH BAILEY