Gary Shannon wrote: >A wildlife biologist I knew once worked in a major zoo near a sport >stadium, and was even able to identify a specific sound the chimps made >when and ONLY when the Goodyear blimp flew over. When she heard that sound >from them, she knew they were quite literally telling each other (and her) >that the blimp was in sight. > Was it by chance the same cry they used when they sighted a predator (e.g. an eagle) overhead??