"Giant panda bleat calls, often emitted during the panda's mating season, have just been deciphered, according to new research," reports Jennifer Viegas of the Discovery Channel. "The study reveals that males broadcast information about their size, while females advertise how old they are. The study, which has been accepted for publication in the journal Animal Behaviour, is the first to examine the informational content of any giant panda vocalization." Researchers determined that both males and females had distinctive masculine and feminine voices, so panda listeners would have no trouble identifying the sex of the caller. Females, they also found, do not bleat reliable information about their body size.